Bear Creek Watershed Assessment

FINAL

7 June 2010

US Department of the Interior, Bureau of Land Management, California State Office Sacramento, CA

in partnership with

Colusa County Resource Conservation District Colusa, CA

Acknowledgments

Funds for outreach, research, and preparation for Bear Creek watershed Assessment have been provided by a grant from the CALFED Watershed Program and administered by the California Department of Water Resources. Additional support has come from the Bureau of Land Management, the US Forest Service, and the Colusa County Resource Conservation District. TABLE OF CONTENTS

LIST OF FIGURES vii

LIST OF TABLES ix

ABBREVIATIONS AND ACRONYMS xii

UNITS OF MEASURE xiv

EXECUTIVE SUMMARY xv

1 INTRODUCTION TO THE WATERSHED ASSESSMENT 1 1.1 Purpose 1 1.2 Goals 2 1.3 Audience 5 1.4 Issues 9 1.5 Guiding Principles 12 1.6 Information Sharing and Public Outreach 12 1.7 Participants in Preparation and Review 13 1.8 Structure and Content of the Following Chapters 14

2 WATERSHED DESCRIPTION 15 2.1 Location and Setting 15 2.2 Watershed Boundaries 21 2.3 Topography 21 2.4 Climate 25 2.5 Hydrology 33 2.6 Geology 43 2.7 Soils 51 2.8 Geomorphology 57 2.9 Vegetation 61 2.10 Wildlife 76 2.11 Ecologically Important Areas and Special Conservation Areas 93 2.12 Air Resources 98

3 SOCIETY, ECONOMY, AND LAND USES IN BEAR CREEK WATERSHED 103 3.1 Characteristics of Watershed Residents 103 3.2 Land Ownership 105 3.3 Ecosystem Services 107 3.4 Water Delivery 109 3.5 Forest and Woodland Management 112 3.6 Livestock Grazing and Crop Production 113 3.7 Mining 118 3.8 Recreation and Tourism 123 3.9 Energy Production and Conveyance 126 3.10 Developed Areas 132 3.11 Transportation 132 3.12 Telecommunications 137 3.13 Scientific Research and Monitoring 137

4 NATURAL DISTURBANCES 140 4.1 Wildfire 140 4.2 Geohazards 153 4.3 Flooding and High Flows 155 4.4 Drought 157 4.5 Information Gaps 159

5 ENVIRONMENTAL CONTAMINANTS 161 5.1 Water Quality Standards 161 5.2 Water Quality Data 165 5.3 Aquatic Biological Data 173 5.4 Sources of Water Contaminants 180 5.5 Permits Affecting Water Quality 187 5.6 Beneficial Uses of Water at Risk 189 5.7 Future Conditions and Target Loads for Water Contaminants 190 5.8 Soil Contamination 191 5.9 Hazardous Waste 194 5.10 Air Quality Contaminants 195 5.11 Identification of Critical Areas for Remediation 196 5.12 Information Gaps 197

6 STAKEHOLDER ISSUES 198 6.1 Toxic Chemicals 198 6.2 Sediment Delivery to Watercourses 200 6.3 Creek Channel Alterations 202 6.4 Creek and Tributary Headcuts 203 6.5 Roads, Trails, and Firelines 204 6.6 Fire 206 6.7 Oak Woodlands 208 6.8 Disturbances to Ultramafic Soils 211 6.9 Non-native Invasive Species 212 6.10 Impacts from Certain Grazing Practices and Browsing and Gnawing Animals 213 6.11 Low Recruitment of Native Woody Riparian Plants 214 6.12 Growing Demand for Recreation and Tourism 215 6.13 Potential Environmental Impacts of Energy Developments 216 6.14 Fiscal and Policy Obstacles for Landowners to Meet Regulatory Targets 218 6.15 Climate Change 219 6.16 Information Gaps 221

7 SYNTHESIS OF WATERSHED CONDITIONS AND FOCAL AREAS FOR MANAGEMENT RESPONSES 223 7.1 Brophy Canyon 223 7.2 Craig Canyon / Eula Canyon 227 7.3 Deadshot Canyon / Trout Creek 229 7.4 Doyle Canyon / Gaither Canyon 233 7.5 Hamilton Area / Warnick Canyon 235 7.6 Leesville 238 7.7 Robbers Flat / Stinchfield Canyon 240 7.8 Thompson Canyon 243 7.9 West of Cortina Ridge 246 7.10 Mill Creek Subwatershed 248 7.11 Sulphur Creek Subwatershed 251 7.12 Upper Bear Creek 258 7.13 Lower Bear Creek, including Lynch Canyon 264

8 NEXT STEPS 271 8.1 Best Management Practices for Watershed Stewardship 271 8.2 Information Acquisition 273 8.3 Stewardship Priorities for Remediation and Restoration 283 8.4 Options for an Updated Bear Creek Watershed Assessment 283

APPENDICES 284

APPENDIX A SUMMARY OF AGENCY MANAGEMENT PLANS FOR LANDS IN BEAR CREEK WATERSHED 284

APPENDIX B SUMMARY OF PLANS FROM REGULATORY AGENCIES FOR PUBLIC RESOURCES IN BEAR CREEK WATERSHED 289

APPENDIX C PRINCIPAL ROCK TYPES FOUND IN BEAR CREEK WATERSHED 295

APPENDIX D COMPARATIVE SYNOPSIS OF FEATURES OF THE PRINCIPAL SOIL SERIES IN BEAR CREEK WATERSHED 297

APPENDIX E LIST OF PLANT ALLIANCES KNOWN OR SUSPECTED TO OCCUR IN BEAR CREEK WATERSHED (KEELER-WOLF 2003) 300

APPENDIX F AIR QUALITY REGULATIONS 305

APPENDIX G WATER QUALITY OBJECTIVES APPLICABLE TO BEAR CREEK WATERSHED 308

APPENDIX H NARRATIVES OF WATER QUALITY OBJECTIVES FOR SURFACE WATER AND GROUND WATER 312

APPENDIX I BACKGROUND TO THE CHEMICAL AND BIOLOGICAL SIGNIFICANCE OF MERCURY IN BEAR CREEK WATERSHED 315

APPENDIX J SUMMARY OF THE STATUS OF CHEMICAL ELEMENTS WITH MCLS IN BEAR CREEK WATERSHED 320

APPENDIX K PROPERTIES OF HYDROTHERMAL SPRINGS IN SULPHUR CREEK SUB-WATERSHED IN REGARD TO CONTAMINANTS AND WATER PROPERTIES 325

LITERATURE CITED 327

GLOSSARY OF TERMS 349

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LIST OF FIGURES

CHAPTER 2 2.1 Geographic Location 16 2.2 Hydrologic Context 18 2.3 US Forest Service Ecological Subsections 20 2.4 Extent of Similar Ecosystem 22 2.5 Bear Creek Subwatersheds 24 2.6 Elevational Contours 26 2.7 Topographic Aspect 27 2.8 Percent Terrain Slope 28 2.9 Average Annual Streamflow Rate in Bear Creek at USGS Stations 37 2.10 Average Monthly Streamflow Rate in Bear Creek at USGS Stations 39 2.11 Springs, Wells, and Ponds 44 2.12 Depth to Water Table 45 2.13 Major Bedrock Types and Fault Lines 47 2.14 Soil Series, Associations, and Complexes 54 2.15 Distribution of Ultramafic Soil 55 2.16 Plant Cover Types 64 2.17 Special Conservation Areas 97

CHAPTER 3 3.1 Land Management Status 106 3.2 Water-related Infrastructure 111 3.3 Agricultural Land Use Classes, 2006 115 3.4 Forage Production in Normal Years 117 3.5 Mine Features 121 3.6 Sections with Historical Mining Claims on Public Lands 122 3.7 Oil and Gas Resources and Exploration 128 3.8 Geothermal Energy Areas 130 3.9 Wind Energy Leases and Permits 133 3.10 Transportation Network 135 3.11 Hazard from Soil Erosion for Maintained Roads 138 3.12 Hazard from Soil Erosion with Off-Road Motorized Trails 139

CHAPTER 4 4.1 Distribution of Human Ignitions by Month, 1997 – 2007 142 4.2 Ignitions, 1997 – 2007 144 4.3 Six decades of wildfire in Bear Creek Watershed, 1950 – 2008 145 4.4 Fuel Rank 148

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4.5 Post-Fire Erosion Potential 149 4.6 Flood Frequency 158

CHAPTER 7 7.1 Brophy Canyon Subwatershed Analysis 226 7.2 Craig Canyon / Eula Canyon Subwatershed Analysis 228 7.3 Deadshot Canyon / Trout Canyon Subwatershed Analysis 232 7.4 Doyle Canyon / Gaither Canyon Subwatershed Analysis 234 7.5 Hamilton Area / Warnick Canyon Subwatershed Analysis 236 7.6 Leesville Subwatershed Analysis 239 7.7 Robbers Flat / Stinchfield Canyon Subwatershed Analysis 241 7.8 Thompson Canyon Subwatershed Analysis 244 7.9 West of Cortina Ridge Subwatershed Analysis 247 7.10 Mill Creek Subwatershed Analysis 250 7.11 Sulphur Creek Subwatershed Analysis 257 7.12 Upper Bear Creek Subwatershed Analysis 260 7.13 Lower Bear Creek Subwatershed Analysis 268

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LIST OF TABLES

CHAPTER 1 1.1 Crosswalk between watershed goals and stakeholder issues 10

CHAPTER 2 2.1 Hierarchical context of Bear Creek watershed 17 2.2 Watersheds and basins in the vicinity of Bear Creek watershed 17 2.3 Subwatersheds of Bear Creek watershed 23 2.4 Gage stations on Bear Creek and Suphur Creek 36 2.5 Average annual streamflow for USGS monitoring gages on Sulphur Creek 38 2.6 Average monthly streamflows for Sulphur Creek and Bear Creek, water years 2001 – 2004 40 2.7 Flows and temperatures of selected hot spring waters from Sulphur Creek subwatershed 42 2.8 Principal bedrock types in Bear Creek watershed 46 2.9 Principal USDA soil series in Bear Creek watershed 52 2.10 Distribution and volume from landslides in Bear Creek watershed north of Highway 20 58 2.11 Longitudinal sections for Bear Creek, Mill Creek, and Sulphur Creek 60 2.12 Special-status plant species in Bear Creek watershed 65 2.13 Invasive plants in Bear Creek watershed 71 2.14 Threatened, rare, and endemic invertebrates in Bear Creek watershed 79 2.15 Special-status vertebrate species in Bear Creek watershed 86 2.16 Crosswalk between California Wildlife Habitat Relationships and CalVeg habitat types for animal species of concern in Bear Creek watershed 89 2.17 Helicopter surveys of elk herds in Bear Creek watershed 91 2.18 Ecologically unique and sensitive areas in Bear Creek watershed 93 2.19 Air quality standard compliance, 2006 – 2008 100 2.20 Gas emissions as a percent of total gas molecules emitted from springs in Sulphur Creek subwatershed, excluding water vapor 102

CHAPTER 3 3.1 Area and percentage of land by land management category 105 3.2 Ecosystem services in Bear Creek watershed 108 3.3 Bear Creek water volume used for irrigation and its value, 1999 to 2007 112 3.4 Mines in Bear Creek watershed and their legacies 119 3.5 Records of deer kills from Bear Creek watershed, 1999-2007 125

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CHAPTER 4 4.1 Fire regimes in Bear Creek watershed 141 4.2 Overview of components of fire regimes for major vegetation classes in Bear Creek watershed 146 4.3 Distribution of the 42 days with Bear Creek flows >50 cubic meters per second by week of the year in which they occurred 157

CHAPTER 5 5.1 Beneficial uses applicable to Bear Creek and its tributaries 162 5.2 Estimated annual budgets of mercury and methylmercury production by sour in Bear Creek watershed 167 5.3 Overview of key locations where chemical elements exceed respective MCLs for drinking water 169 5.4 Status of chemical elements and ions exceeding agricultural water quality objectives 170 5.5 Physical properties of Sulphur Creek water samples from 2001 02 23 and three samples from lower Bear Creek in the same period 172 5.6 Concentrations of total mercury (THg) and methylmercury (MeHg) benthic insect larvae from Bear Creek watershed 174 5.7 Concentrations of total mercury (THg) and methylmercury (MeHg) in benthic insect larvae 175 5.8 Average total mercury concentrations in ppm wet weight in three fish species from Bear Creek, 1997 177 5.9 Data on total mercury concentrations in ppm wet weight in two fish species from Bear Creek, 2000 177 5.10 Principal aquatic invasive species found in Bear Creek watershed 178 5.11 Springs and their associated elements and ions possibly affecting water quality 181 5.12 Hydrothermal spring flows and their mercury loads 181 5.13 Estimated range of annual sediment and mercury erosion at abandoned mine sites 183 5.14 Combined estimates of sediment loads in Bear Creek Watershed from State Highways 16 and 20 by key constituents 186 5.15 Soil concentrations in parts per million for elements with potential risk to human health based on exposure 192 5.16 Contaminant levels for elements higher and 10x higher than the BLM risk management criteria for residents from soil sampling sites in Bear Creek watershed 193

CHAPTER 6 6.1 Crosswalk of issues covered in both the California Climate Adaptation Strategy and the Bear Creek Watershed Assessment 220

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CHAPTER 7 7.1 Summary of the distribution of major issues by subwatershed analysis area 224

CHAPTER 8 8.1 Resource inventories to improve management decisions for Bear Creek watershed 275 8.2 Technical evaluations, syntheses, or modeling to improve management decisions for Bear Creek watershed 277 8.3 Research to improve management decisions for Bear Creek watershed 278 8.4 Monitoring for regulatory requirements and for feedback to stakeholders about management actions 281

APPENDICES F.1 State and national ambient air quality standards for criteria air pollutants 305 G.1 Water quality numeric criteria for chemical elements applicable in California 308 G.2 Water quality numeric criteria for ionic compounds applicable in California 309 G.3 Target reductions of mercury discharges at abandoned mercury mines 309 G.4 Total daily maximum loads for mercury and methylmercury (MeHg) established by the CVRWQCB for Bear Creek and its tributary Sulphur Creek 310 G.5 Standards for maximum amounts of fecal coliform bacteria for safe drinking water in the region covered by the CVRWQCB 310 G.6 CVRWQCB limits for agricultural water quality 311 G.7 California Toxics Rule criteria for protection of freshwater aquatic life protection in inland surface waters 311 H.1 Narrative water quality objectives for constituents and characteristics of surface water in Bear Creek watershed 312 H.2 Narrative water quality objectives for constituents and characteristics of ground water in Bear Creek watershed 314 K.1 Characteristics of major hydrothermal springs in the Sulphur Creek subwatershed 325

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ABBREVIATIONS AND ACRONYMS

ACEC Area of Critical Environmental Concern AGR agricultural - a beneficial use for water APCD Air Pollution Control District AQMD Air Quality Monitoring District ARB California Air Resource Board ATSDR Agency for Toxic Substances and Disease Registry ATV all-terrain vehicle BLM Bureau of Land Management BMP best management practice CALFIRE California Department of Forestry and Fire Protection Cal-IPC California Invasive Plant Council CALTRANS California Department of Transportation CARB California Air Resources Board CAS Climate Action Strategy CCRCD Colusa County Resource Conservation District CDFA California Department of Agriculture CDFG California Department of Fish and Game CDPH California Department of Public Health CERCLA Comprehensive Environmental Response, Compensation, and Liability Act Ck Creek CNPS California Native Plant Society COLD habitat for fish requiring cold water - a beneficial use for water CRMP Coordinated Resource Management Plan CVRWQCB Central Valley Regional Water Quality Control Board DOM dissolved organic matter EE/CA engineering evaluation/cost analysis FCAA Federal Clean Air Act FLPMA Federal Land Policy and Management Act of 1976 Hg0 elemental mercury Hg2+ mercuric mercury - an ion of mercury ICE Information Center for the Environment at UC-Davis IRIS Integrated Risk Information System KGRA known geothermal resource area MAA memorandum of agency agreement MCL maximum contamination limit MeHg methylmercury MOU memorandum of understanding

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NOX nitrogen oxide gases NPDES National Pollutant Discharge Elimination System NRDA Natural Resource Damage Assessment NRDAR Natural Resource Damage Assessment and Restoration NTU nephelometric turbidity units OHV off-highway vehicle OMB Office of Management and Budget PAMP principal areas of mine pollution pers. comm. personal communication pers. obs. personal observation

PM2.5 fine particular matter, less than 2.5 micrometers in diameter PM10 respirable particular matter, less than 10 micrometers in diameter ppb parts per billion ppm parts per million PRP potentially responsible party RAWS remote automated weather stations RCD resource conservation district REC-1 water recreation with bodily contact with water - a beneficial use for water REC-2 water recreation without bodily contact with water - a beneficial use for water REL reference exposure level RMP resource management plan ROG a reactive organic gas RWQCB Regional Water Quality Control Board SCAN soil climate SPWN spawning habitat for fish - a beneficial use for water TCSM Tehama-Colusa serpentinite mélange THg total mercury TMDL total daily maximum load UC-Davis University of California at Davis US EPA United States Environmental Protection Agency VELB valley elderberry longhorn beetle WARM habitat for fish requiring warm water - a beneficial use for water

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UNITS OF MEASURE

°C degrees Centigrade cfs cubic feet per second g yr-1 grams per year kg kilograms (1000 grams) liter-1 per liter liter min-1 liter per minute mg milligrams (0.001 gram) mg liter-1 milligrams per liter mg/m3 milligrams per cubic meter mg kg-1 milligrams per kilogram μg micrograms (0.000001 gram) ng liter-1 nanograms (0.000000001 gram) per liter yd3 cubic yard

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EXECUTIVE SUMMARY

The Watershed Assessment Process The Bureau of Land Management (BLM) received a grant from the CALFED Watershed Program, administered by the California Department of Water Resources, to prepare the Bear Creek Watershed Assessment. Work on this project supports the partnership in Bear Creek watershed between the BLM, the Colusa County Resource Conservation District, and other watershed stakeholders.

The assessment has assembled existing information about the watershed from different sources on multiple, often interconnected topics that speak to stakeholders’ watershed goals and issues in watershed management. To produce the assessment, the authors took the following steps:

1. Gather and organize information from stakeholders, technical literature, agency documents, and data sets that describe past and current conditions in the watershed 2. Describe stakeholders’ goals and stewardship issues for the watershed based on stakeholder input 3. Conduct resource inventories as feasible and identify gaps in needed information 4. Prepare a written solicitation to the public for additional goals and issues and for additional information about Bear Creek watershed 5. Assess water quality, hydrologic function, soil and site stability, and biological resources 6. Identify locations, stewardship practices, and opportunities appropriate for addressing stakeholders’ issues in the watershed through analysis of individual subwatersheds 7. Present a draft version of the assessment for public review and comment on the website of the Colusa County Resource Conservation District 8. Incorporate public comments and any new information into the final draft of the Bear Creek watershed assessment.

Special Features of the Watershed Bear Creek watershed encompasses 103 square miles (266 km2) at the interface of the North Coast Range on the west side of the Sacramento River Valley in Colusa County. The watershed has varied terrain, from the nearly flat Bear Valley floor to steep, highly dissected canyons at the northwest, west, and southeast edges of the watershed. A series of rolling hills of blue oak woodland form the east boundary. Although the watershed is sparsely populated today, people over the past 150 years have transformed large portions of the landscape, particularly in Bear Valley and in Sulphur Creek subwatershed. Mercury mining, cattle ranching, and hot springs resorts have been the mainstays of the economic life of the watershed.

BEAR CREEK WATERSHED ASSESSMENT

The watershed is rural in character, with 55 percent private lands and 45 percent public lands. Existing county and federal land management plans aim to maintain the rural environment and natural character of the watershed, while sustaining traditional economic livelihoods. Public lands emphasize recreation opportunities and conservation of biological diversity as well. Several ranches in the watershed have conservation easements which further protect the natural landscape.

The watershed owes its strong visual contrasts to the interface of the Great Valley Geomorphic Province and the Coast Range Geomorphic Province and resulting geology and plate tectonic shifts along the east side of the Inner Coast Range. Rocks from the Great Valley are sedimentary, having formed from sediments deposited in the Sacramento Valley when it was an ocean floor. Rocks from the Coast Range are mostly ultramafic, formed volcanically on the Pacific Ocean floor and subsequently thrust up to the ground surface over eons.

From the complex geological history, the soils developing from the underlying parent rock are highly diverse. More than 35 soil series are found within the watershed. In upland areas on the east side of the watershed, sedimentary soils such as the Millsholm and Contra Costa soil series predominate. In the southwest quarter, soils consist of Millsholm, Contra Costa, and Sleeper series. Soils in the northwest quarter of the watershed are primarily ultramafic Henneke, Okiota, and Montara soils. Ultramafic soils and their parent rocks have unusually high concentrations of magnesium and iron and are habitat for plants especially adapted to the unusual soil chemistry. Some ultramafic soils west of lower Bear Creek and in Mill Creek subwatershed are extensive barrens, sites largely devoid of vegetation because of extreme soil chemistry.

Ultramafic sediment moving in drainages originating on Walker Ridge has created several alluvial fans on the west side of Bear Valley. Shorter, less steep drainages on sedimentary soils create swales along the east side of the valley. Mixing of both sediment sources has led to creation of ultramafic alluvial soils, the youngest soils in the watershed, on the Bear Valley floor. Three series of these mixed soils (Bear Valley, Leesville, and Venado) are known only from Bear Valley.

Bear Creek flows north to south through the watershed into Cache Creek. Where Bear Creek meets Mill Creek, Mill Creek usually supplies the greater volume of water. Streams from both sides of Bear Valley and from Long Valley east of Leesville add more water to Bear Creek as the creek traverses Bear Valley. The other major contribution of water to Bear Creek comes from Sulphur Creek subwatershed south of Bear Valley. Sulphur Creek water and sediments are important for their contribution of high concentrations of iron, sulfur, dissolved salts, and heavy metals. Very little information exists about groundwater anywhere in the watershed.

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Hydric soils and flooding are not common in the watershed except along portions of Mill Creek and Bear Creek in Bear Valley and along Sulphur Creek. Bear Valley once had more extensive wetlands, and Bear Creek meandered slowly through the valley plain. Riparian woodland and shrub corridors are now greatly altered or lacking altogether in much of the watershed. Willows and cottonwoods are uncommon in riparian areas. One prominent valley oak stand remains along Bear Creek at the south end of the Bear Valley. Modifications to water flow have consisted of channels to divert water to crops and stock ponds and two small dams. Impoundments for livestock water are present in Bear Valley, on the east side north of Highway 20, and in the southern canyons on the BLM Bear Valley Ranch. Some stock ponds are providing aquatic habitats for special status species such as western pond turtle and a variety of plants species that would be otherwise absent. Unusual ultramafic wetlands occur on Walker Ridge, on benches down slope from Walker Ridge, and along Highway 20 near the Colusa-Lake county line. Highway impacts and off-road riding are putting these wetlands at risk.

Vegetation on ultramafic soils is generally sparser and visually distinct species from vegetation on sedimentary soils. Ten of the eighteen rare plant species (CNPS Class 1B) found in the watershed occur exclusively on ultramafic soils. Other endemic species include three endemic insect species that have evolved to inhabit the unique environments generated at hot springs and nearby spring-fed creeks. The serpentine cypress wood-boring beetle is found only in stands of cypresses which themselves are limited to ultramafic soils. Other noteworthy wildlife species that depend on water quality are the naturally high diversity of dragonflies and damselflies, foothill yellow-legged frog, and bald eagle.

Stakeholder Issues Stakeholders identified sixteen issues of concern in Bear Creek watershed to address:

 Toxic chemicals  Impacts from certain livestock grazing  Sediment delivery to watercourses practices, wildlife browsing  Creek channel alterations  Growing demand for recreation and  Creek and tributary headcuts tourism  Roads, trails, and fire lines  Potential environmental impacts of  Fire energy developments  Oak woodlands  Fiscal and policy obstacles for  Disturbances to ultramafic soils landowners to meet regulatory targets  Non-native invasive species  Climate change  Low recruitment of native woody  Information gaps riparian plants

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Most of these stakeholder issues do not stand alone but interrelate in multiple ways. Past land uses such as mining and agriculture have left that are root causes of present-day issues.

Water from Bear Creek and Sulphur Creek contains high amounts of mercury that significantly impact water quality and the biological integrity of aquatic ecosystems downstream in Cache Creek and ultimately in the Bay/Delta. Naturally high concentrations of mercury are present as well in the hot springs along Sulphur Creek and the cold springs east of Deadshot Canyon. Sources of anthropogenic mercury contamination of particular concern are sediment waste around inactive mercury mines in Sulphur Creek subwatershed and the Rathburn-Petray mine complex in Upper Bear Creek subwatershed. Secondary sources of mercury pollution are in areas of sediment deposition on the banks of lower Bear Creek where an estimated 91 pounds of total mercury remain after being transported from Sulphur Creek. The Central Valley Regional Valley Water Quality Control Board has established total daily maximum load targets, one each for mercury and methylmercury, as targets to reduce mercury originating from mercury mines in the watershed and restore water quality in the watershed.

A major concern is the multiple non-native invasive plant species that are displacing native vegetation. Non-native plant species such as barb goatgrass and yellow starthistle are now commanding attention because they are even invading ultramafic soils where they have been previously unknown. Disturbances from mining, roadwork, and livestock grazing are making ultramafic soils more susceptible to exotic plant invasions. Non-native plant species, such as arundo, tamarisk, and perennial pepperweed, are also invading riparian areas rapidly and are difficult and costly to remove.

Sustaining ecosystem services and vegetation productivity concerns both public land managers and landowners. Soil loss from erosion and sediment delivery into streams is a major concern. Reduced surface area produces less of desired vegetation for forage on rangelands in Bear Valley, Long Valley, and the BLM Bear Creek Ranch. Headcuts and channel incision are main sources of sediment to streams. Sulphur Creek, in particular, is experiencing rapid loss of soil as headcuts migrate upstream. With deepening stream channels, the water table in key riparian areas is dropping, making top soil layers drier for longer periods each year. In most cases, the causes of soil loss from headcuts and channel incision are not obvious.

Fires in 2008 burned more acres in the watershed than in other single year since fire records have been kept. Sensitive vegetation types on ultramafic soils in particular deserve special attention because of the slow rate of their natural revegetation post-fire and their many rare plant species, many of which may germinate or regain vigor from periodic fire. The fire-return frequency for ultramafic chaparral is about four times longer than for chaparral growing on sedimentary soils. Fire management to reduce fuels and avoid catastrophic fires will require a careful analysis and planning to make sure that prescribed burns are appropriate to the complex mosaic of soils,

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BEAR CREEK WATERSHED ASSESSMENT vegetation, and topography across the watershed. Impacts from fire suppression include a 20- mile long bulldozer line through previously undisturbed ultramafic chaparral. Another emerging consideration is the amount of mercury that volatilizes and enters the atmosphere as the result of wildfire.

In western Colusa County, past woodcutting and efforts to improve land for livestock grazing resulted in losses of native oak woodlands. Problems with oak regeneration specific to Bear Creek watershed arise from widespread damage to seedlings from animal browsing and to saplings from antler rubbing by deer and elk. Competition from non-native vegetation, especially annual grasses, depletes soil moisture and makes tree establishment impossible at some sites. Fire suppression in the past five or more decades may be shifting the composition and fire- resilient features of mature oak woodlands as fire-prone trees such as gray (foothill) pine become more common and begin to overtop oaks. The value that people place on oaks is changing as people understand the ecosystem service that oaks offer for carbon storage, providing shade for livestock, and habitat for wildlife. Voluntary oak conservation guidelines initiated by the Colusa County Board of Supervisors are now in effect for the watershed and hold promise for stemming the loss of woodlands.

Both renewable and non-renewable energy resources are available in the watershed. People have studied potential development for oil, gas, wind, solar, and geothermal energy resources over the last fifty years. Local residents have already developed small-scale solar and wind energy generation. To meet national energy goals for renewable energy, the BLM is considering a wind energy project, part of which lies on the Bear Creek watershed portion of Walker Ridge. Care is needed in site planning to avoid eroding the predominantly ultramafic soils. Naturally high contents of heavy metals and possibly asbestos in ultramafic soils may contribute to loss in water quality in streams from erosion and debris flows during construction and to risks to workers breathing dust generated at work sites. Access roads and turbine pads on ultramafic soils may also fragment unusual vegetation communities and rare plant habitat. Mortality of bats and raptor birds is known to be high from turbines at other wind energy projects, but no information is available yet for Walker Ridge. Some of the animal and plant species likely to be impacted at Walker Ridge wind energy sites are designated as BLM sensitive species.

With acquisition of the BLM Bear Creek Ranch, recreation opportunities for the public have greatly increased in the watershed over the last decade. One major question for watershed stakeholders is how to manage recreation for the greatest benefit of a growing and increasingly urbanized public who have ever less contact with open space and wild lands. Sustained employment in recreation and tourism can contribute to economic diversification of communities near the watershed. Increased human presence on the public lands is not always beneficial to recreation activities. An increase in illegal marijuana growing in remote parts of the watershed

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BEAR CREEK WATERSHED ASSESSMENT by heavily armed people as well as unauthorized shooting on the BLM Bear Creek Ranch pose threats to the personal safety of recreation visitors to the public lands.

Landowners and land managers must meet the regulatory targets established to accomplish restoration of water quality, air quality, and wildlife habitat for the benefit of society. Of immediate concern to private landowners is the financial burden placed on them to clean up abandoned or inactive mercury mines or, in some cases, to find the responsible parties to pay for the mine cleanups. Regulations regarding cleaning up and closing mines may appear draconic to landowners and may not gain their support to advance mercury remediation. The Central Valley Regional Water Quality Control Board is revising its orders for cleaning up mercury mines on private lands recently because of the need to follow specific procedures about informing potentially responsible parties. The Board is seeking to avoid unintended inequities for current landowners who have had no hand in creating mercury contamination.

Other significant barriers to making progress on improving environmental quality include lack of funding dedicated to revegetate areas that have burned severely or that have enduring scars on the landscape from measures to suppress fire and to prevent landslides. The costs for restoring vegetation on ultramafic soils are high, often greater than $20,000 per acre where both soil and vegetation have been removed. Without a financial commitment to restoration, natural revegetation on highly disturbed sites will proceed very slowly. In the meantime, sediment and soil erosion from disturbed sites is continuing.

Roads and trails in the watershed also contribute large amounts of sediment that impact water quality. Estimates on sediment amounts coming from county roads and off-highway trails are much higher. For example, production of sediment from trails in the vicinity of Sulphur Creek has exceeded 20,000 tons in recent decades. Deteriorating road conditions and unstable cut banks increase soil erosion and sediment deposition in creeks. In Leesville subwatershed, concentrated flows from culverts along county roads are diminishing land productivity for livestock forage. The longstanding deferral of road maintenance is contributing to roadside bank instability and headcuts in addition to creating safety hazards for motorists. Funding for maintaining and upgrading county roads is not adequate to address needed erosion control in the watershed.

Concerns about climate change over different time scales are preoccupying private landowners and public land managers. For landowners, loss of water from short-term droughts seen in recent years and the specter of longer droughts in the future resulting from changing climate conditions puts agriculture at risk in the watershed. One challenge to stakeholders is to formulate actions that directly improve the capacity of the watershed to adapt to climate change and also support State of California and national goals for alleviating impacts to ecosystem services related to climate change. Options to consider for an adaptive response to climate change include: using ecosystem system services to store more atmospheric carbon in vegetation and soils (carbon

BEAR CREEK WATERSHED ASSESSMENT sequestration); conservation planning for biological diversity; increasing hydrologic function to deliver and store more water in Bear Valley; and building a renewable energy infrastructure that does not degrade watershed habitats as it reduces national demand for fossil fuels.

Information Needs Despite all the information, gaps in needed information exist especially in regard to advancing watershed management and sustaining and renewing ecosystem services. Important gaps in information to address include:

 connections between plant species and soil series, to aid in selecting species for successful plant propagation at mine sites and other heavily disturbed sites  vegetation mapping using the most recent vegetation classification system for California  ground water resources, particularly ground water quality and recharge rates  monitoring data for water flows and chemical elements and ions potentially affecting water quality at sites throughout the watershed  weather stations, particularly in Bear Valley, to aid ranchers and to track the long-term trends in climate patterns affecting agriculture  information on channel longitudinal and cross sections to document changes to the shape of stream channels, especially where channel incision and headcuts are occurring  appropriate fire management corresponding to fire behavior modeling, desired fire regime, and soil-plant correlations  documentation of native plants and animals in remote parts of the watershed, focusing on sites with ultramafic soils  best management practices for increasing water retention time and raising water tables in the watershed, with particular attention to hydrologic function in Bear Valley  locations of mercury methylation sites in the watershed for focusing site management to reduce net methylmercury production  distributions and concentrations of other heavy metals in soils downstream from mine sites and in soils with ultramafic properties

Information about the watershed is not evenly available across subwatersheds. Subwatersheds with the least amount of information are: Mill Creek, the canyons west of Cortina Ridge, the Hamilton area, Warnick Canyon, and Leesville. The last four areas are on private land where publicly available data are scant.

Watershed Improvement Projects and Job Opportunities An analysis of individual subwatersheds or groups of similar adjacent subwatersheds helped to clarify the scope and location of strategic watershed improvement projects and where job opportunities exist. Job opportunities are most promising in the following areas:

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 development of low-impact renewable energy infrastructure  closure, remediation, and revegetation of mercury mine sites  restoration projects to improve water storage, restore more natural stream flow, and raise the water table in Bear Valley  environmental education linked to public outreach and recreation opportunities  rangeland management for livestock and environmental benefits from oak woodlands  road maintenance and redesign  monitoring changes in water quality and flow, wildlife and rare plant populations, productivity of vegetation, non-native plant invasions, and recreation use.

Specific projects identified for initiating watershed improvement and providing employment would focus on:

 reforesting oak woodlands to create greater canopy cover, cooling and shading benefits, wildlife habitat improvement, and soil conservation  converting non-native grasslands back to chaparral on public lands to create greater habitat connectivity for native plant and animal species  developing environmental education and recreation programs for the BLM Bear Creek Ranch  cleaning up mercury-contaminated mine sites in Sulphur Creek subwatershed, at the Rathburn-Petray mine complex, and along lower Bear Creek where mercury-rich sediment has accumulated  repairing roads and adjacent slopes, especially along Highway 16 and in Leesville subwatershed  inventorying plants and animals on ultramafic soils, in rare wetlands, and in and around hot springs, with a particular focus on sites being considered for developing renewable energy and the species (e.g., bats, raptors, endemic plants) most likely to be impacted by energy development  Bank stabilization through fencing and revegetation in Bear Valley and the BLM Bear Creek Ranch where wildlife and livestock concentrate

An accompanying publication to this watershed, Bear Creek Watershed Stewardship Priorities, 2010-2014, provides details for watershed management projects designed to improve watershed conditions in the near future.

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Bear Creek Watershed Overview 122°30'W

Grapevine Creek L Sugarloaf i t t le 352 m L I it n Pence Mountain tle S k d ton ree i y Cr ian C a 560 m eek nd n Named Mines Watershed I C Lodoga Peak Lurline Creek r e Location Dead Shot Creek e 694 m 39°15'N k Unnamed1 Mines Perr M ington Creek id d Bear Creek Watershed l Cooks Mountain eek e Fork rout Cr Mill Creek 644 m 39°15'N T LADY RIDGE Land Status

A Bureau of Land Management n LOVE t e ek Lambert Hill l So Cre Gravelly Buttes opUS Forest Service es ut ll 520 m e W t F h F Mi 524 m C ek o Pacific Point ork LADOGA ROAD r e rk State S 1147 m p a n Private/Other is h k e C e ough r r l RED RIDGE e C S MENDOCINO e h n Cre s e y k i tanto k n S e a l NATIONAL p l S a rk o V FOREST F M st i n a ll n E e C l r Bear Valley Buttes e G e k 596 m Split Rock LEESVILLE. 937 m LEESVILLE Sugarloaf ek 496 m Creek re ett epper C artl ilp B K B E A R V A L L E Y ROAD Ma Lake Co nor S lough No BRIM ROAD Colusa Co rth F o C

r a k Indian Reister Rock l W Baldy Mountain v i n o 947 m 1020 m l Bald Hill s f VALLEY BEAR C C 351 m r r e e ek e Grapevine Flat k Reister Knoll Valley k 774 m a Cree shw ter re Three Sisters ROAD F

WALKER 486 m

Reservoir

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r RIDGE CORTINA Bald Mountain G .COWBOY CAMP 631 m Bally Peak BEAR k 657 m e e ey r ll C a s V s n n CREEK ur i B r k k Schoolteacher Hill Pe ree Thompson Canyon C 504 m shy 53 k ru e B RANCH e r C eek CACHE CREEK RIDGE Cr y Round Mountain orth k sw c 545 m Brophy Canyon ole o 16 M R eek CLEARLAKE Cache Cr HIGHLANDS D Olgert Canyon ry C re e k Buck Mountain Baldy Mountain 815 m 638 m LOWER H LAKE e Glascock Mountain ek r re n Sky High n C d 703 m yo o 829 m ler Can n ig C e re Yolo Co S 29 ek

122°30'W

2 0 2 4

Kilometers BEAR CREEK WATERSHED ASSESSMENT

CHAPTER 1

INTRODUCTION TO THE WATERSHED ASSESSMENT

1.1 Purpose The State of California protects the quantity and quality of water for human and ecological uses through water regulation and management. A major focus for State water agencies is the Sacramento-San Joaquin Delta, which supplies 25 million Californians with water. Environmental issues in the Delta of statewide significance include water supply reliability and impairments to water quality. A partnership of state and federal agencies, the CALFED Bay-Delta Program, has worked to resolve these statewide issues in the Delta and San Francisco Bay.

CALFED has supported research to redress impaired water quality, especially impairment arising from mercury in the Delta, and has set the stage for remediating the human sources of mercury loading in its Sacramento River tributaries. Domalgaski (2001) found that the Cache Creek Basin has the highest levels of mercury of all tributary basins to the Sacramento River. Further, from all sites sampled for mercury in the Cache Creek Basin, Domalgaski et al. (2004a,b) found that the second highest concentrations of mercury in Basin water and sediment came from Bear Creek watershed and, more specifically, from Sulphur Creek subwatershed in the area downstream of numerous abandoned mercury mines and natural hot springs with high levels of mercury.

Mercury contamination provided the original impetus for the Bear Creek watershed assessment. However, CALFED and its funding agent, the Department of Water Resources, requested that the watershed assessment have a broader scope of stakeholder concerns about Bear Creek watershed.

The process of Bear Creek watershed assessment consisted of the following eight steps:

Gather and organize information from stakeholders, technical literature, agency documents, and data sets that describe past and current conditions in the watershed Describe stakeholders’ goals and stewardship issues for the watershed Conduct resource inventories as feasible and identify data gaps Prepare a written solicitation to the public for additional goals and issues and for additional information about Bear Creek watershed Assess water quality, hydrologic function, soil and site stability, and biological resources Identify locations, stewardship practices, and opportunities appropriate for addressing stakeholders’ issues in the watershed through analysis areas based on subwatersheds

BEAR CREEK WATERSHED ASSESSMENT

Present a draft version of the assessment for public review and comment Incorporate public comments and any new information into the final draft of the Bear Creek watershed assessment.

By assembling existing information, identifying gaps in information, and analyzing subwatersheds, the watershed assessment can be a reference for stakeholders as they address issues of concern.

The Bear Creek watershed assessment combines the format and subject matter for watershed assessments from two sources: the US Environmental Protection Agency (US EPA) (2003); and the two California Watershed Assessment Manuals (Shilling et al. 2005 and draft undated ms.) prepared for the California Resources Agency. The US EPA guidance focuses on water resources while the California Watershed Manuals use a multiple-resource perspective for a range of stakeholder issues.

1.2 Goals Eight stakeholder goals have guided the assessment process. The following sections discuss each of them.

Improve Water Quality Multiple contaminant chemical elements are impairing or have the potential to further impair water quality in Bear Creek watershed. The principal contaminant of concern is mercury. Most mercury contamination originates from abandoned mercury mine sites. Large quantities of sediment rich in mercury flow into watershed streams, especially during winter storms. The Central Valley Regional Water Quality Control Board (CVRWQCB) has established two total maximum daily load (TMDL) targets for Bear Creek and its tributary Sulphur Creek to recover the beneficial uses of water compromised by mercury contamination. The TMDLs limit amounts of total mercury permissible in Sulphur Creek subwatershed and amounts of methylmercury, the form of mercury that accumulates in aquatic microorganisms, fish, birds, and people, over the entire Bear Creek watershed.

Sediment discharges to watercourses are also occurring from roads, highways, culverts, livestock grazing and contribute to degraded water quality. Excessive sediment in streams is limiting beneficial uses for water such as municipal water supply and quality habitat for fisheries, frogs, turtles, and other aquatic organisms.

New threats to water quality are developing. Recently, law enforcement officers have found illegal marijuana gardens in the watershed where pesticides and fertilizers were used carelessly and are contaminating the soil and water. The extent of contamination in Bear

BEAR CREEK WATERSHED ASSESSMENT

Creek watershed from illegal marijuana growing is not yet known.

Restore Hydrologic Function A watershed has three primary water-related functions: capturing water, storing it in the soil, and releasing it beneficially for people and the environment (Bedell and Buckhouse 1995, Pellant et al. 2005). Across Bear Creek watershed, people’s modifications to uplands and riparian zones over time have altered how and when water flows. Eroding soils resulting from mining, certain range management practices, poorly designed roads, altered stream channels, and floodplain loss have combined to reduce the ability of the watershed to capture, store, and release water. Symptoms of decreased hydrologic function are soil compaction, low vegetative cover, poor soil infiltration, and accelerated flows in streams. A major concern for stakeholders is the resulting drop in the water table in several parts of the watershed.

During its visit to Bear Creek watershed in 2001, the National Riparian Service Team from the Bureau of Land Management and the US Forest Service found low channel width-to- depth ratios on private lands in Bear Valley and Sulphur Creek valley and on the Bureau of Land Management’s Bear Creek Ranch. Channel incision, lowered water table, creek channels disconnected from historic floodplains, headcuts, gullies, and sparse riparian vegetation were noted as symptoms of poor hydrologic function. These conditions intensify the erosion power of water during rainstorms and reduce the “sponge” capacity of floodplains to retain water longer in the watershed.

Roads alter water movement across the landscape and below ground. Compacted road surfaces decrease infiltration and increase water runoff. Road cuts on slopes intercept and bring groundwater to the surface. Ditches along roads and culverts divert surface and subsurface water flows and concentrate storm runoff, increasing its velocity and accelerating soil erosion.

Conserve Topsoil and Stabilize Erosion-prone Areas Land instability and soil erosion are one symptom of degraded hydrologic function. Soil supports vegetation, retains moisture, and sustains agricultural production. Rates of soil movement and loss in many parts of the watershed are agricultural production and ecosystem services such as wildlife habitat. Management appropriate to the soil type and desired land use entails careful stewardship to avoid soil loss. For example, improvised OHV trails and poorly designed roads built on steep or unstable slopes can trigger unintended soil loss (Weaver and Hagens 1994).

BEAR CREEK WATERSHED ASSESSMENT

Protect and Enhance Biological Diversity Scientists, land management agencies, and the public recognize the significant ecological values of Bear Creek watershed. Highlights include: spectacular wildflower fields; alkali wetlands; ultramafic soils and their associated rare plants in seep, riparian, grassland, and mixed chaparral environments; extensive blue oak savannas; and the Bear Creek Botanical Management Area. Professor Ellen Dean at UC-Davis (pers. comm.) and her colleagues have documented 387 native plant species from the BLM Bear Creek Ranch alone, including 25 species found only on ultramafic soils and 18 CNPS Class IV rare species.

Professor Peter Moyle at UC-Davis (pers. comm.) considers Bear Creek a rare aquatic ecosystem, harboring native fishes, yellow-legged frog (Rana boylii), western pond turtle (Clemmys marmorata), beaver (Castor canadensis), and river otter (Lontra canadensis). It is a major corridor for neotropical migratory birds (P. Hoffman, pers. comm.) and a wintering area for bald eagles (Haliaeetus leucocephalus). Tule elk (Cervus elaphus nannodes), once nearly extinct in California but re-introduced to the watershed in the 1920’s, are thriving again. Bear Creek is one of six known hot-spots in California for damsel- and dragonflies (K. Biggs, pers. comm.). Three rare insects are known only from the Wilbur Hot Springs area.

Enhance Recreation Recreational opportunities abound in the watershed. Each year thousands of people from around the world visit Wilbur Hot Springs, stay in an historic hotel, and hike on trails in Sulphur Creek subwatershed. An estimated 32,000 people visit the federal public lands in the watershed annually for hiking, hunting, equestrian riding, camping, and nature exploration (calculated from the federal Recreation Management Information System 2008). Limited OHV recreation is available in the Walker Ridge area. Wildflower displays in Bear Valley and scenic vistas from Walker Ridge draw people to the watershed. A current proposal to create the Berryessa-Snow Mountain National Conservation Area would include all federally and state-managed lands within Bear Creek watershed and would give national recognition to the recreation resources and the natural setting of the watershed. Focus on recreation can provide economic opportunities for travel and tourism businesses and options to private landowners for income diversification based on the natural resources of their lands.

Develop Energy Resources The federal government and the State of California intend to develop renewable energy resources to achieve greater national self-sufficiency in energy production and limit carbon emissions to the atmosphere. Private landowners in the watershed have already begun tapping solar and wind power for their own use. Energy generation on public lands and on private lands where the federal government manages subsurface geothermal, oil, and gas

BEAR CREEK WATERSHED ASSESSMENT rights in Bear Creek watershed are possible in the future. Bear Creek watershed is unusual because it has the potential to supply energy from five sources: oil, gas, geothermal, solar, and wind. Few other places in California have as many potential energy resources so close together. A proposal to lease federal public lands in the watershed to install wind turbines is now under consideration.

Maintain Economic Livelihoods and Create Jobs Bear Creek watershed is a working landscape producing multiple goods, services, amenities, and values for stakeholders. Stakeholders are interested in knowing what options are possible for deriving or diversifying incomes based on natural resources found in the watershed. New opportunities may keep traditional livelihoods viable.

Activities in the watershed that are generating employment include: livestock and crop production, beekeeping, resort management, revegetation, mine remediation, road and culvert redesign and installation, invasive plant removal, repair of streambanks and headcuts, diverse recreational opportunities, and tourism. Ranching has been the cornerstone economic enterprise for many generations in the watershed. Livestock production creates income, provides food, maintains wildflower fields, promotes conservation programs, and protects these large landscapes from commercial development and residential subdivisions. Two ranches within the watershed have conservation easements, providing outside funding sources for ranching enterprises and land protection on private lands.

Stakeholder issues generate possibilities for employment as issues are addressed to reach watershed goals. Past stewardship projects have already generated employment, through project funding amounting to more than $1.5 million. This assessment identifies project options and employment opportunities that enhance the landscape quality and natural resources of Bear Creek watershed.

Reduce the Likelihood and Impacts of Catastrophic Events Maintaining basic ecological functions such as hydrologic function, soil fertility, and the natural diversity of the watershed is essential to its continued utility as a working landscape. Catastrophic events, especially in combination, have the potential to alter the watershed and its productivity in ways that will not benefit people. Five categories of catastrophic environmental events known to have occurred in the watershed are under discussion: contaminants and sediments that impair water quality; adverse outcomes from large-scale and intense fires; abnormal floods; extended drought; and climate change. Strengthening the capacity of the watershed to be resilient to catastrophic events works to the advantage of people because flows of goods and services from the watershed are more likely to be sustained in times of environmental and economic change.

BEAR CREEK WATERSHED ASSESSMENT

1.3 Audience The audience for this assessment consists of individuals or groups such as property owners, businesses, academic and research institutions, government agencies, advocacy groups, and any other persons who have an interest or “stake” in Bear Creek watershed. One of the challenges for this assessment has been to adequately characterize the issues for as many stakeholders as possible. As might be expected, interests among stakeholders differ for a range of reasons, and stakeholders have diverse expectations, values, economic needs, and professional obligations. Although we have attempted to be inclusive and comprehensive, we recognize that many gaps in our knowledge about stakeholder’s values, interests, and aspirations exist.

The following descriptions outline the general categories of stakeholders and their roles in the watershed.

Private Individual Landowners Some private landowners have lived all or most of their lives in the watershed. Their families may have settled in the region generations ago. From their direct experience and knowledge received from their families, they have a deep understanding of the watershed. Other landowners may have purchased property more recently because they appreciate the lands in the watershed and the opportunities and amenities that these lands afford. In many cases, the household economies of private landowners are based on using and managing natural resources in the watershed. Important concerns for this group are: economic resiliency and diversification; continuity of an independent, rural lifestyle; protection of private property rights; and concern about legal liabilities from trespass and from abandoned mines.

Private Business Landowners These landowners mostly do not reside in Bear Creek watershed. Their businesses continue traditional economic enterprises such as livestock ranching both in and outside the watershed. They have broader interests geographically and do not depend solely on conditions in the watershed for their economic well-being. Net profit is important for retaining their land base in a portfolio of business assets. If the highest and best economic use of their land or available tax and stewardship incentives should change, these landowners might change land uses to maximize their benefits from the land.

Non-Landowner Employees and Residents People whom landowners employ to manage property operations share many of the same skills with private individual landowners. The stakes of these employees in the watershed are not property-based; nonetheless, they are likely to care about environmental conditions in the watershed. Other non-landowning residents in the watershed residents rent homes in

BEAR CREEK WATERSHED ASSESSMENT the watershed and commute to jobs outside the watershed.

Former Residents The population of the watershed was once much larger than it is now and included more multi-generation families. Opportunities elsewhere have drawn people away from Bear Creek watershed, but memories and emotional bonds from a sense of place link former residents to the watershed. They care about the places that were their past homes; they also may have key information about past events in the watershed important to understanding watershed conditions. This group also includes Native Americans whose ancestors were residents in the watershed and for whom the watershed is a landscape of cultural heritage.

Non-Resident Consumptive Resource Users Businesses, individuals, and advocacy groups outside the watershed have a stake in extracting non-renewable resources from the watershed, such as minerals, decorative rock, petroleum, and natural gas. Stakeholders in this group may seek easements or leases to acquire belowground minerals and energy reserves. Changes in commodity values in the marketplace and government incentives may spur these stakeholders to extract the natural resources of interest to them.

Some consumptive resource uses are renewable. Non-resident stakeholders use water for domestic use and agriculture, produce food and animal forage, hunt game animals, and forage for traditional food plants are examples. The sustainability of these resources depends on maintaining a healthy and resilient watershed.

Non-Resident Non-Consumptive Resource Users Individuals, corporations, and advocacy groups who promote non-consumptive resource use of Bear Creek watershed include tourism and recreation interests. Their economic and environmental significance can be considerable, particularly for public lands. Some stakeholders may come to the watershed from great distances and are interested in public lands for touring, sports, wildlife and wildflower viewing, and other leisure activities.

Potentially Responsible Parties for Abandoned Mines Historic mining in the watershed has left a legacy of contaminated landscapes and modified hydrologic conditions. Responsible parties for cleaning up mines abandoned before 1980 are the corporations or individuals who created the hazardous waste sites, or their successors. Federal law requires that they must pay to clean up abandoned mine sites. In some cases, these stakeholders may not wish to participate because of the liability to remediate conditions and reclaim land at abandoned mines.

BEAR CREEK WATERSHED ASSESSMENT

Agencies Providing Public Works and Protection This group consists of agencies in the federal, state, or county government that have responsibilities to provide public services such as transportation infrastructure, law enforcement, and fire protection.

Agencies Managing Public Lands and Resources Federal and State of California agencies that manage public lands and resources in trust for citizens have multiple mandates to produce goods, services, amenities, and other values. Best choices for management are seldom clear-cut, and other watershed stakeholders frequently challenge public land management agencies on their management decisions at public meetings, during hearings, and in court. Appendix A of this assessment summarizes current management plans from land management agencies for public lands in Bear Creek watershed.

Agencies Regulating Public Resources Many resources, such as air, water, soil, and biological diversity, are held in public trust regardless of who owns the surface land rights. Regulation of air and water quality and of populations of threatened or endangered species falls to specific Federal and California state agencies. Appendix B of this assessment describes current planning and regulations of resource agencies that refer to Bear Creek watershed.

Elected Officials Elected officials advocate for their constituents’ interests. When stakeholders gain the attention of their elected officials for initiating a political action in regard to the watershed, the elected officials become stakeholders as well.

Appointed Officials Some regulatory agencies have boards of directors appointed by the Governor of California, the California State Senate, and the California State Assembly. These appointed officials have received recognition from political leaders as excellent decision-makers regarding trust resources. They may be active advocates for using State of California funds for projects in Bear Creek watershed.

Outsiders Professional expertise for understanding and managing a watershed frequently comes from outside people. Their knowledge and ability to analyze watershed conditions can facilitate people’s understanding of watershed conditions and possibilities for change. These individuals can also work with stakeholders groups to design novel solutions that would likely not have been created without the group interaction. For example, these professionals may be local, state, or federal extension agents; researchers and faculty members of

BEAR CREEK WATERSHED ASSESSMENT universities; or specialists employed at profit or not-for-profit consulting firms.

1.4 Issues Stakeholders have furnished sixteen issues for Bear Creek watershed assessment that serve to orient management actions for achieving watershed goals. Chapter 6 covers the scope and implications of each stakeholder issue identified thus far in greater detail. The list of issues follows:

 Toxic chemicals  Sediment delivery to watercourses  Creek channel alterations  Creek and tributary headcuts  Roads, trails, and fire suppression lines  Fire  Oak woodlands  Disturbances to ultramafic soils  Non-native invasive species  Low recruitment of native woody riparian plants  Impacts from certain livestock grazing practices and browsing and gnawing animals  Growing demand for recreation and tourism  Potential environmental impacts of energy developments  Fiscal and policy obstacles for landowners to meet regulatory targets  Climate change  Information gaps

Most stakeholder issues relate to more than one watershed goal. Table 1.1 below furnishes a crosswalk between stakeholder issues and watershed goals. In the last column of the table, the listed section numbers correspond to parts of the watershed assessment that relate to a particular issue. The table can guide the reader to the parts of the document of greatest interest.

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Table 1.1 – Crosswalk between watershed goals and stakeholder issues Watershed Goals

prone

Relevant

Stakeholder Issues function

Watershed Assessment esources r Sections areas events Restore Develop Improve Enhance recreation livelihoods water quality nergy and create jobs e biological diversity Maintain economic hydrologic Protect and enhance Conserve topsoil and Reduce likelihood a stabilize erosion impacts of catastrophic

2.6, 2.7, 3.7, 4.1, 5.1-5.12, 6.1, 7.11- Toxic chemicals X X X X X X 7.13, 8.2, Appendices G & H 2.7, 2.8, 3.5-3.7, 3.9-3.11, 4.1-4.3, 5.1, Sediment delivery to X X X X X X 5.4, 6.2, 7.1, 7.3, 7.5, 7.6, 7.8-7.13, 8.2, watercourses Appendices G & H 3.4, 3.6, 3.7, 3.11, 4.3, 6.3, 7.1, 7.6, 7.7, Creek channel alterations X X X X X X 7.10-7.13, 8.2 Creek and tributary 3.4, 3.6, 3.7, 3.11, 4.3, 6.3, 7.6, 7.10- X X X headcuts 7.13, 8.2 Roads, trails, and fire 2.7, 2.9, 2.10, 3.4, 3.6-3.12, 5.4, 6.5, X X X X X X X suppression lines 7.3-7.7, 7.11-7.13, 8.2 2.9, 2.11, 3.2, 3.3-3.6, 3.10, 3.11, 4.1- Fire X X X X 4.3, 6.6, 6.7, 7.1, 7.3, 7.8-7.11, 7.13, 8.2 2.3, 2.4, 2.7, 2.9, 2.10, 2.11, 2.12, 3.2- Oak woodlands X X X X X 3.9, 4.1, 6.7, 7.2, 7.5-7.13 Disturbances to ultramafic 2.6-2.11, 3.5-3.9, 3.11, 4.1, 4.2, 5.1-5.4, X X X X soils 5.6-5.8, 6.1, 6.8, 7.2-7.4, 7.7, 7.11-7.13 2.4, 2.7, 2.9, 2.10-2.12, 3.4-3.6, 3.8- Non-native invasive species X X X 3.11, 4.1, 4.4, 5.3, 6.9, 7.2, 7.5-7.8,

7.11-7.13, 8.2 2.7, 2.9, 2.10, 2.12,3.3-3.6, 3.11,4.3, Low recruitment of native X X X 4.4, 5.3, 6.9-,6.11,7.3, 7.5-7.8, 7.10- woody riparian plants 7.13, 8.2

BEAR CREEK WATERSHED ASSESSMENT

Watershed Goals

prone

Relevant

Stakeholder Issues function

2.5, 2.7, 2.9-2.11, 3.2, 3.4-3.6, 5.1, 5.4, Impacts from animals X X X X 6.9-6.11, 7.1, 7.2, 7.5-7.13, 8.2 2.1, 2.3-2.6, 2.9-2.13, 3.5, 3.8, 3.9, Growing demand for X X X X 3.11, 5.6, 6.12, 7.1, 7.2, 7.4, 7.8, 7.11- recreation and tourism 7.13 Potential impacts of energy 2.3-2.13, 3.2-3.5, 3.8-3.11, 4.1-4.3, 5.4, X X X X X developments 6.13, 7.3, 7.4, 7.11 Obstacles for landowners to 2.6, 3.1-3.4, 3.7, 5.1-5.7, 6.14, 7.6, X X meet regulatory targets 7.11-7.13 2.4, 2.9-2.10, 2.13, 3.3-3.6, 3.9, 4.1, Climate change X X X X X X 4.3, 4.4, 6.16, 7.1-7.4, 7.6, 7.7, 7.9-

7.13, 8.2 2.7-2.11, 3.3-3.12, 4.1, 4.3, 4.4, 5.2-5.4, Information gaps X X X X X X 5.6-5.8, 5.10, 5.12, 6.1-6.16, 7.2-7.4,

7.7-7.13, 8.2

BEAR CREEK WATERSHED ASSESSMENT

1.5 Guiding Principles In preparing the watershed assessment, we used the following guiding principles to guide the work:

respect for all stakeholders appreciation for the unique places and resources in Bear Creek watershed desire to share information commitment to make the assessment easy to access, understand, and use inclusion of stakeholders in assessment input and review to the extent that they are interested and had time continual search for available information about Bear Creek watershed the value of science, data, and assessment to inform thinking about the watershed.

1.6 Information Sharing and Public Outreach In the first phase of the assembling the watershed assessment, the authors informally contacted and visited with stakeholders (including landowners, resource and land management agencies, researchers familiar with the watershed, and resource users), visited remote sites in the watershed, and developed the scope and outline of the watershed assessment. Contractors were engaged to provide new information about the watershed geomorphology in the northern two-thirds of the watershed as well as to analyze the roads and erosion in Sulphur Creek subwatershed. The authors collected and organized data sets covering a wide spectrum of environmental data about the watershed, including geology, soils, hydrology, plants, fish and wildlife, geochemistry, and land uses.

Once an initial set of watershed goals and stakeholder issues were identified, the assessment authors produced an Introduction to the Assessment on December 01, 2008, to present goals and issues and to request additional information from the stakeholders that could expand the scope of the watershed. Public presentations were provided for the BLM California State Office Natural Resources Division staff, the BLM Ukiah Field Office staff, the Colusa County Resource Conservation District (RCD) Board Members and staff, the Northwest California Resource Advisory Council members, and the Cache Creek Forum. Many residents of Colusa County, all watershed landowners including those living outside the county, governmental agencies, non-governmental organizations, and user groups received the introduction in a version emailed, sent by post, or downloaded from the Colusa County RCD website at www.colusarcd.org.

After an internal review by core stakeholders and by the BLM National Operations science team, the Colusa County RCD posted a revised draft version for full public review on December 10, 2009. Copies again were delivered by download from the RCD’s website.

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People were requested to submit new information, goals, and issues as well as detailed comments for improving the assessment during a 45-day comment period. Public meetings at the time of release of the draft version took place at the offices of the Colusa County RCD, the Yolo County RCD, and the BLM Ukiah Field Office.

In February 2010, the final draft of the watershed assessment appeared on the Colusa County RCD website. Public meetings to present the final assessment took place at the Colusa County RCD, Yolo County RCD, and the BLM Ukiah Field Office.

1.7 Participants in Preparation and Review

Watershed Assessment Authors James F. Weigand Craig D. Thomsen

Bureau of Land Management Editorial Review David Christy Sandra McGinnis

Bureau of Land Management National Operations Center Science Review Karl Ford Craig Goodwin Don Prichard Bill Ypsilantis

Stakeholder Technical Review Residents and landowners in Bear Creek watershed Staffs of the BLM Ukiah Field Office and the Mendocino National Forest Jack Alderson, USDA Natural Resource Conservation Service Dr. Janis Cooke, Central Valley Regional Water Quality Control Board Dr. Joseph Furnish, Aquatic Ecologist, US Forest Service, Region 5 Margie Graham, Department of Water Resources, Northern District Dr. Susan Harrison, University of California at Davis Stefan Lorenzato, Yolo County Flood Control and Water Conservation District Patti Turner, Colusa County RCD

BEAR CREEK WATERSHED ASSESSMENT

1.8 Structure and Content of the Following Chapters Chapter 2 describes Bear Creek watershed in terms of its physical setting, key natural resources, and ecosystem functions.

Chapter 3 presents the historic and current information about land uses, the economy, and watershed residents.

Chapter 4 introduces natural disturbances that affect the appearance and function of the watershed: fire, geological hazards, floods, and drought.

Chapter 5 assesses water and air quality, sources and types of pollutants, and impacts to aquatic ecosystems from pollutants.

Chapter 6 takes up stakeholders’ issues, discusses the factors that contribute to creating or alleviating issues.

Chapter 7 examines subwatersheds to determine priorities and draws attention to coordinated actions to benefit the watershed and provide job opportunities.

Chapter 8 summarizes watershed assessment findings, discusses the use of best management practices, and makes recommendations to stakeholders for inventories, monitoring, and research to support decision making in watershed management. A separate document accompanying the assessment describes projects that are funded or likely to be funded over the period 2010 to 2014.

Following Chapter 8, appendices provide greater detail on subjects discussed in the preceding chapters. Appendices cover selected watershed resources, the scope of public land management, and the government regulations in place.

A bibliography of references used for this watershed assessment and a glossary of terms are found at the end of the document.

BEAR CREEK WATERSHED ASSESSMENT

CHAPTER 2

WATERSHED DESCRIPTION

2.1 Location and Setting Bear Creek watershed lies on the east side of the North Coast Range at the interface with the west side of the Sacramento River Valley, in northern California. The watershed encompasses 102.9 square miles (266.4 km2) between 38º 55’ 35” N and 39º 15’ 43” N latitude and between 122º 19’ 1” W and 122º 35’ 42” W longitude. It is elongated 23 miles in a NNW to SSE direction, parallel to the regional orientation of the Coast Range and major geological faults in the area. At its widest point, the watershed extends 9.5 miles east to west.

Geopolitical Setting The watershed lies entirely within Colusa County and comprises the southwest corner of Colusa County at its border with Lake County. By area, it occupies 8.9 percent of the County. Colusa County has a dominant rural character and is not part of a metropolitan or micropolitan statistical area as defined by the Federal Office of Management and Budget (OMB) (US Census Bureau 2009).

The City of Colusa, the county seat of Colusa County, is 23 air miles east of the watershed. The City of Williams along Interstate Highway 5 in Colusa County is 15 air miles east, and the City of Clearlake, in Lake County to the west, is also 15 air miles away. The postal zip code for Williams (95987) covers residents’ street addresses in Bear Creek watershed.

The closest large urban areas are Yuba City (Sutter County), 40 air miles to the east, and Sacramento (Sacramento County), 56 air miles to the southeast. Clearlake (Lake County), a Federal OMB micropolitan area 25 miles west, is the closest small-scale urban area to Bear Creek watershed.

The watershed is part of California District 2 in the U.S. House of Representatives. Assembly District 2 and Senate District 4 cover the watershed area in the California state legislature. At the county level, County Supervisor District IV includes the entire watershed.

Figure 2.1 shows the watershed location in relation to Colusa, Lake, and Yolo counties.

Watershed Location Bear Creek watershed is part of the California Water Resource Region, defined as the drainage area that ultimately discharges into the Pacific Ocean through the State of

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California. It is one of the 88 watersheds that lie within the Sacramento River Hydrologic Region as defined by the California Department of Water Resources for the California Water Plan (California Department of Water Resources 2005).

Water originating from Bear Creek watershed flows to the Pacific Ocean, passing through Cache Creek, the Sacramento River, the Sacramento-San Joaquin Delta, and San Francisco Bay. Although its drainage area into the Delta and the Bay is comparatively small (Figure 2.2), water from Bear Creek contains high amounts of mercury that significantly impact water quality and biological integrity of the Delta and Bay ecosystems.

Table 2.1 - Hierarchical context of Bear Creek watershed DWR Administrative Area Unit Name Unit (square miles) Hydrologic Area Bear Creek Watershed 103 Hydologic Basin Upper Cache Creek Basin + Lower Cache Creek 1,666 Hydrologic Subregion Sacramento River 27,245 -- Sacramento / San Joaquin Delta Drainage 42,509 -- San Francisco Bay Drainage 47,032 Water Resource California 256,931 Region Sources: Seaber et al. (1987), Interagency, CalWater, Version 2.2.1 (2004), USDA Natural Resource Conservation Service (2008)

Table 2.2 – Watersheds and basins in the vicinity of Bear Creek watershed Watershed Basin (Hydrologic Area) (Hydrologic Unit) Bear Creek Middle Cache Creek Cache Creek North Fork Cache Creek Cortina Creek Whisky Hill Cortina Creek Stone Corral Creek Fouts Springs Stony Creek

Six other watersheds surround Bear Creek watershed, all of which also drain to the Sacramento River Hydrological Region. Two of these watersheds are part of the Cache Creek Hydrologic Unit: Middle Cache Creek to the south and North Fork Cache Creek directly west of the watershed. Bear Creek flows into Middle Cache Creek near the point where the boundaries of Colusa, Lake, and Yolo counties meet.

Ecological Setting The USDA Forest Service has divided California into ecological subsections based on similarities of climate, geology, topography, soils, vegetation, and wildlife (Miles and

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Goudey 1997). Three subsections occur in the watershed and contribute to a landscape of notable diversity over the watershed area. Following are brief descriptions of the subsections, and Figure 2.3 displays the distribution of subsections in the watershed.

Eastern Franciscan (Subsection M261Ba) The Eastern Franciscan Subsection comprises the smallest area of the three ecological subsections in the watershed, occupying only the highest elevations of the western and northwestern edges of the watershed, which are also the coolest and wettest areas. The terrain consists mostly of mountains bisected by narrow canyons. Landslides and stream erosion are common due to the unstable geology formations. Mixed conifer forests predominate and contrast distinctly with the chaparral vegetation to the east and south.

Stony Creek Serpentine (Subsection M261Bc) Regionally, the Stony Creek Serpentine Subsection forms a narrow ecoregion typically underlain by ultramafic (high magnesium and iron) rock types. Stony Creek Serpentine lies between the Coast Range Thrust on the west and the Stony Creek Fault on the east, forming the eastern edge of the North Coast Range. Landslides and stream erosion are widespread because of the unstable terrain. Compared to the Eastern Franciscan Subsection, the climate is hotter and drier. Vegetation consists of conifers and evergreen shrubs tolerant of ultramafic soils or chaparral dominated by chamise (Adenostoma fasciculatum) on sites with non- ultramafic soils. The vegetation of Bear Valley, the lowest-elevation part of the Stony Creek Serpentine subsection, includes predominantly herbaceous wet meadow and prairie species, with mixtures of non-native and native grasses, annual and perennial forbs.

Western Foothills (Subsection M261Ca) Watershed lands east of the Stony Creek fault belong to the Western Foothill subsection. They are notable for their contrast in topography, geology, soils, and vegetation from the Stony Creek Serpentine portions of the watershed. Soils are sedimentary in origin. The steep Western Foothills environments at the east margin of Bear Valley run roughly parallel to the Sacramento River Valley. Fluvial erosion occurs frequently. Blue oak (Quercus douglasii) woodlands predominate in this ecological subsection, with smaller areas of mixed-species and chamise chaparral.

The Stony Creek and Western Foothills are dominant in Bear Creek watershed, and the watershed constitutes a part of a NNW-to-SSE trending band 150 miles long by 17 miles wide spanning northwest Solano County to southeast Shasta County (Figure 2.4).

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2.2 Watershed Boundaries Bear Creek watershed consists of the topographic area that drains surface water to Bear Creek. The watershed boundary delineation (Figure 2.1) comes from CalWater, Version 2.2.1 (2004).

The northwest and west boundaries of the watershed consist of a series of ridgelines from south to north: Cache Creek Ridge, County Line Ridge, Walker Ridge, Red Ridge, and Love Lady Ridge. These ridges separate Bear Valley from the main stem of Cache Creek on the southwest and Little Indian Valley (North Fork Cache Creek) to the west. The southern tip of the watershed is the confluence of Bear Creek with Middle Cache Creek. Cortina Ridge marks the southeastern boundary of the watershed. Cortina Ridge, Blue Ridge, and other unnamed ridges northward at the east boundary of Bear Valley constitute the westernmost edge in a series of north-south foothill chains extending to the Sacramento River Valley floor. In the north-central and northeast portions of the watershed, Gravelly Buttes, Bear Valley Buttes, and low rolling hills separate Bear Creek watershed from Fout Springs Creek watershed.

Subwatersheds of Bear Creek Watershed Subwatershed delineations are useful for planning watershed improvements as they are logical management units for evaluating ecological conditions and water quality issues. Table 2.3 gives acreages and geographic descriptions for each subwatershed delineated by Jack Alderson, USDA Natural Resource Conservation Service (NRCS). Chapter 7 expands on the watershed issues present in each subwatershed.

2.3 Topography Love Lady Ridge, at the northwest watershed boundary, contains the highest elevations in the watershed. East of Walker Ridge and Love Lady Ridge on the west boundary, the otherwise steep terrain gives way to several bench terraces, including Davis Flat, Robbers Flat, Deadshot Flat, and Malaney Flat, before sloping steeply again to the floor of Bear Valley. From Sulphur Creek subwatershed south, mid-elevation bench terraces are absent and a highly dissected canyon landscape characterizes the watershed west of Bear Creek.

In the southeast, low-elevation but steep canyons roughly perpendicular to Cortina Ridge and Blue Ridge open into lower Bear Creek. The series of uniform low and rounded foothills at the eastern boundary makes a striking visual contrast to the steep westside slopes. Leesville Gap in the northeast breaks the chain of eastern hills to permit drainage from Long Valley westward into Bear Valley.

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Table 2.3 – Subwatersheds of Bear Creek watershed Subwatershed Acres Description Upper Bear Creek Bear Creek Upper 14,526 Overland flow drainage area directly to the main stem of Bear Creek north Stem of the south end of Bear Valley Deadshot Canyon 684 Drainage east from Walker Ridge through Deadshot Canyon to Bear Valley Doyle Canyon 946 Drainage east from north end of Walker Ridge and Grapevine Flat to Bear Valley Gaither Canyon 1,676 Drainage directly south from Doyle Canyon, flowing east to Bear Valley Leesville 1,997 NE corner of the watershed flowing north and then west into Bear Valley Mill Creek 10,646 NW corner of the watershed flowing SE to Bear Valley Robbers Flat 824 Drainage east to Bear Valley Stinchfield Canyon 461 Drainage south of Robbers Flat east into Bear Valley Trout Creek 2,342 Drainage from Walker Ridge and Cold Spring Mountain east to Bear Valley Lower Bear Creek Bear Creek Lower 8,627 Drainage area directly to the main stem of Bear Creek south of the south Stem end of Bear Valley Brophy Canyon 2,168 Most southerly subwatershed on west side of Bear Creek Craig Canyon 737 SE flowing drainage just north of Thompson Canyon Eula Canyon 254 SE flowing just north of and parallel to Craig Canyon Hamilton 2,932 SW drainage to Bear Creek Hamilton Canyon 799 Drainage NW from Blue Ridge into Bear Creek east of Coyote Peak Holsten Canyon 409 Small west-flowing drainage from Cortina Ridge Holsten Chimney 323 Small west-flowing drainage from Cortina Ridge Canyon Jackson Canyon 1,112 Small west-flowing drainage from Cortina Ridge Lawson Canyon 210 Small west-flowing drainage from Cortina Ridge Lynch Canyon 480 North flowing drainage to Bear Creek Olgert Canyon 457 Most southerly subwatershed on east side of Bear Creek Shale Spring Flat 295 Small west-flowing drainage from Cortina Ridge South Jackson 1,219 Small west-flowing drainage from Cortina Ridge Canyon Sulphur Creek 6,525 Drainage SE from County Line and Walker ridges to Bear Creek Thompson Canyon 3,999 Largest drainage below Sulphur Creek, flowing east to Bear Creek Warnick Canyon 278 Small south-flowing drainage to Bear Creek from Blue Ridge Source: Jack Alderson, USDA Natural Resource Conservation Service, Colusa, CA, 2008

At the north edge of the watershed, large boulder outcrops form the Bear Valley and Gravelly buttes that reflect the abrupt contrasts with geology in the landscape at the interface between the North Coast Range and the Central Valley. At the southern end of Bear Valley Buttes, two smaller valley forks converge to create Bear Valley. At its widest extent, Bear Valley is slightly more than two miles wide. The gentle Bear Valley terrain comprises the heart of the upper watershed and provides the largest drainage area for Bear Creek. Canyons on the west side of Bear Valley empty into prominent alluvial fans on the Valley floor.

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Below Bear Valley, narrow canyons extend about five miles. Then, below the intersection with Sulphur Creek Valley, a broad 2.5-mile long flood plain opens. The flood plain closes and Bear Creek courses through the complex hill and canyon landscape along Highway 16 before Bear Creek empties into the main stem of Cache Creek at the Colusa / Yolo county line.

Elevation Elevation above mean sea level within the watershed ranges from 635 ft at the confluence of Bear Creek with Cache Creek (39° 55’ 34.90”N, 122° 20’ 00.00”W) to 3,862 ft on Love Lady Ridge (39° 12’ 50.84”N, 122 35’ 50.90”N) at the westernmost point in the watershed. The steepest elevation changes are in Mill Creek subwatershed , extending from Love Lady Ridge. In the shortest distance (six miles) between the Ridge and valley floor opposite Gravelly Buttes, Mill Creek drops in elevation 2,017 feet or about 330 feet per straight-line mile. In contrast, from the foot of Bear Valley Buttes to the southern end of Bear Valley, a distance of 6.45 miles, the change in elevation is 67 feet, or about ten feet per mile. This wide range of elevation changes over similar distances changes the speed at which water moves through the watershed. The meandering pattern of Bear Creek in Bear Valley indicates an overall slower current than for Mill Creek. Figure 2.6 displays elevation contours in Bear Creek watershed.

Aspect Aspect determines how much solar energy (light and heat) reaches a piece of ground. The predominant aspect across the watershed is SSE. Areas with northern aspect tend to be wetter and cooler in comparison to drier, hotter sites having a southern aspect. Figure 2.7 shows the distribution of terrain aspect throughout the watershed.

Slope The watershed has a broad range of slopes (Figure 2.8). The sedimentary rock surfaces on the east side of the watershed are generally less steep due to faster rates of erosion than on igneous and metamorphosed igneous rocks on the west side of the watershed.

2.4 Climate The watershed has a Mediterranean climate, characterized by cool, wet winters and hot, dry summers. Different microclimates occur due to the wide range of elevations, slopes, and aspects, often varying within short distances.

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Climate conditions set limits to agricultural production in Bear Creek watershed. Additionally, data for temperature, rainfall, wind speed, temperature, solar radiation, and evapotranspiration are all necessary to develop a watershed model for Bear Creek that simulates hydrologic functioning in the watershed, including surface runoff and water yields.

Available data describing the climate of Bear Creek watershed come principally from the two remote automated weather stations (RAWS) located just outside the boundaries of the watershed: County Line station, in Lake County just a few feet west of the county line with Colusa County, and Stonyford station in Colusa Couty, seven miles north of the northeast end of Love Lady Ridge. Other data come from the Leesville Keegan Ranch station which operated between 1959 and 1977.

Temperature Average monthly temperatures for the two RAWS stations are nearly identical. Daily midwinter temperatures average 45° F. Temperatures peak in July with daily average temperatures near 80° F.

Precipitation Rainfall timing and amounts in Bear Creek watershed, however, vary greatly from year to year, a pattern typical of regions with Mediterranean climates (Gasith and Resh 1999, Domagalski et al. 2004b). The maximum values of annual rainfall in the watershed are approximately double the annual mean (Lustig and Busch 1967). For example, abnormally high rainfall in 1998-1999 exceeded 40 inches. During the severe drought in 1976, only 5.41 inches of rain fell at the Leesville Keegan Ranch weather station (Western Water Research Institute archive data).

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Fluctuations in annual precipitation result from weather patterns generated by the El Niño/Southern Oscillation in the southern Pacific Ocean. Strong El Niño conditions bring high rainfall as in 1998, while strong La Niña conditions bring drought. When surface water warms more than 0.5ºC in the southern Pacific Ocean, the resulting decrease in air pressure in the eastern Pacific Ocean causes the number of winter storms reaching California to increase. Conversely, cooling of surface water causes the number of winter storms to drop and may lead to drought in California. An important consequence of the El Niño rainfall pattern in the California Coast Ranges is that soil erosion increases as the number of storm events increases.

The second feature of precipitation in Bear Creek watershed is its seasonality, also a trait of Mediterranean climates (Gasith and Resh 1999). Precipitation mostly falls during winter- season storms. Regionally, 85 percent of rainfall occurs between November 1 and March 31 (Lustig and Busch 1967).

The number of days of significant measurable precipitation also characterizes the distribution and impact of precipitation. During the rainy season, precipitation falls principally during major storm events rather than as a moderate and steady input throughout the season. The most frequent rainfall and most intense storms occur during December through February. The one-day maximum precipitation recorded was 4.1 inches at Leesville Keegan Ranch on January 21, 1967.

Most precipitation in Bear Creek watershed falls as rain. Duration and volume of precipitation affect how much water evaporates back to the atmosphere, percolates into the soil, runs overland, and exits the watershed via Bear Creek. Snowfall occurs infrequently in

30 BEAR CREEK WATERSHED ASSESSMENT winter on the floor of Bear Valley but often accumulates for weeks at a time at the highest elevations. The amount of time that snow remains on the ground, however, is too brief to accumulate a snowpack that then releases melting water downstream outside of the rainy season. The one-day maximum snowfall recorded at the Leesville Keegan Ranch station of 12 inches occurred on January 4, 1974. On October 17, 1874, an extraordinary foot of snow fell in the Bear Valley area (Rogers 1891, page 142).

Solar Radiation RAWS station data provide daily readings of actual solar radiation, the total amount of energy from the sun that reaches the ground. The presence of cloud cover and decreased day length create conditions of reduced solar radiation in winter months. December and January have about one-quarter of the solar radiation available in June and July.

Wind Throughout the year, winds come predominantly from the west and WSW directions. Wind speed varies across Bear Creek watershed, with higher elevations being more exposed and windier. Wind speeds from County Line RAWS station average up to three times faster than those concurrently recorded from Stonyford RAWS station, situated at a lower, more sheltered elevation.

A renewable energy company has been collecting information on wind speeds at selected sites on Walker Ridge (Figure 3.10). Information from those wind stations is not public information at present.

Evapotranspiration Evapotranspiration is the sum of water lost from the soil through direct evaporation plus the amount of water lost to the air from plants through transpiration. A soil moisture deficit occurs in summer and early autumn months in Bear Creek watershed because precipitation is usually absent and fails to recharge soils with moisture. At the same time, low humidity and high temperatures cause soils and plants to lose moisture faster through evapotranspiration. Drought occurs when evapotranspiration exceeds precipitation (see below). Plants continue to transpire more water until they wilt for lack of soil water to take up through their roots.

The natural drought curtails plant growth between March and November at the County Line RAWS station and between April and October at the Stonyford RAWS station. The differences in the length of growing season between the two sites result from differences in site inputs from the physical environmental factors such as wind speed, air temperature, humidity, and soil moisture. These differing microclimate conditions can affect biomass acccumulation in vegetation and agricultural crop productivity. For summer-season crops that require non-drought conditions in the soil, farming in Bear Creek watershed requires

31 BEAR CREEK WATERSHED ASSESSMENT irrigation. Attention to specific microclimate conditions is also important to successful revegetation with native plants.

Note: A langley is a unit of solar radiation equal to one gram-calorie per square centimeter. A gram-calorie is the amount of heat required to raise the temperature of one gram of water one degree Celsius.

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Information Gaps A larger set of RAWS and SCAN stations, including resumption of station readings for Bear Valley, would provide landowners and land managers with more localized records of weather conditions at areas of greatest concern.

2.5 Hydrology The interaction among water, geology, topography, soils, geology, vegetation, and the atmosphere is the hydrologic cycle, an ecological process that helps to shape the unique

33 BEAR CREEK WATERSHED ASSESSMENT character of Bear Creek watershed. This section discusses water sources, water supply, water storage, and water flow in the watershed.

Water Sources Water supplies in the watershed have two principal sources. The more abundant source is meteoric water, or water on the surface, in the ground, and in the atmosphere that originates from rainfall. The other source of water is geologic water, which has remained embedded in below-ground strata for thousands or even millions of years. This water source is critical to hydrology in the watershed because over time geologic water has come to contain unusually high amounts of dissolved chemical elements and ions originating in rock underlying the watershed.

Most geologic water in Bear Creek watershed is connate water. Connate water was once seawater that subsequently became trapped in sedimentary rocks as they formed under pressure from sediments deposited on the ocean floor of what is now the Central Valley (Goff et al. 1993). Over eons, the pressure on connate water has built up so that the water bursts through sedimentary rocks at weak points along geologic faults and forms artesian springs that push the ancient water aboveground (Davisson et al. 1994). Another source of geologic water results from subterranean formation of metamorphic and volcanic rocks. No data are available about the amounts of geologic water presently stored underground in the watershed.

Overland Flow (Surface Runoff) Yates (1989) has estimated that annual runoff per unit area in Bear Creek watershed averages five inches (12.7 cm). Diverse topography, soils, vegetation, and runoff amounts vary across the watershed.

The timing of overland surface flows follows the pattern of rainfall closely, with flow rate responding with less lag time than stream flow does. The volume, speed, and energy with which precipitation becomes overland flow depend on the amount, duration, and intensity of precipitation plus the capacity of the ground surface to absorb water into the soil. Actual measures of overland flow from specific sites, however, are not available for the watershed.

A major issue for the watershed (refer to Section 6.2) is the impact of soil erosion and transport of mine waste sediments overland. In particular, the force of overland flows during and after winter storms erodes soils and mine sediments known to have high mercury content, and transports these sediments into Bear Creek and its tributaries (Cooke and Stanish 2007). The assessment sections that follow consider the effects of the amounts of sediment, organic matter, and solutes transported by overland flow and in-stream water as well as the implications for their delivery downstream.

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Hydrography The dendritic (branch-like) network of streams in Bear Creek watershed constitutes the watershed hydrography (Figure 2.5). The National Hydrography Dataset managed by the US Geological Survey is the national mapping standard for the Bear Creek stream network. Of the total 277 miles of streams in Bear Creek watershed, 80 miles (or 29 percent of the total length) are intermittent streams. Intermittent streams, where water flows only seasonally, predominate in the southern third and in the northwest corner of the watershed.

Bear Creek originates midway along the northern perimeter of the watershed on gentle terrain, just west of Gravelly Buttes. It runs north to south through the east side of Bear Valley and then through the dissected canyon landscape of the southern third of the watershed to the confluence with the mid-reach of Cache Creek. Most tributaries to Bear Creek in Bear Valley arise from steep ridges at the west perimeter of the watershed.

Mill Creek, the largest tributary to Bear Creek, begins in the northwest corner of the watershed from three branches draining Love Lady Ridge and flowing southeast to Bear Valley. Steep canyons constrict the channels of Mill Creek branches. At its confluence with Bear Creek in northwest Bear Valley south of Brim Road, Mill Creek often has a greater flow volume than Bear Creek. Because Mill Creek subwatershed is difficult to access, hydrologists have not studied the creek, and little information about Mill Creek exists.

The second largest tributary to Bear Creek is Sulphur Creek which drains southeast from the southern third of Walker Ridge. Because of the economic importance of mining, mercury issues, and the unusual chemistry of its water sources, Sulphur Creek, has been the most studied tributary in the watershed. Trout Creek is the other major stream descending from Walker Ridge, flowing belowground where the coarse gravelly texture of its creek bed allows water to rapidly infiltrate.

Tributaries on the east side of Bear Valley are mostly small channels in swales, flowing at low volumes after rain storms. Streams from Leesville and Hamilton Canyon subwatersheds are the major streams flowing west into Bear Valley and Bear Creek. In the southern third of the watershed, Brophy Canyon, Lynch Canyon, and Thomson Canyon subwatersheds on the west side of Bear Creek and Holsten Canyon, Lawson Canyon, and South Jackson Canyon on the east have the only permanent tributaries.

Stream Flows Water arrives in Bear Creek and its tributaries from several sources: overland flow, groundwater moving laterally into the streams, and springs and seeps. Flow in watershed streams displays distinct seasonality within a year and considerable variability in total flow

35 BEAR CREEK WATERSHED ASSESSMENT from year to year. The main stem of Bear Creek flows continuously except in the most extreme drought years. Data on stream flows, measured as the cubic feet of water flow per second (cfs), comes from four gage stations maintained by the US Geological Survey. Apart from stations on Sulphur Creek, no flow data are available for other tributaries of Bear Creek. Figure 2.9 depicts flow amount at USGS gage stations.

Table 2.4 – Gage stations on Bear Creek and Sulphur Creek USGS Drainage Area Period of Record Gage Name Flow Variables Tracked Gage No. (square miles) Start Date End Date Sulphur Creek at discharge, water 11451690 9.87 1999 10 29 2004 09 30 Wilbur Springs quality*, real time flow Sulphur Creek 11451700 tributary near Wilbur 4.49 1961 10 01 1963 09 30 discharge Springs Bear Creek (main discharge, stem) above Holsten 11451715 94.90 1997 11 20 current river stage, water Chimney Canyon, near quality*, turbidity* Rumsey Bear Creek (main 11451720 100.00 1958 10 01 1998 01 04 discharge (mean) stem), near Rumsey *this variable tracked for only a part of the period of record

Flow volume from USGS monitoring station 11451715, located on Bear Creek three miles upstream from its confluence with Cache Creek and 7.5 miles northwest of Rumsey, CA, best approximates the volume contribution of Bear Creek to the total water budget of the Cache Creek basin.

Annual Flows Data in Figure 2.9 are expressed in cubic meters per second rather than cubic feet per second to give the graph a smaller scale (1 cubic meter = 35.3147 cubic feet). The annual water volume from Bear Creek flowing into Cache Creek averaged 1.455 billion cubic feet during the nine-year period between 1999 and 2007. Changes year to year in water flow volumes have varied widely. For example, the water flow for the 2007 water year was ten percent of the flow recorded for the 2006 water year. A look back at data from the USGS station that operated nearby from 1959 to1980, shows both higher and lower annual flows than seen in recent years. Water flow from Bear Creek into Cache Creek averaged 1.566 billion cubic feet annually for that 21-year period. The larger average flow volume (+7%) may be a function of the larger (+5%) drainage area included for station 11451720 rather than evidence of a lower flow during the period 1999 to 2007 for station 11451715. Although there is widespread concern about the possibility of long-term declines to water supplies on account of climate change, data from Bear Creek are insufficient to draw any conclusions about trends.

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Figure 2.9 – Average Annual Stream flow Rate in Bear Creek at USGS Stations

Station 11451715, 1999 - 2007

2.5

1.5

0.5 Cubic Meters Cubic Second per

0 1999 2000 2001 2002 2003 2004 2005 2006 2007 Water Year

Station 11451720, 1959 - 1980

3.5

2.5

1.5

1 Cubic Meters per Second Cubic Meters 0.5

0 1959 1960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 1975 1976 1977 1978 1979 1980 Water Year

Sulphur Creek is the other drainage for which stream flow data exist, but the data series for Sulphur Creek covers two brief time intervals, 1962-1963 and 2001-2004 (Table 2.5).

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Table 2.5 – Average annual stream flow (volume per second) for USGS monitoring gages on Sulphur Creek Water Station Basin Area Flow Year No. (square miles) (cfs) 1962 0.49 11451700 4.49 1963 1.39 2001 1.99 2002 3.95 11451690 9.97 2003 4.73 2004 6.56

Monthly Stream Flows Monthly stream flows in Bear Creek are variable, with flow lowest in the late summer and early autumn months just before the rainy season (Figure 2.10).

For water years 2001 through 2004, Sulphur Creek subwatershed contributed nearly ten percent of the total water flow in lower Bear Creek (Figure 2.10, Table 2.6). The months with the greatest percentage of contribution to Bear Creek from Sulphur Creek are in September and October – months when total Bear Creek stream flow is lowest. This pattern likely results from discharge of geologic water from springs in Sulphur Creek subwatershed. Flow from deep (geologic) spring sources is more evenly distributed throughout the year than rainfall-dependent (meteoric) stream flow and proportionally provides a greater share of total flow in the driest rainless months. By contrast, Bear Creek stream flow derives largely from meteoric water sources.

Low Flows Inadequate groundwater recharge has caused Bear Creek to run dry during the summer in only three years over the period of water flow records. From 1961 through 2007, days with no flow in Bear Creek have amounted to 2.4 percent of all days of record. The severe drought in 1976 and 1977 was the cause of the most days with no flow in Bear Creek. Intervals longer than seven days of no flow in Bear Creek occurred for the following dates:

July 3, 1972 to September 12, 1972 71 days June 27, 1976 to July 4, 1976 8 days July 7, 1976 to August 7, 1976 32 days June 4, 1977 to November 11, 1977 159 days

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Figure 2.10 – Average Monthly Stream flow Rate in Bear Creek at USGS Stations Station 11451715, 1999 - 2007

4.5 4 3.5 3 2.5 2 1.5 1

Cubic Meters per Second per CubicMeters 0.5 0 Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Month

Station 11451720, 1959 - 1980

Cubic Meters per Second per CubicMeters 1

0 Oct Nov Dec Jan Feb Mar Apr May Jun Jul Aug Sep Month

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Table 2.6 – Average monthly stream flows for Sulphur Creek and Bear Creek, water years 2001 - 2004 Stream flow (cfs) Sulphur Creek Month Sulphur Creek Bear Creek Percent of Bear Gage Gage Creek Total 11451700 11451715 Oct 0.272 2.090 12.9 Nov 1.031 8.984 11.5 Dec 16.009 165.638 9.7 Jan 10.075 109.303 9.2 Feb 12.846 140.568 9.1 Mar 6.926 79.591 8.7 Apr 2.390 23.990 10.0 May 1.317 15.115 8.7 Jun 0.420 4.787 8.8 Jul 0.184 2.333 7.8 Aug 0.148 1.589 9.4 Sep 0.208 1.656 12.5 Annual 4.285 45.928 9.6 Total

When flow stops in Bear Creek, considerable lag time passes before enough groundwater and runoff accumulate to recharge creek flow. Apart from the exceptional five-month period of no flow in 1977, days of no flow in lower Bear Creek have occurred from the last days of June through August. The 1999 to 2007 record of water years had no days without flow in Bear Creek.

Ponds and Lakes No natural ponds or lakes are present in Bear Creek watershed. Section 3.4 Water Delivery presents information on man-made ponds and dams in the watershed.

Groundwater

Bear Valley Groundwater Basin Bear Valley Groundwater Basin (Basin 5-64) lies entirely within Bear Creek watershed and extends an estimated 9,100 acres. The Bear Valley Groundwater Basin drains to the south, roughly following the course of Bear Creek. No estimate of the water volume in the groundwater basin is available, but the volume is relatively small and much less economically important in comparison to the Central Valley Groundwater Basin to the east, which produces about nine million acre-feet of water annually (Ferriz 2001). The Colusa County Groundwater Management Plan (2008) does not cover the Bear Valley Groundwater Basin as the Basin does not contribute to the supply of water for agriculture in the Central Valley.

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The California Department of Water Resources has no information about water-bearing formations, groundwater flow rates, infiltration rates, and trends in groundwater levels, or groundwater quality in the Basin. The Groundwater Basin consists mostly of meteoric water, but geologic water contributes to the groundwater supply through many deep rock fissures associated with the Stony Creek fault complex that bisects the watershed through Bear Valley.

Capay Valley Groundwater Basin Bear Creek recharges water downstream south into the Capay Valley Groundwater Basin (Basin 5-21.68). This recharge is critical because the water quality of Bear Creek could affect the groundwater quality of the Capay Valley, an important agricultural region in Yolo County. Bear Creek is a major source of boron and other high concentrations of minerals flowing into Cache Creek and the Capay Valley Groundwater Basin (Swartz and Hauge 2003). The assessment addresses chemical elements, their loads, and downstream impacts in Chapter 5 Contaminants.

Sulphur Creek Geothermal Reservoir The precise origin of the mineral-rich geothermal waters beneath Sulphur Creek subwatershed is unclear. Water from the deepest parts of the reservoir are thought to reach 180°C (Thompson 1993), far hotter than the spring waters at the surface where they flow into Sulphur Creek and other Bear Creek tributaries.

McLaughlin et al. (1989) proposed that geologic water has intruded through faults and other rock fractures deep below the surface and has become encased in mostly impermeable ultramafic rocks. Subsequently escaping the pressurized surroundings of these rocks, mineral-rich geologic waters of volcanic origin have mixed with connate waters found in the overlying sedimentary bedrock. Further mixture with percolating meteoric water produces waters with unique chemical properties found in springs of the watershed. The Sulphur Creek geothermal reservoir has not been a commercial source of energy generation (Goff et al. 1993).

Springs and Seeps Springs and seeps furnish vents for subsurface water sources to aboveground water flow throughout Bear Creek watershed. Currently, locations for more than 80 springs and seeps are known, and new sources are being discovered by geologists (Slowey and Rytuba 2008) and botanists (J. Alderson, pers. comm.) working in the watershed. Figure 2.11 displays locations of described springs and seeps in the watershed. Forty-five percent of all springs known to date are in Sulphur Creek subwatershed, known internationally for its mineral hot springs. Eaton Springs and Malaney Flat on Walker Ridge are particularly noteworthy for

41 BEAR CREEK WATERSHED ASSESSMENT supplying water to wetlands found on ultramafic hydric soils.

Information about water temperatures and flows from springs is fragmentary. Table 2.7 provides water temperatures and flow rates for selected springs in Sulphur Creek subwatershed. Section 5.4 Sources of Water Contaminants characterizes the chemical elements in waters from individual springs. Geologists have calculated proportions of geologic and meteoric waters in spring waters originating from Sulphur Creek subwatershed based on proportions of isotopes of key elements dissolved in spring waters (Goff et al. 2001).

Table 2.7 – Flows and temperatures of selected hot spring waters from Sulphur Creek subwatershed Estimated Temperature Subsurface Flow Spring at Spring Reservoir (liters min-1) Source °C Temperature °C† Blanck Hot Spring 36 - 44 >121 1 - 14 Elbow Hot Spring 70 - 74 >88 0.5 Elgin Hot Spring (Main) 67 - 70 >133 20 - 26 Jones Fountain of Life* 53 - 62 >101 0 - 95 Unnamed Spring 52 >76 ≤ 0.5 Wilbur Spring (Don White) 54 - 57 >151 5 Wilbur Spring (Main) 55 - 57 >161 20 *Geyser properties of this spring account for the wide range reported † Based on chalcedony as a geothermometer Sources: Goff et al. (2001), Suchanek et al. (2004)

At present, no data describe flows from cold spring waters that occur in subwatersheds other than Sulphur Creek subwatershed. The few data on temperatures recorded from wells and cold springs range from 14.5 to 24.5°C, based on just four readings (Barnes et al. 1973a, Thompson et al. 1978, White et al. 1973).

Depth to the Water Table The Colusa County Soil Survey (Reed 2006) provides a wet and a dry season model of the distribution of the depth to the water table for Bear Creek watershed. The average depth to the water table changes seasonally in Bear Creek watershed, but in 95 percent of the watershed, the depth to the water table exceeds two meters (78 inches) year round. Other small areas with shallow water tables (< 2 meters depth) consist of wet Venado clay soils associated with alluvial fans at the base of Walker Ridge. Historic accounts of Bear Valley imply that the depth to the water table was formerly much shallower year-round in the Valley. The causes for the drop in water table are not precisely known. A combination of natural causes, land use changes, and intentional or inadvertent alterations to stream channels is likely (J. Alderson, pers. comm.).

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Information Gaps Gaps in knowledge about the hydrology of Bear Creek watershed are significant. They include:

water flow information for Mill Creek, the largest tributary of Bear Creek and for Bear Creek above the confluence with Sulphur Creek information about the Bear Valley groundwater basin continuous, long-term flow data for the lower main stem of Bear Creek and in Sulphur Creek from existing stations; existing data, while informative, has been intermittent and provides only a short-term view of changes to stream flow. volumes and trends in seasonal and inter-annual spring flows as well as their associated mineral contents.

The CALFED program has proposed a performance measure (Performance Objective 3, Performance Measure 3) to ascertain with greater certainty the deliveries of water to the Sacramento-San Joaquin Delta for each water year (Performance Measures Subcommittee 2007). Closer monitoring and evaluation of water flow in the Bear Creek watershed are important to water managers’ understanding of all water flows from watersheds supplying the Delta. Multiple gage stations strategically placed across the watershed would provide better monitoring data on water flows.

2.6 Geology The earth subsurface controls the movement of water deep in the earth up to the soil surface, shapes current watershed flow through geomorphology, impacts water quality through the mineral content of rocks and soils, and strongly contributes to vegetation patterns in the watershed. Also, Bear Creek watershed geology both facilitates and limits economic production of natural resources in Bear Creek watershed, including industrial minerals, geothermal and fossil energy resources, and water quality.

The most detailed geological information comes from Sulphur Creek subwatershed, a historically important mining area and the core of the Sulphur Creek Mining District.

The Great Valley Geomorphic Province Rocks from the Great Valley Geomorphic Province are sedimentary rocks (developed from eroded sediments) and metamorphosed sedimentary rocks (chemically altered) from sediment that eroded from the Sierra Nevada (Dickinson and Rich 1972) into the Sacramento Valley when the Valley was an ocean floor. Pressure transformed these deep

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sediments into sedimentary rocks 169 to 65 million years ago. Sedimentary rocks now underlie the eastern half and southern third of the watershed.

Coast Range Geomorphic Province The Coast Range Geomorphic Province is the source for three bedrock types on the west side of Bear Creek watershed. Frequent and complex earth movements from the San Andreas Fault and associated faults along the coast of California have deformed and jumbled the rock layers of different origins into three different bedrock mixes: (1) the mafic and ultramafic igneous (formed from magma) rocks formed in ancient mid-Pacific Ocean earth mantle and crust; (2) metasedimentary rocks from sediments that accumulated over the mid-Pacific Ocean; and (3) complex mixtures of volcanic, metavolcanic, and metasedimentary rock types known as “Franciscan Assemblages”.

When the Pacific Plate and associated plates pushed against the continental North American Plate 175 to 150 million years ago, igneous rocks in the plate crust and mantle of the Coast Range Geomorphic Province thrust themselves upward and overtopped Great Valley sedimentary rocks. Overthrust volcanic and metavolcanic bedrock occupies a smaller area in the NW part of Bear Creek watershed. These rocks originated from volcanic activity around Clear Lake, Lake County.

Major Bedrock Types in Bear Creek Watershed Table 2.8 provides information on the total area and proportion of area in the watershed occupied by each bedrock unit in Bear Creek watershed, and Figure 2.14 shows the distribution of underlying rock formations in the watershed.

Table 2.8 – Principal bedrock types in Bear Creek watershed* Total Percent of Bedrock Unit Watershed Watershed Acres Area Bear Valley Alluvial and Terrace Sedimentary 8,736 13.2 Great Valley Geomorphic Province Subtotal 34,781 52.6 Cortina Sedimentary 5,370 8.1 Lodoga Sedimentary 20,432 30.9 Stony Creek Sedimentary 8,979 13.6 Coast Ranges Geomorphic Province Subtotal 22,548 34.2 Franciscan Metasedimentary 782 1.2 Franciscan Volcanic and Metavolcanic 2,149 3.3 Tehama-Colusa Serpentinite Mélange 19,617 29.7 Total 66,065 100.0 *arranged by geomorphic province of origin and in reverse chronology of formation 46

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Great Valley Sequence Sedimentary Bedrock Units Great Valley Sequence bedrocks arose in the ocean-filled Sacramento Valley when submarine avalanches occurred after earthquakes along the tectonic plates underlying the watershed. Sediments sorted vertically in the aftermath of submarine avalanches, with the densest sediments settling first and lowest thus creating a columnar structure of sediment layers with relatively uniform sediment textures. The resulting sedimentary rocks often contain gold deposits and pockets of fossil fuels, the latter a legacy of biomass from ancient marine organisms. Over millions of years changes in sediment deposition took place, sedimentary rock layers tilted due to upthrusts and lateral shifts at fault lines, and pressure metamorphosed sedimentary rock layers (Dickinson and Rich 1972). These processes created different kinds of sedimentary rocks termed “petrofacies” (Dickinson and Rich 1972, Ingersoll 1983). The three petrofacies found in Bear Creek watershed are, in chronological order of formation: Stony Creek, Lodoga, and Cortina. Differences are based on relative proportions of plagioclase feldspar, polycrystalline quartz in total quartz-derived sediments, and total lithic pieces (gravel, pebbles, and cobbles).

Major Coast Ranges Bedrock Units Unlike the Great Valley bedrock units, the bedrock units from the Coast Ranges Geomorphic Province sources in Bear Creek watershed are significantly different from one another, originating as marine igneous rocks, sedimentary rocks, and volcanic igneous rocks.

Tehama-Colusa Serpentinite Mélange The Tehama-Colusa Serpentinite Mélange (TCSM) originated 160 million years ago from ultramafic igneous rocks, extending in a narrow north-to-south band up to four miles wide and 56 miles long from western Tehama County through Glenn County to just south of Highway 20. The TCSM constitutes the easternmost element of the Coast Ranges Geomorphic Province in the watershed. These rocks were part of the Pacific Plate and upthrust after contact with the North American Plate. They consist mostly of serpentinite, a metamorphosed igneous rock type with greater than 90 percent mafic minerals (rich in iron and magnesium minerals). The high percentage of mafic minerals and less than 45 percent silica, potassium, and calcium content qualify the bedrock type as “ultramafic”, as defined by the International Union of Geological Sciences. These rocks have formed unique outcrops and several ultramafic barrens, largely devoid of vegetation, in Bear Creek watershed.

The TCSM arose from an “ophiolite” column of igneous rock layers formed from magma beneath the mid-Pacific Ocean (Hopson and Pessagno 2005). Mafic rocks such as basalt formed the submarine crust layer of the ophiolite. In the upper mantle below the crust, heavier ultramafic rocks predominated. Ultramafic peridotite, the basal rock portion of the

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ophiolite, metamorphosed gradually to serpentinite. As the ophiolite structure became jumbled by plate shifts and uplifts, the ophiolite structure disassembled into a mix (or mélange) of serpentinite rocks with blocks of basalt, chert, and slate intermixed. As the TCSM bedrock tilted to the east over millenia, the formation came to uplift and expose less weathered peridotite rock on the west side of the TCSM. Thus, greater serpentinite on the east side of Walker Ridge contrasts with more prevalent peridotite on the crest of Walker Ridge at the west watershed boundary.

Franciscan Metasedimentary Assemblage Bedrock This bedrock type occupies only small zones at the western margin of Bear Creek watershed: just east of Walker Ridge (three zones) and east of Love Lady Ridge (one zone). These rocks have undergone extensive metamorphism and deformation (Bergfeld et al. 2001). Deposition layers of Pacific Ocean sediments in the Franciscan Metasedimentary Assemblage are jumbled, unlike the orderly pattern of the Great Valley Sequence petrofacies.

Franciscan Volcanics and Metavolcanics Bedrock of volcanic origin occupies a small area in the northwest part of the watershed in Mill Creek subwatershed. The bedrock layer consists principally of volcanic breccias, conglomerate tuff, and basalt pillows. A small volcanic rock peak appears near the confluence of Sulphur Creek with Bear Creek. Other information about these bedrock types is not available.

Bear Valley Alluvial and Terrace Sedimentary Bedrock The newest bedrock found in Bear Creek watershed began forming less than two million years ago on the Bear Valley floor. Sediment sources came from decomposed sedimentary rocks from the north and east sides of Bear Valley and from sediment derived mostly from ultramafic rocks on the west side Bear Valley. Characterization in detail of this complex bedrock unit has yet to be undertaken.

Rock Types Characteristic of Bear Creek Bedrock Units Appendix C provides information on the major rock types found in the watershed, their origin, and mineralogy.

Plate Tectonics and Geologic Faults Movement and deformation of the earth crust (“tectonics”) is responsible for the diverse geology and landforms of Bear Creek watershed. The Pacific Plate and the associated Juan de Fuca, Kula, and Farallon plates have converged with the North American Plate and are moving underneath (subducting) the North American Plate, far beneath what is now the

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North Coast Range. Subduction of the Pacific Plate has caused the plate crust to partially melt from the subterranean heat from the earth’s core. In the submarine environment of the subduction, an ophiolite series of rock types develops from magma. Subsequent deformation of the earth crust by rock upthrust and folding has exposed the ophiolite rock sequence at the earth surface as the Tehama-Colusa Serpentinite Mélange.

The interface between the Coast Ranges and the Great Valley geomorphic provinces creates the Coast Ranges-Great Valley thrust fault system. A thrust faults results from compression where one rock layer pushes up and over another layer. Other faults are strike-slip faults where one rock formation slips past another. Regional faults mostly move (“strike”) to the northwest, paralleling the course of the San Andreas Fault. Smaller cross, tear, and transverse faults lie at opposing angles to regional faults.

The Stony Creek Fault The Stony Creek Fault creates a major divide in Bear Creek watershed. It comprises the contact that separates the TCSM on the west from the Stony Creek Petrofacies on the east. The zone around Wilbur Springs is the south terminus of this fault in Bear Creek watershed, but the fault reappears in the Knoxville region of Napa and Lake counties just south of the watershed (Sherlock 2005). The fault is nearly vertical. Contact is generally sharp, well- defined, and with little movement over geologic time. Earthquakes rarely occur along this fault.

Coast Range Fault The Coast Range Fault appears at several sites on the west edge of the watershed to divide the TCSM from the Franciscan Formation volcanic and metavolcanic bedrock.

Resort Fault The young, steeply dipping Resort Fault (Rytuba et al. 1993) passes on a northwest to southeast track through the TCSM and passes northeast of Wilbur Springs. Churchill and Clinkenbeard (2003) propose that this fault may have helped form the Rathburn-Petray mercury deposits.

Little Indian Valley Fault This fault may be an important conduit for geothermal fluids and asociated thermal springs are areas of hydrothermal alteration and mercury mines (Churchill and Clinkenbeard 2003). It passes by Elgin Mine and Cherry Mine east to west through Sulphur Creek subwatershed.

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Bear Fault Slowey and Rytuba (2008) describe this newly discovered fault. This fault does not appear in Figure 2.14. It has led to a creation of a series of cold springs with high mercury content on the floor of Bear Valley.

Clear Lake Volcanic Field Volcanic fields occur where the earth crust has melted repeatedly from heat in the earth’s mantle or where opposing tectonic plates have stretched the earth’s crust so that the earth mantle rises close to the earth surface. In the Coast Ranges Geomorphic Province, the crust is seldom so thin that the crust heats sufficiently to melt and to release lava. The major exception is the Clear Lake volcanic field, the center of volcanism in the Coast Range geomorphic province (Rytuba et al. 1993). The Clear Lake volcanic field has not been active for more than 10,000 years. On its southwest side, the Clear Lake volcanic field contains the Geysers Geothermal Field, the most economically important geothermal field in the world. At its eastern edge, the volcanic field affects the belowground crustal formation and geothermal properties of the western portion of Bear Creek watershed, especially Sulphur Creek subwatershed (Moiseyev 1968). The Clear Lake volcanic field supplies mineral deposits in the subwatershed, including mercury and gold, from magma that has cooled below the earth surface and become concentrated as deposits of rocks rich in minerals (Sherlock 2005).

2.7 Soils Bear Creek watershed soils and their distribution in the landscape resemble those found elsewhere along the interface between the inner North Coast Range and the Central Valley from northern Solano County to southwest Shasta County. However, the watershed also has unique soils not known to occur elsewhere.

Major Soil Series in Bear Creek Watershed Soils in the watershed are diverse and complex in their distribution. A total of 39 soil map units as defined by USDA NRCS soil scientists occur in Bear Creek watershed. Table 2.9 lists the nineteen principal map units which cover 96 percent of the watershed area, and Figure 2.15 displays the distribution of these soils. The most extensive single soil is the Millsholm series, encompassing 20 percent of the watershed. Henneke and Okiota soils, the two most common ultramafic soils, comprise together about 24 percent of the watershed area.

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Some 20 other soil types occur as minor components of the watershed area and cover three percent of the watershed area. About one percent of soils are designated as unknown. Apart from Arand and riverwash, which are hydric soils, these minor soil series are not discussed further.

Appendix D provides a synopsis of comparable soil properties for the principal soil series in the watershed summarized from the official USDA NRCS monographs of each soil series available online at http://soils.usda.gov/technical/classification/osd/index.html. Distributions and topographic positions of the soil series specific to Bear Creek watershed landscape are also included.

Table 2.9 – Principal USDA soils series in Bear Creek watershed Percent Soil Series Land Acres Base Millsholm 20.6 13,350 Henneke 14.9 9,636 Okiota 9.6 6,200 Skyhigh 7.3 4,754 Leesville 7.0 4,558 Venado 4.8 3,124 Montara 4.8 3,089 Contra Costa 4.6 2,967 Sleeper 4.5 2,895 Saltcanyon 2.8 1,830 Maymen 2.1 1,359 Sehorn 1.9 1,263 Etsel 1.9 1,236 Dubakella 1.8 1,152 Boar 1.6 1,025 Bear Valley 1.5 945 Livermore 1.2 780 Hillgate 1.1 704 Misc. Haploxererts 0.9 683 Others and Unknown 4.1 2,676 Source: USDA, NRCS Colusa County Soil Survey (Reed 2006) Note: Soils highlighted in yellow are ultramafic. The total number of acres does not equal the total surface area of the watershed because water bodies and rock outcrops are omitted from the acre tally.

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Ultramafic Soils Ultramafic soils, including serpentine soils, derive from ultramafic parent rocks such as peridotite or metamorphosed ultramafic rocks such as serpentinite. These soils are globally rare, covering less than one percent of the earth surface but are significant in the North Coast Range of California including Bear Creek watershed. Brooks (1987) summarizes four traits common to ultramafic soils as follows:

low concentrations of the plant macronutrients nitrogen, phosphorus, and potassium unusually high concentrations of elements such as nickel, cobalt, cadmium, chromium, and iron a high ratio of magnesium to calcium a specialized endemic flora that can tolerate the unusual chemistry of ultramafic soils.

In Table 2.9, soil series highlighted in yellow are ultramafic (or “magnesic”) soils. These soils are major drivers in determining plant species composition and vegetation patterns, and ultimately the water chemistry and sediment beds of many watershed streams (Holloway et al. 2009a). Ultramafic soils comprise 42 percent of the surface area of the watershed, and ultramafic rock contributes an additional three percent to the ground surface of the watershed. The small amount of phosphorus in ultramafic soils reduces their fertility and usually makes them unsuitable for agriculture and forestry but often very productive for mining economically important metals such as chromium and nickel.

Hydric Soils The USDA NRCS defines hydric soils as soils “that formed under conditions of saturation, flooding or ponding long enough during the growing season to develop anaerobic conditions in the upper part” (Hurt and Vasilas 2006). In Mediterranean climate zones, hydric soil types often have seasonal or spatial phases that are not hydric, depending on water table, flooding, and ponding characteristics of local sites. Areas with a water table within 50 cm (20 inches) of the soil surface are uncommon even during the winter (Figures 2.12a and 2.12b). Flooding is rare over most of Bear Creek watershed (Figure 4.6), and ponding is present only in very small areas of Bear Creek watershed. Figure 12 does not display several smaller but significant winter-season hydric areas in Bear Valley. Much of the historic hydric soil environment in the watershed (Rogers 1891) may have been lost in the late nineteenth century.

The indicators used to make onsite determinations of hydric soils are specified in “Field Indicators of Hydric Soils in the United States” (Hurt and Vasilas 2006). Hydric soil criterion 4 from the USDA NRCS (undated) qualifies these soils as hydric: “soils that are frequently

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flooded for long duration or very long duration during the growing season.” Hydric soils in Bear Creek watershed include alluvial riverwash (unconsolidated alluvial materials along waterways not attributed to a specific soil series) and the Arand soil series. Riverwash soils are ultramafic, comprising a portion along Mill Creek west of Gravelly Buttes; and a very small area at the south end of Bear Valley along Bear Creek. Arand soils mixed with riverwash are typical of the stream corridor of Sulphur Creek in its mid-reach as the creek opens into a valley northwest of Wilbur Springs and in the vicinity of Eaton Springs. Soils in these locales are watered by perennial, comparatively slow-moving streams in nearly level terrain.

Ultramafic Venado clay soils may range from hydric to non-hydric depending on the location of the soil within Bear Valley, and approximately fourteen percent of the ultramafic Venado clay soils there are hydric (USDA Natural Resource Conservation Service 2009). A map of the exact extent of hydric Venado soils is not available.

Hydric soils are important because of their role wetland function, water storage, associated flora, and wildlife habitat. Anaerobic conditions in wetlands with hydric soils also create favorable environments for certain soil bacteria to “methylate”, i.e., add methyl (-CH3) groups, to elements such as antimony, arsenic, and mercury to form organic compounds. These methylated compounds allow the toxic elements to be absorbed more readily into plants, aquatic organisms, and eventually people’s bodies. The restricted distribution of hydric soils in the watershed, their associated unusual vegetation, and potential for mercury methylation warrant their protection and careful management.

Unique Soils Most ultramafic soils are found on steep and dissected terrain. The Bear Valley, Leesville, and Venado soil series are unusual as ultramafic soils in that they occur in flat terrain on the Bear Valley floor. These soils are blends of ultramafic and sedimentary materials and have a higher than average ratio of calcium to magnesium to qualify overall as ultramafic soils. Their hybrid origin makes the three ultramafic soils in Bear Valley noteworthy because these soils, unlike most other ultramafic soils, have supported agriculture – primarily livestock grazing – for over 150 years.

South of Highway 20 another ultramafic soil called only by its soil taxonomic name “Haploxererts, Unidentified” occupies about one percent of the watershed area. Much of the area covered with this soil consists of serpentine barrens, and recent botanical explorations indicate that this soil has many rare plant species and unusual plant alliances (E. Dean, UC Davis Herbarium, pers. comm.). In the remote Mill Creek subwatershed, ultramafic soils and

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a large barren have yet to be investigated.

Non-ultramafic Buttes soil formed from conglomerate rock is locally unique, limited to the Gravelly and Bear Valley buttes at the north end of the watershed. The soil has a coarser texture than other soils in the watershed. The island-like form of the buttes and the unusual soil host plant species and vegetation communities not found elsewhere in the watershed or elsewhere in the foothills of Colusa County (J. Alderson, pers. comm.).

Information Needs Hydric soils are more widespread than indicated by the soil survey. Permanent wetlands are present on benches above the west side of Bear Valley, Walker Ridge, and the BLM Bear Creek Ranch. These ultramafic hydric soil sites are rare globally and deserve special study because of their unusual ecology. The little information available indicates that they support specialized plants species. Hydric soils and their wetlands are also important because they may be focal points for bacterial methylation of heavy metals. Information is incomplete about the locations and rates of methylation.

2.8 Geomorphology Geomorphology is the study of the characteristics, origin, and development of landforms. Two parts of Bear Creek watershed are the focus for description and assessment of land forms: hill slopes and streambeds. The following subsections discuss these two processes and how they interact. Other environmental features that affect Bear Creek land forms include geologic faults, rock properties, topography, soils, climate, vegetation, and land uses. These features are described under their own separate headings in the assessment.

Hill Slope Geomorphology and Mass Wasting Soil and rock become mobile when a disturbance such as an earthquake, cumulative wearing of rock faces, or a rainstorm overcome the cohesive physical or chemical forces in soil and rock. These materials move down slope at different rates, depending on gravitational force. Mass wasting may proceed as slow creep, a landslide, mud or debris flows, toppling, or falling. Where soil and rock come to rest and accumulate in the landscape, debris dams and talus piles may develop.

Two studies of landslides have considered parts of Bear Creek watershed. Manson (1989) mapped the southernmost part of Bear Creek watershed; few landslides had occurred on the Skyhigh and Millsholm soils in the area covered. Hoorn et al. (2008) interpreted aerial photographs between 1937 and 2005 to locate landslides and other earth movements in Bear

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Creek watershed north of Highway 20. Landslides, most from natural causes, are not randomly or uniformly distributed in the watershed. Table 2.10 summarizes the distribution and magnitude of volumes of landslides north of Highway 20 by subwatershed.

Subwatersheds on the east side of Bear Valley (Hamilton, Hamilton Canyon, Leesville, Warnick Canyon) and at the north end of Walker Ridge (Doyle Canyon, Gaither Canyon, Robbers Flat, Stinchfield Canyon) have low frequency and volume of landslides. In the 22- year period between 1984 and 2005, the subwatersheds most prone to landslides have been Mill Creek (high frequency and high volume), Sulphur Creek (high frequency), and the main stem of Bear Creek, particularly in the canyon areas between Bear Valley and Highway 20.

Table 2.10 – Distribution and volume from landslides in Bear Creek watershed north of Highway 20 pre-1937 1937-1984 1984-2005 Subwatershed sediment sediment Sediment landslides landslides landslides yd3 yd3 yd3 Bear Creek, Lower 5 42,887 4 19,799 8 14,593 Bear Creek, Upper 3 5230 0 0 4 12,622 Deadshot Canyon 4 102,166 0 0 4 3,963 Doyle Canyon 0 0 0 0 0 0 Gaither Canyon 1 793 0 0 2 2,874 Hamilton 0 0 0 0 1 1,039 Hamilton Canyon 0 0 1 23,728 1 734 Leesville 0 0 0 0 0 0 Mill Creek 26 117,775 2 14,703 8 30,260 Robbers Flat 0 0 0 0 2 7,508 Stinchfield Canyon 0 0 0 0 0 0† Sulphur 32 203,512 6 842 10 5,109 Trout Creek 5 26,727 4 30,090 5 3,524 Warnick Canyon 0 0 0 0 0 0 ______Source: Hoorn et al. (2008) yd3= cubic yards †One landslide in Robbers Flat occurred at the ridgeline with Stinchfield Canyon.

Gullies Gullies are erosion channels caused by runoff water becoming concentrated outside of stream banks. Hoorn et al. (2008) found that large gullies (49 in all) detected in Bear Creek watershed from aerial photographs are associated predominantly (84 percent) with human land uses, especially mining, road and trails, or water storage bodies such as stock ponds. The largest gully formations, however, all appear to be unrelated to land uses.

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As human land uses in Bear Creek watershed have changed over time, causes of gullies and their accompanying sediment flows have changed over time. The locations of new gullies have shifted over time from steeper sites with chaparral vegetation to low-slope grasslands in recent years. This pattern coincides with the cessation of large-scale mining. With one exception, the largest gullies from mine sites originated before 1937, whereas the largest gullies appearing during the period 1984 to 2005 came from erosion in Upper Bear Creek rangelands.

Stream Morphology Descriptions of stream channels for Bear Creek and its tributaries according to classification systems such as by Rosgen (1996) have occurred for small portions of Bear Creek, principally in Bear Valley (J. Alderson, pers. comm.). No historical photography or data are known to chronicle the change in streambeds although the streambeds in Bear Valley and in parts of Bear Creek Ranch have dropped over time (J. Alderson, C. Thomsen, pers. comm.). Channel cross sections of Bear Creek and its tributaries are not available for existing or past conditions from which to estimate bankfull water volume and model creek water flow. Table 2.11 depicts elevation changes with longitudinal sections for Bear Creek, Mill Creek, and Sulphur Creek.

Fluvial Geomorphology Sediment transported by slides and gullies contributes to sediment loads in streams and streambeds in Bear Creek and its tributaries. Sediment control in its own right is critical to water quality and stream and streambank function. Keeping sediment in place in the watershed for an extended time takes on added importance now that sediments derived from mercury-rich mine waste have caused Bear Creek and Sulphur Creek to be listed as impaired waters by the State Water Quality Control Board and the US EPA.

The environments most likely to exhibit changes in stream morphology, especially in sinuosity and shifting location, are the main stems of Bear Creek, Sulphur Creek, the lower reach of Mill Creek, and the creek in Long Valley near Leesville. These creeks pass through valley floor locations. As gullies and headcuts have been developing in these areas, alluvial soil, eroded from surrounding hillsides and deposited on valley floors, has become mobile once again and is entering the stream channel and moving downstream. Hoorn et al. (2008) estimated that the stock of stored sediment in floodplains of these creeks is declining over time and that the rate of decline may have been actually increasing in recent decades. Approximately 650,000 yd3 were eroded from terraces and floodplains of Upper Bear Creek/Mill Creek in the 48 years between 1937 and 1984 (annual average 13,500 yd3); for the 22-year period between 1984 and 2005, the net loss to erosion is estimated at 681,500 yd3

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(annual average 31,000 yd3).

Table 2.11 – Longitudinal sections for Bear Creek, Mill Creek, and Sulphur Creek

Note: Data were interpolated using Google Earth with a standardized interpretative method. Bear Creek was tracked to its headwaters. Data for Mill Creek and Sulphur Creek track from their confluences with Bear Creek back to the point of confluence of their first major branch. Measures were at every quarter mile of creek length.

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One symptom of undesired fluvial geomorphic change appears presently in Sulphur Creek above Wilbur Springs. Four headcuts have developed in the main stem since 1937, three of them since 1968. These nearly vertical downward shifts, ranging from two to eight feet, in the longitudinal profile of Sulphur Creek cause sudden jumps in the velocity of Sulphur Creek flow (Hoorn et al. 2008). The added power erodes adjacent banks and releases considerable sediment from the Arand and riverwash soils stored in the floodplain. These riparian and floodplain soils are known to contain, locally at least, high mercury concentrations. Hoorn et al. (2008) estimated that the volume of sediment from upstream migration of the two largest headcuts (moving 2,262 ft and 2,717 ft since 1937) have generated soil loss equal to 24,900 yd3 of sediment since 1937; 19,900 yd3 alone have been lost since 1968.

Information Gaps Basic information on geomorphology would be helpful for planning potential watershed improvement projects, especially related to fluvial systems and hillslope stability:

repeated field data collection for stream longitudinal sections and selected cross sections for Bear Creek and major tributaries, particularly from subwatersheds with ultramafic soils: Deadshot Canyon, Mill Creek, Sulphur Creek, and Trout Creek a model of the probable original structure of stream channels, banks, and floodplains as a basis for decision making about restoring the structure and function of streams a complete geological hazard map for the entire watershed to assist in better land use management and planning

2.9 Vegetation Managing vegetation is essential for attaining watershed goals identified by stakeholders. Plant species, vegetation alliances/associations, and distribution patterns change markedly across Bear Creek watershed as a function of physical features, biological interactions, and disturbance history (including human land use). Vegetation influences hydrologic function, site stability, biological integrity, and water quality by moderating the impact of rainfall, holding soil in place, cycling nutrients, providing browse and forage for animals, habitat for wildlife, and storing carbon above and below ground. In large measure, vegetation also determines capability for land uses and needs for watershed management.

The Jepson Manual of Higher Plants of California (Hickman 1993) places Bear Creek watershed within the Inner North Coast Range subregion of the Northwest Region of the

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California Floristic Province. This subregion extends from northwest Solano County to central Tehama County, along the east slopes of the Coast Range. Ultramafic rocks and soils are important for their role in providing unusual habitats for many species of rare plants and several animal species with restricted ranges.

Information about the flora of Bear Creek watershed to date covers parts of the watershed. Plants lists for specific areas are available for: the BLM Bear Creek Ranch (E. Dean, C. Thomsen, pers. comm.); the Bear Creek Botanical Management Area (C. Thomsen, pers. comm.); the lower drainage of Sulphur Creek subwatershed (Gennis and Associates 1978); and Walker Ridge and Bear Valley (Clark and Magney 1997, updated on line at http://www.sacvalleycnps.org/conservation/plantlists/BearValleyNosal.pdf).

Vegetation Classification The CDFG leads the current effort to establish uniform and consistent standards, techniques, and documentation for classifying and mapping vegetation alliances and associations in California (Sawyer et al., 2009), consistent with national standards adopted by the Federal Geographic Data Committee. Using this classification protocol as a guide, Thorne et al. 2004 mapped the lands for the BLM Bear Creek Ranch consistent with the criteria for mapping habitats in nearby Napa County. The map is not presented here because it only covers part of the watershed and still requires groundtruthing.

Vegetation mapping with CalVeg 94 (Figure 2.16), the classification system developed by CALFIRE and the US Forest Service, covers the entire watershed. It has a forestry focus and only uses general categories to classify vegetation dominated by shrub and herbaceous plants. The “Lower Montane Chaparral” rubric in the vegetation classification system refers to the diverse serpentine, chamise, and mixed-species chaparral shrub vegetation found on most of the east-facing slopes from Walker Ridge and Mill Creek subwatershed. Riparian vegetation is not explicit in the vegetation map.

Major Vegetation Alliances The wide range of environmental conditions in the watershed underlies the diversity of plant species and vegetation alliances present. Abrupt transitions in the chemical properties between adjoining sedimentary and ultramafic soils create differences in distributions of plant species and vegetation cover and in the appearance of landscapes. Ultramafic soils in Bear Creek watershed principally support chaparral shrublands, but also smaller areas of conifer woodlands, prairies, barrens, and wetlands. In contrast to sedimentary soils, the vegetation on ultramafic soils is often dwarfed, sparse in cover, reduced in overall species

BEAR CREEK WATERSHED ASSESSMENT richness, and high in endemic species.

Appendix E describes the vegetation alliances known or suspected in the watershed, based on the California vegetation classification scheme established by Sawyer et al. (2009) plus notes on soils and environmental conditions (Reed 2006). Because mapping of vegetation alliances in Bear Creek watershed is incomplete, the presence of specific vegetation alliances and associations in the landscape remains uncertain. The large number of plant alliances in this comparatively small watershed underscores the high biological diversity in the watershed.

Rare and Sensitive Plant Species No known federally listed plant species occur in Bear Creek watershed, but Indian Valley brodiaea (Brodiaea coronaria ssp. rosea), a State of California listed endangered species, is present in Bear Creek watershed. In addition, the California Native Plant Society (Rare Plant Database 2009) and databases from California herbaria have documented seventeen rare plant species (CNPS List 1B). Fifteen of these species are found on federal public lands and qualify as US Forest Service and BLM California Sentive Plant Species. Most rare species are found on ultramafic soils and most are annuals thought to require fire to spur seed germination.

Dr. Ellen Dean (per. comm.) is conducting a rare plant search of the areas covered by the four USGS quads that include and surround the watershed. Her botanical inventories thus far on the BLM Bear Creek Ranch have documented seven CNPS List 1B and eleven CNPS List 4 species. Habitats where these plants occur are displayed in the subwatershed analyses in Chapter 7. Section 2.11 provides greater detail on habitats set aside specifically to protect rare plant species and vegetation types.

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Table 2.12 – Special status plant species in Bear Creek watershed Listing Conservation Management Species Habitat Status Status Concerns in the Watershed Mosses habitat loss from the Norris' beard moss Walker Fire (2008); Distribution poorly known; No management to Didymodon norrisii CNPS List 2.2 cypress woodland road maintenance and habitat loss will likely mean date Pottiaceae construction and wind popuation losses energy development Dicots Big-scale balsamroot Recent searches have BLM SS chaparral, woodland, OHV trails through Protected under Balsamorhiza macrolepis shown that this species USFS SS grassland, facultative habitat, livestock management; no var. macrolepis occurs more widely than CNPS List 1B on ultramafic soils grazing intervention to date Asteraceae herbarium records indicate Pappose tarplant non-native invasive Protected under Centromadia parryi ssp. BLM SS chapparal, meadows, plants, livestock No information on any management; no parryi CNPS List 1B seeps, grassland grazing, road changes to populations intervention to date Asteraceae maintenance

Hall's harmonia mining operations and Protected under BLM SS chaparral on No information on any Harmonia hallii their legacies, wind management; no CNPS List 1B ultramafic soils changes to populations Asteraceae energy development intervention to date

Colusa layia chaparral, woodland, Protected under BLM SS none identified for the No information on any Layia septentrionalis grassland, on sandy management; no CNPS List 1B watershed changes to populations Asteraceae ultramafic soils intervention to date Bent-flowered fiddleneck Protected under BLM SS none identified for the No information on any Amsinckia lunaris woodland, grassland management; no CNPS List 1B watershed changes to populations Boraginaceae intervention to date

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Listing Conservation Management Species Habitat Status Status Concerns in the Watershed Deep-scarred cryptantha Protected under BLM SS woodland, on sandy none identified for the No information on any Cryptantha excavata management; no CNPS List 1B or gravelly soil watershed changes to populations Boraginaceae intervention to date Morrison's jewel-flower chaparral and Protected under BLM SS none identified for the No information on any Streptanthus morrisonii cypress woodland on management; no CNPS List 1B watershed changes to populations Brassicaceae ultramafic soils intervention to date Sonoma canescent manzanita Protected under BLM SS chaparral , facultative wind energy No information on any Arctostaphylos canescens management; no CNPS List 1B on ultramafic soils development changes to populations ssp. sonomensis intervention to date Ericaceae Jepson's milk-vetch chaparral, woodland, Protected under Astragalus rattanii var. BLM SS wind energy No information on any grassland, facultative management; no jepsonianus CNPS List 1B development changes to populations on ultramafic soils intervention to date Fabaceae This population has been Cobb Mountain lupine geothermal reported on private land in Lupinus sericatus CNPS List 1B chaparral, woodland development, road Protected by CDFG Sulphur Creek Fabaceae maintenance subwatershed. Round-leaved filaree Protected under More than 20 populations California macrophylla BLM SS woodland, grassland, none identified for the management; no are present on Bear Creek (=Erodium macrophyllum) CNPS List 1B often at seeps watershed intervention to date Ranch. Geraniaceae

Drymaria-like western flax BLM SS conifer woodlands, Protected under Hesperolinon mining operations and This species is known from USFS SS chaparral, grassland, management; no drymarioides off-road vehicles Love Lady Ridge. CNPS List 1B on ultramafic soils intervention to date Linaceae

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Listing Conservation Management Species Habitat Status Status Concerns in the Watershed livestock grazing, This species is known from Brandegee’s woollystar BLM SS chaparral, woodland weed competition, Protected under Mill Creek subwatershed Eriastrum brandegeeae USFS SS on volcanic, sandy off-road vehicles, road management; no and has been recently Polemoniaceae CNPS List 1B soils construction, energy intervention to date found on Walker Ridge. development Snow Mountain This species is known from BLM SS energy development, Protected under buckwheat chaparral on the Frenzel Creek Research USFS SS mining, and off-road management; no Eriogonum nervulosum ultramafic soils Natural Area at the edge of CNPS List 1B vehicles intervention to date Polygonaceae the watershed. The single record for this Bolander's horkelia chaparral, meadows, none identified for the species in the watershed Horkelia bolanderi CNPS List 1B Protected by CDFG seeps, wet grasslands watershed comes from the Leesville Rosaceae area in 1884. Pink creamsacs openings in livestock grazing, Protected under Castilleja rubicundula ssp. BLM SS chaparral, meadows, mining, off-road No information on any management; no rubicundula CNPS List 1B seeps, grassland, on vehicles, and road changes to populations intervention to date Scrophulariaceae ultramfic soils construction Monocots Protected under Indian Valley brodiaea BLM SS knobcone pine off-road vehicles, management; the Populations may be Brodiaea coronaria ssp. USFS SS woodland, chaparral, dumping, wind energy BLM established the declining but no monitoring rosea CA grassland on development, illegal Indian Valley ACEC to data are available. Liliaceae Endangered ultramafic soils plant collecting protect this species livestock grazing, off- Adobe lily chaparral, woodland, road vehicles, mining, Protected under BLM SS No information on any Fritillaria pluriflora grassland, often on wind energy management; no CNPS List 1B changes to populations Liliaceae adobe-like soils development, non- intervention to date native invasive plants Sources: California Native Plant Society (2009), Jepson Herbarium Consortium (2009), CalFlora (2009); BLM wind energy leases database (2009)

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Culturally Important Native Plant Species Bear Creek watershed is part of the ancestral lands of the Southern Wintun (Patwin) people. Two rancherias are near the boundary of Bear Creek watershed: the Cortina Band of Wintun Indians of California and the Yoche Dehe Wintun Nation. The ethnobotanical studies of Wintun people have focused on Wintun bands at the north end of the Sacramento Valley (Merriam 1966, Johnston 1973). Little is known about historic plant uses (M. Kat Anderson, pers. comm.) of the Hill Patwin people who resided in the watershed, and a complete list of plant foods was never obtained (Johnson 1978). Moreman (undated) lists the following major plant species found in Bear Creek watershed known to be used by neighboring tribes in the inner North Coast Range:

Food: blue, scrub, and valley oak (Quercus douglasii, Q. dumosa, and Q. lobata) acorns; blackberries (Rubus spp.); native grape (Vitis californica); elderberry (Sambucus nigra); foothill pine (Pinus sabiniana) nuts; manzanita (Arctostaphylos spp.) berries; biscuitroots (Lomatium spp.); yampahs (Perideridia spp.); native clovers (especially Trifolium fucatum); many bulbs (“onions”) in the lily family; and saltgrass (Distichlis spicata) burned to obtain salt.

Basketry: redbud (Cercis canadensis)

Weaponry: chamise (Adenostoma fasciculatum) for bows and arrows

Medicinal/Cosmetic: wavyleaf soap plant (Chloragalum pomeridianum)

Apart from hunting and gathering, Southern Wintun people actively managed native grasslands in Bear Valley by burning for forage attractive to game species. Particular species were cultivated such as soap plant by breaking off stems, replanting root crowns, sowing seeds, and burning to stimulate growth and seed production. Also, valley oak woodlands and savannahs were traditionally managed to promote tree vigor by reducing the shrub understory and to encourage the growth of herbaceous plants that provided seeds and bulbs (Anderson 2005).

Range Improvement Species People have introduced many range plants in Bear Creek watershed as animal forage and for erosion control. Among introduced grass and legume species are: tall fescue (Schedonorus phoenix), hardinggrass (Phalaris aquatica), orchardgrass (Dactylis glomerata), rye grasses (Lolium spp.), rose clover (Trifolium hirtum), birds-foot trefoil (Lotus corniculatus), and vetches (Vicia spp.) (Harradine 1948, Harrison et al. 2006). Tall wheatgrass (Thinopyrum

BEAR CREEK WATERSHED ASSESSMENT ponticum), now a prominent invasive weed in Bear Valley and lower Bear Creek, was originally introduced for livestock production in Bear Valley. Smilograss (Piptatherum miliaceum), originally introduced for re-seeding burned over chaparral lands, has been observed spreading along the Sulphur Creek corridor, and is locally common in some drainages on the BLM Bear Creek Ranch. After a chaparral site dominated by chamise burned in the summer of 1998, smilograss flourished at the site in the spring of 1999.

Non-Native Invasive Plant Species Non-native invasive plant species are a major issue for Bear Creek watershed stakeholders. These species, often introduced to provide economic benefits to people, may eventually entail high economic costs to eradicate or control their populations and to restore sites to native vegetation and productivity. Adverse impacts encompass increased competition with native plants, habitat degradation for land uses, genetic stock alterations, and changes to soil properties (Drenovsky and Batten 2007). Controlling plant invasions is at the core of protection of biological diversity and ecosystem productivity in the watershed.

Table 2.13 provides background information on the major non-native invasive plants in Bear Creek watershed. The most abundant upland noxious weeds are: barb goatgrass (Aegilops triuncialis), medusahead (Taeniatherum caput-medusae), and yellow starthistle (Centaurea solstitialis), but many other non-native grasses and forbs have also helped change the character of the pre-European native grassland-prairie communities and blue-oak woodland understory. Perennial pepperweed (Lepidium latifolium), small-flowered tamarisk (Tamarix parviflora), and tall wheatgrass are the dominant riparian weeds along the Bear Creek corridor. Section 5.3 Aquatic Biological Data presents more information on riparian and aquatic invasive species.

Some parts of Bear Creek watershed harbor more non-native plants than others. For example, non-native grasses and yellow starthistle predominate in many parts of Bear Valley after 150 years of agriculture, but chaparral vegetation on undisturbed sedimentary upland soils has few non-native invasive plant species (Harrison et al. 2003). Generally, where soil disturbances from land use have been less intensive, non-native plants invade less readily. Vegetation management is particularly important for controlling non-native plants along corridors such as roads and trails and riparian areas. Bulldozed fire lines are now a prominent feature in the watershed. These soil disturbances coupled with wildfire have the potential to accelerate the rate of spread of non-native plants into previously unoccupied chaparral habitats.

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With their unusual chemistry and low human use, ultramafic soils and vegetation have been been historically resistant to non-native plant invasions. Few exotic invasive species have acclimated to chaparral vegetation sites on ultramafic soils in Bear Creek watershed. Annual non-native grasses and forbs from the Mediterranean basin are present but are much less extensive than in grasslands on non-ultramafic soils (Harrison et al. 2003). However, yellow starthistle, barb goatgrass, and bromes (Bromus spp.) are locally abundant on abandoned mine sites and livestock rangeland (Gelbard and Harrison 2003, 2005). Limited knowledge about best vegetation restoration practices for ultramafic soils makes controlling plant invasions difficult at present.

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Table 2.13 – Invasive plants in Bear Creek watershed with ratings from the California Integrated Plant Council and the California Department of Food and Agriculture (CDFA), status, and preliminary management recommendations

USDA Common CDFA Name, Scientific weed Occurrence and Abundance Preliminary Management Recommendations Resource value

Name, and Family Impacts rating Distribution Invasiveness

Dicots Poison hemlock A riparian species, occasional in moist disturbed Conium maculatum B B B - No action recommended Pollinator support areas Apiaceae

Hedgeparsley Torilis arvensis C B B - Common, but no apparent impacts No action recommended - Apiaceae Italian thistle Carduus B B A C Occasional in disturbed areas No action recommended Pollinator support pycnocephalus Asteraceae Tocalote Centaurea B B B C Occasional in grasslands and oak woodlands No action recommended - melitensis Asteraceae Nearly all treatments should be regarded as suppression because the species is widespread and its seedbank is One of the most abundant noxious weeds in persistent. Protection of non-target plant species is Yellow starthistle grasslands, forming dense, spiny canopies in recommended when Transline is used. Current grazing Pollinator support, Centaurea A B A C summer. Known also from ultramafic sites such as practices appear ineffective and are probably leading to forage value before solstitialis Rathburn-Petray mines, the Bear Valley floor, and increases. The BLM has used an integrated approach, becoming spiny Asteraceae Bear Creek Botanical Management Area. using prescribed burns and Transline applications to suppress this plant. Thomsen and Alderson have also reduced populations along Sulphur Creek.

Smooth cat's ear Hypochaeris glabra C B B - Occasional to locally common No action recommended - Asteraceae

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Black mustard Brassica nigra B B A - - Brassicaceae Occasional in disturbed areas No action recommended Field mustard Brassica rapa C B B - - Brassicaceae Hoary cress Rare, only known from Cowboy Camp on the BLM Control efforts are warranted, although it is probably not Cardaria draba B B B B - Bear Creek Ranch highly invasive here with its current limited occurrence. Brassicaceae

Summer mustard Hirschfeldia incana B B A - Occasional No action recommended - Brassicaceae A riparian species, increasing along Bear Creek and This is a priority species for control but controlling its rapid often the dominant in deep, moist soils; locally spread is difficult. Prompt response could contain the Pollinator support abundant in the BLM Bear Creek Ranch in the Sulphur Creek population. This species is the likely and additional study Perennial Cowboy Camp meadows and at “Road Kill Café”. replacement plant once tamarisk is eradicated and when needed to better pepperweed A A A B 40+ patches documented as a recent arrival in no active native plant revegetation follows. The most understand its Lepidium latifolium Sulphur Creek valley. Current status in Bear Valley effective herbicide, Telar, is not registered for riparian ecological impact Brassicaceae along Bear Creek is unknown, although it was rare settings. Control efforts are necessary in upper riparian beyond displacing in 2001. This species also occurrs on ultramafic zones on Bear Creek Ranch where rare and unusual plants native plants soils. occur. Occasional to locally abundant on moist sites, Common teasel especially along Bear Creek near Highway 20 and Dipsacus fullonum B B B - No action recommended Pollinator support east along Highway 20, also Sulphur Creek Valley Dipsacaceae near the spring below Manzanita Mine Bird's foot trefoil Pollinator support A riparian species abundant along Bear Creek in Lotus corniculatus D B B - No action recommended and host plant for moist floodplain and swales Fabaceae lycaenid butterflies Bur medic Medicago C C A - Occasional, impact minor No action recommended Forage value polymorpha Fabaceae Sweet clover Melilotus officinalis D C C - A riparian species common along Bear Creek No action recommended Forage for tule elk. (= M. alba) Fabaceae

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Rose clover Trifolium hirtum C B B - Uncommon, minor impact No action recommended - Fabaceae Hairy vetch Locally abundant along Bear Creek and in its Vicia villosa D C B - floodplain and some upland settings, especially in No action recommended Some forage value Fabaceae wet years. Redstem filaree Erodium cicutarium C C A - Widespread No action recommended Forage value Geraniaceae Cutleaf geranium Geranium C B A - No obvious impact No action recommended - dissectum Geraniaceae White horehound Marrubium vulgare C C B - Uncommon, impacts minor No action recommended - Lamiaceae Curly dock Rumex crispus C C A - Widespread in grasslands and meadows No action recommended - Polygonaceae Controlling with applications of appropriate herbicides Tree of heaven Present along Bear Valley Road in the canyon oncut stumps or hack-and-squirt to reach the root system Ailanthus altissima B B B C between Bear Valley and Highway 20, forming occurs late in the growing season. Establishing a dense - Simaroubaceae single-species stands canopy of native tree species needs to follow eradication to shade out any further tree of heaven seedlings. Source population along three miles of Sulphur Creek is controlled; currently, some spot treatments are needed to Small-flowered remove seedlings. Herbicide residues can limit Early season A riparian species, with heavy infestations along tamarisk revegetation for at least four years. Control has led to pollinator support, A A B B Bear Creek with Sulphur Creek as the original Tamarix parviflora rapid breakdown of some tamarisk hummocks and cover and perching source of the infestation Tamaricaceae sediment release to streams. Downstream biocontrol is value for birds promising but not yet certain. If a biocontrol program is successful, most herbicide use is not warranted. Monocots Abundant in Bear Valley and expanding on the BLM Barbed goatgrass Some forage value to Bear Creek Ranch, especially on ultramafic soils. Controlling newly established populations is a high Aegilops triuncialis A A B B livestock, especially Still relatively rare on west side of the ranch. Only priority. Ongoing surveillance is necessary. Poaceae germinating seeds one known location within Sulphur Creek valley.

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Commercially grown Cut or mow mature stems in the fall, apply herbicide to Giant reed for musical Locally present in Bear Valley and along Highway 20 stems, leave stalks on the ground, apply herbicide to new Arundo donax A B A B instrument reeds on the east side of the watershed shoot growth not suppressed by overlain dead mature Poaceae and structural stems 3 to 12 weeks later material Slender wild oat Avena barbata B B A - Poaceae Prescribed burning and livestock grazing may be Common in grasslands Forage value Wild oat warranted in some sites to reduce thatch buildup. Avena fatua B B A - Poaceae Ripgut brome Forage value prior to Bromus diandrus B B A - Occasional to common in grasslands No specific action recommended, although prescribed flowering Poaceae burning and livestock grazing may be warranted in some Soft brome sites to reduce thatch. Bromus hordeaceus B C A - Common in grasslands Forage value Poaceae Red brome Bromus rubens A B A - Common in grasslands No action recommended - Poaceae A riparian species abundant along Bear Creek, Bermuda grass mixed in with native grasses such as saltgrass, Control without significant damage to non-target plants is Cynodon dactylon B B B C - creeping wildrye (Leymus triticoides), and scratch unlikely; thus no action is recommended. Poaceae grass (Muhlenbergia asperifolia)) Seaside barley Hordeum marinum B B A - Poaceae Mediterranean Locally abundant No action recommended - barley B B A - Hordeum murinum Poaceae Prescribed burning and livestock grazing may be Italian ryegrass warranted in sites to reduce thatch and seed output. Four Lolium multiflorum B B A - A serious weed in moist areas. Forage value years of prescribed burning on the Bear Creek Botanical Poaceae Management Area did not reduce abundance. Harding grass Forage value for Control with glyphosate at pond sites to reduce its Phalaris aquatica B B B - Limited, locally abundant at one stock pond livestock and presence. Poaceae probably tule elk.

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Smilo Increasing along Sulphur Creek, occasional along Piptatherum Bear Creek, and locally abundant after fires in Gather more information about distribution and C B B - - miliaceum chaparral; abundant downstream along Cache abundance. Poaceae Creek in scoured floodplain settings. Rare, thus far only known from Craig Canyon where Ravenna grass the BLM has grubbed it out. However, it is Follow-up monitoring is needed. Individual plants are easy Saccharum B A C abundant downstream along Cache Creek. to grub out. A 3-percent glyphosate solution prior to fall - ravennae Infestations are coming from North Fork Cache dormancy is effective. Poaceae Creek.

Tall fescue Locally dense stands along Bear Creek in several Control with early fall applications of glyphosate, Schedonorus B B A - locations. Probably many more undocumented combined with native plant revegetation in specific zones - phoenix locations along Bear Creek floodplain. on the BLM Bear Creek Ranch. Poaceae

Widespread in grasslands and understory of blue Medusahead Prescribed burns are the most effective means of oak woodland. Along with yellow starthistle, this is Taeniatherum controlling large infestations. Livestock trampling breaks Some forage value, A A A C the most common weed on non-ultramafic soils. It caput-medusae up thick layers of thatch and closely timed, intensive prior to flowering forms dense thatch due to high silica content in Poaceae grazing reduces seed output. flower heads that resists decomposition. Priority action is needed to protect prairie remnants and Some forage value, riparian sites. The relative ease of controlling parent although often plants justifies a control program with spot applications of avoided due to Tall wheatgrass This riparian species, now a major weed along Bear glyphosate. Reinfestation from upstream sources will be coarse, "stemmy" Thinopyrum Creek, affects all zones along the riparian corridor It an ongoing issue. Failure to act will continue the loss of -- - - growth. Mowed by ponticum is not yet recognized by Cal-IPC as an invasive native plants along Bear Creek. Thousands of plants have ranchers to remove Poaceae weedy species been removed manually by conservation crews at Cowboy old material and to Camp and in revegetation research sites. This rapidly stimulate fresh culm spreading plant occurs where perennial pepperweed is developement absent. Rattail fescue Vulpia myuros B B A Abundance unknown Suppress -

Poaceae

California Invasive Plant Council Ratings: A = Severe, B = Moderate, C = Limited in California California Department of Food and Agriculture Ratings: "A" – Eradication, containment, rejection, or other holding action at the state and county level. "B" – Eradication, containment, control or other holding action at the discretion of the commissioner. "C" – State endorsed holding action and eradication only when found in a nursery; action to retard spread outside of nurseries at the discretion of the commissioner

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Exotic Plant Pathogens No evidence for sudden oak death caused by the root fungus Phytophthora ramorum exists in Colusa County oak woodlands as of 2006 according to the OakMapper database (California Oak Mortality Task Force, undated). Meetemeyer et al. (2004) state that woodlands in western Colusa County are too dry to support P. ramorum; thus the risk of sudden oak death in Bear Creek watershed is low.

No other exotic insect, bacterial, fungal, and non-native parasitic plant species are known to be problematic in the watershed.

Information Gaps Gaps in information about vegetation are having a significant impact on outcomes for land management in Bear Creek watershed. Addressing the following information gaps would assist land managers and property owners to increase land productivity or recover native vegetation and watershed processes:

developing ecological site descriptions of the vegetation associated with the soil mapping units found in Bear Creek watershed from the Colusa County Soil Survey (Reed 2006) to correlate presence of major plant species with soils mapping of native and non-native vegetation alliances described in Sawyer et al. (2009) for the entire watershed, with special attention to delineating plant alliances on ultramafic soils continuing systematic surveillance and mapping of non-native invasive plants for GIS analysis and restoration planning surveying and documenting the flora of Walker Ridge and upper Mill Creek subwatershed, with special emphasis on locating US Forest Service and BLM sensitive plant species.

2.10 Wildlife In keeping with federal and California state agency mandates for protecting and enhancing native biological diversity, public land managers manage species and habitats to ensure their long-term viability. Wildlife species are important for ecological services that they provide, such as subsistence food production, recreational opportunities for hunting, nature tourism, and wildlife viewing.

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This section covers both invertebrate species (mollusks and insects) and vertebrate species (fish, amphibians, reptiles, birds, mammals). Species of major interest are special-status species and game species. To assist habitat planners, this section also presents a table that relates special-status wildlife species to the plant and aquatic communities identified and mapped in the 1994 version of CalVeg. Information on focal aquatic species used in water quality monitoring appears in Section 5.3.

Special-Status Species: Sensitive Species and Species of Special Concern In addition to animal species listed as threatened or endangered under the Federal Endangered Species Act or the California Endangered Species Act, BLM and the US Forest Service compile lists of sensitive species. These species receive special management protection from the agencies to ensure that federal land management actions do not contribute to the species becoming listed under endangered species acts.

The California Department of Fish and Game (CDFG) also maintains an equivalent list of “species of special concern”. Species of special concern are undergoing long-term declines in California or already have small populations that put them at risk of. The Department also has a category of “fully protected animals” that may not be hunted or captured at any time except for permitted scientific research and animal relocation.

Significant Invertebrates A full discussion of all terrestrial invertebrates in Bear Creek watershed is beyond the scope of this assessment. However, the role of invertebrates in the watershed can be profound. For example, the grasshopper Melanoplus devastator can multiply to huge populations. The capacity of the species to defoliate vegetation in some years can cause yellow starthistle to fail to bloom (J. Alderson, pers. comm.). Several classes of invertebrate species are important because of their remarkable diversity in the watershed or their importance to agriculture.

Dragonflies and Damselflies (Class Odonata) Bear Creek is an important hotspot of diversity for dragonflies and damselflies (Odonata) that has national attention (K. Biggs, pers. comm.). Forty-eight dragonfly and damselfly species are known to occur at Bear Creek, comprising 42 percent of all the species found in California. The City of Williams, east of Bear Creek, was chosen as the site of the 2003 Annual Meeting of the Dragonfly Society of the Americas because of its proximity to Bear Creek. One hypothesis for this high diversity of dragonflies is the diverse range of water chemistry and varied aquatic habitats available for larval dragonflies in Bear Creek

BEAR CREEK WATERSHED ASSESSMENT watershed. None of the Odonata species found in Bear Creek watershed are listed as part of the CDFG’s Special Animals list (2008). Researchers have conducted multiple studies on dragonflies and damselflies (Grether 1996, Luttbeg et al. 2009, Switzer and Grether 2000) located in the watershed.

Butterflies (Class Lepidoptera) Eighty-five butterfly species (80 confirmed and five more expected) occur in Bear Creek watershed (Arthur Shapiro pers. comm.). Several butterfly species are the only known pollinators of several plant species limited to ultramafic soils (Shapiro and Manolis 2007), particularly in the genera Eriogonum (buckwheats) and Lomatium (biscuitroots). Maintaining populations of plants limited to rare soils and their butterfly pollinators is a core task of biodiversity conservation.

Threatened, Rare, and Endemic Insects and Mollusks The Federal Endangered Species Act lists one insect, the Valley elderberry longhorn beetle, which may occur in the watershed. The BLM in California includes no additional insect or other invertebrate species among its sensitive species for special management. The US Forest Service, Pacific Southwest Region, has recently updated its sensitive species category in California to include invertebrate species that merit conservation management (J. Furnish, pers. comm.); however, no Forest Service sensitive invertebrate species are definitely known from US Forest Service lands in Bear Creek watershed.

The CDFG (Biogeographic Data Branch 2009) has prepared a list of special animals that includes rare and endemic insects and other invertebrates in California. One of these, the serpentine cypress wood-boring beetle, is present on BLM public lands and is very likely in the National Forest lands in the watershed. Table 2.14 lists invertebrate species known to occur or suspected to occur in Bear Creek watershed. In November 2008, shells of a mollusk, the California floater (Anodonta californiensis), were found in Bear Creek along Bear Valley Road. This species has all but disappeared from National Forests in California (J. Furnish, pers. comm.).

Four special environments host endemic invertebrate species in Bear Creek watershed: the Bear Creek riparian and aquatic corridor; the springs of Sulphur Creek subwatershed; the Sulphur Creek riparian corridor; and the MacNab cypress (Cupressus macnabiana) woodlands on Walker Ridge.

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Table 2.14 – Threatened, rare, and endemic invertebrate species in Bear Creek watershed Federal California Order Family Common Name Scientific Name Protection Protection Status Status Mollusks Unionoida USFS Anodonta (Freshwater Unionidae California floater Sensitive None californiensis Mussels) Species Insects Serpentine cypress Buprestidae Trachykele hartmani None None wood-boring beetle Desmocerus Coleoptera Valley elderberry Cerambycidae californicus ssp. Threatened None (Beetles) longhorn beetle dimorphus Wilbur Springs Hydraenidae Ochthebius recticulus None None minute moss beetle Wilbur Springs shore Diptera (Flies) Ephydridae Paracoenia calida None None fly Hemiptera Wilbur Springs Saldidae Saldula usingeri None None (True Bugs) shorebug

Valley Elderberry Longhorn Beetle (VELB) VELB is known to occur 3.5 miles southeast of the south end of the watershed in the Capay Valley, Yolo County. Biologists from the US Fish and Wildlife Service have observed markings on plants at Wilbur Hot Springs, thought to be VELB exit holes (C. Thomsen, pers. comm.).

Elderberry (Sambucus nigra = S. mexicana) shrubs are critical to the life cycle of VELB and is one of few native shrubs that regenerate in Bear Creek riparian zones under the canopy of dead tamarisk shrubs after herbicide treatments (C. Thomsen, pers. obs.). Collinge et al. (2001) found that VELB thrives in dense clumps of elderberries having branches two to four inches thick at a foot or more aboveground. Holyoak and Koch-Munz (2008) found that VELB populations are higher in mature elderberry sites with some dead and damaged stems from animal browse and flooding. Expanding elderberry shrub cover along Bear Creek as tamarisk control proceeds may promote VELB conservation. Details of habitat size, water flow and flood pattern, and time needed to grow elderberry shrubs suitable for VELB are critical for successful riparian restoration and VELB conservation (Talley 2007).

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Serpentine Cypress Wood-Boring Beetle The habitat of this species consists of native cypress trees on ultramafic soils in the Interior Coast Range from Napa to Colusa counties. In Bear Creek watershed, this species occurs on Walker Ridge in stands of McNab cypress. Because it is restricted to cypress trees, this species is especially vulnerable to habitat changes, such as the stand-replacing 2008 Walker fire.

Endemic Insects in the Vicinity of Wilbur Springs Three insect species are known only from the vicinity of Wilbur Springs. These species have evolved to adapt to the unusual chemical and temperature conditions at spring sites and creek waters in Sulphur Creek subwatershed.

The Wilbur Springs minute moss beetle inhabits the edges of Sulphur Creek. A major threat to this species would result from unintended consequences of management of the creek margin, for example, placing large riprap pieces over the side of Wilbur Springs Road for bank stabilization along Sulphur Creek. The CDFG lists no records for this species more recent than 1971.

The Wilbur Springs shore fly is endemic to Wilbur Springs and favors water temperatures between 20 and 40°C flowing from that complex of springs. Changes in the spring flow and water use could eliminate this highly restricted species. Scientists have not formally documented the presence of this species since 1984.

By contrast the Wilbur Springs shorebug occurs more widely at multiple thermal and cold springs and their effluent areas in the Sulphur Creek watershed, even being adapted to sites with very high sodium and lithium concentrations in spring water (Resh and Sorg 1983). One major prey species for the Wilbur Springs shorebug is the Wilbur Springs shore fly. The shorebug derives its fluids by preying on the larvae of the shore fly rather than from direct consumption of spring waters with their high chemical ion content (Resh and Barnaby 1987). Development of geothermal energy at hot springs may adversely impact populations of the shorebug and the shore fly if management practices are not in place to protect species habitat. The latest museum specimen of this species is from 1979. This species was the first invertebrate species to be proposed as federally listed threatened or endangered species in the United States (New 1995).

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Special-Status Vertebrate Species Table 2.15 lists all special-status vertebrate species known from Bear Creek watershed. The table summarizes required habitat features for the species, stakeholders’ concerns, and the status of species populations and their habitats. The following is a description of watershed issues and land uses that may affect the conservation of these species.

Special-Status Fish Species There are no special-status fish species in Bear Creek watershed. Dr. Peter Moyle, however, considers Bear Creek a rare aquatic ecosystem, in part due the intact populations of resident native fishes. Unusual water chemistry in many parts of the watershed may be an important factor to limiting the invasion of non-native fishes and keeping the natural assemblage of native fishes intact in the watershed.

Special-Status Amphibians and Reptiles One special-status amphibian and one special-status reptile occur in the watershed: foothill yellow-legged frog (Rana boylii) and western pond turtle (Actinemys marmorata), respectively. Foothill yellow-legged frogs appear to be absent from the lower reach of Sulphur Creek but are present in Bear Creek and its other tributaries. Watershed residents have noted western pond turtles using the Sulphur Creek bed as a travel corridor during seasons with low water flow.

The following watershed issues may affect populations of these species in Bear Creek.

Toxic Chemicals High loads of mercury and perhaps other toxic elements in Bear Creek and its tributaries may reduce survival, inhibit growth, and impair reproduction of amphibians (Unrine et al. 2004). Tadpoles consume algae and invertebrates from creek beds and take in mercury at the same time. Adults consume invertebrates, mostly insects, many of which may have larval stages that inhabit streambeds and accumulate mercury that they pass on to adult frogs. Tissue samples gathered from all foothill yellow-legged frogs in Harley Gulch immediately west of Bear Creek watershed had concentrations of methylmercury in excess of the US EPA criterion for issuing human health advisories about fish consumption (Hothem 2008).

Sediment Delivery Western pond turtles deposit their eggs in stream banks that may eventually erode so that the banks are out of reach for turtle use. High sediment loads may degrade water quality and foraging habitat for yellow-legged frog tadpoles.

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Non-Native Species Bullfrogs (Lithobates catesbeianus) predate very young western pond turtles and all life stages of foothill yellow-legged frogs. Non-native sunfish prey on the frog and may limit frog populations. No information is available about the presence of non-native aquatic fungi in Bear Creek watershed that are lethal to foothill yellow-legged frogs.

Climate Change A drying climate may reduce the amount of permanent water available as suitable habitat for frogs and turtles in Bear Creek and its tributaries.

The land uses that are potentially harming aquatic amphibians and reptiles include: mining (mercury legacy), agriculture (sedimentation, altered stream channels), recreation (habitat disturbance, pet trade), and transportation (vehicle collision, habitat fragmentation).

Special-Status Birds Eagles, falcons, kites, and owls, all collectively known as “raptors,” comprise a large portion of special-status birds found in the watershed. One raptor bird species that occurs in the watershed is Swainson’s hawk (Buteo swainsonii) is a State of California endangered species and a BLM sensitive species. The hawk recently nested just north of Bear Creek watershed (California Natural Diversity Database 2009). This species could occur in grasslands and foothill woodland in Bear Valley and in the Leesville area.

Other noteworthy breeding birds, indicative of the diversity of habitats in the watershed, include common merganser (Mergus merganser), spotted sandpiper (Actitis macularius), and greater roadrunner (Geococcyx californianus). The first two species nest along lower Bear Creek in the BLM Bear Creek Ranch. Roadrunners, thought of usually as desert birds, occur in the foothill woodland and open chaparral habitat in the watershed. The local population is one of the few remaining in the inner North Coast Range in northern California. Notable large flocks of long-billed curlews (Numenius americanus) overwinter on ranch lands in Bear Valley.

Land Uses Potentially Harming Bird Species The following existing land uses have the potential to harm birds: agriculture (habitat disturbance), forestry (tree cutting), mining (mercury poisoning), recreation (habitat disturbance, falconry), and transportation (road kills). Development of wind energy on Walker Ridge may cause mortalities to raptor birds, some of which are species of concern for the CDFG.

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Special-Status Mammals The special-status mammals are poorly known in Bear Creek watershed. Three of the species are nocturnal: Townsend’s big-eared bat (Corynorhinus townsendii), pallid bat (Antrozous pallidus), and ringtail (Bassaricus astutus). The other special-status mammal, American badger (Taxidea taxus) occurs with a low population density in Bear Valley so that monitoring and field studies for badgers are difficult.

The first Townsend’s big-eared bat population noted in Sulphur Creek subwatershed was in 1966 (P. Leitner, pers. comm.). Two hundred bats were noted at that time at the colony site, and Pierson and Rainey (1998) found 145 bats at the same site, indicating that the colony had remained intact between 1966 and 1994. The colony is part of the inner North Coast Range population subgroup which is one of the four remaining strongholds for these bats in California. Bats are using abandoned mines for summer roosts, and hibernating bats have been found in three features (Pierson 1988).

Land Uses Potentially Harming Mammal Species The following land uses may be impact mammals: agriculture (habitat disturbance or creation), forestry (tree cutting/habitat loss), recreation (habitat disturbance, pet trade), and transportation (road kills, habitat fragmentation)

Crosswalk of Habitats of Species of Concern and CalVeg Vegetation Communities Managing the habitats of species of concern is an important element of a conservation strategy in the watershed to sustain species populations. Wildlife biologists work to maintain the landscape pattern of connectivity and patch sizes of key habitats to maintain the life histories of animal species of concern. The US Forest Service in California has developed a crosswalk between the habitat types specified by the California Wildlife Habitat Relationships from Zeiner et al. (1988 – 1990) and vegetation types mapped in the CalVeg database (1994 version). Table 2.16 presents the crosswalk for Bear Creek watershed animal species of concern by CalVeg habitat types.

Sport Fish and Game Species A major management focus for public lands in Bear Creek watershed is development and conservation of game species. The CDFG stocks both native and non-native fish and game species. Information on hunting is part of the Section 3.8 (Recreation and Tourism). The most detailed analysis of the distribution of game species in the area comes from Mann (1974) and the BLM (1982).

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Sport Fish Information on past fish stocking is not available. Trout of uncertain origin have been present in Mill Creek and Trout Creek, and local anglers fished these creeks in past decades (J. Garr, pers. comm.). The present status of trout stocking and persistence of populations is unclear.

Game Birds The following game bird species are present in the watershed: wild turkey (Meleagris gallopavo), mountain quail (Oreotyx pictus), California quail (Callipepla californica), band-tailed pigeon (Patagioenas fasciata), and mourning dove (Zenaida macroura). Quail and mourning dove forage most commonly in chaparral, tamarisk thickets, and open oak woodland edge. Band-tailed pigeons frequent oak woodland and riparian woodland corridors. Wild turkeys are not native to California, but the CDFG has introduced them to diversify game bird species. Turkeys now thrive in oak woodlands where acorns are a favored food source.

Black-tailed Deer (Odocoileus hemionus) Bear Creek watershed occupies part of the regional range of the East Park – Capay deer herd. The herd ranges from western Solano County north to the Glenn-Tehama county line west of Interstate 5, covering approximately 1,286 square miles. Historically, the total deer herd population reached more than 11,000 in 1960 and then again in 1968. A strong downturn in population numbers led to fewer than 2,300 animals by 1973 (Thornton et al. 1983). Livestock grazing is the dominant land use in the herd’s range. Competition with livestock, loss of oak woodlands for habitat cover and acorns (a major fall food source), fire suppression and resulting loss of regenerating shrub and grass species, and urbanization are thought to have been causes of the population decline. Major animal predators are coyotes (Canis latrans), feral dogs (C. lupus familiaris), and mountain lions (Puma concolor).

Management for deer habitat emphasizes prescribed burning particularly in chamise- dominated chaparral and protecting oak woodlands (Thornton et al. 1983). Since the downturn in the early 1970s, more intensive herd management has allowed the East Park – Capay deer herd to stabilize. At the south end of the BLM Bear Creek Ranch that burned a decade ago, deer are thriving in the patches of mixed chaparral and oak woodland (J.Alderson, pers. comm.).

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Tule Elk (Cervus elaphus nannodes) Overhunting long ago extirpated tule elk from Bear Creek watershed. Today’s elk herds originated from animals imported from Monterey County in 1922 by the CDFG (McCullough et al. 1996). With assistance from the Rocky Mountain Elk Foundation and the CDFG, tule elk are once again thriving in the area. Two elk herds use the watershed: the Cache Creek herd in the southern third of the watershed and the East Park herd in the northeast corner of the watershed at Leesville. The hunting zone for the Cache Creek herd coincides with the boundary of the Cache Creek Natural Area (Figure 2.17).

The BLM Cache Creek elk herd management plan emphasizes prescribed burning to improve browse for elk in chamise chaparral and mixed chaparral habitats, some of which may be overdue for burning according to the expected fire-return cycle (BLM 1985). Currently, off-highway vehicles and most cattle grazing are kept away from rutting and calving areas for the Cache Creek elk herd. Restoration of native willows and cottonwoods to the riparian zone of lower Bear Creek is also a cornerstone of enhancing elk habitat in the watershed. To date, however, efforts to reestablish them have not been possible because of heavy beaver and elk browsing on young plants. Since acquisition of the Bear Creek Ranch, the BLM focuses on developing alternate water sources for tule elk from ponds designed originally for domestic livestock.

The Bureau of Reclamation is the lead agency in managing the East Park elk herd on public lands. The objective of the elk habitat at East Park Reservoir is to create attractive wetland and marsh areas so that tule elk remain off of private ranch lands (TetraTech undated). A full management plan for the East Park herd is not yet in place.

The Cache Creek herd, managed by the CDFG, ranges across approximately 100,000 acres of oak woodland, grassland, and chaparral habitat in Colusa, Lake, and Yolo counties. Historical data indicate that the Cache Creek herd has remained stable in the long term as the January 1985 helicopter survey similarly showed a total of 167 animals (BLM 1985), in line with results from 2005 and 2008.

In most years, the CDFG surveys the two elk herds by helicopter both inside and outside the watershed. Table 2.17 displays results of recent helicopter surveys for the two herds that use the watershed.

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Table 2.15 – Special-status vertebrate species Protection Management in the Species Habitat Concerns Population Status Status Watershed Amphibians Resides in sites with Foothill yellow- Predation by bullfrogs, loss BLM SS permanent water, without Development projects in the Populations appear robust legged frog of permanent habitat from CA SSC highly unusual chemical ten-year floodplain of the at present in contrast to Rana boylii stream alterations and FS SS properties. Feeds on algae, watershed require a permit. many other sites. Ranidae long-term drought invertebrates, and detritus Reptiles Western pond turtle Resides near permanent Required permit for BLM SS Trapping for the pet trade, Western pond turtles Actineyms water. Nests are in nearby development projects in the CA SSC loss of high-quality habitat appear to have stable marmorata uplands and require soil ten-year floodplain of the FS SS and water quality numbers. Emydidae moisture and depth > 4” watershed Birds Nests and roosts in dense BLM SS Now more common than White-tailed kite tree stands. Forages in CA Shooting, loss of woodland Conservation easements on a century ago, kites are Elanus leucurus open grasslands, meadows, Fully cover for nest sites private lands most frequent in Bear Accipitridae and wetlands. Feeds on Protected Valley rodents. The non-breeding foraging Bald eagle BLM SS Roosts in large trees and High mercury content of Conservation of all large population uses the lower Haliaeetus CA snags, often next to creeks. prey fish, loss of woodland oaks on public lands; Bear Creek corridor most leucocephalus Endangered Forages along creeks for cover for roosting sites, conservation easements on frequently. The Accipitridae FS SS fish. shooting private lands population is stable. Ranges widely to hunt in Shooting, loss of Golden eagle CA foothill and grassland undisturbed habitat for Conservation easements on Nesting status is not Aquila chrysaetos Fully terrain. Nests on cliffs and nesting, potential mortality private lands known at present. Accipitridae Protected in oak stands. from wind energy projects

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Protection Management in the Species Habitat Concerns Population Status Status Watershed

Nests on cliffs and in large Trapping for captive use in Prairie falcon CDFG This species nests in the trees in open areas. Ranges falconry; shooting; Conservation easements on Falco mexicanus locally watershed. Its numbers widely to hunt in foothill potential mortality from private lands Accipitridae significant are thought to be stable. and grassland terrain. wind energy projects

Winters on grasslands in Between 50 and 150 birds Long-billed curlew CDFG Bear Valley and the BLM Shooting, globally small overwinter in the Numenius Conservation easements on locally Bear Creek Ranch. Feeds on population, loss of breeding watershed. Population americanus private lands significant insects, spiders, and other habitat numbers are thought to Scolopacidae invertebrates. be stable.

Conservation of all large Nests in abandoned nests oaks on public lands; Long-eared owl of other large birds near or conservation easements on Information on population Long-term population Asio otus CA SSC in riparian zones. Feeds on private lands; required trend in the watershed is decline Strigidae rodents, occasionally other permit for development not available. birds. projects in the ten-year floodplain of the watershed

Nests in burrows or Shooting, strikes from This species nests in the Burrowing owl BLM SS culverts in drier grasslands motor vehicles, large Conservation easements on watershed. Population Athene cunicularia CA SSC in Bear Valley. Hunts day or reduction in breeding private lands numbers over the years Strigidae night for rodents. population across California are not documented.

Nests in dense shrubs or This species nests in the Loggerhead shrike trees in grassland and Large reduction in breeding Conservation easements on watershed. Population Lanius ludovicianus CA SSC woodland habitats. Feeds population in northern private lands numbers over the years Lanidae on insects, occasionally California are not documented. other small vertebrates

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Protection Management in the Species Habitat Concerns Population Status Status Watershed Mammals Recorded in Sulphur Creek Forages in dry, open Human disturbances at Pallid bat subwatershed (Gennis and BLM SS habitats; roosts in cliffs, roosts cause bats to Conservation easements on Antrozous pallidus Associates 1978). Current CA SSC caves, and mines most abandon sites; loss of private land Vespertillionidae population status is commonly native grassland habitat unknown. Roosts where young are Townsend’s nig- Human disturbances at nursed are using caves and Appropriate bat gating for eared bat roosts cause bats to First studied by Leitner BLM SS abandoned mines with the species undertaken by Corynorhinus abandon sites; scarcity of (pers. comm.) and Pierson CA SSC warm temperatures; winter the private landowner; townsendii suitable habitat; steep (1988). Population FS SS hibernation takes place in conservation easements on Vespertillionidae decline in populations appears to be stable. cold-temperature caves private land throughout California and mines. Burrows in easily dug out American badger Trapping and poisoning; soils. Forages widely in No information is Taxidea taxus requirement for large Conservation easements on CA SSC woodland, chaparral, and available on population Mustelidae range; low population private lands grasslands for prey, mostly trends. density consisting of rodents. Conservation of all large Inhabits riparian areas oaks on public lands; Ringtail CA where trees and shrubs are conservation easements on No information is Bassariscus astutus Fully plentiful. Rears young and Trapping for the pet trade private lands; required available on population Procyonidae Protected hides in crevices, tree permit for development trends. cavities, and burrows projects in the ten-year floodplain of the watershed Abbreviations: BLM SS = Bureau of Land Management Sensitive Species in California, CA SSC = California Department of Fish and Game Species of Special Concern, FS SS = US Forest Service Sensitive Species in California Sources: California Department of Fish and Game (CDFG) and Paul Hofmann, CDFG associate wildlife biologist (pers. comm.); Bureau of Land Management (BLM) California State Office and Gregg Mangan, BLM Cache Creek Natural Area Manager (pers. comm.); and US Forest Service, Region 5

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Table 2.16: Crosswalk between California Wildlife Habitat Relationships and CalVeg habitat types for animal species of concern in Bear Creek Watershed

Species

Grass / Forb Grass Cattail

- Annual Blue Oak Interior Live Oak Foothill Pine Knobcone Pine McNab Cypress Sargent Cypress Tule Wet Meadows andPastures Crop Agriculture Agricultural Ponds, Water Features Ceanothus Chaparral Chamise Chaparral MontaneLower Mixed Chaparra Manzanita Chaparral Scrub Oak Perennial Herbs WaterGeneral Riparian Mixed Shrub California floater x

Serpentine cypress x x wood-boring beetle Valley elderberry x longhorn beetle Wilbur Springs minute x moss beetle Wilbur Springs shore x fly Wilbur Springs x shorebug Foothill yellow-legged x x x x x frog Western pond turtle x x x x x

Golden eagle x x x x

White-tailed kite x x x x x x x x

Bald eagle x x x x x

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Species

Grass / Forb Grass Cattail

Long-billed curlew x x x x x x

Long-eared owl x x x x x x x x

Burrowing owl x x x x

Loggerhead shrike x x x x

Pallid bat x x x x x x x x x x x x

Townsend's big-eared x x x x x x x x x x x x Bat Ringtail x x x x x x x x x x x x x

American badger x x x x x x x x

Source: USDA Forest Service, Pacific Southwest Region (2004)

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Pronghorn (Antilocarpa americana) Pronghorn, also known as “antelope”, was once a common species in Bear Valley, as the Antelope Valley northeast of Bear Valley attests. Efforts regionally sponsored by the CDFG are underway to reintroduce pronghorn into the Inner North Coast Range landscape. Surviving animals from a herd released east of Cortina Ridge (Paul Hofmann, pers. comm.) eventually left the area, migrating north to Willows in Glenn County. Otherwise, pronghorn have been absent from the watershed in recent times.

Other Game Animals Mann (1974) lists the following game animals as popular for hunting in the region: brush rabbit (Sylvilagus bachmanii), black-tailed jackrabbit (Lepus californicus), western gray squirrel (Sciurus griseus), coyote, gray fox (Urocyon cineroargenteus), black bear (Ursus americanus), raccoon (Procyon lotor), bobcat (Lynx rufus), and wild pig (Sus scrofa).

Table 2.17 – Helicopter surveys of elk herds in Bear Creek watershed Cache Creek Elk Herd Survey Results Bulls Total Total Year Cows Calves Yearling Raghorn Mature Unk Bulls Elk 2005 9 0 37 1 47 85 24 156 2006* 5 5 18 0 28 46 17 91 2008 9 9 17 0 35 110 42 187

East Park Elk Herd Survey Results Bulls Total Total Year Cows Calves Yearling Raghorn Mature Unk Bulls Elk 2005 no data 2006 9 10 16 0 35 19 15 69 2008 6 8 21 0 35 39 21 95 The 2006 Cache Creek Herd data included only the elk located in Bear Creek watershed and the North Fork Cache Creek watershed. Source: Joe Hobbs (pers. comm.), associate wildlife biologist, CDFG

Although listed as a California species of special concern by the CDFG, the Department also allows trapping of American badger. Beaver (Castor canadensis) may also be trapped. Trappers used to “cache” or hide their beaver pelts along creeks in the region, hence the name for Cache Creek (G. Mangan, pers. comm.).

Stakeholder Issues in regard to Large Game Animals Stakeholders value large game animals in Bear Creek watershed. The major concerns for stakeholder issues are: 91

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Fire Lack of fire in oak woodlands and chaparral reduces the available forage and browse for large game animals such as elk and deer. By reinstating fire regimes more similar to a historical pattern through prescribed burning, elk and deer may have more and higher-quality food.

Oak woodlands Oak woodland habitat is scarcer than in the past. Blue oaks are important to wildlife for their acorn crops and provide thermal cover for young animals.

Impacts from browsing and gnawing animals + Low recruitment of native woody riparian plants A major concern is damage to regenerating riparian vegetation when elk browse and rub their antlers on stems of small trees (C. Thomsen, pers. obs.).

Several landowners in the watershed have also mentioned that poaching is becoming more frequent.

Proposed Management for Big Game Management Management planning for deer and elk (Thornton et al. 1983, BLM 1985, respectively) emphasizes habitat management that protects all native riparian vegetation, implements prescribed burning, and develops alternative watering sources for game away from Bear Creek and its major tributaries. One especially important proposed feature of management is to protect and enhance the diversity of native vegetation within a 300-foot radius of all meadows, glades, springs, and seeps in the watershed. These management practices also begin to address stakeholder issues of creek channel alterations and headcuts, soil erosion, sediment delivery to waterways, and impaired water quality.

Information Gaps Gaps in information and integration needed to protect rare species and conserve game species include:

 distribution maps of the invertebrate species limited to springs and creek edges in Sulphur Creek subwatershed, riparian edges along Bear Creek, and cypress woodlands on Walker Ridge and Mill Creek subwatershed  best management practices to protect unique spring and creek environments in Sulphur Creek subwatershed, with special focus on the three endemic insect species  an updated BLM tule elk management plan  vulnerability of wildlife species to habitat changes, critical habitats likely to be lost, likely new species to arrive, habitats likely to develop, and a strategy to provide corridors and minimize habitat barriers to help species adapt to climate change.

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2.11 Ecologically Important Areas and Special Conservation Areas

Ecologically Unique and Sensitive Areas Locations of biologically unique and ecologically sensitive areas are mapped as part of subwatershed analyses in Chapter 7. Table 2.18 lists these areas and provides background information on them.

Table 2.18 – Ecologically unique and sensitive areas in Bear Creek watershed Resource Site(s) Subwatershed(s) Background buttes Bear Valley Mill Creek, Upper These striking north-south buttes at the north end of Bear Creek Buttes, Bear Creek watershed provide high-quality habitat for raptor birds. Little is known Gravelly Buttes about other species of plants and wildlife that inhabit the buttes. The buttes consist of non-ultramafic rocks and soil. rare ultramafic Bear Creek Craig Canyon, Outcrops and small barrens dot the landscape of ultramafic chaparral (serpentine) plant Ranch, Love Deadshot Canyon, mixed with unusual plant alliances of knobcone pine (Pinus attenuata), alliances, including Lady Ridge, Eula Canyon, Gaither cypress stands, and Eriogonum wrightii. Trout Creek carries enough barrens Walker Ridge Canyon, Mill Creek, water to support an ultramafic riparian forest deserving closer study. Robber’s Flat, Four hundred species of vascular plants occur on Walker Ridge alone, Stinchfield Canyon, of which 60 are found only on ultramafic soils (Hunter 2005). Thirteen Sulphur Creek, BLM Sensitive Plant Species are found on public lands on the Colusa Thompson Canyon, County side of Walker Ridge. McCarten and Rogers (1991) have Warnick Canyon recorded Snow Mountain buckwheat and drymaria-like western flax near Love Lady Ridge. springs and seeps Bear Valley, Sulphur Creek, Upper Most thermal springs occur in Sulphur Creek subwatershed, while Bear with unusual water Wilbur Hot Bear Creek Valley has only cold springs. Both have high concentrations of mercury chemistry Springs and other heavy metals in their waters. The unusual water chemistry of springs and seeps has created unique habitats for three endemic insects in the vicinity of Wilbur Hot Springs. Microbes are another element of unusual diversity, particularly those living in anaerobic environments. They facilitate combining heavy metals with methyl- organic compounds that can subsequently enter the biological food chain (Bentley and Chasteen 2002; Holloway et al. 2009b). stock ponds Bear Creek Brophy Canyon, Stock ponds created for watering livestock increase biological diversity Ranch, Bear Hamilton, Hamilton and supplement the naturally occurring wetlands. Aquatic flora not Valley, Long Canyon, Jackson typical of Bear Creek watershed appears at these sites. Ponds that hold Valley, West of Canyon, Leesville, a year-round supply of water become an important water source and Cortina Ridge South Jackson aquatic habitat for wildlife, including the western pond turtle. Canyon, Upper Bear Creek valley native Bear Valley Upper Bear Creek Designated by the CDFG as important statewide for landscape grasslands conservation of rare native plant alliances, the Bear Valley grasslands occur on ultramafic Venado clay soils that remain moist in the winter and hold water longer than adjacent oak woodlands. valley oak stands Bear Valley Lower Bear Creek, A 35-acre valley oak woodland stands at the south end of Bear Valley Upper Bear Creek on the border between Upper and Lower Bear Creek subwatersheds. Valley oaks occur typically in bottomland riparian forests, and were once common on the best agricultural land in central California. The woodland is dense enough to support nesting pileated woodpeckers (Dryocopus pileatus) at an unusually low elevation (Scheidt 2000). variant native Bear Valley Upper Bear Creek Variant grasslands also occur in Bear Valley. Alkali ultramafic meadows grasslands on Venado soils have saltgrass and meadow barley (Hordeum brachyantherum) as dominants. A small blue wildrye (Elymus glaucus) grassland has remained on seasonally wet soils in east-central Bear Valley (Thomsen 2001). wetlands on Destinella Flat, Gaither Canyon, The species found in these rare wetlands are poorly known. Each ultramafic soils Eaton Springs, Sulphur Creek, Lynch wetland is in proximity of a highway, road, or BLM-designated OHV outside Bear Valley Walker Ridge Canyon trail. None of the areas is afforded protection at present.

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Resource Site(s) Subwatershed(s) Background wildflower fields Bear Valley Upper Bear Creek Designated by CDFG as important statewide for landscape and prairies conservation of areas with spectacular wildflower bloom, the famous Bear Valley wildflower areas occur on ultramafic Bear Valley, Leesville, and Venado soils. Coarser, fast-draining Bear Valley soils support annuals, while Venado soils produce longer flower displays with a larger share of perennial plants (Thomson 2001). Gelbard and Harrison (2003) found that the diversity of wildflowers benefitted from livestock grazing that reduces the vigor and seeding of non-native annual grasses.

Special Conservation Areas in Bear Creek Watershed Special conservation areas occupy relatively little territory on public lands in Bear Creek watershed compared to adjacent watersheds such as the North Fork Cache Creek and the Middle Cache Creek. Figure 2.17 displays those conservation areas having defined boundaries. The following sections describe the areas and their conservation management.

Bear Creek Biological Study Area and Bear Creek Botanical Management Area The 31-acre Bear Creek Biological Study Area takes in the California Department of Transportation’s right-of-way on both sides of Highway 20 for one mile west from the intersection with Highway 16. Twelve plant alliances are present in the study area: non- native annual and perennial grasslands, mixed species ultramafic grassland, purple needlegrass grassland, saltgrass grassland, baltic rush wetland, cattail wetland, common spikerush wetland, sedge wetlands, bulrush wetlands, blue oak woodland, and foothill pine woodland. The University of California at Davis promotes and maintains the growth and spread of the high native plant diversity present at the site (California Department of Transportation 2006).

The most sensitive native grassland alliances in the Study Area cover 5.6 acres of remnant prairie, known as the Bear Creek Botanical Management Area. More than 100 species of native prairie plants, including eleven species of native grasses, make the Botanical Management Area a remarkable example of Inner Coast Range vegetation in just a small area. Past management has focused on control of invasive plants – primarily yellow starthistle and barb goatgrass – through prescribed burning, mowing, and hand removal. Boundary data for the areas are not available in GIS.

The reconstruction of the Bear Creek Bridge has required the Department of Transportation to disturb large areas of the Biological Study Area. The biological and visual quality of the Study Area will be restored to the condition before project construction. After mitigation to restore cut slopes, the native vegetation originally present will once again cover the ground disturbed during the project.

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Cache Creek Area of Critical Environment Concern (ACEC) Cache Creek Area of Critical Environmental Concerns extends over 11,228 acres along the main stem of Cache Creek. A small part of the ACEC overlaps into Bear Creek watershed at the confluence of Bear Creek with Cache Creek at the south end of the watershed. The ACEC protects riparian habitats, the resident bald eagle population, and the Cache Creek tule elk herd. Protection of cultural resources and opportunities for primitive recreation are also important management goals. Considerable eradication of small-flowered tamarisk is ongoing in the ACEC.

Cache Creek Natural Area More than 70,000 acres of BLM public lands as well as 4,700 acres of CDFG and County of Yolo public lands comprise the Cache Creek Natural Area. Management of the Area is undertaken cooperatively by the three partners. Blue oak woodlands, non-ultramafic chaparral, and ultramafic barrens characterize the dominant vegetation in the part of the Natural Area in Bear Creek watershed. Past grazing management created extensive non- native annual grasslands. The BLM acquired most of the Bear Creek watershed portion of the Natural Area in 2003 with funding from the State of California Wildlife Conservation Board and the Rocky Mountain Elk Foundation.

The Cache Creek Coordinated Resource Management Plan (Bureau of Land Management 2004) directs management for the Natural Area. Management permits only primitive, non- motorized recreation and encourages mountain biking, equestrian riding, and hiking. Elk herd and habitat management, control of invasive non-native plants, management for aquatic species diversity at stock ponds, riparian zone restoration, ecosystem services, and research for ecosystem restoration are major emphases for the Bear Creek watershed portion of the Natural Area.

Indian Valley Area of Critical Environmental Concern (ACEC) and Research Natural Area (formerly Indian Valley Brodiaea ACEC) Originally established to protect populations of the Indian Valley brodiaea at the north end of Indian Valley Reservoir in the North Fork Cache Creek watershed to the west of Bear Creek watershed, the ACEC was renamed and expanded under the BLM Ukiah Field Office Resource Management Plan (2006) to include to nearly 700 acres in Sulphur Creek subwatershed which have a number of BLM Sensitive Plant Species. The California Native Plant Society (Hunter 2005) has proposed expansion of the ACEC to cover all BLM public lands on Walker Ridge.

Special Conservation Areas Immediately Adjacent to Bear Creek Watershed Particularly along the main stem of Cache Creek south of Bear Creek watershed and in Lake County west of the watershed, multiple layers of special conservation are in place to maintain

BEAR CREEK WATERSHED ASSESSMENT the natural features of the Inner Coast Range landscape.

Cache Creek State Wild and Scenic River In 2005, Governor Schwarzenegger signed Assembly Bill 1328 to designate 31 miles of Cache Creek as a California Wild and Scenic River. This designation covers Cache Creek from one-quarter mile below Cache Creek Dam (Lake County) to Camp Haswell (Yolo County) as well as the North Fork Cache Creek from the Highway 20 bridge in Lake County to the confluence with the main stem. Various segments are designated as wild or scenic. The Wild and Scenic River stretch passes the mouth of Bear Creek. Much of the length of the Wild and Scenic River travels through the Cache Creek Corridor ACEC. The California Resources Agency administers the Cache Creek Wild and Scenic River.

Cache Creek Wilderness and the Northern California Chaparral ACEC President George W. Bush signed into law in 2006 the Northern California Coastal Wild Heritage Wilderness Act designating Cache Creek Wilderness. The wilderness consists of 27,245 acres in Lake County and directly adjoins the southwest side of Bear Creek watershed. Most of the Wilderness is also part of the Cache Creek Natural Area. Wildlife flourishes here, including breeding and wintering bald eagles. No mechanical recreation is permitted in the Wilderness. The Northern California Chaparral ACEC is wholly included in the Cache Creek Wilderness. It was established as a research natural area to protect botanical values found in undisturbed chaparral habitat.

Frenzel Creek Research Natural Area This Research Natural Area lies just to the north of Love Lady Ridge on the Mendocino National Forest. It has been established for preserving and studying its MacNab cypress and Sargent cypress stands (Cheung 2004). In addition there are many ultramafic-endemic herbaceous plants (McCarten and Rogers 1991). Most of the plant alliances resemble those on Walker Ridge: ultramafic and non-ultramafic chaparral, serpentine barrens, and ultramafic riparian.

Information Gaps Parts of Bear Creek watershed merit further study as to their special natural resources. Obtaining information in the following areas would assist in conservation planning within the watershed:

multi-season wildlife monitoring, including for invertebrate species, and botanical inventories, especially during the entire length of spring-early summer flowering period, in areas with unusual soils inventories of the biological diversity of springs and seeps with unusual water chemistry, focusing on documenting their microbial diversity

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inventories of plants and animals in Mill Creek subwatershed, including Gravelly Buttes and the large serpentine barrens in the center of the subwatershed wetland delineations to create a benchmark upon which to base wetland restoration or enhancement projects in Bear Valley and elsewhere information on environmental change at ecological reference sites having rare plant alliances (native grasslands, ultramafic chaparral, and riparian habitats).

2.12 Air Resources Bear Creek watershed lies entirely within the Sacramento Valley Air Basin, an eleven-county region that extends 217 miles in a north-south direction and has a maximum width of 90 miles. However, the location of the watershed at the western boundary of the Air Basin and its topographic isolation within the Air Basin requires taking into account conditions in the adjacent Clear Lake Air Basin.

Meteorological Basis for Poor Air Quality Persistent temperature inversions, where the air temperature increases with height, often limit the dispersion of air pollutants vertically in the Basin. Air quality problems arise when high- pressure air masses keep low-pressure air, which bring rain and winds, away from the Sacramento Valley for much of the year. Warm air above cold air in the inversion prevents air movement as the heavier, cooler air does not rise above the warm air. Stagnation in air movement generates and traps ozone and raises concentrations of particulate matter less than

10 microns in diameter (PM10). Summer inversions usually occur at about 2,000 feet. When storms are absent, winter inversions also keep cold air near the ground below warmer air at night; these inversions typically occur between 500 and 1,000 feet above the Valley. Being at considerable distance west of Sacramento Valley inversions, Bear Valley watershed generates a low amount of PM10 and health impacts from inversions are not reported. Smoke from wildfires and outdoor burning may create health problems, however.

Criteria Pollutants The Clean Air Act requires that air quality agencies monitor criteria pollutants according to established protocols, or analogous protocols with the same or better detection capability. Monitoring determines whether a particular pollutant has concentrations equaling or exceeding criteria set by state and federal agencies that regulate air quality. The primary air quality problems with criteria pollutants in the Sacramento Valley Air Basin come from ozone and particulate matter.

Ozone Ozone becomes a problem in the Sacramento Valley Air Basin especially from April through October when it can aggravate asthma other breathing ailments, and heart disease in sensitive

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people. Chemical reactions in the air between nitrogen oxide gases (known as NOX) and reactive organic gases (ROGs) produce ozone at about 2,000 ft elevation. Sunlight is the catalyst for these reactions. In turn, NOX and ROGs stem principally from human activities: combustion of fuels in the case of NOX – mostly by motor vehicles; and for ROGs, the volatile organic compounds emitted from vehicles, refuse burning, and evaporation of volatile organic compounds such as industrial solvents. The latter two sources of emissions are likely not significant in Bear Creek watershed normally. Spills of industrial solvents resulting from truck accidents and wildfire smoke would be exceptional events. Low traffic volume also makes for low ozone generation in the watershed. Refer to Section 3.11 for vehicle traffic counts.

Suspended Particulates (PM2.5 and PM10) Suspended particulate matter consists of tiny solid or liquid particles in the air. Substances in particulate matter relevant to this assessment include dust, soot from wildland fires, and vaporized mercury. Of greatest concern for human health are the particulates that people inhale into their lungs, generally particulates less than 10 microns in diameter (PM10). Finer particles less than 2.5 microns in diameter (PM2.5) are a subset of PM10.

Dust in Bear Creek watershed is most likely to come from fugitive dust from agricultural and ranch lands and from vehicle travel on unpaved roads and off-road trails. More development and more dirt roads would further increase dust generation unless road maintenance addressed dust reduction. . Nitrogen Oxide (NOx) Gases

NOX gases are precursors to ozone formation. The major component of NOX, nitrogen dioxide (NO2), is a reddish-brown gas often visible to the eye during air inversions in the Sacramento Valley Air Basin. NOX results primarily from the combustion of fossil fuels on hot days with high atmospheric pressure. NOX gases affect people sensitive to chronic bronchitis, and irritations to lungs and eyes.

Hydrogen Sulfide Hydrogen sulfide stems from geothermal energy extraction, hot springs, and confined animal facilities. It impacts people with an unpleasant odor of rotting eggs and can cause dizziness, nausea, and headaches.

Attainment of Air Quality Standards The US EPA and the California Air Resources Board (CARB) evaluate how well counties are meeting state or federal air quality standards (“attainment”). Neighboring Lake County has the highest air quality in California and attains both US EPA and CARB standards for all criteria pollutants. Predominant winds from the west and southwest, the proximity to Lake

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County, the remoteness of the watershed from atmospheric conditions that create nonattainment for some criteria pollutants in the Sacramento Valley, the watershed’s low population, and rural economy, all point to air quality conditions that resemble those found in Lake County.

Appendix F contains information about standards and regulated actions in effect to protect air quality in Bear Creek watershed.

Table 2.19 -- Air Quality Standard Compliance, 2006 - 2008 Lake County Colusa County Criteria Pollutant Regulatory Standard CARB US EPA CARB US EPA Ozone – 8 hour Attainment Attainment Transitional Attainment Ozone – 1 hour Attainment not applicable Moderate not applicable

PM 2.5 Attainment Attainment Unclassified Attainment

PM 10 Attainment Attainment Nonattainment Attainment Carbon Monoxide Attainment Attainment Unclassified Attainment Nitrogen Dioxide Attainment Attainment Attainment Attainment Sulfur Dioxide Attainment Attainment Attainment Attainment Sulfates Attainment not applicable Attainment not applicable Lead Attainment Attainment Attainment Attainment Hydrogen Sulfide Attainment not applicable Unclassified not applicable Sources: State of California Air Resources Board, Air Quality Data Branch (2006) US Environmental Protection Agency, Green Book Data (2008)

Other Gases Commonly of Concern No state or national air quality standards for these gases discussed below are presently in effect.

Carbon Dioxide Carbon dioxide is the major “greenhouse” gas. Bear Creek watershed does not produce high amounts of carbon dioxide from either vehicular or industrial sources. One outcome of maintaining low human density and having public lands as open space is that Bear Creek stores carbon (as a “carbon sequestration” site) taken from the atmosphere. Land management can promote maximizing biomass accumulation in vegetation aboveground and in plant root systems and soil belowground over a long time. Through photosynthesis, plants transform atmospheric carbon dioxide into carbohydrates that create plant biomass.

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Methane Methane is an odorless gas that absorbs and reflects terrestrial radiation back to earth. It figures as a key “greenhouse gas”, contributing to global warming and climate change. Methane is emitted into the environment naturally from hot springs and from livestock and livestock manure. One hot spring in Sulphur Creek subwatershed, Jones Fountain of Life, emits a large proportion of methane in its total gas output (44 to 52%) but the total volume over time is not now known (Goff et al. 2001). Large confined livestock holding facilities, major sources of methane pollution in California, are not present in the watershed.

Ammonia

Although not a criteria pollutant, ammonia is a precursor to PM2.5. The California Office of Environmental Health Hazard Assessment has established acute and chronic reference exposure levels (REL’s) for ammonia. Ammonia is generated from decomposition of manure. It is a strong alkali that reacts in the atmosphere with sulfuric acid (a criteria pollutant in California) and nitric acid to produce fine particulates of ammonium sulfate or ammonium nitrate (part of PM2.5).

In Bear Creek watershed, sources of ammonia in unknown amounts come from anaerobic decomposition of manure and in small quantities from hot springs.

Air Quality Monitoring The Air Resources Board does not monitor air quality in the watershed. The closest air quality monitoring station is 23 miles away at the Colusa County Airport south of the City of

Colusa. The site monitors ozone and PM2.5. Three monitoring sites to the west and slightly farther away in Lake County monitor for hydrogen sulfide, and another site in Lakeport on the west side of Clear Lake monitors for ozone. Hydrogen sulfide is a concern for the Air Resources Board in Lake County because of emissions from geothermal sites.

No data are available from emissions from vehicle combustion or agricultural and ranch enterprises in the watershed.

The only data pertaining to air quality in Bear Creek watershed are instantaneous readings taken of the percent of emissions of gases from hot springs in Sulphur Creek subwatershed. Gases such as ammonia, hydrogen sulfide, methane, and carbon dioxide from hot springs are the same gases emitted from confined animal facilities in the Sacramento Valley.

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Table 2.20 – Gas emissions as a percent of total gas molecules emitted from springs in Sulphur Creek subwatershed, excluding water vapor Carbon Hydrogen Springs Hydrogen Methane Nitrogen Ammonia Argon Oxygen Sampling Years Dioxide Sulfide (# Samples) mol-% Wilbur Hot Spring 83.8 – 91.1 3.14 – 3.16 <0.003 2.87 – 4.88 0.84 – 8.45 <0.002 0.02 – 0.13 <0.023 1995, 1996 (3) Elbow Hot Spring 95.5 – 95.8 1.83 – 1.93 0.27 – 0.47 1.61 – 1.89 0.17 – 0.59 <0.001 < 0.011 <0.005 1993, 1995, 1996 (3) Elgin Spring, Main 97.0 – 97.1 2.09 – 2.12 <0.008 0.64 – 0.75 0.07 – 0.23 <0.003 <0.005 <0.002 1993, 1996, 1997 (3) Jones Fountain of Life 40.7 – 53.3 0.37 – 1.08 0.04 – 0.18 44.0 – 51.9 2.03 – 6.76 <0.149 0.01 – 0.04 0.03 – 0.14 1991, 1992, 1996 (5) Source: Goff et al. (2001)

Carbon dioxide orginates from inorganic carbonate minerals in thermally heated rocks. Cold springs found in Bear Valley discharge almost entirely carbon dioxide (Barnes 1973b). Nitrogen originates from magma emissions trapped belowground (Goff et al. 1993).

In the presence of the subterranean carbon dioxide, ultramafic peridotite rocks deep in the spring metamorphose into serpentinite, the major ultramafic mineral in Bear Creek watershed. As a result, hydrogen gas is produced. Sulfates and carbonates dissolved in the spring water combine with the hydrogen to form methane and hydrogen sulfide, both criteria pollutants. It is likely that total gas emissions from spring sources are small and contribute insignificantly to total hydrogen sulfide emissions calculated for Colusa County by the Air Resources Board.

Other Unmonitored Airborne Particulate Matter of Potential Concern Refer to Section 5.10 Air Quality Contaminants for the account of air-borne asbestos and mercury.

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CHAPTER 3

SOCIETY, ECONOMY, AND LAND USES IN BEAR CREEK WATERSHED

Chapter 3 describes the residents and communities in Bear Creek watershed (Sections 3.1 and 3.2) and characterizes past, current, and potential land uses in the watershed beginning with Section 3.3. An analysis of land uses in Bear Creek watershed helps to understand people’s roles in creating, continuing, or resolving environmental issues that affect the quality and access for key resources in Bear Creek watershed. Knowledge of past land uses is critical as well to locating sources of environmental damage and to prioritizing and designing restoration or remediation projects that reduce adverse impacts from past uses.

With the arrival of settlers with cultural roots mostly in Europe, land uses changed markedly from Native American hunting, gathering, and tending of traditional resources for food and material culture. Actions over the last 160 years to facilitate travel, water delivery, agriculture, and mining have affected hydrologic function, soil stability, and biological integrity in ways that are costly to repair today. Examples of present-day outcomes from past human land uses include: altered stream flows; loss of a flood plain capacity; degradation of water quality; introduction of non-native invasive species; and changes to soil physical properties and increased soil erosion.

As stakeholders look to the future and back to the past at the same time, the need for stewardship of Bear Creek watershed becomes apparent. One responsibility of watershed stewardship is to limit transferring costs of current land uses to future generations as the result of poor decision making today. People can repair past damages now, and people can also avoid creating future legacies of damage from current and planned land uses. By applying existing knowledge and best land management practices, stakeholders leave a legacy of land use that does not discount the value of resources for future generations.

3.1 Characteristics of Watershed Residents

Population Current Population Information on the population of Bear Creek watershed comes from Census 2000 of the US Census Bureau. Data collected by the Bureau represent the most recent snapshot of residents of Bear Creek watershed.

Census data from 2000 show five census tracts that cover all or part of the watershed. Together, the tracts tallied 57 residents, of which perhaps only 20 people are full-time

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BEAR CREEK WATERSHED ASSESSMENT residents in Bear Creek watershed. Eighty-two percent of the Census 2000 tract populations identified themselves as white, nine percent as black, and nine percent as mixed race. Slightly more than five percent of residents also listed themselves as Hispanic. Adults comprised 91 percent of the population, with roughly equal numbers of men and women. Nearly 30 percent of residents are older than 65 years.

The watershed population differs from the population overall of Colusa County, where 71 percent of the population consists of adults, 12 percent of people are older than 65 years, and 52 percent of residents are Hispanic (US Census Data 2009). Whereas Colusa County’s population rose from 12,430 in 1970 to 18,804 in 2000 (California Department of Finance 2007a,b), the population of Bear Creek watershed may been stable for that same period. .

Of the 32 households in the tracts, half were single-person households, and only sixteen percent of households consisted of more than two people. Most households (64 percent) resided in owner-occupied houses.

Past Residents Native Americans resided in Bear Valley until at least 1872 (Rogers 1891). One Wintun (Patwin) village, Suku, is known from the south end of Bear Valley (Johnson 1978). The Yawisel group of Hill Patwin people inhabited another village called Yawi along Sulphur Creek near Wilbur Springs (Mabel McKay undated interview as related in Gennis and Associates, Engineers 1978). The first Americans of European ancestry came to settle in Bear Valley in 1854 (Rogers, op. cit.). During the 19th century Chinese-American farm workers tended orchards and vineyards in Bear Valley. The population of Bear Creek watershed was greatest during the peak of mercury mining and refining during the 1890s, reaching more than 300 residents.

Communities No incorporated municipalities lie within the watershed. Gateway communities to Bear Creek watershed are: Clearlake Oaks (Lake County), Rumsey (Yolo County), Williams, and Lodoga (the latter two both in Colusa County).

Income The US Census Bureau does not publish income data about residents at the geographic level of Bear Creek watershed census blocks because statistical information about the small number of residents in each block might compromise privacy of residents. Most people working in the watershed pursue livelihoods in resort tourism, farming and ranching, public land management, and fire suppression.

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Languages English is the major language of residents, although Spanish is the first language for some workers.

3.2 Land Ownership The watershed has multiple land ownerships, including private citizens, limited liability corporations, trusts, and government agencies. Table 3.1 gives the number of acres for each ownership type, and Figure 3 depicts the geographic distribution of these acres.

Table 3.1 - Area and percentage of land by land management category Land Management Acres Percent of Total Area Private Ownership 34,594 52.6 State of California 665 1.0 Lands Commission 658 1.0 Department of Forestry and Fire Protection 7 < 0.1 Federal 30,505 46.4 Bureau of Land Management – Ukiah Field Office 26,345 40.1 US Forest Service – Mendocino National Forest 4,104 6.2 Total 65,708 100.0

Federal Lands The US Federal Government manages public Federal lands in Bear Creek watershed under the auspices of two agencies: the US Department of Agriculture Forest Service, through the Mendocino National Forest, and the US Department of Interior Bureau of Land Management, through its Ukiah Field Office.

State of California Lands The California Department of Conservation and the California Department of Forestry and Fire Protection (CALFIRE) manage State of California lands in Bear Creek watershed. Land holdings by state agencies are considerably smaller in extent than federal land holdings. CALTRANS manages highways and the easements along Highways 16 and 20.

Tribal Lands No tribal lands lie within Bear Creek watershed. The following tribes have lands in adjacent watersheds: the Cortina Rancheria of Wintun Indians in the Cortina Creek watershed to the east and the Yocha Dehe Wintun Nation (formerly Rumsey Band of Wintun Indians) in the Middle Cache Creek watershed to the south.

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Local Government Lands Apart from county roadways and easements along these roadways, the County of Colusa does not manage any county public lands in the watershed. No municipal land holdings are present as well.

Private Lands The largest category of land is under private ownership with corporate entities having the largest holdings. Seven corporations owning property in Bear Creek watershed operate as trusts or limited liability corporations. The remaining private land is divided among 32 individuals or families, who mostly reside outside the watershed.

3.3 Ecosystem Services Ecosystem services are specific benefits to people from natural processes in the environment. The services enhance human life and maintain the quantity and quality of goods produced by land uses in a watershed (Brown et al. 2007). Ranches, for example, provide multiple ecosystem services to residents and other people regionally. Services include: wildlife habitat, open space, recreation lands, forage plants for honey bees and native pollinators, fire control, weed management, and water (County of Colusa Board of Supervisors 2008). Table 3.2 lists key ecosystem services in Bear Creek watershed that benefit the local and regional economy.

These services usually come at no direct cost to people but require stewardship to ensure their continued functioning in support of people’s land uses. People often leave out consideration of how land uses affect ecosystem services when they make economic decisions. By not assigning an economic value to ecosystem services, landowners and resource managers may unintentionally ignore and impair the watershed functions that furnish the ecosystem services that in turn make land uses possible. The result is a loss of land productivity and lower economic returns for people.

The cost to restore a degraded ecosystem service and to regain its productivity can be high. A major example in Bear Creek watershed is the poor water quality that results from the impaired service of water purification, resulting in turn from the poor mining practices in the past. These past practices cause the current release of unnaturally large quantities of toxic mercury into streams. Mine site cleanups of mercury and its associated mine waste will require a significant societal investment. Recovering natural water quality in Bear Creek watershed due to mine pollution could cost as much as $33,393,300 (TetraTech 2003, expressed in 2007 dollars).

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Table 3.2: Ecosystem services in Bear Creek watershed Dependent Examples of Relevance to the Local and Regional Ecosystem Service Land Uses Economy Provide the substrate, chemistry, and nutrients for Soil Fertility and all land uses growing plants, holding water, storing carbon, and Stability maintaining land for agriculture water delivery, Maintain water quality of stream flows from Water Purification development, contamination by toxic elements and compounds, agriculture, recreation bacteria, and parasites Slow water flow during times of high rainfall for more even supply of water to uplands, wetlands, riparian Flood Control and water delivery corridors, and downstream users; regulate the exit of Mitigation water from watershed soils and streams; minimize soil erosion and stream sedimentation Provide high air quality in the watershed and adjacent recreation and Lake County, which has the best air quality in California, Air Purification tourism, human health and lower healthcare costs, especially for children and the elderly Support the complex and diverse interactions among species that support agriculture, recreation (e.g., wildlife and wildflower viewing), landscape stability, and Biological Diversity all land uses resilience to catastrophic changes (e.g., natural restoration of land productivity after avalanches, droughts, fire) Pollinate legume forage crops in Bear Valley; pollinate Native Pollinators agriculture native plants that create wildflower displays recreation and Make available diverse recreation opportunities, solitude, Open Space tourism, subsistence and wildlife habitat, resources at an increasing premium hunting in the three-county region around the watershed Maximize the amount of carbon in soils and vegetation; forest and woodland reduce carbon in the atmosphere linked to climate Carbon Storage management, grazing change and potential economic disruptions; and make soil and agriculture, organic matter available for forage and crop production Provide shade from the sun, local cooling, and wind Partial Stabilization of forest and woodland breaks with the structure of vegetation for the benefit Temperature and management, grazing animals and plants; reduce the force of rainfall impact Wind and agriculture and erosion on soils Habitat for Game Furnish private landowners and state agencies with recreation and Animals and income from hunting; give people alternative food subsistence gathering Economic Plants sources and plant materials for cultural uses

The scope of projects needed to restore this and other impaired ecosystem services in Bear Creek watershed is part of the accompanying document Stewardship for Bear Creek Watershed: Priorities, 2010 – 2014.

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3.4 Water Delivery People have reworked the landscape and hydrology of Bear Creek watershed to enhance water delivery for uses benefitting landowners in the watershed. Wells, dams, stock ponds, bridges, culverts, and channel diversions modify the natural water flow in Bear Creek watershed. Figure 3.2 shows the locations of water-related infrastructure designed to alter water flow and delivery

Wells Development of groundwater for human uses in the watershed is not extensive. The Colusa County Groundwater Management Plan (2008) maps seven wells in Bear Creek watershed, all found on private lands: three irrigation wells along the lower main stem of Mill Creek and four domestic water wells in elsewhere in Bear Valley and Sulphur Creek subwatershed. The wells are less than 250 feet deep with one exception. No information is available on the impact of human use of groundwater on its recharge, depletion, and trends in groundwater quality (Department of Water Resources 2003). The California Department of Water Resources and the US Geological Survey have no well monitoring stations in the watershed.

Dams and Stock Ponds Large dams are absent from Bear Creek and its tributaries. Two small dams on private property, with a total capacity of 351 acre feet, fall under the jurisdiction of the California Department of Water Resources, Division of Safety of Dams. These dams provide water for crop irrigation and livestock operations and represent only a small portion of the total annual flow in the watershed.

Reservoir National ID Reservoir Area Name Year Built Type Capacity Number (acres) (acre feet) CA 00554 York Hill 1952 17 Earthen 245 CA 00555 Rancho Rubini 1955 10 Earthen 106 Source: California Department of Water Resources, Division of Safety of Dams, Dams within the Jurisdiction of the State of California

Small stock ponds are present throughout Bear Creek watershed: 32 permanent ponds covering 33 acres and twenty intermittent ponds covering six acres (USGS National Hydrography Database 2008), all of which are man-made. These ponds alter water flows at least seasonally.

The 1998 update to the California Water Plan (California Department of Water Resources 1998) postpones indefinitely consideration for a large-scale water project and dam in Bear Creek watershed because of environmental concerns and conflicts with federal land management policies.

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Stream Alterations Most stream alterations were constructed on private lands and relate to supplying water to stock ponds and forage crop fields. A more complete analysis to identify all locations of alterations is needed. More information on steam alterations is found in Section 6.3 Creek Channel Alterations.

Culverts Culverts placed to drain water are a major investment in infrastructure in Bear Creek watershed. More than 335 have been inventoried in the watershed. Along Highway 20 west of the Bear Creek Bridge, for example, the California Department of Transportation has installed an elaborate system of long, wide-diameter culverts to feed water running off of ultramafic rock slopes from the south side of Highway 20 more effectively into Bear Creek without creating slope erosion on creek banks that would impact stream water quality and undermine the highway itself. Figure 3.2 shows the distribution of culverts in the watershed.

Contribution and Value of Bear Creek Water to Agricultural Water from the Cache Creek Basin Landowners in the watershed use its water to a limited extent in Bear Valley for irrigating forage crops and for livestock water. The greater economic contribution of water from Bear Creek watershed occurs when the water reaches the main stem of Cache Creek. The Yolo County Flood Control and Water Conservation District uses the Capay Diversion Dam in the Capay Valley south of the watershed to supply water to agricultural enterprises in Yolo County. Bear Creek contributes to the Yolo County water delivery system at the beginning of the irrigation season, beginning variously in March through May depending on winter rainfall, and ending in October or November. Water diversions come during the time of year when Bear Creek flows are at their lowest. Water during the high-flow winter months is not used for agriculture. Table 3.3 shows the variable nature of the contribution of Bear Creek and the market value of the water delivered from Bear Creek watershed.

The estimated annual contributions in volume and value of Bear Creek water to the irrigation water supply for agriculture in Yolo County between 1999 and 2007 ranged widely. By volume, Bear Creek watershed contributes on average usually less than three percent of the total water delivered to Yolo County agricultural water customers. Most water used for irrigation comes instead from Clear Lake and from Indian Valley Reservoir in the North Fork Cache Creek watershed.

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Table 3.3 – Bear Creek water volume used for irrigation and its value, 1999 to 2007 Total Annual Irrigation Water Water Price Value Year from Bear Creek in constant in constant 2007 (acre feet) 2007 dollars dollars 1999 3709.2 $ 17.41 $ 64,565 2000 4614.1 $ 16.45 $ 75,921 2001 7540.2 $ 16.28 $ 122,725 2002 1324.9 $ 15.81 $ 20,070 2003 5226.0 $ 16.56 $ 86,557 2004 3959.8 $ 15.89 $ 62,927 2005 5142.5 $ 15.36 $ 78,975 2006 5176.9 $ 15.20 $ 78,668 2007 1238.8 $ 15.50 $ 19,201 Sources: USGS water gage records for remaining years from station 11451715 (Bear Creek at the mouth of Holsten Chimney Canyon north of Rumsey, CA); nominal water prices per acre foot from the Yolo County Flood Control and Water Conservation District (M. Stevenson, pers. comm.) Note: Water prices in constant 2007 dollars are adjusted for inflation based on the average annual Total Producer Price Index time series from the Bureau of Labor Statistics stored at www.economagic.com.

3.5 Forest and Woodland Management Timber production is not an economic activity in the watershed. The common conifer species in Bear Creek watershed, foothill pine, knobcone pine, and McNab cypress, do not have the high-value wood properties required by the construction industry.

Oak woodlands provide the greater economic value as fuel- and firewood. In earlier times, miners used oak timbers for fueling retort furnaces to extract mercury from cinnabar ore. Photographs show extensive treeless slopes in Sulphur Creek subwatershed at the beginning of the 20th century (Goff et al. 2001). The dense even-aged oaks stands found today near mercury mine sites indicate that blue oak woodlands and other tree species regenerated naturally after deforestation for industrial and domestic fuelwood ceased in the Wilbur Springs area.

Oak harvesting continues at a low level on private lands, but data are not available. No commercial timber or fuelwood harvests have been reported from Colusa County since 2003 in records kept by the California State Board of Equalization under the California Timber Yield Tax Law (Revenue and Taxation Code, Division 2, Part 18.5).

Several opportunities are available for oak conservation. With the passage of the California Land Conservation Act of 1965 (the “Williamson Act”), the County of Colusa may contract

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The Oak Woodland Conservation Act of 2001 now makes funds available through the Wildlife Conservation Board to private landowners to protect oak woodlands once a landowner’s county has prepared a management plan for oak woodlands. In 2008, the Colusa County Resource Conservation District prepared and the Colusa County Board of Supervisors approved the Colusa County Voluntary Oak Woodlands Management Plan.

No permitted oak harvesting occurs on the Mendocino National Forest or BLM public lands in the watershed. In 2006, the BLM Ukiah Field Office completed its Record of Decision for the Field Office Resource Management Plan. A core conservation management action in the Plan is a ban on cutting oak trees on the BLM public lands except in cases of safety hazards.

At Wilbur Springs and on the BLM Bear Creek Ranch, efforts are underway to promote reestablishment of oak woodlands.

3.6 Agriculture: Livestock Grazing and Crop Production The California Department of Conservation, through its Farmland Mapping and Monitoring Program, evaluates the land use status and productivity of agricultural lands in Colusa County every two years to detect changes in rural land use (Figure 3.3). Although many other agricultural areas in California are undergoing rapid population increases and urbanization, agricultural land in Bear Creek watershed has remained virtually unchanged since 1986 when mapping began. The constancy of rural land uses has conserved the character of the watershed and its agricultural landscapes.

The bulk of agricultural land falls under the category of “farmland of local importance” and includes lands covering most of Bear Valley, the Leesville area, Sulphur Creek subwatershed, and the BLM Bear Creek Ranch. This farmland is principally used for livestock grazing. Crop yields for these lands, even with irrigation, are not likely to be as high as on prime farmland or farmland of statewide importance. Where existing vegetation is suitable only for livestock grazing, lands are classified as “grazing land”, even though

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Crop Production The agricultural crop economy of Bear Creek watershed differs significantly from the portion of Colusa County in the Sacramento River Valley where rice and other irrigated crops are dominant. A water district does not cover the watershed, and irrigation water in commercial quantities is not available for summer crops.

Because water for irrigation is scarce, dryland farming has traditionally dominated agriculture in the watershed. Since the 19th century, most crops have been grains or forage crops such as alfalfa and hay; wheat, barley, and oats were dominant crops exported from the valley in the 1880s. In 1941, the Agricultural Extension Service of Colusa County estimated that 4,608 acres were suitable for grain production in Bear Valley. At mid-century, wheat and barley were principal grain crops, mostly grown on three-year rotations with hay production and fallowing. Before 1900, a few vineyards and orchards were present (Green 1950).

An estimated 212 acres of the watershed (0.3 percent of total area) were devoted to crops in 2006. Two ranches currently irrigate summer crops. In past decades, grain crop production has declined. Recent increases in grain prices, however, have revived wheat growing at the north end of Bear Valley.

Figure 3.4 shows the distribution of potential forage production during a year with average rainfall and temperature range. It serves as a surrogate for site fertility and suitability for crop production. The BLM Bear Creek Ranch, central Bear Valley, and the upper portion of Leesville subwatershed are the most productive agricultural areas

Livestock Grazing Grazing on Private Lands Livestock grazing is the main agricultural source of income in Bear Creek. Estimated livestock carrying capacity is ten acres per animal per year (Agricultural Extension Service of Colusa County 1941). Past or current data on the average number of livestock in the watershed are not available. Grazing in the watershed is mostly winter grazing.

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Grazing on Public Lands Public lands of the Mendocino National Forest in Bear Creek watershed were at one time part of the Goat Rock grazing allotment, now closed to grazing. In 1941, the Agricultural Extension Service rated the quality of rangeland on what are now the BLM lands north Highway 20 as poor, due principally to the low forage productivity of vegetation growing on ultramafic soils. Permitted grazing continues on the BLM Bear Valley Ranch south of Highway 20 as a tool to suppress non-native grasses, principally medusahead.

Marijuana Cultivation Marijuana (Cannabis sativa), a recent introduction to the crop economy of Bear Creek watershed, is grown both legally on private lands for authorized medical use and illegally under trespass on public lands. Illegal cultivation of marijuana has been occurring since at least 2007 in remote public lands of Bear Creek watershed. In 2007, BLM law enforcement staff halted a single operation; that number rose to three operations intercepted in 2008.

Beekeeping Beekeepers benefit greatly from the native and introduced plants in Bear Valley. Yellow starthistle is the major nectar resource for European honeybees (Apis mellifera). Bear Valley provides an important niche for beekeepers in the early summer, after they complete pollinating nearby orchard crop trees and before they move on to higher and more northern areas for the late summer. The economic value of honey produced from Bear Valley is not known.

Traditional Native American Subsistence The Southern Wintun people who have traditionally fished, hunted, and gathered plants for food, medicines, and fiber plants in the watershed benefitted from the abundant elk, deer, and pronghorn that were plentiful the watershed (Green 1950). Oak woodlands and riparian areas are particularly important subsistence gathering sites. In past decades, private landowners in Bear Creek watershed held most of the land that produced traditional Native America foods, medicines, and material culture. Now that more lands are open to public access, opportunities for collecting and managing for native crops in oak woodlands and riparian areas for traditional products are again possible.

In 2007, the US Forest Service, Region 5, and the BLM California State Office established a common Traditional Gathering Policy for their public lands in California. This policy supports native cultural practitioners gathering traditional plants for non-commercial uses. In general, free use of plants, without permits, is granted for traditional cultural gathering. Federal land managers work locally with Tribes and traditional practitioners to identify, restore, and enhance important plant resources.

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3.7 Mining In the past, mining was central to the economy in the watershed. Settlers found coal in Bear Valley in 1855, and in 1863 a coal bed about two miles south of Wilbur Springs was briefly commercially mined (Rogers 1891). Copper, the first metal mined in the watershed, and gold were discovered in 1863. Commercial gold mining started in 1865 at Manzanita Mine, and gold has been historically the second-most important mining product in the watershed after mercury. The Sulphur Creek Mining District has been one of the three main gold-producing districts in the North Coast Range (Sherlock 2005). However, the potential yield for gold from sources in Sulphur Creek subwatershed was too low for economic profitability in the 1980s, the last time that gold was mined in the Coast Range.

Other minerals have been commercially developed for brief periods. Starting in 1866, sulfur was shipped commercially in large quantities. One mine, probably developed for extracting chromite, is found in Mill Creek subwatershed and marks the southern end of the chromium belt that runs from Colusa County to Tehama County. Prospecting has occurred in a few other sites in the watershed, notably on the ridgeline between Gaither Canyon and Trout Creek subwatersheds but has not resulted in commercial mineral production.

Table 3.4 outlines information on the commercial mines in Bear Creek watershed. Figure 3.5 shows the locations of major mines, quarries, and prospects plus areas designated by the California Department of Conservation as Principal Areas of Mine Pollution (PAMPs).

Mercury Mining Initial commercial production of mercury in California coincided with the gold mining era from the 1850s to 1890s. Mercury was widely used to separate metallic gold from its rock ore at mining sites in the Sierra Nevada foothills and a smaller number of mines in the inner North Coast Range. Mercury mines in the Coast Range produced the mercury needed for gold extraction throughout California.

Mercury was discovered in the watershed in 1865. Mines in Bear Creek watershed and vicinity were the third largest source of mercury in California. Mercury mining was intermittent because of irregular demand and fluctuating prices that determined the feasibility of mining operations. During periods of mercury mining, ranchers and farmers in Bear Creek watershed commonly shifted to work in the mines because of the higher wages. No mercury mines are operating in the watershed now. The most recent commercial mining, limited to the Rathburn-Petray mine complex, ceased in the early 1970s (Tetra Tech 2003).

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Table3.4 - Mines in Bear Creek watershed and their legacies Mid-Range Amount of Volume of Sources of Treatment Estimate for Principal Current Mine Years of Mercury Treated Mine Mine Name Subwatershed Mercury Acres of Cleanup and Products Ownership Features Operation Contamination Waste Volume Contamination Mine Waste Remediation (pounds per year) (cubic yards) Cost chromium Mendocino Black Bird Mill Creek 1 tunnel unknown none known none n.a. n.a. $200,000 copper NF mine cuts, 1891 to waste rock, Central Sulphur Creek mercury private 4 adits early 1900s, tailings, 0.01 to 0.07 2.0 166 $ 372,300 1926, 1942 processing facility waste rock gold see next to Cherry Hill Sulphur Creek mercury private 2 adits Manazanita Sulphur Creek <2.5 1.0 1,420 $ 428,600 silver Mine and around old stamp mill 2 shafts, tailings, Clyde Sulphur Creek gold BLM 1886 - 1890 0.09 to 0.15 n.a. n.a. n.a. 3 adits bulldozer cuts 3 adits 1875, 1892- and waste rock, Elgin Sulphur Creek mercury private 1893, 1905, 8.60 to 20.50 1.9 4,227 $ 772,900 open tailings, retort 1916 cuts waste left at 1873, 1875, Empire Sulphur Creek mercury private 3+ adits site and in the 0.09 to 0.13 0.5 5,748 $ 45,300 1890, 1926 retort mine cuts, 1863-1891, waste rock, many 1902-1909, tailings in gold, Manzanita Sulphur Creek private adits and 1911, 1917, Sulphur Creek 0.66 to 14.33 4.1 300 $ 877,100 mercury shafts 1929-1934, floodplain and 1942 sediment in Sulphur Creek

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Mid-Range Amount of Volume of Sources of Treatment Estimate for Principal Current Mine Years of Mercury Treated Mine Mine Name Subwatershed Mercury Acres of Cleanup and Products Ownership Features Operation Contamination Waste Volume Contamination Mine Waste Remediation (pounds per year) (cubic yards) Cost Rathburn- waste rock, Petray mine contaminated Petray Upper Bear BLM and mercury open pit complex sediment in a 0.09 to 8.37 6.9 9,837 $ 1,147,400 North Creek private was the Bear Creek largest tributary Petray Upper Bear BLM and producer waste rock, mercury open pit 0.88 to 1.76 4.1 400 $ 194,300 South Creek private before 1900, overburden Upper Bear closed in waste rock, none outside Rathburn mercury BLM open pit 1.5 6,546 $ 547,500 Creek 1916, retort site the site relocated in waste rock, 1956 and contaminated Rathburn- Upper Bear mercury BLM open pit produced sediment in a 1.54 to 43.43 9.1 191,792 $ 4,399,700 Petray Creek until the Bear Creek early 1970s tributary waste rock and see sediment West End Sulphur Creek gold private 3 adits Manazanita <0.01 to 2.43 0.8 3,722 $ 480,600 contaminating Mine Sulphur Creek

mine cuts, 1874-1877, waste rock, 1932, 1936- Wide Awake Sulphur Creek mercury private shafts tailings, 0.04 to 0.97 3.2 10,014 $ 1,270,300 1937, 1942- processing 1943 facilities

Source: Churchill and Clinkenbeard (2003), TetraTech (2003), costs expressed in 2007 US dollars

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Mining Legacies and Costs for Remediation and Restoration In Sulphur Creek subwatershed and in the Rathburn-Petray mine complex, the legacy of mining operations is especially visible with pits, adits, trails, and remains of processing facilities. Past mining activities continue to discharge unacceptably large amounts of mercury to creeks in the watershed. Mercury discharged from the mines and mine waste passes into creek channels and floodplains downstream from the mines. Over time, these mercury-rich wastes move downstream where they enter Cache Creek and ultimately the Sacramento River and the Bay/Delta region.

3.8 Recreation and Tourism Data on recreation and tourism specific to Bear Creek watershed are scant. Studies of current and potential recreation uses, user demographic profiles, and economics of travel and tourism in the watershed are not available. Characterization of recreation activities is mostly qualitative.

Major Recreation and Tourism Uses Both private landowners and public land management agencies provide opportunities and access to a full spectrum of recreation activities and pastimes in the watershed. Based on the federal Recreation Management Information System (RMIS) data from the BLM Ukiah Field Office for the Cache Creek Natural Area, which overlaps with Bear Creek watershed, an estimated 32,622 people visited state and federal public lands in the watershed during fiscal year 2008. Data for visitors to private lands are not available, but annually thousands of visitors come to Wilbur Springs, lodge in an historic hotel, and hike on private lands in Sulphur Creek subwatershed.

Recreation and tourism activities include automobile touring, birding, other wildlife and wildflower viewing, camping, cycling, equestrian sports, hiking, horse and buggy travel, hunting, long-distance running, mineral spa visits, off-highway motor vehicle riding, and rafting. The Capay Valley Hiking Club, a recreation group in the greater Cache Creek Basin, has annotated areas of scenic and recreational value in Bear Creek watershed on Google Earth (A. Fulks, pers. comm.).

In 2011, the BLM Ukiah Field Office will be considering expansion of the network of routes for off-highway riding on Walker Ridge public lands.

Major Tourism Resources Bear Valley is home to one of the most spectacular wildflower displays in California (Ornduff et al. 2003), and visitors come from as far as Europe and Japan to view the Valley each spring. Many rare plants are also viewable along Walker Ridge Road and Brim Road.

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Hospitality and lodging have a century-old tradition in the watershed. J.H. Cain constructed the first hotel at Leesville in upper Bear Valley in 1874 to accommodate travelers bound to and from the popular mineral spas of in western Colusa, Lake, and Mendocino counties (Rogers 1891). Today it is a private home. Many of the hot springs in Sulphur Creek subwatershed, have been famous as spa sites since the late-nineteenth century. Two elegant hotels offered guests a tranquil setting and good food at Wilbur Springs and Blanck Spring.

Anderson (1898) described the springs thus:

“These mineral springs are located thirty miles from Colusa in Colusa County. They are pleasantly situated and have acquired considerable reputation from their therapeutic properties. At the springs are good accommodations in the hotel and cottages and excellent camping facilities. The resorts are reached by railroad to Williams and thence by stage…”

The springs remain a tourist destination and a holiday getaway for health-conscious visitors.

The 12,000-acre BLM Bear Creek Ranch, part of the Cache Creek Natural Area (Bureau of Land Management 2004) comprises most of the southern third of the watershed. Highway 16 and Highway 20 form the east and north boundaries of the Ranch respectively. Recent public acquisition of this privately held ranch has made more recreation open space accessible. The Ranch is a destination for diverse non-motorized recreation and camping in a scenic rural landscape. Management for the Ranch focuses on maintaining natural biological diversity and ecosystems and high-quality recreation settings in intact landscapes. The Cowboy Camp recreation area is the hub for people to stop at a scenic viewpoint, learn from interpretive panels about the setting, and start on hikes or equestrian riding in the Ranch. Other entry points to the Ranch are spaced along Highway 16. Developed camping sites are available only at Cowboy Camp. Hunting is allowed but target shooting is not permitted.

Walker Ridge is a topographically diverse landscape that attracts many types of visitors annually. The area is ideal for camping, mountain biking, hiking, and equestrian use. It is a favored destination for botanists who visit the Ridge in search of its many rare and endemic plants, and for hikers looking for solitude and scenic vistas. Geology, botany, and natural history classes from UC-Davis frequently have field trips to Walker Ridge. Walker Ridge Road is a BLM-designated OHV trail.

Hunting Opportunities Opportunities to hunt many game species in Bear Creek watershed draw people, both for sport and subsistence hunting. Archers report deer taken occasionally but most hunters use firearms.

Adjacent to the watershed at two locations in Lake County, the CDFG maintains two areas with a hunting focus: the Harley Gulch Unit of the Cache Creek Wildlife Area and the Indian

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Valley Wildlife Area. A parking area for access to the Harley Gulch Unit by way of the Judge Davis trailhead lies 0.35 miles west from the watershed boundary along Highway 20. From there, hunters have non-motorized access east to the BLM Bear Creek Ranch. Indian Valley Wildlife Area to the west of Walker Ridge covers the shoreline of the Indian Valley Reservoir. Both Walker Ridge Road and Brim Road in Bear Creek watershed provide important travel corridors to access the Wildlife Area.

The BLM Bear Creek Ranch and the corridor along lower Walker Ridge are the major deer hunting areas in the watershed, based on CDFG deer tag data about where hunters report their deer kills (“spotkills”). Deer hunting on the Ranch has increased since the BLM assumed management in 2004. Private landowners in Bear Valley also allow fee hunters to hunt on their lands. Most deer reported as kills come from public lands, however. The CDGF maintains records of deer kills, and Table 3.5 shows the number of tags for deer kills reported since 1999 in the watershed. The total number of deer taken in the watershed has remained nearly constant. A shift has taken place where the public lands now provide the larger share of deer kills. Before the BLM acquired Bear Creek Ranch, most recorded deer kills were on private lands in Bear Valley.

Table 3.5 – Records of deer kills from Bear Creek watershed, 1999 - 2007 Public Lands Private BLM Year Walker Total Lands Bear Creek Ridge Ranch* 1999 13 6 1 20 2000 14 4 1 19 2001 11 5 1 17 2002 n.a. n.a. n.a. n.a. 2003 1 11 2 14 2004 5 13 3 21 2005 2 12 1 15 2006 6 9 1 16 2007 2 12 5 19 Source: Paul Hofmann, CDFG (pers. comm.) *The Bear Creek Ranch was in private ownership through 2003 but is included in the total for public lands for all years.

Information about the number of elk, wild pig, and game birds taken, and the economic value of the recreational and subsistence food hunting in the watershed is not available.

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Potential Recreation Benefits to Regional Communities Members of the public have recently proposed creation of the “Berryessa Snow Mountain National Conservation Area” comprising 500,000 acres of federal public lands managed by the BLM, the Bureau of Reclamation, and the US Forest Service. The Conservation Area may encompass the federal public lands in Bear Creek watershed. Background research in support of establishing the Conservation Area found that designating the Area would increase recreation and tourism to the area and would support economic diversification for gateway cites to the Conservation Area such as Winters and the Clear Lake communities (Vatland 2008). No projections are available yet to show how Conservation Area designation might affect Bear Creek watershed residents or the City of Williams, which is another gateway city to the watershed or the proposed National Conservation Area.

3.9 Energy Production and Conveyance Few watersheds the size of Bear Creek watershed have the suite of potential energy resources found there: geothermal, natural gas, petroleum, biofuel, wind, and solar energy. Not all energy sources are likely to be developed commercially. The watershed lies at the interface between the Arbuckle oil and gas field in the Central Valley and the Clear Lake - Geysers geothermal zone in the North Coast Range. Current energy production is on a small scale on private lands for self-sufficiency. However, geologists and engineers have studied options for extraction or development of energy resources extensively in the watershed (Gennis and Associates 1978, Goff et al. 1993). Development of new technologies, changes in energy prices and availability, and national interest in energy sustainability and self-sufficiency are prompting reconsideration of possibilities for energy production in the watershed.

New projects to develop energy resources, export energy generated in the watershed, or convey energy across the watershed in utility lines would create significant ground disturbance during construction and maintenance. These disturbances could alter hydrologic conditions, destabilize steep terrain, impair visual quality for people, and degrade wildlife habitat.

Hydrocarbons: Oil and Gas Naturally occurring hydrocarbon seeps appear locally in Bear Creek watershed. Geologists have traditionally relied on locations of natural seeps to discover oil or gas fields in California. Uplifted sedimentary rock sources from the Great Valley Sequence contain hydrocarbon compounds that originated from remains of ancient oceanic organisms that accumulated on the floor of the Central Valley when the Valley formed a primeval ocean bottom. Sedimentary rocks containing at least one percent total organic carbon are potential sources of natural gas, tar, and petroleum. Where concentrations of hydrocarbons are particularly high, subsurface pressure may push volumes of fossil hydrocarbons through

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BEAR CREEK WATERSHED ASSESSMENT breaks in the sedimentary rock to the surface. Naturally occurring hydrocarbon seeps containing tar or oil may contaminate water sources, but seeps found in Bear Creek watershed are not known to impact water quality.

Figure 3.7 displays the specific locations of known petroleum and gas seeps as well as areas where seeps are known to occur but are poorly documented. Information about most seeps comes from less precise 19th-century sources. Hodgson (1987) found that many seeps reported a hundred years ago were no longer visible. Most petroleum seeps are in southeast Bear Valley and the Blue Ridge area north of the junction of State Routes 16 and 20.

Presence of seeps has led geologists to drill exploratory wells in the watershed in search of commercial quantities of hydrocarbons. Petroleum was first noted near Wilbur Springs in 1863 and later elsewhere in Bear Valley but only in small amounts (Rogers 1891). Two early entrepreneurs constructed a water-wheel to tap the energy of Sulphur Creek to operate drills to explore for oil.

Figure 3.7 also displays locations of well sites and the extent of closed oil and gas leases managed by the Bureau of Land Management and the California Department of Conservation, Division of Oil, Gas, and Geothermal Resources, in Bear Creek watershed. The earliest corporate exploratory drilling for commercial oil and gas reserves occurred in 1909, and the last well was closed in 1984. No commercial production of oil or gas has come from the watershed. Some state and federal government leases involve subsurface rights to oil and gas beneath private property.

The US Geological Survey has designated additional areas of likely valuable oil and gas resources for commercial extraction at the east edge and southern third of the watershed. Local officials in Colusa County have expressed concern over the number of natural gas wells that are being drilled in Colusa County (Northern California Water Association 2006) because of potential cumulative impacts to groundwater. There are no plans to drill for oil or gas resources in Bear Creek watershed.

Geothermal Energy Hot springs indicate potential sources for extracting geothermal energy in Sulphur Creek subwatershed. Water sufficiently hot for energy use is available from these springs at relatively shallow depths (<1,000 m) (Division of Mines and Geology 1980). Blanck Springs, Elgin Spring, Jones Fountain of Life, and Wilbur Hot Springs are the major named springs. Other unnamed springs with geothermal potential are also present.

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The BLM manages federal rights to subsurface geothermal energy resources in Bear Creek watershed. Of particular significance are the federally designated Known Geothermal Resource Areas (KGRAs). KGRAs include one or more geothermal fields, most of the geothermal wells, and additional promising sites in a region where geothermal resources have a high potential for economic use. The major geothermal springs in Bear Creek watershed comprise the northeast edge of the Geysers KGRA, the most productive of all geothermal regions in the United States. Because the springs lie distant from the core geologic faults in the KGRA, the volume of accessible water and amount of energy capacity is less than at the KGRA core (S. Hagerty, BLM geothermal resource specialist, pers. comm.). No energy for economic use has thus far come from geothermal sources in the portion of the KGRA in Bear Creek watershed. Litigation halted planning for a geothermal project in the 1970s in Sulphur Creek subwatershed.

The other KGRA designated within Bear Creek watershed was the Love Lady Ridge KGRA, established in 1970. The Area was thought to constitute a secondary concentration of geothermal resources. Love Lady Ridge KGRA spans both BLM and US Forest Service lands in the northwest corner of the watershed. BLM offered 5,517 acres in the Love Lady Ridge KGRA for lease sales in 1982. At the time, BLM received no bids for leases, and BLM subsequently delisted the area as a KGRA. Remoteness and difficulty of access to the Love Lady Ridge KGRA are obstacles to economic feasibility of geothermal resources there.

The Sacramento Geothermal Resources District (District 6) of the State of California Department of Conservation, Division of Oil, Gas, and Geothermal Resources, represents State of California jurisdiction over State of California and private lands in Colusa County. No State of California geothermal fields are found in Bear Creek watershed.

Figure 3.8 provides a map of the Geysers KGRA and currently closed geothermal lease areas.

The Energy Policy Act of 2005 changed the way that the federal government awards leases for geothermal fields. Formerly, competitive bidding for leases only covered lands within the federally designated KGRAs. Other lands required only a flat processing fee plus a per-acre fee. Now competitive bidding is required for all leases for access to federal subsurface geothermal resources. This provision is designed to generate larger federal revenues from individual geothermal energy leases

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Recent technical innovations may permit efficient capture of geothermal energy from smaller sites with cooler water temperatures with the help of binary (closed-cycle) technology. Binary technology systems for capturing geothermal energy pump water under pressure into a heat exchanger. Isopentene or isobutene gases take up the energy transferred from water vapor and run turbines to generate energy. This system prevents emissions of water vapor and associated geothermal gases from being released into the atmosphere. Instead geothermal water remains on site. Efficiency is increased because geothermal sources down to 95°C are feasible in contrast to 160°C for traditional “flash” technology with vapor emissions.

Prospectors have drilled three geothermal wells in the watershed, all of them in Sulphur Creek subwatershed, one each in 1965, 1968, and 1982. Increasing energy prices may interest corporate energy providers or Bear Creek watershed households to apply for permits from the BLM to tap into the geothermal sources in the watershed. One commercial leaseholder has rights to parts of the Geysers KGRA in Bear Creek watershed.

The BLM Ukiah Field Office Resource Management Plan Appendix H (2006) anticipates up to 30 new geothermal wells across 6,000 acres of geothermal leases in the Geysers-Clear Lake KGRA and the nearby Calistoga KGRA. However, the Plan is not explicit about how many, if any, of the new geothermal wells will be drilled in the small portion of the Geysers-Clear Lake KGRA inside the Bear Creek watershed.

Wind Energy Technology for capturing wind energy is evolving quickly in California. One private landowner already uses wind energy from a wind mill for home use. About 7,865 acres of BLM public lands are potentially available for wind energy development on Walker Ridge and seven smaller ridges branching off of the north-south axis of Walker Ridge at the west flank of Bear Creek watershed. The leaseholder, AltaGas Income Trust, has an authorized right of way and is investigating the economic feasibility of installing wind turbines there.

The BLM Ukiah Field Office Resource Management Plan Appendices J and K (2006) discuss the practicality of deploying a commercial array of wind turbines on Walker Ridge. Any development of wind energy facilities would follow BLM best management practices to protect wildlife, avoid soil erosion, and maintain recreation opportunity. Terrain with slopes greater than fifteen percent would be avoided for turbine placement. New service roads and upgraded off-highway vehicle trails would be necessary for energy development.

Initial scenario models conducted by the BLM and the US Department of Energy cited in the Resource Management Plan indicate that the Walker Ridge area has medium to low capacity for generating wind energy. In scenarios developed by the Department of Energy, National Renewable Energy Laboratory, up to 73 1.5-megawatt turbines could occupy feasible sites in

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BEAR CREEK WATERSHED ASSESSMENT the Walker Ridge lease area. Turbines would be distributed partially in Bear Creek watershed and the adjacent North Fork Cache Creek watershed.

Solar Power One watershed landowner has installed solar panels to supply virtually all domestic and business energy needs. Commercial arrays of solar panels designed for export to urban areas are not planned for the watershed.

Hydropower No licensed hydropower operations are present in Bear Creek watershed.

Energy Transmission Pacific Gas and Electric Company maintains an electrical transmission line that bisects the watershed from northeast to southwest in the steep terrain south of Bear Valley and across Sulphur Creek subwatershed.

3.10 Developed Areas Developed areas comprise a very small fraction of the total land area of Bear Creek watershed. One indicator of development is human-made impervious surfaces such as roads, concrete pads, and houses. Most impervious surfaces are from asphalted state highways and portions of some county roads. Developers have put forward concepts for residential development when ranches have been put up for sale, but new home building did not occur during the last decade. Suphur Creek and Leesville subwatersheds remain the centers of human-occupied portions in the watershed as they were 100 years ago but with much smaller numbers of residents. Two privately owned ranches currently have conservation easements on their properties. These easements limit options for commercial and residential development to maintain the traditional rural character and economy of ranch lands in the watershed.

3.11 Transportation Locations of public roads, the designated off-highway vehicle trail network, and non- motorized recreation trails appear in Figure 3.10. These elements comprise the transportation system of Bear Creek watershed.

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Major Traffic Corridors State Highway 20 connects Bear Creek watershed to Interstate Highway 5 at Williams to the east with the Clear Lake region in Lake County and then on to State Highway 101 in Mendocino County to the west. To the north of Highway 20, Bear Valley Road, a county- maintained dirt-surface road 17.4 miles long connects to the paved Lodoga Road that exits the watershed north to the settlement of Lodoga, East Park Reservoir, and a main road into the Mendocino National Forest. To the south of Highway 20, State Highway 16 travels along lower Bear Creek in Colusa County, enters Yolo County at the confluence of Bear Creek and Cache Creek, passing Yolo County’s Cache Creek Canyon Park, and then turns south to Rumsey and other Capay Valley communities.

From the northwest side of the watershed, Brim Road (an extension of Bartlett Springs Road in Lake County) runs from Walker Ridge Road east to Bear Valley Road. On the northeast side of the watershed, Leesville Road connects the northern part of the watershed to Williams more directly than by way of Bear Valley Road.

Numerous roads maintained by private landowners are present. Private roads were not surveyed or mapped as part of this assessment. Pacific Watershed Associates has mapped all roads in Sulphur Creek subwatershed, with landowner permission, because of the critical need to redesign roadways in the subwatershed to curb sediment and mercury flowing into Sulphur Creek and its tributaries (Hoorn et al. 2008).

Road Mileages and Surfaces The miles of publicly maintained roads are broken out by type of road surface and by responsible agency as follows:

Paved Road Miles Unpaved Road Miles CALTRANS Route 16 6.9 0.0 Route 20 4.9 0.0 Subtotal 11.9 0.0

Colusa County Department of Public Works Bear Valley Road 17.4 Brim Road 1.4 Leesville Road 2.7 Lodoga Road 1.6 Wilbur Springs Road 1.0 0.7 Subtotal 5.3 19.5 TOTAL 17.2 19.5

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The existing travel network has a density of 0.36 public road miles per square mile in Bear Creek watershed. The road networks tend to follow Bear Creek and Sulphur Creek closely, indicating the care needed to ensure that roads do not contribute to the total sediment load in watershed streams.

Traffic Counts The daily volume of traffic in both directions on Highway 20 at the intersection of Highways 20 and 16 totals 11,200 vehicles per day (2007 traffic volume data from CALTRANS, Traffic Data Branch), a 3.7 percent increase since 2004. During the peak travel month, the travel volume increases to 13,600 vehicles per day. Traffic volume on Highway 16 at the Yolo- Colusa county line at the south end of Bear Creek watershed is much less: 1,400 vehicles per day in both directions on average, rising to 1,650 vehicles per day in the highest traffic month. Traffic data for county roads or for off-highway vehicle trails are not available.

Bridges In 2008, CALTRANS began reconstruction of the Bear Creek Bridge on Highway 20 and realignment of the roadbed to provide better visibility and meet current design standards for state highways. Bear Creek flooded Highway 20 most recently in December 1983 and January 1997, and the Highway 20 Bear Creek Bridge has been inundated six or more times since 1965 (California Department of Transportation 2006). Loss of the bridge from flood waters and interruption of commercial traffic on Highway 20 would be an immediate economic detriment to the regional economy. The dimensions of the old bridge have also been insufficient to keep debris from tangling among the bridge columns, and water scouring was exposing the bridge footings.

Bridges on Highway 16 are less problematical because the highway is mostly situated high above the canyon course of Bear Creek at bridge crossings. Flooding in Bear Creek upstream of Highway 20 and in Sulphur Creek, however, could damage bridges over each of these creeks and restrict movements of residents, tourists, and business people. These bridges are in the 100-year floodplain zones of the two creek courses and are vulnerable.

Erosion Hazard on Roads and Trails Construction of new roads and off-highway vehicle trails pose challenges to engineers in parts of Bear Creek watershed where soil erosion and landslides are more likely. Erosion hazard has the potential to damage resources such as water quality or harm riders. Figures 3.11 and 3.12 display the erosion hazard ratings from the Colusa County Soil Survey (Reed 2006) for state- and county-maintained roads and for off-highway vehicle trails respectively.

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3.12 Telecommunications The BLM provides rights of way to communications companies and to other government agencies on public lands in Bear Creek watershed. American Telephone and Telegraph (AT&T) Corporation, CALFIRE, and the Colusa County Sheriff’s Department all have telecommunications relay towers on Walker Ridge. The 2008 Walker fire destroyed one telecommunications facility.

3.13 Scientific Research and Monitoring The US Geological Survey, the California Department of Water Resources, and the Yolo County Flood Control and Water Conservation District all maintain permanent water monitoring sites in lower Bear Creek. In 2008, the University NAVSTAR Consortium (UNAVCO), a non-profit research institute for earth sciences arranged for an earthquake monitoring station on BLM public lands in the watershed. In addition, university faculty and graduate students in geology, plant ecology, wildlife biology, and other disciplines have conducted research in Bear Creek watershed since the 1950s. Institutions recently engaged in scientific research include the University of California at Davis and Berkeley, Stanford University, and Harvard University.

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CHAPTER 4

NATURAL DISTURBANCES

Natural disturbances have the potential the shift watershed conditions and processes in unprecedented ways, especially if the disturbance is sufficiently severe, frequent, widespread, or enduring. Climate scientists predict that the frequency and intensity of many natural disturbances will increase with global warming. This chapter considers four categories of natural disturbances in Bear Creek watershed: fire, geological hazards, floods, and drought. This chapter also describes the environmental and social impacts from these disturbances, and the efforts to manage them, and, in addition, outlines considerations for disturbances in the development of land uses. Gaps in information needed for managing or responding to natural disturbances are summarized at the end of the chapter.

4.1 Wildfire Fire may extend landscape disturbances over tens of thousands of acres and interrupt ecosystem services that support human land uses. In some cases, fire is essential for maintaining biological diversity of native species, particularly plants species (Sweeny 1956, Keeley and Fotheringham 2000), or it can put species at risk by degrading or destroying habitat. It can variously control or spread invasive non-native species (di Tomaso and Johnson 2006; Keeley 2002). Controlling the destructive impacts of wildfire and facilitating vegetation regeneration after fires is a major management focus.

Fire Ecology Impacts to water quality and supply, soil nutrient chemistry, soil erosion rates, air quality, vegetation, and animals may result from fires. Rapid loss of vegetation after intense and extensive fires can change how water moves through the watershed. Lost vegetation can no longer intercept rainfall and dissipate the force of rain on soils. Water from rain storms then moves with greater speed over land, often leading to high rates of soil erosion and stream sedimentation.

Situated at the juncture of the North Coast Bioregion and the Central Valley Bioregion (Hoshovksy 1992), the watershed shares traits of fire history and ecology from both bioregions. The oak savanna woodlands and semi-arid grasslands in the watershed are similar to those of Central Valley foothills and contrast with the chaparral and conifer woodland on steeper parts typical of the higher-elevation rugged terrain in the North Coast Range.

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Fire Regimes A fire regime consists of a set of factors that determine the severity of a fire: source of ignition, seasonality of fire, fire frequency (“fire-return interval”), existing fuel conditions in different vegetation communities, watershed topography, and weather. The Mediterranean climate naturally creates fire-prone conditions in Bear Creek watershed. Particularly during the summer and early autumn drought, total water in the watershed is at its lowest amount, and live vegetation and organic debris fuels are driest. In general, fire moves more quickly across the steeper topography of the west half and southern third of the watershed. Higher amounts of aboveground live and dead biomass contribute to larger fuel loads and greater fire hazard.

In the fire regime classification of Sugihara et al. (2006), Types I, II, and III are characteristic of different parts of Bear Creek watershed. The distribution of fire regime classes depends on vegetation types and fuel loading, i.e. the type, amount, and distribution of combustible matter. Chaparral vegetation, conifer woodlands, oak woodlands, and grasslands, all major vegetation types in Bear Creek watershed, are flammable, each in different ways.

Table 4.1 Fire regimes in Bear Creek watershed Regime Frequency Severity I 0-35 years Low (mostly surface fires) – grasslands II 0-35 years High (mostly stand replacing fires) - chaparral III 35-100+ years Mixed (patches of low- and high-intensity fires) – woodland

Sources of Ignitions: Lightning and People Lightning is the natural cause of fire in Bear Creek watershed. In the western half of California lightning is a comparatively rare phenomenon, comprising three percent or less of total ignitions in northern California west of the Sacramento River Valley (Keeley 2006; van Wagtendonk and Cayan 2008). In Bear Creek watershed between 1997 and 2007, lightning on three dates ignited five fires (Figure 4.2). CALFIRE and BLM fire crews quickly suppressed these fires.

People have probably been the major agents of fire in the watershed for millenia. Native Americans ignited fires in the region regularly until the 1840s (Stuart and Stephens 2006), accounting for most fires in the North Coast Range before European settlement. The fire ignitions displayed in Figure 4.2 do not include prescribed fires intentionally set for management purposes. Between 1997 and 2007, 32 ignitions (86 percent of the total displayed) not relating to prescribed burns resulted from human actions. Four of these ignitions were the acts of arson. The arson fires occurred along lower Bear Creek along Highway 16.

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Transportation corridors are frequently points for ignitions. Records from the California Department of Forestry and Fire Protection (CALFIRE) show that motor vehicles were involved in at least eight of the 32 ignitions. CALFIRE estimated costs from these eight fires, totaling nine acres, at $42,000.00. Ignitions from other equipment burned 280 acres during the same period.

Most large fires since 1950 in the past have not originated in the watershed. For example, in June 2008, the 14,500-acre Walker Fire started outside Bear Creek watershed at the southern end of Indian Valley Reservoir when the metal undercarriage of a vehicle struck a rock on a road. The fire started in the Indian Valley, moved up the west side of Walker Ridge and down the east side into Bear Creek watershed, eventually burning more than 6,325 acres in the watershed.

Seasonality of Fire Fires generally occur when fire hazard is greatest, under conditions of low humidity and soil moisture and high temperature and wind. These conditions tend to prevail from June through October in the watershed. Rare lightning events leading to fire are also seasonal. Between 1997 and 2007, lightning ignitions occurred in the months of July and September only.

Human alteration of fire regimes comes in part from human-caused ignitions outside the summer/autumn fire season. Most human-caused ignitions between 1997 and 2007 occurred in July and September, but other fires in February and November are well outside a natural fire regime based on lightning strikes.

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Planned ignitions used by land managers and landowners often depart from the natural ignition pattern of lightning. For example, the Mendocino National Forest conducts most prescribed burns for fuels management once autumn rains begin in the cooler months from mid-October through May. In those months, the moisture is usually sufficient to confine a burn easily. Higher moisture conditions and cooler temperatures facilitate controlled burning. The differences in fire effects on Mediterranean-climate vegetation produced by wet-season burns in contrast to summer fires are not well understood.

Annual Frequency of Large Wildfires Between 1950 and 2007, nineteen large wildfires burned across 11,292 acres, or seventeen percent of Bear Creek watershed (CALFIRE database). Fires burned a second time over 1,430 acres during the 58-year period, mostly in perimeter areas: along the north edge of Mill Creek watershed, on Bear Valley Buttes, along lower Bear Creek, and on Cortina Ridge. Three fires originating west of the watershed stopped at the crests of Walker Ridge or Love Lady Ridge. Fires on ultramafic soils were much less frequent than fires on non- ultramafic soils.

The infrequency of fire belies the presence of fire-prone vegetation. With large loads of flammable fuels and summer weather conditions that set the stage for wildfire, vigilant fire suppression has likely been the key to keeping the number of large wildfires low within the watershed in the past 60 years.

Fire Intensity and Severity Fire intensity describes the physical features of fire behavior while it is burning. Fire severity, by contrast, describes the outcomes of fire regimes on vegetation, wildlife, and water resources.

Severity of a fire can significantly alter vegetation in the aftermath of the fire. In the past, people have used unnaturally high fire frequency to increase fire severity with a goal to removing mixed-species and chamise chaparral (Haidinger and Keeley 1993) and creating more grassland for livestock forage. This conversion occurs often when invasive non- native (mostly annual) grass species have shifted the species mix in the soil seed bank. Abnormally frequent burning can eventually exhaust the capacity of chaparral shrubs to reseed or re-sprout. Grassland patches developed for livestock grazing, particularly south of Highway 20 and in parts of Mill Creek watershed are examples of the use of fire severity as a management tool for vegetation.

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Figure 4.3 – Six Decades of Wildfire in Bear Creek Watershed, 1950 - 2008

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Table 4.2 - Overview of components of fire regimes for major vegetation classes in Bear Creek watershed Vegetation Fire-Return Season Size Complexity Intensity Severity Fire Type Type Interval Foothill June - Small to Low to Low to Short High Surface Woodland October Medium Moderate Moderate Valley June - Medium Moderate Short Low Low Surface Grassland October to Large to High Knobcone April - Medium - Large Low High High Crown Pine October Long Cypress April - Medium - Low to Moderate Large High Crown Woodland October Long Moderate to High Chaparral, Short - ? ? ? High Low Crown SS* Medium Chaparral, Medium - ? Small Low Moderate Moderate Crown US* Long Source: Davis and Borchert (2006), Keeley (2008 pers. comm.), Safford and Harrison (2004), Wills (2006) *SS=chaparral on sedimentary non-ultramafic soils, US=chaparral on ultramafic soils

Fire Fuels The flammability of fuels depends on the physical properties of the vegetation. The important factors are: the total biomass of vegetation available as the fuel source; size of the individual pieces of fuel; surface area to volume ratio for fuel ignition; moisture content of the fuel; the compactness of fuels (“packing ratio”); and the spatial placement and continuity of fuels in the landscape (Husari et al. 2006, van Wagtendonk 2006).

Fires in grasslands and oak woodlands are usually ground fires with short flame lengths. In woodlands, oaks with fire-resistant bark and boles without dead lower branches create a break in the continuity of fine fuels on the ground and tree canopy fuels consisting of branches, twigs, and foliage. Without a “fuel ladder”, ground fires do not spread to tree crowns. By contrast, shrubs and some trees maintain a continuous fuel supply from both dead and live branches between the ground and the tree canopy that frequently gives rise to crown fires which began as ground fires. Chaparral shrubs produce low-canopy fires: the fire burns close to the ground because the canopy is near the ground. Conifer species in Bear Valley watershed, such as knobcone pine and McNab cypress, grow densely, maintain their dead lower branches on the bole, and give rise to stand-replacing high-canopy fires. In other cases, particularly in wetter streamside woodlands, herbs and shrubs in the woodland understory feed flames that then may reach into canopies of overstory trees in a relay system of ladder fuels.

Chaparral vegetation on non-ultramafic soils has high flammability with its dense, closed canopy. Thus, fires in chaparral shrub ecosystems burn hot and usually remove the standing shrub vegetation. After the fire, chaparral shrubs may sprout from root crowns or germinate prolifically from seeds stored in the soil. Although fires in chaparral are usually hot (intense) because of fuel flammability, the ability of chaparral shrubs to reseed or resprout

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from root crowns means that the long-term severity of chaparral fires is usually low and shrubs recover rapidly under normal conditions.

In contrast, chaparral vegetation growing on ultramafic soils grows more slowly and less densely. Safford and Harrison (2004) found that annual height growth of chamise found on ultramafic soils had less than half the height growth of chamise growing on sandstone- derived soils. Because ultramafic chaparral vegetation is not as dense, the litter of dead leaves and branches on the ground (fine fuels) is less extensive and forms a shallower layer on the ground compared to chaparral on other soil types. Until 2008, most large fires burning in chaparral did not burn across ultramafic soils on the east slope of Walker Ridge in Bear Creek watershed.

CALFIRE has developed a fuel ranking system to depict the fuel load and its flammability characteristics (Figure 4.4). The fuel rank is useful for prioritizing sites for prescription burning treatments designed to reduce fuel loads and catastrophic fire. Upper Mill Creek subwatershed, Walker Ridge, a band of steep terrain at the west edge of Bear Valley, and the complex terrain between Highway 20 and the south end of Bear Valley are areas that may benefit from fuel load reduction.

Interaction between Wildfire and Erosion Soil erosion the capacity of soils to store carbon, increases the amount and speed of runoff, and decreases soil moisture. After wildfires, soil erosion rates increase due to exposed ground surfaces. The ecological alteration from wildfire may induce further disturbances by way of landslides and debris flows. CALFIRE has analyzed terrain in Bear Creek and elsewhere in California using the Revised Universal Soil Loss Equation (Figure 4.5). This analysis helps stakeholders quickly identify problem areas from erosion in the aftermath of a wildfire. The following two areas are likely to need emergency stabilization: Cortina Ridge in the southeast corner of the watershed and the steep slopes on the southwest side of Sulphur Creek subwatershed.

Considerations for Fire Management in Bear Creek Watershed Applying fire treatments to areas with ultramafic soils and chaparral vegetation may need to be different from fire treatments on sedimentary soils with chaparral vegetation. On average, fires burn hotter and faster in sedimentary chaparral. The fire-return interval for chaparral vegetation on ultramafic soils is about four times longer than for chaparral on sedimentary soils (74 years vs. 19 years). Higher productivity on more fertile soils causes faster accumulation of biomass and shorter intervals between fires. In contrast, vegetation on less fertile ultramafic soils accumulates biomass more slowly than non-ultramafic sites (Safford and Harrison 2004).

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Fires in chaparral ecosystems increase plant species diversity, largely through an increase in herbaceous species. One adverse effect is that fire in chaparral ecosystems exposes the burned sites to greater risk of invasion of non-native plant species. Safford and Harrison (2004) found that the number of non-native plant species tripled after chaparral fires on both sedimentary and ultramafic soils.

Mercury Emissions from Wildfires During fires, mercury is released from the soil as a gas into the atmosphere. The Mediterranean Basin, for example, emits an estimated annual average of 4.3 metric tons of mercury (Cinnirella et al. 2008) from wildfires. An initial estimate of the annual range in the United States is between 19 to 64 metric tons of mercury (Wiedinmeyer and Friedli 2007).

The relation between mercury and wildfires is an emerging topic of research. Mercury emissions from wildfires in other parts of the world with environmental conditions similar to those of the inner North Coast Range in California (frequent wildfires and high background levels of naturally occurring mercury) are now under scrutiny for potential long-term ecological and human health impacts (Cinnirella and Pirrone 2006).

Although scientists have not collected data from Bear Creek watershed, recent research gives an idea of the quantities of mercury being released during wildfires. Biswas et al. (2008) have estimated that one wildfire in Washington State in 2001 released 6.7 grams per hectare (equivalent to 9.5 pounds per square mile) of mercury from the soil. Changes occur to amounts of mercury in soils as well. In Wyoming, Biswas et al. (2007) found that post- fire soil samples from a burned watershed had only 25 percent of the amount of soil mercury found in samples from an adjacent unburned watershed with same soil type (38 parts of mercury per billion vs. 158 parts per billion).

Past Prescribed Fire Treatments in Bear Creek Watershed A historical record of prescribed fire treatments in Bear Creek watershed is not available in a GIS layer for display here. In past decades, landowners burned extensive areas of chaparral or cut and burned oak woodland habitats at the north end of the watershed and on the BLM Bear Creek Ranch at the south end to accomplish “type conversion” of vegetation to grasslands intended for increased forage for livestock. Recently, the BLM has prescribed burns for meadows in the Ranch. CALTRANS and CALFIRE have burned portions of the Bear Creek Botanical Management Area along Highway 20 to suppress invasive non-native plants and to promote native plants, especially herbaceous prairie species. Occasionally, prescribed fire treatments burn out of control and become wildfires. Such an incident, the Bear Fire, occurred on private land on the east slope of Walker Ridge in May, 2002.

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Hazard to Communities at the Urban-Wildland Interface CALFIRE has modeled the hazard to communities throughout California. The greatest hazard to communities is at the south end of the watershed, the area closest to the Capay Valley. The single rural community of concern for fires spreading from Bear Creek watershed is the town of Rumsey, 5.8 miles southwest of the mouth of Bear Creek along the main stem of Cache Creek in Yolo County. The BLM manages the public lands where the fire hazard is greatest. As part of fire planning, the BLM has made the following composite hazard rating and component hazard evaluations for the community of Rumsey:

Resource & Fire Catastrophic Composite Fuels Ignition Wildland Economic Protection Fire Rating Hazard Risk Fire History Values Capability Potential

Moderate High Moderate High Moderate Moderate High

Source: Bureau of Land Management (2008 draft)

Sources of ignition risk include: presence of power lines, multiple kinds of popular recreation, a nearby urban population, outdoor burning, woodcutting, fireworks, and arson. Fire features of concern are high (> eight feet) flame lengths, high potential for crown fires, and steep and elevated terrain in the area. Resources at high risk on the public lands for the community of Rumsey are Native American cultural resources, wildlife and fisheries, domestic water supply, riparian habitat and flood protection, visual quality, and soils. Air quality and standing timber are secondarily important.

Fire Agency Authority and Collaboration Fire management authorities for governmental agencies fall into two categories: management for fire suppression and management for prescribed burning to benefit land uses.

Fire Suppression BLM and the CALFIRE have a Memorandum of Understanding where CALFIRE leads fire suppression and property protection efforts for the BLM public lands in northern California, including lands in Bear Creek watershed. CALFIRE has lead responsibility for suppressing fires on private lands and on public lands managed by California state agencies as well. The US Forest Service has lead authority for fire suppression for the portion of the Mendocino National Forest in the watershed.

CALFIRE has two stations in the watershed: the Leesville station at the north end of the watershed (currently closed) and the Wilbur Springs station at the intersection of Highways 16 and 20.

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Prescribed Agricultural and Wildland Burning The Colusa County Air Pollution Control District (APCD) regulates all planned agricultural and wildland vegetation burning in Bear Creek watershed. Regulations established by the Colusa County APCD support the goals of the regional Sacramento Valley Air Basin Plan. The Control District requires burn plans at least seven days in advance of a prescribed ignition. No more than 640 acres (one square mile) total of wildlands in Colusa County may burn by prescription during a single day.

The California State Air Resources Board has established the Bear Valley-Indian Valley Fire Protection District office in Stonyford, north of Bear Creek to cover Bear Creek watershed. An Air Pollution Control Officer there issues permits for agricultural, forestry, and wildland burning.

Bear Creek watershed differs from the Sacramento Valley portion of Colusa County, where agricultural debris is common. In the watershed, most prescribed burning is done to achieve goals for ecosystem services such as invasive plant suppression, forage improvement for livestock, wildlife habitat improvement, and reduction of fire hazard.

Interagency Collaboration for Fire Suppression and Prescribed Burning Common interests among different agencies charged with fire management have promoted long-term collaboration among agencies, especially in situations where the need for fire suppression is urgent and requires more resources than one agency alone can provide. Locally, the BLM Cache Creek Natural Area Manager and the CALFIRE Wilbur Springs fire station staff have collaborated on prescribed burning. Public lands offer a training ground for CALFIRE staff, and CALFIRE helps the BLM accomplishes management goals specified for the Cache Creek Natural Area (Bureau of Land Management 2004).

Fire Modeling Modeling fire hazards, risks, and future fire behavior uses the suite of modeling tools known as LANDFIRE, created jointly between the wildland fire management programs of the US Forest Service and the US Department of the Interior land management agencies, including the BLM. Federal fire managers have not yet used LANDFIRE (www.landfire.gov) in Bear Creek watershed. Critical data for vegetation and fuels are not updated for modeling purposes. Once data are available for the watershed, the data for analyses of fire behavior will consist of GIS layers of vegetation composition and structure, surface and canopy fuel characteristics, and historical fire regimes. The model is capable of producing raster data on a 30-meter grid.

The goal of LANDFIRE analysis is to identify priorities to reduce hazardous fuels watershed-wide and to restore ecosystem conditions in the watershed that enhance multiple

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resources such as biological diversity, landscape visual resources, soil conservation, water quality, and recreation. Fire program managers at CALFIRE, the BLM, and the US Forest Service can jointly use information from modeling to support decision making about scheduling and funding fire management programs. Collaborative planning across boundaries of management jurisdiction is intended to reduce high costs for fire suppression in the region and to integrate fire resources seamlessly.

There is concern that climate change is changing fire behavior in California. A range of fires scenarios of climate change indicate that a warmer, drier climate will create losses from fire in the cover of oak woodlands resulting in the expansion of grasslands (Lenihan et al. 2008). Modeling of future fire behavior specifically for Bear Creek watershed is not yet available.

4.2 Geological Hazards A geological hazard may cause environmental changes, damages to resources, or pose risks to human health and safety. Most geological hazards are small in scope but can at times attain catastrophic proportions and significantly transform landscapes. Knowledge of geological hazards comes from interdisciplinary research into past geology, plate tectonics, soil science, and geomorphology of a region. While knowledge of the past can give a sense of likely future geological hazards, this information can rarely forecast the timing and size of a future geological hazard. This section covers specifically earthquakes and landslides as the principal hazards known to have occurred over the last two centuries in Bear Creek watershed.

Earthquakes Seismic Activity A historical record of earthquakes in the inner North Coast Range extends back 150 years. The two largest earthquakes originating locally occurred in April 1892; they had local earthquake magnitudes greater than 6.2 and 6.5 respectively. Other strong earthquakes in the area occurred in 1885 (Rogers 1891), 1898, 1906 (the San Francisco earthquake), and 1980-1985 (URS Corporation 2006).

The watershed lies in a less active seismic zone in contrast to the 68-mile long Barlett Springs Fault Zone just west of the watershed. As a result, few earthquakes have their epicenters in the watershed itself (URS Corporation 2006). The fault likeliest to generate an earthquake in the watershed is the Resort Fault, which passes through Sulphur Creek subwatershed.

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Seismic Hazard Peak ground acceleration (PGA) is the standard measure of the seismic hazard from ground shaking during an earthquake. PGA estimates the intensity of shaking expected at a set chance (10% likelihood) of occurring within a specified time (50 years). The California Geological Survey has mapped the distribution of PGA in Bear Creek watershed. Areas with higher PGAs for the fifty-year period are at greater risk of damage to structures from earthquakes. Ground shaking from earthquakes in the watershed is likely to be highest on the west side of the watershed: at the headwaters of Mill Creek, along Walker Ridge, in Sulphur Creek subwatershed, and west of Highway 16. Overall, the risk for Bear Creek watershed is moderate in contrast to high-earthquake activity areas in California along the San Andreas Fault, in the Los Angeles Basin, and in the Humboldt Bay region.

Earthquakes also can trigger landslides. At present, no information about correlations between landslides and earthquakes exists. However, the density of landslides appears to largely overlap the likely zones of highest ground shaking – the steeper parts of the west side of the watershed.

Concerns With its current small population, the watershed has a low probability of loss of life and property from earthquakes. Should the population of the watershed increase or should new land uses develop such as commercial energy production, optimal siting for buildings and infrastructure will be critical to reducing earthquake hazards.

Landslides Manson (1989) mapped landslides for the main stem of Cache Creek, and that effort included a small part of the southern end of Bear Creek watershed where landslides are infrequent. Until recently, the extent of landslides in the watershed was poorly understood. Hoorn et al. (2008) analyzed landslide sites in Bear Creek watershed north of Highway 20 based on aerial photographs. Of the 118 landslides occurring between 1937 and 2005, all but six stabilized after the initial slope failure and did not slide further downslope later. Debris slides were the most frequent (96 percent) and most massive (98 percent of volume) form of landslide. Debris flows, occurring after water has saturated steep slopes, were rare events, and only a single complex debris landslide was recorded. The eight largest landslides mapped (all >20,000 cubic yards) comprised 44 percent of the volume from all landslides. None of the largest landslides originated from specific land uses or human ground disturbances.

Relation to Landform Steep inner gorge slopes (≥ 30°) and streamside slopes (< 30°) were the sources of 43 percent and 48 percent of all landslides respectively. A much smaller share of landslides

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occurred at locations where slopes change abruptly (“headwalls”). On average, rock and soil debris delivered to streams was nearly twice as high from individual slides coming off the steeper inner gorge slopes than off streamside slopes (7,200 cubic yards vs 4,380 cubic yards).

Relation to Vegetation and Soils Fifty-one percent of all landslides occurred at sites dominated by chaparral shrubs on higher-elevation slopes with ultramafic soils in the western half of Bear Creek watershed. Six of the eight largest landslides occurred at sites with ultramafic Henneke soils on steep slopes (>30°) slopes (Hoorn et al. 2008, J. Weigand GIS analysis).

Oak woodlands, found for the most part on sedimentary soils, had about 30 percent of detected landslides. However, this percentage corresponds to the relative proportion of oak woodlands across the entire watershed and does not indicate a correlation between landslide frequency and vegetation type. Most oak woodland slides were at lower elevations and at streamside sites with gentler slopes and deeper soils.

Relation to Land Uses Hoorn et al. (2008) found that 69 percent of all landslides and 89 percent of the total sediment volume delivered to watershed creeks and streams north of Highway 20 originated from landslides unrelated to a land use. Roads and trails were the most common cause of landslides associated with a human land use and accounted for six percent of total sediment delivery. The largest single slide caused by roads is along Highway 20 west of Bear Creek Bridge, with an estimated debris volume of 16,400 cubic yards. Grazing, mining, and reservoirs together contributed another five percent of all landslide debris.

Concerns Three of the largest natural landslides have occurred in Sulphur Creek subwatershed. The subwatershed is also prone to erosion after fires (refer to Section 4.1 above). A landslide triggered near mercury mines has the potential to destabilize extensive mercury-rich waste piles and increase the passage of mine waste into Sulphur Creek.

4.3 Flooding and High Flows Flooding affects water quality, sediment deposition patterns, fish and wildlife habitats, and options for habitat restoration. When inundated, floodplains can temporarily expand habitats at key life stages for fishes, amphibians, and aquatic invertebrates. Floods scour sediments from stream banks and terraces, redistribute streambed substrates, erode soil, uproot vegetation, and rearrange patterns of sediment deposition areas along waterways. Floods may directly impact landowners economically in Bear Valley if losses to livestock

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result.

The Colusa County Soil Survey (Reed 2006) predicts frequent winter flooding along three stretches of Sulphur Creek, the lower reach of Mill Creek, and at one site in the lower Bear Valley. Periodic flooding is likely to occur elsewhere on the east side of Bear Valley and in the Cowboy Camp area south of Highway 20. Elsewhere, flooding is rare or non-existent. Figure 4.6 displays a generalized winter flood frequency map from the Colusa County Soil Survey.

Data on past flood frequencies in Bear Creek watershed are not directly available but may be inferred from flood data from the closest National Weather Service station downstream in Middle Cache Creek at Rumsey. These data provide an indication of the frequency and timing of flooding in Bear Creek watershed. Flood crests of Cache Creek at Rumsey Bridge have occurred on ten dates between 1960 and 2007 (National Weather Service data 2008).

Intense rainfall can generate a high-flow response in Bear Creek within just a few hours of the start of a heavy rainstorm, especially if soils in steep topography are already saturated with water. Bear Creek and its tributaries then produce a quick-response, short-term (“flashy”) water flow pattern typical of steep landscapes with a Mediterranean climate (Gasith and Resh 1999).

Of concern downstream on Cache Creek is the potential contribution of Bear Creek watershed to floods in the Western Yolo floodplain. The towns of Madison and Esparto are vulnerable to flooding, and the City of Woodland has protections in place for only a 10- year flood. A 100-year flood in Cache Creek would inundate approximately 35 percent of the City of Woodland according to the Federal Emergency Management Agency (2009).

Yates (1989) has estimated the 100-year one-day maximum flow for Bear Creek at 5,120 cubic feet per second (145 m3 s-1). For the periods of record for water gages in lower Bear Creek (water years 1959 – 1980 and 1999 – 2007), 42 days exceeded an average daily water flow of 1,765 cubic feet per second (50 m3 s-1) and five days exceeded an average daily flow of 3,530 cubic feet per second (100 m3 s-1). The highest flow recorded on Bear Creek during the periods of record was 4,377 cubic feet per second (124.0 m3 s-1) on February 5, 1965.

High flows in Bear Creek appear over an eleven-week interval from mid-December through the end of February, with a peak in mid-January.

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Table 4.3 – Distribution of the 42 days with Bear Creek flows >50 cubic meters per second by week of the year in which they occurred

4 Numberof High-Flow Days

5 15 25 35 45 Week in Calendar Year

Source: USGS data from Bear Creek water gages, water years 1959 – 1980 and 1999 – 2007

High flows usually last less than 24 hours in Bear Creek. Of the 42 days of high flows on Bear Creek (greater than 1,765 cubic feet per second), periods of multiple days of sustained high flows occurred on only six occasions for the periods of record as follows:

1973 February 11/12 1978 January 14/15/16/17 1980 February 12/13 1980 February 17/18/19 1999 February 2/3 and 1999 February 6/7.

All multi-day high flows occurred in El Niño winters.

4.4 Drought Droughts affect the resilience of Bear Creek watershed differently depending on their duration and severity. Studies of past droughts on the environment of Bear Creek watershed have not been undertaken. However, studies in other parts of California and the Southwest provide past evidence of drought disturbance and shed light on the outcomes of different kinds of droughts.

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Multi-year droughts have occurred three times since 1960 in Bear Creek watershed. Although lower Bear Creek ceased flowing aboveground in the summer during the 1976/1977 drought, fish populations and aquatic processes rebounded in subsequent years. However, centuries-long droughts that indicate climate change in the past have led to more drastic changes. Enduring drought such as occurred 10,900 to 10,600 years ago across North America contributed to altered habitats and extinction of large mammal species such as mastodons and mammoths (Haynes 2002).

Drought may also predispose a watershed to other disturbances. For example, insect infestations and fungal pathogens can more easily kill drought-stressed trees and shrubs. The resulting standing dead wood in woodlands and chaparral then increase fire hazard and alter fire frequency (Brunelle and Anderson 2003).

Long-term drought may contribute to cumulative large-scale geographic impacts when drought extends across several adjacent bioregions at the same time. The medieval climate anomaly (9th through the 14th centuries) caused by long-term cooling in the Pacific Ocean off California created a series of droughts across the entire state lasting 30 to 60 years. These droughts altered or extinguished once vital human communities in the Southwest when people were powerless to prevent water shortages (deMenocal 2001). A future long- term drought across the Sacramento River system, including Bear Creek, would fail to provide water for Californians and create economic and societal instability (MacDonald et al. 2008). To alleviate impacts from future droughts, whatever their durations and severities, landowners and resource managers need to coordinate water conservation measures in the watershed.

4.5 Information Gaps Resource management can be challenging when managers must deal with unscheduled natural disturbances in combination with disturbances resulting from human land uses. Addressing gaps in information about the following topics can help assist stakeholders understand, prepare for, and manage disturbances in the watershed. Major information needs are:

 Best practices for fire management on sites with ultramafic soils, for (1) enhancing populations of associated rare plant species; (2) reducing the likelihood of landslide hazards in the aftermath of fires; (3) preventing invasion of ultramafic-adapted non- native invasive plant species after fire; and (4) reducing damage to ultramafic landscapes during fire suppression actions

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 Long-term effects of wet-season prescribed fires on vegetation and fuel characteristics in comparison with effects from natural dry-season fires

 Methods and strategies to regenerate stands of conifer tree species (e.g., cypress species) as a hedge against their extirpation as the result of a catastrophic wildfire and loss of viable seed banks

 Potential mercury emissions and human health impacts from wildfires in the watershed

 Updated vegetation information on non-Forest Service lands in the watershed to make the entire watershed compatible for modeling fire behavior with LANDFIRE

 Responses by vegetation, wildlife, and soils to prescribed burning over time to ascertain which practices are most effective for achieving management goals for these resources

 Maps and analyses of landslides south of Highway 20

 Best management practices designed to retain water in Bear Creek watershed longer (e.g., grazing practices, floodplain and wetland restoration, road and drainage design)

 Water flows and flood frequencies in Bear Valley, Sulphur Creek and Mill Creek subwatersheds, and the Cowboy Camp area

 A watershed hydrologic model.

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CHAPTER 5

ENVIRONMENTAL CONTAMINANTS

This chapter summarizes current knowledge about environmental contaminants that are or may be adversely affecting the quality of water, soil, air, and biotic resources in Bear Creek watershed. Contaminants are important to stakeholders when they are obstacles to achieving the watershed assessment goals described in Chapter 1. To assist in developing watershed projects to achieve goals, this chapter identifies contaminants, where they are known to occur in the watershed, and how contaminants relate or respond to natural features and human land uses in the watershed.

5.1 Water Quality Objectives In California, water quality objectives are complex. The Central Valley Regional Water Quality Control Board (CVRWQCB) has established water quality objectives for Bear Creek watershed in the Water Quality Control Plan (Basin Plan) for the Sacramento River Basin and the San Joaquin River Basin (4th edition, as amended 2007). Objectives consist of three elements: designated beneficial uses; numeric and narrative criteria; and antidegradation policies and procedures. Their purpose is to define goals, contaminant limits, and protection requirements for water quality in the watershed.

Information about chemical and biological contaminants from the watershed is critical in support of water quality objectives. Scientific investigations and monitoring in Bear Creek watershed are helping stakeholders to know which contaminants require management, where management should take place, and how much the amounts of contaminants are changing in response to watershed remediation projects designed to improve water quality and meet regulatory requirements.

Existing and Potential Beneficial Uses for Water Amendments to the Basin Plan (Cooke and Morris 2005) specified beneficial uses for water in the Cache Creek Basin from the Clear Lake Dam (Lake County) to the Yolo Bypass (Yolo County). Bear Creek watershed is part of this section of the Cache Creek Basin. Beneficial uses orient water quality management in Bear Creek watershed. In 2007, the CVRWQCB specifically amended the Basin Plan in Resolution R5-2007-0021 to delete municipal and domestic water supply (MUN) as a beneficial use for lower Sulphur Creek from Schoolhouse Canyon to its confluence with Bear Creek. Table 5.1 lists the existing beneficial uses currently applicable to Bear Creek watershed.

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Table 5.1 – Beneficial uses applicable to Bear Creek and its tributaries Beneficial Uses Status Agricultural Supply, Irrigation and Stock Watering (AGR) Existing Commercial and Sport Fishing (COMM) Existing *†‡ Freshwater Habitat, Cold (COLD) Potential Freshwater Habitat, Warm (WARM) Existing Industrial Process Supply - uses not dependent on water quality Existing (PROC) Industrial Service Supply - uses dependent on water quality (IND) Existing Municipal and Domestic Supply (MUN) Existing *‡ Recreation, Contact Water and Canoeing & Kayaking (REC1) Existing‡ Recreation, Non-Contact Water (REC2) Existing Spawning, Reproduction, and/or Early Development (SPWN) Existing Wildlife Habitat (WILD) Existing‡ Sources: Cooke and Morris (2005), Cooke and Stanish (2007) * COMM and MUN do not apply to Sulphur Creek from Schoolhouse Canyon to the confluence with Bear Creek (Basin Plan as amended 2007) † A fish advisory from the California Office of Environmental Health Hazard Assessment in 2005 recommends against people consuming any fish or other species found in Bear Creek watershed. ‡ Uses considered impaired due to mercury

The designated beneficial uses for water in Bear Creek and its tributaries apply to the following land uses: ecological services [COLD, WARM, SPWN, WILD], recreation [COMM, REC1, REC2], agriculture [AGR], potable water supply [MUN, in part], and industry [PRO, IND]. MUN, PRO, and IND are economically important largely to stakeholders downstream of the watershed.

Impairment to Beneficial Uses The California State Water Quality Control Board includes Bear Creek and its tributary Sulphur Creek on the State of California’s Clean Water Act 303(d) list of impaired water bodies. Causes given for impairment to beneficial uses are: elevated concentrations of mercury in streams, methylmercury in fish tissue, and an existing advisory against consuming fish caught in Bear Creek watershed.

Numeric Criteria for MUN Water Quality Objectives Numeric criteria indicate the known toxic concentration of a water contaminant in drinking water or a threshold amount designed to avoid a risk to human health. The numeric criteria apply to: contaminant chemical elements and their compounds; inorganic nitrogen-, sulfur-, and phosphorus-containing ions; ion indicators of salinity and alkalinity; and toxic industrial organic compounds such as solvents and pesticides.

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Chemical Criteria for Quality Objectives for Drinking Water Regulatory numeric objectives for water quality criteria in California come from the following sources:

1. Drinking water objectives established by the California Department of Public Health (CDPH) for the maximum contaminant limit (MCL) to total concentrations of elements and compounds in water 2. California State Notification Levels and Response Levels for Drinking Water from the CDPH for elements and compounds that do not have MCLs 3. Total daily maximum load (TMDL) limits to contaminants not otherwise covered by the existing MCLs 4. California Public Health Goals established by the California Office of Environmental Health Hazard Assessment (OEHHA), which solely considers human health based on best available scientific information and works with the CDPH in determinations of MCLs.

Other sources taken into consideration are:

5. US EPA’s California Toxics Rule standards for priority toxic pollutants for which the State has not set water quality objectives 6. The National Toxics Rule 7. US EPA’s IRIS database for carcinogens 8. World Health Organizations criteria.

The first numeric three objectives apply to all water supplies having MUN as a beneficial use in California on all land jurisdictions, including federal public lands. Part of Sulphur Creek no longer has MUN as a beneficial use and does not technically need to meet these objectives.

Water quality objectives established by the CDPH (#1 above) have primary and secondary MCLs. Primary MCLs are legally enforceable objectives that apply to public water systems. Secondary MCLs are non-enforceable guidelines for contaminants (for example, iron) or water characteristics (taste, odor, color) in drinking that create unpleasant sensations for people.

In addition, the CDPH requests that operators of water systems with an MUN designation notify the CDPH, county governments, the CVRWQCB, and local citizens whenever the amounts of certain elements and compounds in drinking water exceed a “notification level” of concentration (#2 above). When the particular element or compound exceeds the higher “response level” concentration, CDPH recommends that the water management agency remove the water source exceeding the response level from service until the operator is able to

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As part of its Cache Creek Watershed Mercury Program, the CVRWQCB has established a TMDL (#3 above) for methylmercury in all of Bear Creek watershed and a TMDL for total mercury for part of Sulphur Creek.

Appendix G contains specific data on the regulatory and advisory limits of each water contaminant of concern in Bear Creek watershed. Section 5.2 discusses the data and status of each water quality contaminant of concern in the watershed.

Criteria for Fecal Coliform Bacteria Affecting MUN Water Quality Fecal coliform bacteria in water originate in the excrement of vertebrate animals. Presence of these bacteria in stream water with an MUN beneficial use indicates potential water contamination from other bacteria injurious to human health. The threshold criteria for using fecal coliform bacteria as an indicator of likely adverse impacts to water quality are set forth in the Basin Plan (as amended 2007). Table G.6 in Appendix G provides details of the objectives for these bacteria.

Narrative Criteria for MUN Water Quality Objectives The CVRWQCB has adopted narrative criteria where specific characteristics of water quality do not have numeric criteria or where numeric criteria need further clarification. These narratives convey the context, conditions, and full intent of water quality protection efforts. Appendix H summarizes the desired objectives for the following components of surface water quality: bacteria, color, dissolved oxygen, fertilizers (“biostimulatory substances”), floating material, methylmercury, oil and grease, pH (an indicator of alkalinity or acidity), pesticides, radioactivity, sediment, settleable material, suspended material, tastes and odors, temperature, toxicity, and turbidity.

Some constituents such as methylmercury, sediment, and toxic amounts of some elements occur naturally in the watershed. However, land uses and management practices may be adding to natural background concentrations of these constituents in the Bear Creek and its tributaries.

Appendix H also details the water quality objectives for ground water applying to Bear Creek watershed. Narratives for ground water pertain principally to human impacts on domestic or municipal supplies (MUN) and consider the following water quality characteristics: bacteria, radioactivity, tastes and odors, and toxicity. Ground water from hot springs in Sulphur Creek subwatershed has naturally high concentrations of some chemical elements and odors from sulfur-containing gases. MUN is not a beneficial use for much of Sulphur Creek because the

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Recommended Numeric Water Quality Objectives for AGR The CVRWQCB uses guidelines from Ayers and Westcot (1985) to determine suitable concentrations for chemical elements in agricultural water. Of particular concern to agricultural customers for water from Bear Creek and Cache Creek Basin as whole, is the concentration of boron. Table G.5 in Appendix G gives the recommended objectives for boron in water destined for agricultural uses.

Recommended Numeric Water Quality Objectives for Freshwater Aquatic Life (SPWN, WARM, and WILD) The California Toxics Rule of 2000, as amended, has established limits for toxic elements to protect human health and aquatic life in freshwater and saltwater environments. Objectives for some chemical elements are constant over all conditions; but most objectives for elements consist of a range of values that correspond to the hardness (alkalinity) of the water. These objectives are criteria to evaluate aquatic life in freshwater ecosystems. Table G.6 in Appendix G gives the criteria concentrations under the California Toxic Rule for key metals for freshwater aquatic ecosystems.

Antidegradation Policies The antidegradation policies of Section 13000 of the Water Code and CVRWQCB Resolution 68-16 (“Statement of Policy with Respect to Maintaining High Quality Waters California”) require that high-quality waters of the State shall be maintained “consistent with maximum benefit to the people of the State.”

Implementing policies to prevent or minimize surface and ground water degradation is a high priority for the CVRWQCB. The Board applies these directives when considering issuing a construction permit or a waste discharge permit where the quality of surface and ground water may be impacted. Careful permitting usually prevents pollution and is more cost-effective compared to cleanup costs. At present, pollutant sources in Bear Creek watershed such as abandoned mines, roads, and grazing are not operating under permits (J. Cooke, CVRWQCB, pers. comm.).

5.2 Water Quality Data This section summarizes data from multiple sources on regulated water contaminants found in Bear Creek watershed. Most pollutants found in Bear Creek watershed originate from chemical elements, ions, compounds, or sediments occurring naturally in the watershed.

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Contaminant materials imported into the watershed from industrial sources are thought to be insignificant except possibly mercury gas and ions deposited onto the watershed from the atmosphere.

This assessment does not take up industrial organic compounds. Data collected by the California Department of Water Resources in 2001 for a sample of organic compounds showed that the compounds did not exceed State of California water quality objectives in the watershed. No industries in the watershed are manufacturing contaminants such as organic solvents and pesticides that could contaminant watershed streams. However, more data need to be collected to verify the little information currently available.

Most data on concentrations of regulated constituents of water pertain to hot springs in Sulphur Creek watershed and the stream water in Sulphur Creek itself. Few data come from lower Bear Creek, from just above the confluence of Sulphur Creek to the confluence of Bear Creek with the main stem of Cache Creek. Even fewer data are available for Upper Bear Creek and Mill Creek. Goff et al. (2001) and Suchanek et al. (2002) provide the most extensive examinations of the chemical constituents of the thermal springs. Suchanek et al. (2002), Cooke and Morris (2005), and Cooke and Stanish (2007) also provide detailed information along the length of lower Sulphur Creek between Elgin Mine and the mouth of Sulphur Creek and parts of Bear Creek.

Work done on saline cold springs in Bear Valley is scant and dates from the 1970s or earlier; past data do not furnish a reliable basis to assess water quality in these poorly known springs. Ground water data concerning contaminants is lacking.

Stream Data for Mercury and Methylmercury High concentrations of mercury and methyl mercury are the major concern for watershed management in Bear Creek watershed. Appendix I provides background to understanding the chemical and biological significance of mercury in Bear Creek watershed and impacts mercury on people and wildlife.

The CalFed Bay/Delta Program has worked to improve California water supplies and the ecological function of San Francisco Bay, the Sacramento-San Joaquin Delta, and their watersheds. The Program has sought to clarify the sources, movement, and impacts of mercury to the Bay and Delta from river networks around the Central Valley, including Bear Creek watershed. CalFed research along with additional research by scientists at the US Department of Energy, US Geological Survey, and the University of California at Davis provide the basis for evaluating mercury and methylmercury in Bear Creek watershed.

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Foe and Croyle (1998) found that Cache Creek Basin, to which Bear Creek belongs, contributes as much as half the yearly load of mercury to the Sacramento River. Studies of mercury in Bear Creek watershed streams and springs have focused on Sulphur Creek subwatershed, which produces the most total mercury in the watershed.

Concentrations of total mercury and the methylmercury at a stream site do not necessarily correlate well with one another (Slotton et al. 2004). For example, in the north end of Bear Creek watershed, the amount of total mercury is low compared to other monitored areas in the watershed, but the amount of methylmercury is mid-range among reported concentrations from across the watershed.

Table 5.2 displays the most current estimates of mercury and methylmercury production by source in Bear Creek watershed.

Table 5.2 – Estimated annual budgets of mercury and methylmercury production by source in Bear Creek watershed All Bear Creek Watershed Only Sulphur Creek Subwatershed Sources Total Mercury Methylmercury Total Mercury Methylmercury Natural Sorces kg per year kg per year kg per year kg per year Soil Erosion 4.9 – 75.9 from all sources 1.2 from all sources Geothermal Springs 1.4 1.4 Abandoned Mines 9.9 – 32.7 9.2 Grazing Erosion ? ? Road Erosion ? ? Mixed Sources kg per year 0.021* kg per year 0.008 Atmospheric 4.6 0.03 Deposition Volatilization to 1.9 – 43.6 1.9 – 12.3 Atmosphere Sources: Churchill and Clinkenbeard (2003), Gustin (2003), Cooke and Stanish (2007) *Bear Creek at Highway 20 Note: Not all mercury that volatilizes into the atmosphere from Bear Creek watershed is exported to other watersheds; some, as yet unknown, percentage of the mercury precipitates back on the ground or vegetation in the watershed.

Unfiltered Total Mercury The amount of total mercury in (unfiltered) water leaving Bear Creek watershed fluctuates, often greatly, from year to year. Rough estimates of the annual mercury load exported from Bear Creek into Cache Creek are 3.6 kg (2000) and 2.0 kg (2001); and for Sulphur Creek into Bear Creek, 2.7 kg (2000) and 1.6 kg (2001) (Domagalski et al. 2004b). Over the length of Sulphur Creek from Elgin Mine to the confluence with Bear Creek, the total mercury load increases five fold, yielding a load larger than the total mercury loads from either Clear Lake or Indian Valley Reservoir (Domagalski et al. 2004c) elsewhere in Cache Creek Basin.

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A midwinter annual spike in the total mercury concentration was apparent in all Bear Creek watershed stream sites monitored in the study. Maximum values recorded for the midwinter spike at the upstream Bear Creek site (north of the Sulphur Creek confluence) were relatively small: 5.4 and 3.8 ng (nanograms) liter-1 for 2000 and 2001 respectively. Mid-winter concentrations of mercury in Sulphur Creek were two to three orders of magnitude greater than those upper Bear Creek. Near the confluence of Bear Creek with Cache Creek, concentrations of total mercury in mid-winter ranged from one-half to one-tenth of the concentrations registered at the same time upstream in Sulphur Creek. Nonetheless, Bear Creek had the second highest concentrations of total mercury found in the Cache Creek Basin and the largest amount of total mercury annually directly entering Cache Creek (Domagalski et al. 2004a).

Bosworth and Morris (2009) investigated Bear Creek and ten of its tributaries to provide a first appraisal of where high concentrations of mercury occur in sediment deposits downstream of abandoned mines. Sulphur Creek had the highest concentrations of mercury sediment across all sediment particle sizes, with levels greater than 0.4 ppm, the level designated by the Regional Board as mercury-enriched. The unnamed second tributary on Bear Creek north of the confluence of Sulphur Creek (Bosworth and Morris op. cit.) and the tributaries and cold springs east of the Rathburn-Petray mercury mine complex (Slowey and Rytuba 2008) are the only other tributaries having concentrations significantly above the enriched-mercury threshold. The 32 sediment deposition areas along Bear Creek from the south end of Bear Valley Road to the mouth of Bear Creek are significant as these sites collectively contain an estimated 91 kg of total mercury. Controlling the movement of these deposited sediments further downstream may be a critical management action.

Methylmercury In the low rainfall years of 2000 and 2001, Domagalski et al. (2004b) found that the second highest concentrations of methylmercury in the entire Cache Creek Basin came from Sulphur Creek subwatershed.

The Basin Plan (2007 as amended) found that 21.1 g yr-1 methylmercury come from Bear Creek north of State Highway 20. This amount is 17.3 percent of the methylmercury produced in the entire Cache Creek Basin. Out of that amount, 8.0 g yr-1 methylmercury comes from Sulphur Creek alone (6.6 percent of the Cache Creek Basin total).

Peaks in methylmercury concentrations from Bear Creek watershed streams are bimodal (Domagalski et al. 2004a). The highest concentrations occur in summer months (June through August) when water volume is low, with a second, smaller peak in mid-winter when the erosional force of water mobilizes soils and mine sediments with high mercury concentrations.

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Other Chemical Elements Potentially Affecting MUN Water Quality Available data indicate that the following elements regulated under primary or secondary MCLs for drinking water do not occur at concentrations above established MCLs in Bear Creek or Sulphur Creek: beryllium, cadmium, chromium, copper, nickel, selenium, silver, strontium, thallium, vanadium, and zinc. Table 5.3 indicates the chemical elements and their locations in the watershed where their respective concentrations exceed MCLs for drinking water. Data from Mill Creek and upper Bear Creek are lacking. These concentrations would require water treatment for the elements before the water would be available for MUN.

Table 5.3 – Overview of key locations where chemical elements exceed respective MCLs for drinking water Water Flow from Sulphur Creek Mouth of Lower Bear Element Abandoned Mine Thermal Springs Sulphur Creek Creek Sites Aluminum yes yes yes no Antimony yes yes yes no Arsenic yes yes yes no Barium yes yes n.d. n.d. Chloride* yes yes yes yes Fluoride yes yes n.d. n.d. Iron* yes yes yes yes Lead yes no no no Manganese yes yes yes no Mercury yes Yes yes no Nitrite yes n.d. n.d. no Sulfate yes n.d. n.d. no Sources: Goff et al. (2001), Suchanek et al. (2002), Cooke and Morris (2005), California Department of Water Resources (2001 – 2006) n.d. = no data *elements specified by secondary MCLs, non-enforceable guidelines for unpleasant but non-toxic water quality

In many cases the concentrations of key chemical elements such as antimony and arsenic become sufficiently diluted by the time water exits from Bear Creek watershed so that the concentration of an element no longer exceeds its respective MCL. A key ecological service of the main stem of Bear Creek may be to dilute water Sulphur Creek and make water from the creek more beneficial downstream than if Sulphur Creek were to drain directly into Cache Creek. Maintaining the dilution capacity of Bear Creek is, therefore, an important to overall watershed management.

Further information on the significance of the elements and ions listed in Table 5.3 for water quality in the watershed appears in Appendix J.

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Chemical Elements Affecting Water Quality for AGR Agricultural objectives for water quality are less strict than those for municipal and domestic water supplies. Based on data from Goff et al. (2001) from 1989 to 1995 and on data from Suchanek et al (2002) from February 2001, the following table relates the data to the objectives for agricultural water, to detect if limitations are present for Bear Creek water used for agricultural water in Bear Creek watershed and downstream in Yolo County. Table 5.4 shows which elements exceed the agricultural water objectives in Sulphur Creek and in lower Bear Creek. Currently, no data exist for upper Bear Creek and Mill Creek.

Table 5.4 - Status of chemical elements and ions exceeding agricultural water quality objectives Chemical Mouth of Sulphur Element or Bear Creek Ion Creek Aluminum ? no Arsenic no no Boron yes yes Cadmium no no Chloride yes yes Chromium (VI) no no Cobalt no no Copper no no Fluoride yes n.d. Iron ? no Lead no no Manganese yes no Molybdemum no n.d. Nickel no no Selenium ? no Sodium yes yes Vanadium no n.d. Zinc no no pH yes yes Source: DWR readings 2001-2006 near the mouth of Bear Creek n.d. = no data ? = uncertain

Boron Naturally occurring boron in drinking water usually does not pose a health risk to people. The greater concern is for agriculture. Boron is an essential plant micronutrient that quickly becomes toxic to plants at concentrations slightly above nutritional requirements. High concentrations of boron in irrigation water and farm soil adversely affect soil fertility and crop yields.

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Most boron found in the Cache Creek Basin originates in Bear Creek watershed, and, more specifically, in Sulphur Creek subwatershed. Boron concentrations in Sulphur Creek thermal springs are fairly even throughout the year and exceed 225 mg liter-1. Thompson et al. (1978) also recorded high boron levels in a saline cold spring in Bear Valley. Boron concentrations in Sulphur Creek seasonally exceed 100 mg liter-1 (Goff et al. 2001). These concentrations are higher than the recommended threshold concentration of 10 mg liter-1 (response level) to close a drinking water supply and the 0.7 mg liter-1 maximum for agricultural uses.

The Yolo County Flood Control and Water Conservation District has monitored boron concentrations since the late 1930’s in the lower Bear Creek watershed. Dissolved boron collected there averaged 13.9 mg liter-1 in 250 samples collected between 1988 and 2006 (Stevenson 2007). Data collected by the US Geological Survey from 1968 to 1978 found concentrations in lower Bear Creek between 2.1 to 21.0 mg liter-1 with no apparent seasonal trend.

The District uses Bear Creek water during its irrigation season, which usually extends from April through October. This period coincides with the time of annual lowest flows from Bear Creek when Bear Creek supplies on average 2.8 percent of the total Cache Creek flow diverted by the District for irrigation (J. Weigand and M. Stevenson, pers. comm.). The much larger water contributions from Clear Lake and Indian Valley Reservoir to the main stem of Cache Creek effectively dilute the high summer concentration of boron in the small water volume coming from the Bear Creek. Water treatment to dilute or remove boron may not be cost effective or necessary, as long as the water flow in Cache Creek upstream of the confluence of Cache Creek and Bear Creek continues to dilute boron from Bear Creek before water is diverted for irrigation in Yolo County (M. Stevenson, pers. comm.).

Other Constituents Naturally occurring chloride and sodium ions remain at concentrations that could be detrimental to agricultural uses when Bear Creek enters Cache Creek. Given the small amount of water from Bear Creek used for irrigation and the corresponding dilution effect with water from the main stem of Cache Creek, the impact to agriculture is likely not significant. pH (Concentration of Hydrogen Ions in Water) for AGR The concentration of hydrogen ions in water is expressed as pH. Water quality objectives for agriculture recommend that pH in water must range between 6.5 and 8.4. pH values at sites in Sulphur Creek approach or exceed the upper range limit, indicating alkaline water.

Data for pH from USGS data station 11451720 collected between 1969 and 1978 near the mouth of Bear Creek had values greater than 8.4 on 18 out of 112 days of record on dates at all times of year. By comparison, data for pH from the nearby USGS data station 1141715 on

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Bear Creek showed that all ten days of record for 2000 (the only year for which data are available) exceeded pH 8.4.

Table 5.5 – Physical properties of Sulphur Creek water samples from 2001 02 23 and three samples from lower Bear Creek in the same period Electro- Specific Redox Field conductivity Water Sources Temp °C Conductance Potential pH (μS at field (μS at 25°C) (volts) temp) In-Stream Water from Sulphur Creek Sulphur Creek INDEX STATION 7.0 8.14 1.41 2.15 111.6 • SUL-540 Sulphur Creek below Wilbur 7.2 8.09 1.38 2.09 -37.4 Springs Resort • SCM-600 Sulphur Creek above Wilbur 9.5 7.98 0.93 1.32 -34.8 Springs Resort • SCM-601 Side Stream to Sulfur Creek 8.2 8.72 0.30 0.44 -183.8 • SCM-602 Sulphur Creek above "Jones 9.8 8.40 0.86 1.21 -185.1 Fountain" geyser • SCM-604 Sulphur Creek above 605/606 9.0 8.39 0.80 1.12 -143.5 input • SCM-607 Sulphur Creek above all mines 8.7 8.38 0.68 0.97 -86.4 except Elgin • SCM-608 Creeks Flowing into Sulphur Creek Creek from Wide Awake Mine 16.0 7.97 7.18 8.67 -306.6 • SCM-605 Sulfurous creek by Cherry Hill 10.0 8.46 1.39 1.94 -160.1 • SCM-606 In-Stream Water from Lower Bear Creek USGS Station 1141715 -- 8.50 ------2001 02 20 USGS Station 1141715 -- 8.80 ------2001 02 27 DWR Station A1825000 7.5 8.30 ------2001 03 01 Sources: Suchanek et al. (2002), USGS Station Data, and CA Department of Water Resource Water Data Library

Chemical Elements Affecting Water Quality for Aquatic Life (SPWN, WARM, WILD) Data collected at the California Department of Water Resources gage station in lower Bear Creek showed that none of the critical chemical elements included in the California Toxic Rule for aquatic life exceeded the Rule limits. The high alkalinity of Bear Creek stream water raises the not-to-exceed critical threshold amounts for many chemical elements well above concentrations found in Bear Creek at monitoring station site A1825000.

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Bacteria Affecting Water Quality for MUN and REC1 No sampling of ground water in Bear Creek watershed has been undertaken to determine whether coliform bacteria are less than 2.2 per 100 milliters, the count acceptable for any seven-day sampling period (Basin Plan 2007).

No data are available to determine whether fecal colifornm bacteria counts in Bear Creek and its tributaries are within the State of California water quality objectives for contact recreation given in Appendix H. Fecal coliform bacteria are likely to be high in Bear Creek on account of livestock grazing (J. Alderson, pers. comm.).

Oxygen Dissolved in Water (SPWN, WARM) Schwarzbach et al. (2001) found that the dissolved oxygen concentration in Sulphur Creek in October 1998 was 7.63 mg liter-1 or 72 percent of the concentration found nearby in Bear Creek. The percent value from Sulphur Creek was the lowest of recorded values in the Cache Creek Basin at the same time. Near the mouth of Bear Creek, readings of dissolved oxygen ranged from 7.9 mg liter-1 (June 2005) up to 13.7 mg liter-1 (March 2005) at the Department of Water Resources monitoring station. The values recorded to date exceed the minimum amounts set by the CVRWQCB for both SPWN (7.0 mg liter-1) and WARM (5.0 mg liter-1).

Sediment The concentration of total mercury in suspended sediments in Sulphur Creek (Wilbur Springs) was about ten times greater (25 micrograms per gram dry weight of sediment) compared to concentrations near the mouth of Bear Creek (Domagalski et al. 2004b). The Wilbur Springs site and the USGS gage on Sulphur Creek had the highest instantaneous mercury loads (averaging > 1000 nanograms per liter) recorded at stream sites in Cache Creek Basin (Cooke and Morris 2005, Domagalski et al. 2004b). Bosworth and Morris (2009) found, however, that individual sediment deposition areas along the lower Bear Creek contained up to 19 kg of total mercury.

5.3 Aquatic Biological Data This section describes existing biological data for Bear Creek watershed in regard to aquatic species exposed to water contaminants, especially methylmercury. These species are indicators, or “bio-sentinels”, to alert people to the condition of the stream environment, and in particular water quality. This assessment examines three categories of aquatic species: benthic macroinvertebrates, fishes, and foothill yellow-legged frog.

Existing data are few but indicate the spatial and temporal distribution of methylmercury in watershed creeks and among species at different trophic levels in the aquatic food web. Total mercury (including methylmercury) concentrates (“bioaccumulates”) as the trophic level of

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Benthic Macroinvertebrates Aquatic biologists and geochemists sample many kinds of aquatic insect and worm species (benthic macroinvertebrates) that live on the bottom of a stream (the benthos). These animals are indicators to track the presence and dispersion pattern of water contaminants. Three studies for regional sampling of benthic macroinvertebrates in the Cache Creek Basin have included data from Bear Creek (Schwarzbach et al. 2001; Slotten et al. 1997, 2004).

Benthic macroinvertebrates indicate relative levels of methylmercury in streams because invertebrates accumulate methylmercury directly from sediment and from predation on other invertebrates. Methylmercury originates in the stream benthos where an anaerobic (oxygen- less) environment creates a favorable habitat for bacteria to transform mercury into methylmercury. The levels of methylmercury detected in these organisms are not direct predictors of mercury toxicity to people or wildlife, however.

Macroinvertebrate surveys showed that the highest concentrations of total mercury in macroinvertebrates came from Sulphur Creek. There, concentrations ranged from 5.0 to 8.7 ppm dry weight. Concentrations of total mercury in damselfly larvae were 25 times higher at Sulphur Creek than in Bear Creek above its confluence with Sulphur Creek (Schwarzbach et al. 2001).

Table 5.6 – Concentrations of total mercury (THg) and methylmercury (MeHg) benthic insect larvae from Bear Creek watershed Anisoptera Megaloptera Trichoptera Dragonflies dobsonflies caddisflies Sites from north to south THg MeHg THg MeHg THg MeHg parts per million, dry weight Mill Ck @ Brim Rd 0.035 0.032 -- -- 0.036 0.033 Sulphur Ck @ Wilbur Spr 1.349 0.180 -- -- 0.348 0.035 Rd Bear Ck below Sulphur Ck 0.077 0.058 0.495 -- 0.103 0.062 Bear Ck @ Hamilton Cyn 0.036 0.030 -- -- 0.026 0.017 Bear Ck @ Highway 20 0.433 0.259 0.245 0.168 0.429 0.176 Bear Ck @ 15-37 0.235 0.159 0.204 0.151 0.534 0.255 Source: Schwarzbach et al. 2001

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Table 5.7 – Concentrations of total mercury (THg) and methylmercury (MeHg) in benthic insect larvae Odonata Anisoptera Hemiptera dragonflies Trichoptera dragonflies true bugs and caddisflies Sites from north to south damselflies THg MeHg THg MeHg THg MeHg THg MeHg micrograms per gram wet body weight Bear Creek in Bear Valley 0.031 0.030 0.041 0.033 n.d. n.d. 0.034 0.033 Sulphur Creek n.d. n.d. 0.416 0.139 1.987 0.290 n.d. n.d. Bear Creek below Sulphur 0.343 0.286 0.465 0.306 0.168 0.138 0.425 0.359 Ck confluence Bear Creek near Cache Ck n.d. n.d. n.d. n.d. n.d. n.d. 0.250 0.074 confluence Source: Slotton et al. 2004, collection dates: May 8-9, 2000 for all insect larvae except February 15, 2001 for larvae in Bear Creek near its confluence with Cache Creek

The total mercury concentration in some insect larvae groups from Sulphur Creek subwatershed is at least an order of magnitude higher than at the north end of Bear Valley (Mill Creek at Brim Road) (Schwarzbach et al. 2001). But, the benthic environment most conducive for mercury methylation is in Bear Creek below the confluence with Sulphur Creek (Slotton et al. 2004). The stream environment in Bear Creek near the bridge at Highway 20 may furnish, at least seasonally, better conditions for bacterial mercury methylation and subsequent methylmercury uptake by invertebrates as evidenced by the high ratio of methylmercury to total mercury found in invertebrates there.

Methylmercury concentrations in invertebrates at the lower Bear Creek site peaked in mid- summer (June to August), with a smaller February peak. In July 2001, methylmercury values reached nearly 1.0 microgram per gram wet body weight in Bear Creek invertebrates (Slotten et al. 2004). Slotten et al. (2004) also examined a site in Bear Valley above the confluence with Sulphur Creek where methylmercury concentrations in invertebrates ranged just up to 0.160 micrograms per gram wet body weight during the mid-summer peak. They propose that the winter methylmercury peak in invertebrates results from high storm flows that mobilize methylmercury-enriched bed material. Summer peaks in invertebrate methylmercury, on the other hand, point to sites of high methymercury uptake, linked to locally high rates of bacterial mercury methylation during low flows where stream sediment is less mobile and warm creek water is oxygen-deficient.

Away from the lower main stem of Bear Creek, larvae from tributaries in Lynch Canyon, Thomson Canyon, and the unnamed canyon closest to the mouth of Bear Creek had concentrations of methymercury about ten percent of concentrations found in Bear Creek itself.

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Both Schwarbach et al. (2001) and Slotten et al. (2004) found a high methylmercury to total mercury ratio in Mill and Bear creeks in Bear Valley, indicating a high methylation rate for a comparatively low concentration of total mercury in these streams. One explanation for the high methylation rate at these locations is the extensive presence of algal mats that create anaerobic sites for methylating bacteria.

Fish in Bear Creek Fish are critical to water quality management in Bear Creek because the watershed TMDL established for methylmercury requires monitoring it in fish tissues to ascertain whether the watershed is attaining goals set by the CVRWQCB to reduce methylmercury. Several factors determine the amounts of total mercury and methylmercury that fishes accumulate: the species of fish (and its trophic level), mercury concentrations in stream sediment, and the rate of bacterial methylation, which in turn depends on the availability of sulfate, iron, bacterial nutrients, and organic matter. Different stretches of Bear Creek have fish with differing concentrations of mercury. Bear Creek has fish with higher concentrations of total mercury and methymercury below the confluence with Sulphur Creek (mid-Bear Creek) than in Bear Valley above the confluence.

For comparable size classes, different fish species have differing mercury levels as a function of their diets. Carnivorous fishes such as the Sacramento pikeminnow (Ptycholeilus grandis) prey on other fish and generally have higher levels of mercury than detritivore (eating organic debris) fishes such as the Sacramento sucker (Catostomus occidentalis). Therefore, different TMDL amounts of methylmercury apply to different fishes depending on their diets and their position as predators (trophic level) in the food chain.

Fish Consumption Advisory OEHHA issued a health advisory and consumption guidelines for fish and shellfish from Bear Creek and its tributaries (Gassel et al. 2005) on January 20, 2005. The advisory states that no one should eat any fish or shellfish from Bear Creek watershed because of the risk of damage to people’s central nervous systems from methylmercury toxicity. Risks are highest for young children, particularly nursing children, and unborn children whose mothers eat mercury-laden fish. The health advisory responds to findings that average methylmercury concentrations found in Sacramento pikeminnow and Sacramento sucker in Bear Creek, exceeded OEHHA’s standards for health safety.

Total Mercury and Methylmercury in Fish Both Schwarzbach et al. (2001) and Slotten et al. (2004) found that fish sampled from Bear Creek had markedly higher concentrations of total mercury and methylmercury than elsewhere in the Cache Creek Basin. For example, total mercury concentrations in fish sampled at a mid-Bear Creek monitoring site were greater than concentrations found in fish

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BEAR CREEK WATERSHED ASSESSMENT from the main stem Cache Creek below Bear Creek: about seven times greater in Sacramento pikeminnow and nine times greater for Sacramento sucker. All fish at the mid-Bear Creek site had mercury levels sixteen and eighteen times greater respectively than at the Clear Lake outflow and in the North Fork Cache Creek. Muscle tissue in California roach (Hesperoleucus symmetricus) weighing less than 0.6 kg from a Bear Creek site 6.25 miles downstream of the Sulfur Creek confluence had methylmercury concentrations up to 0.95 micrograms per gram fish wet weight. This amount is more than three times greater than the US EPA Recommended Fish Tissue Criterion for methylmercury in fish at 0.30 micrograms of methylmercury per gram fish wet weight (Slotten et al. 2004).

Within Bear Creek itself, total mercury concentrations in fish in upper Bear Creek (Bear Valley) averaged about a third or less of the total mercury concentrations in fish from mid- Bear Creek below Sulphur Creek (Tables 5.8 and 5.9).

Both carnivore Sacramento pikeminnows and detritivore Sacramento suckers had higher than expected methylmercury levels at an upper Bear Creek site, by comparison. This finding corresponded to high ratio of methylmercury to total mercury concentrations in upper Bear Creek invertebrates.

Table 5.8 – Average total mercury concentrations in ppm wet weight in three fish species from Bear Creek, 1997 Sacramento Sacramento California Location Pikeminnow Sucker Roach Bear Ck above Sulphur Ck 0.577 (n=10) 0.125 (n=11) 0.363 (n=10) Bear Ck below Sulphur Ck 0.337 (n=3) 0.351 (n=8) 0.418 (n=9) Bear Ck at Highway 20 1.655 (n=1) 1.047 (n=6) 0.872 (n=10) Schwarzbach et al. (2001), Appendix C

Table 5.9 – Data on total mercury concentrations in ppm wet weight in two fish species from Bear Creek, 2000 Mean Fork Maximum Mercury (ppm) Average THg Sample Species Length (ppm)* Upper Bear Middle Bear Size (mm) Creek Creek Sacramento 2.20 (1.23 – 3.17) 273 1.15 6.43 15 Pikeminnow Sacramento 0.62 (0.33 – 0.90) 220 0.43 1.65 17 Sucker Source: Gassel et al. (2005) *numbers in parentheses comprise the range of values for 95 percent of all data for that species

Amphibians Until recently, researchers have not monitored amphibians, and in particular frogs, for mercury. Hothem et al. (in press) sampled total mercury concentrations in three frog species in Bear Creek: foothill yellow-legged frogs (Rana boylii), bullfrogs (Lithobates catesbeianus),

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BEAR CREEK WATERSHED ASSESSMENT and Pacific treefrog (Pseudacris regilla).

Other chemical constituents of Bear Creek water may affect frog populations. High concentrations of boron and chloride in Bear Creek may contribute the absence of California red-legged frogs (Rana draytonii) in watershed, for example (letter from Dr. K. Shawn Smallwood to Cecilia Brown, US Fish and Wildlife Service, Sacramento, dated July 18, 2000).

Invasive Aquatic and Riparian Species Invasive aquatic and riparian species are threatening native vegetation, aquatic species biodiversity, and hydrologic function in Bear Creek and its tributaries. In the Report of Independent Science Advisors for the Yolo County Natural Community Conservation Plan, Spencer et al. (2006, p. 43) state that “conservation of Bear Creek watershed and restoration of riparian vegetation there should be a high priority”. Enhancing and restoring riparian habitat is critical for many rare riparian species of concern and for creating habitat for large game animals, protecting riparian forests, and stabilizing stream buffers in Bear Creek watershed.

One benefit of riparian tree and shrub cover is the effect of shade on moderating stream temperatures. Maintaining cooler water temperatures in Bear Creek, particularly during May and June when exotic fish generally reproduce, may also reduce non-native fish invasions. Many exotic species, particularly bass (Micropterus spp.), have difficulty reproducing in cold water conditions. Restoration and maintenance of riparian vegetation along Bear Creek would help to reduce local stream temperatures in Bear Creek during warm months and favor better reproduction of native fish species.

The California Aquatic Invasive Species Management Plan (Invasive Species Program 2008) has identified 48 critically important non-native invasive aquatic species. Control of these species in the watershed would contribute to reestablishing native aquatic and riparian species. Eight of these species are definitely known to occur in the watershed and four others are likely to occur.

Table 5.10 – Principal aquatic invasive species known or likely to occur in Bear Creek watershed Species Locations in or near Bear Creek Scientific Name Eradication Treatments to Date Watershed Family Name Vascular Plants Perennial pepperweed Leesville Road, Bear Creek Ranch Lepidium latifolium Grazing with goats along Bear Creek Brassicaceae

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Species Locations in or near Bear Creek Scientific Name Eradication Treatments to Date Watershed Family Name Parrot feather milfoil Likely to encounter but no known Myriophyllum aquaticum None detections Haloragaceae Eurasian milfoil Likely to encounter but no known Myriophyllum spicatum None detections Haloragaceae Small-flowered tamarisk Herbicide treatment; the tamarisk Sulphur Creek, Bear Creek Ranch, Tamarix parviflora defoliator Diorhabda elongata Bear Valley Road Tamariceae may move into Bear Creek Waterthyme (Hydrilla) Hydrilla verticillata Possible but no known detections None Hydrocharitaceae Giant reed (Arundo) Sulphur Creek, along Highway 20 Arundo donax Eradication has been initiated east of Highway 16 Poaceae Curly pondweed Potamogeton crispus Leesville Road, Bear Creek Ranch None Potamogetonaceae Invertebrate Animals New Zealand mudsnail Not yet recorded but found Potamopyrgus antipodarum nearby in the Putah Creek and None Hydrobiidae Russian River watersheds Vertebrate Animals Green sunfish Lepomis cyanellus occurs in lower Bear Creek None Centrachidae Bluegill Lepomis macrochirus occurs in lower Bear Creek None Centrachidae Smallmouth bass Micropterus dolomieui occurs in lower Bear Creek None Centrachidae Bullfrog Lithobates catesbeianus occurs in lower Bear Creek None Ranidae Sources: Consortium of California Herbaria, Marchetti et al. (2004), Montana State University New Zealand Mudsnail Project on-line, G. Mangan, pers. comm. (2006)

Stream Survey Data Stream surveys of channel types, bedloads, substrates, stream bank stability, slump potential, large woody debris, and riparian vegetation have not occurred uniformly across the watershed. In 1999, the BLM Ukiah Field Office conducted an aerial survey of the streams on remote public lands at the north end of the watershed using the BLM Proper Functioning Condition protocols for riparian areas (Prichard 1998, 1999). All streams in Mill Creek subwatershed and in the subwatersheds draining east from Walker Ridge were found to be in proper functioning condition based on hydrology, vegetation, and sediment indicators. Streams south

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BEAR CREEK WATERSHED ASSESSMENT of Highway 20 were not surveyed at the time because the lands were in private ownership at the time.

5.4 Sources of Water Contaminants High concentrations of contaminants in Bear Creek watershed stem almost entirely from naturally occurring materials in the watershed. However, land uses have increased the conversion of contaminants to more toxic chemicals and have spread contaminants in the watershed and further downstream.

Contaminants in the watershed are considered “non-point” sources rather than “point” sources because they accumulate in stream water from multiple, diffuse sources across the watershed rather than from a single identifiable source point in the landscape. Non-point source pollution usually involves rainfall striking the ground, running overland, infiltrating through the soil, or eroding stream banks. Contaminants may then become part of aquatic environments, precipitate to solids become part of soils or streambeds, or reach ground water.

This chapter section takes up the natural sources of water contaminants and, then, the sources of contamination from current and past land uses in Bear Creek watershed.

Hydrothermal Springs White et al. (1973) first identified the role of hydrothermal springs in conveying mercury from deep in the earth up to surface water in Sulphur Creek subwatershed. Peters et al (1993) and Sherlock (2005) have characterized properties of hydrothermal spring waters in the Sulphur Creek area as follows:

 hot (> 50°C) water originating from deeply-buried ancient seawater similar to the subsurface water found in the Arbuckle oil and gas field in the Sacramento Valley  high concentrations of mercury, antimony, and arsenic  highly alkaline (pH > 7.0)  concentrations of chloride (Cl-) lower than in sea water but abnormally high for hydrothermal springs 2-  concentrations of chloride greater than the concentrations of sulfate (SO4 ) but both present in high concentrations to promote mercury methylation

 high concentrations of hydrogen sulfide (H2S), ammonia (NH3), and boron originating in deeply buried marine sediments.

Table 5.11 lists the major springs near Sulphur Creek and summarizes their chemical elements and ions that may impact water quality downstream. More detailed data on the variability in readings from the uniform data collection efforts by Goff et al. (2001) and Suchanek et al. (2002) are available in Appendix K. 180

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Table 5.11 – Springs and associated elements and ions possibly affecting water quality Elements and Ions with concentrations that may affect water quality down Spring Sources stream in Bear Creek Wilbur Spring Don mercury, barium, boron, chloride, fluoride, nitrite, sulfate White’s Wilbur Spring, Main mercury, arsenic, barium, boron, chloride, fluoride, manganese Jones Fountain of Life mercury, arsenic, barium, boron, chloride, fluoride, iron, lead, manganese Blanck Spring mercury, arsenic, barium boron, chloride, fluoride, nitrate, sulfate Elbow Spring mercury, barium, boron, chloride, fluoride, manganese, nitrate, sulfate Elgin Spring Main mercury, barium, boron, chloride, fluoride, iron Elgin Spring Orange Tub barium, boron, chloride, fluoride, sulfate Unnamed Hot Spring mercury, barium, boron, chloride, fluoride Source: Goff et al. (2001), Suchanek et al. (2002)

Table 5.12 – Hydrothermal spring flows and their mercury loads Annual Average Mercury Flow Geothermal Hydrothermal Springs Load cfs Mercury Load (mg liter-1) (lbs) Wilbur Spring Main 0.047 5.556 0.51 Jones Fountain of Life 0.012 26.642 0.63 Blanck Spring 0.008 6.900 0.11 Elbow Spring 0.0003 61.000 0.04 Elgin Spring Main 0.015 11.000 0.32 Total 1.61 Source: Goff et al. (2001)

Of the major springs in Sulphur Creek subwatershed, Jones Fountain of Life and the main Wilbur Spring are the principal known suppliers of mercury to Sulphur Creek. Other spring sources may be significant but no data are available. The CVRWQCB does not intend to manage natural sources of mercury coming from hydrothermal springs as these sources are natural (or background) features of the watershed.

Cold Mineral Springs The contribution of cold mineral springs in Bear Creek watershed to mercury loads is less well understood. This category of springs occurs outside Sulphur Creek subwatershed, and studies of these springs thus far have short-term and infrequent.

Slowey and Rytuba (2008) report on cold springs associated with an alluvial fan at the southwest corner of the Bear Valley floor. These springs along the newly discovered Bear Fault have naturally high concentrations of mercury in water dissolved by means of reactions with sulfate ions or with organic acids to form methylmercury. Water from these spring sources shares features of the hydrothermal springs in Sulphur Creek subwatershed: high amounts of chloride (salinity), boron, alkalinity (high pH), and total mercury. However, water

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BEAR CREEK WATERSHED ASSESSMENT temperatures are about 25°C cooler during the early summer compared to hydrothermal springs and drop to 10°C during winter months. The springs often go dry by the end of the summer if water from rainfall stored in the ground water is insufficient (J. Rytuba and J. Weigand, field obs., October 2007). Dry-season total mercury concentrations from spring water samples along the Bear Fault ranged from 0.0076 to 0.690 mg liter-1. Fluctuations in concentrations of total mercury and methylmercury depend on the availability of cinnabar (the source of mercury), carbonate, dissolved organic acids, and the amount of rainwater mixing with the connate spring water to dilute total mercury and methylmercury.

No estimate is available yet of an annual background amount of total mercury and methylmercury flowing naturally from saline cold springs on or just above the floor of Bear Valley. Boron, chloride and sulfate ions are the only other potential water contaminants known from these cold spring sites.

Stream Bank Erosion Flowing water erodes stream banks and streambeds, especially during powerful winter storms. The erosion impact of these high-velocity flows depends as well on the stability of the bank material. For instance, sand will erode more easily than gravel or silt. Stream bank erosion is a significant natural non-point source of mercury and other chemical elements.

Land uses have added to stream bank erosion as well. Local engineering of Bear, Sulphur, and Mill creeks has led to straightening streams and loss of natural meander, with the outcome that stream water gains velocity and power to erode banks. Bear Valley Road and Wilbur Springs Road have encroached on Bear Creek and Sulphur Creek at several sites. Efforts to stabilize banks alongside roads in Sulphur Creek and in lower Bear Creek with riprap and boulders is displacing the erosion force of water to the opposite bank or further downstream and does not appear to provide a solution to curtailing erosion. Channel incision is the most prevalent recent manifestation of stream bank erosion. Hoorn et al. (2008) estimated that 20,080 yd3 of sediments migrated from six incised sites along Sulphur Creek between 1968 and 2005.

Background Soil and Sediment Erosion Rate Related to Mercury No baseline studies provide actual field data on background soil erosion in Bear Creek watershed. Churchill and Clinkenbeard (2003), however, have estimated the annual background erosion rate of total mercury at 10.1 to 208.1 lbs for the entire Bear Creek watershed. The wide range in values reflects impacts of widely differing rainfall amounts from year to year. Mercury-rich sediment may erode but not necessarily reach a stream during a given storm; therefore, the amount of mercury reaching Bear Creek and its tributaries may be less than the total mercury erosion projected.

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Atmospheric Deposition of Mercury onto Bear Creek Watershed The rate of mercury deposition from the atmosphere onto the ground surface is likely much less than the volatilization of mercury to the atmosphere from the watershed. Churchill and Clinkenbeard (2003) projected atmospheric mercury deposited onto Bear Creek watershed from the atmosphere at an annual rate of 11.2 lbs. No other data exist at this time.

Abandoned Mercury Mines and Mine Waste The California Department of Conservation developed the PAMP (Principle Areas of Mine Pollution) database in 1972 to identify known or potential mine sources compromising water quality. Five PAMP areas lies within Bear Creek watershed, four of them within Sulphur Creek subwatershed, the other originating with the Rathburn Petray mine complex and possibly associated with the alluvial fan into the main stem of Bear Creek in southwest Bear Valley (Figure 3.5).

Hoorn et al. (2008) estimated total sediment delivery from mine waste to streams in Bear Creek watershed north of Highway 20 to be at least 18,400 tons (13,600 cubic yards). Sediment from mine waste moves primarily by way of gullies rather than by debris landslides into streams. The gullies are of human origin rather than part of natural processes in the watershed. Although only two percent of the volume of sediment derives from mines and mine waste, the mercury content in the sediment is cause for concern.

Cooke and Morris (2005) and Cook and Stanish (2007) have underscored the significance of sediment stemming from abandoned mercury mines as sources of mercury contamination. Sediment erosion and accompanying cinnabar and metacinnabar transport from abandoned mines in Sulphur Creek and Upper Bear Creek subwatersheds have been unmanaged until recently. Table 5.13 gives estimates of annual mercury erosion from individual mines

Table 5.13 – Estimated range of annual sediment and mercury erosion at abandoned mine sites Total Mercury Sediment Mine pounds per Type of Material tons per year year Central 0.85 – 1.76 0.01 – 0.07 tailings, retort Cherry Hill 0.02 0.00 – 2.20 waste Clyde 17.7 – 36.0 0.09 – 0.15 waste rock, tailings Elgin 27.9 – 52.8 8.60 – 20.50 waste rock, retort Empire 0.41 – 0.61 0.09 – 0.13 waste rock Manzanita 0.98 – 11.0 0.66 - 14.33 waste Rathburn - Petray 2.9 – 26.0 2.65 – 53.57 waste rock West End 0.02 – 5.9 0.004 – 2.43 waste rock Wide Awake 2.7 – 17.0 0.002 – 1.1 waste rock, retort Total 53.5 – 151.1 12.1 – 94.4 Source: Churchill and Clinkenbeard (2003)

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Agriculture and Livestock Grazing Agricultural and grazing contamination covers five topics: (1) herbicides and pesticides; (2) fertilizers; (3) fecal bacteria; (4) dissolved organic matter; and (5) stream bank loss from livestock trampling.

Herbicides and Pesticides Herbicides and pesticides have been applied for agricultural uses at times in the watershed to protect crops, particularly in Upper Bear Creek and Leesville subwatersheds. But, the impact is likely to be minor because crop agriculture in the watershed is on a small scale. BLM law enforcement officers have found contraband herbicides and pesticides (rodenticides in particular) in illegal marijuana gardens on public lands in the watershed. Other applications of herbicides have related to invasive plant control projects in riparian zones along lower Bear Creek (C. Thomsen, pers. comm.).

Fertilizers Illegal marijuana farming operations use high quantities of nitrogen fertilizers to promote crop growth on infertile ultramafic soils. Data collected from Sulphur Creek subwatershed, Bear Valley, and from lower Bear Creek do not show abnormally high nitrogen concentrations in water sampling thus far. However, the existing sampling data may pre-date the start of actual illegal marijuana cultivation in the watershed.

Fecal Bacteria Both domesticated livestock and wild animals contribute fecal matter and fecal coliform bacteria to Bear Creek and its tributaries. If fecal coliform bacteria counts are high, the counts serve as indicators that Bear Creek water is not suitable for MUN and REC1 beneficial uses. No public data are available at present for counts of coliform bacteria in the watershed.

Dissolved Organic Matter Slowey and Rytuba (2008) have hypothesized that plant matter in livestock excrement in Bear Valley is providing a large amount of dissolved organic matter to Bear Creek and its tributaries. Dissolved organic matter is an essential component for forming methylmercury in streams and wetlands. Geochemists are presently preparing scientific articles (E. Suess, pers. comm.) about the correlation between high dissolved organic matter and rates of mercury methylation in Putah Creek watershed to the south of Bear Creek watershed.

Erosion of Stream Banks from Livestock Trampling Stream bank collapse and resulting bank erosion also may stem from excessive soil trampling along stream banks where large animals, including livestock and game animals, concentrate. North of Highway 20, livestock grazing in Bear Creek watershed does not appear to have been a major direct source of new landslide erosion into Bear Creek and its tributaries in the

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BEAR CREEK WATERSHED ASSESSMENT last seventy years. Hoorn et al. (2008) found only one stream channel erosion event related to livestock grazing since 1937 that generated sediment delivery greater than 1,000 cubic yards. Three pre-1937 erosion sites, however, were more severe (sites 62, 63, 64), with a combined sediment delivery of more than 7,000 cubic yards.

The legacies of livestock grazing on erosion in the watershed south of Highway 20 may have a different pattern. More intensive grazing in steeper terrain where blue oaks (Quercus douglasii) and chaparral shrubs were removed to provide more non-native grassland forage may have led to the numerous landslides on haploxeralf soils (Reed 2006) on Bear Creek Ranch and to abnormally high sediment transport from upland ultramafic soils to Bear Creek.

No information is available on livestock impacts to sediment and dissolved organic matter from Mill Creek subwatershed.

Tree Cutting Cutting oaks in Sulphur Creek subwatershed may increase the impact of rainfall on soils, increase soil erosion overland, and mobilize mercury-rich sediments from soils and abandoned mine waste (Cooke and Morris 2005). Data on erosion from tree cutting in the watershed do not exist.

Wildlife Big game species such as tule elk, deer, and non-native wild pig, can disturb soils, destabilize stream banks, and add organic matter to streams in ways similar to livestock. No studies at present document the impact of these species on water quality in Bear Creek or other inner North Coast Range watersheds.

Transportation Estimates of sediment production stemming from the motorized transportation infrastructure in Bear Creek watershed come from two sources: CALTRANS modeled estimates for the state highways in the watershed and Hoorn et al. (2008) for road-related erosion in the watershed north of Highway 20.

Of all human management and land use impacts, roads and trails are the largest source of sediment in Bear Creek watershed north of Highway 20 (Hoorn et al. 2008). Travel and maintenance engineering on county roads, off-highway motor vehicle trails, and new and enlarged access roads for eventual energy projects in uplands could add to the sediment loads reaching Bear Creek.

Impermeable road surfaces consist of State Highways 16 and 20 and county-maintained roads in the northeast part of the watershed. These surfaces can present challenges to dispersing the

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BEAR CREEK WATERSHED ASSESSMENT loads and force of water. The Office of Water Programs at the California State University at Sacramento has estimated annual stormwater sediment loads for planning purposes from the stretches of Highways 16 and 20 that pass through Bear Creek watershed. Table 5.14 gives the estimated amounts of total solids and selected elements and nutrients. Estimates of total mercury and methylmercury transported on state highways are not available. No estimates or data on erosion and chemical elements in sediment from county roads are available.

Table 5.14 – Combined estimates of sediment loads in Bear Creek Watershed from State Highways 16 and 20 by key constituents Tons per Chemical Constituents Lbs per Year Year Elements Total dissolved solids 12.27 Arsenic 0.99 Total suspended solids 12.07 Cadmium 0.15 Dissolved organic carbon 2.68 Copper 2.34 Suspended organic carbon 0.21 Lead 9.72 Nutrients Lbs per Year Nickel 6.33 Nitrate 308.65 Zinc 70.77 Source: California State University at Sacramento, Office of Water Programs at: http://stormwater.water-programs.com/wqpt/HSA.asp?HSA=551320&ID=3019

Management of stormwater runoff from paved surfaces that have cut through ultramafic rock and soil may be important to reducing mercury-rich sediment that enters into the sediment and bed load of Bear Creek. CALTRANS scraped a 10.6-acre block of ultramafic rock and soil along the east side of Highway 20 between the Colusa-Lake county line and the bridge over Bear Creek, to remove a landslide hazard to the highway. Erosion from the unvegetated block onto the highway may be contributing ultramafic sediment and contaminant chemical elements. The site has been the subject of revegetation studies to reduce sediment flow and stabilize slopes (O’Dell and Claassen 2006 a,b). The cost for successful vegetation restoration in the remaining soils and on the parent rock has been very high (V. Claassen, UC-Davis soil scientist, pers. comm.).

Off-Highway Routes and Trails BLM and National Forest Service field staffs have mapped existing off-highway trails on federal lands in Bear Creek watershed. The Mendocino National Forest has completed designation of authorized OHV trails on National Forest lands. The BLM Ukiah Field Office designated some OHV trails in its Resource Management Plan (Bureau of Land Management 2006) and will be considering additions to the designated OHV route network for the Walker Ridge area. At present, 24 miles of trails are designated as open to off-highway vehicles on federal lands in the watershed. Some of the nearly 110 miles of undesignated routes will require restoration to natural conditions to prevent erosion and link currently fragmented vegetation and wildlife habitat.

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Sulphur Creek subwatershed has the highest density of currently unauthorized off-highway routes and trails. The region around the Rathburn-Petray mine complex in Upper Bear Creek subwatershed is another area of concentration. The presence of off-highway routes at abandoned mercury mine sites raises concerns about water quality and for ride safety in the unstable terrain.

Stream Fords At several points a BLM-designated off-highway trail traverses stream beds and a rare ultramafic wetland. These disturbances may impair hydrologic function and increase sediment transport downstream.

Fire Management CALFIRE created a 21-mile dozer fire line across watershed terrain in 2008 to halt the progress of the Walker Fire into Bear Valley. The fire line creates management issues: increased soil erosion, invasive plants, little natural revegetation, and unauthorized vehicle travel.

Recreation Non-motorized recreation in Bear Creek watershed is mostly low-impact as recreation activities are dispersed. At sites such as Cowboy Camp, facilities are engineered to accommodate large numbers of visitors and small numbers of campers in ways that minimize the human imprint on the public land. In the Cache Creek Natural Area, the BLM has established 35.9 miles of trails for mechanical and non-mechanical recreation (mountain bike riding, equestrian use, hiking). The BLM manages this non-motorized trail system to avoid sediment erosion and channel incision in seasonal and permanent streams that flow from side canyons into lower Bear Creek.

Septic Systems Documentation on septic systems in the watershed does not presently exist. Homes and lodging facilities are few in number and not likely to limit the capacity of soils to decompose or disperse loads of nutrients (nitrogen, phosphorus) and bacteria.

5.5 Permits Affecting Water Quality National Pollutant Discharge Elimination System (NPDES) permits regulate pollutant discharges at specific locations from pipes, outfalls, and conveyance channels (point sources). The CVRWQCB issues NPDES permits covering Bear Creek watershed. Permits relate to roadwork affecting surface water discharges and to controls on storm water runoff from mine sites. In addition, the CVRWQCB sets objectives for permits, determines compliance with permits, and enforces compliance when necessary.

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Permits for confined animal facilities and wastewater treatment do not apply to conditions in Bear Creek watershed where no confined animal facilities are present.

Phase II Stormwater Permits Phase II stormwater permits are required for construction sites between one and five acres in extent. These sites need not be for industrial purposes. Phase I stormwater permits do not apply to Bear Creek watershed because of the small human population and the lack of industry requiring a storm sewer system.

Construction projects in the watershed since 1990 needing stormwater permits to manage altered stormwater flow coming from constructed sites have been few in number. The two permittees in the watershed are CALTRANS for work on Highways 16 and 20, and the BLM for development of recreation and visitor services facilities at Cowboy Camp and at High Bridge Camp. No storm water permitting has occurred in the last eighteen years on private property.

Place ID Place Name Type Status 218591 Cowboy Camp Facilities Development BLM Facility Terminated March 22, 2004 633082 High Bridge Annex Group Horse Camp BLM Facility Terminated May 12, 2006 633083 High Bridge Trailhead and Parking Area BLM Facility 262307 CA DOT District 3 DOT Facility Teminated Source: California State Water Quality Control Board database

No violations for wastewater treatment or storm water management occurred from January 1, 1990 through June 30, 2008.

Permits Required for Bear Creek Bridge Reconstruction and Highway 20 Realignment In 2008, CALTRANS initiated reconstruction of Bear Creek Bridge on Highway 20 and related highway realignment. Bear Creek Bridge and the stretch of State Route 20 between milepost 2.8 and milepost 3.8 have flooded during ten-year flood events. The existing culverts had not been large enough to convey floodwaters. Consequently, during heavy rainstorms the culverts were not functioning adequately, and Bear Creek overflowed the bridge and highway. The following permits have been required for compliance during new construction:

 a United States Army Corps of Engineers Section 404 Permit for filling or dredging waters of the United States  a CDFG 1602 Agreement for Streambed Alteration  a CVRWQCB Section 401 Water Quality Certification

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5.6 Beneficial Uses of Water at Risk The following beneficial uses assigned to Bear Creek watershed are at risk of degradation:

AGR – Agricultual Supply, Irrigation, and Stock Watering Mercury-rich water intended for crop irrigation may be building mercury concentrations from Bear Creek environmentally across a much broader area of arable land than might naturally occur, i.e., by way of Cache Creek stream diversions, the Cache Creek Settling Basin, and the Yolo Bypass before reaching the Bay-Delta marshes and wetlands. Boron concentrations might become a problem and require ongoing monitoring.

COMM – Commercial and Sport Fishing High concentrations of mercury in tissues of wild fishes have led to advisories against consuming fish caught for sport or subsistance use in Bear Creek and its tributaries. The CVRWQCB has deleted COMM as a beneficial use for Sulphur Creek because no fish live in Sulphur Creek on account of the naturally high concentrations of dissolved salts.

MUN – Municipal and Domestic Supply Concentrations of total mercury in Sulphur Creek led to the CVRWQCB to remove MUN as a beneficial use. Monitoring mercury loads downstream from the confluence with Bear Creek is critical to ensure that MUN is not put at risk elsewhere.

REC1 – Recreation, Contact Water and Canoeing and Kayaking Children playing occasionally in the streambed of Sulphur Creek or lower Bear Creek are unlikely to have exposure to methylmercury in toxic quantities. A greater concern for contact recreation is a health risk from bacteria in streams excreted by livestock and wildlife.

REC2 – Recreation, Non-Contact Water None

SPWN – Spawning, Reproduction, and/or Early Development Native fishes in Bear Creek watershed may be unfit for spawning, and young fish may develop circulatory or nervous system maladaptations. There is no local data on adverse effects in fish (J. Cooke, CVRWQCB, pers. comm.).

WARM – Freshwater Habitat, Warm Summertime low flows on Bear Creek create warm quiet shallows and pools that become incubators for bacteria to transform mercury into methylmercury (Schwarzbach et al. 2001). Methylation also increases where organic matter builds up in the stream during low flows. Successive predators at higher trophic levels amass higher bodily concentrations of

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methylmercury. These concentrations may impair the reproduction of some vertebrate species.

WILD – Wildlife Habitat The resident populations of fish-eating bald eagles, ospreys, and river otters build up potentially harmful concentrations of methylmercury in their bodies over time as they fish along lower Bear Creek. The riparian zone and stream water in lower Bear Creek, in particular, may become degraded habitat for foothill yellow-legged frogs and western pond turtles, both US Forest Service and BLM sensitive species.

5.7 Future Conditions and Target Loads for Water Contaminants

Abandoned Mines The CVRWQCB has established target total daily maximum load (TMDL) concentrations for mercury from inactive mines, load allocations for methylmercury in water (total mass but not instantaneous concentration), and water quality objectives for methylmercury in fish. The TMDLs also contain an aqueous methylmercury concentration goal (0.06 nanograms per liter) that is linked to the fish tissue objectives, but the goal is not enforceable. Additional TMDL requirements for total mercury in stream water apply to Sulphur Creek subwatershed. Table G.5 in Appendix G summarizes the load allocations.

The CVRWQCB has planned to complete mercury mine cleanup and control mercury discharges into Bear Creek watershed streams by the end of 2011, but this date may need revision. Legally determined responsible parties and current owners of abandoned mines shall develop and submit to the CVRWQCB Executive Officer a cleanup and abatement plan and schedule to reduce anthropogenic mercury loading in Sulphur Creek. The goal is to reduce loads of mercury from mining or other anthropogenic activities by 95 percent consistent with State Water Resources Control Board Resolution 92-49 (Basin Plan as amended 2007). The responsible parties shall be in compliance with this requirement when cleanup actions and maintenance activities follow the approved plans resulting from the cleanup and abatement orders.

Separating natural and anthropogenic sources of mercury is not always straightforward. For example, mercury and methylmercury produced by interaction of the natural Elgin thermal springs with mine wastes from the Elgin Mine are considered entirely part of anthropogenic loading.

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The Basin Plan also requires landowners and public land managers to have special permitting for activities that result in discharges of mercury within the ten-year floodplains of Bear Creek, Sulphur Creek, and their tributaries.

Methylmercury The goals for methylmercury are: a 50 percent reduction in Bear Creek at the southernmost bridge crossing on Bear Creek Road, a 90 percent reduction for Sulphur Creek subwatershed in methylmercury load, and an 85 percent reduction for Bear Creek at Highway 20 (Basin Plan 2007). The past contribution of Bear Creek watershed north of Highway 20 has average 17 percent (or 21.1 grams per year) of the Upper Cache Creek Basin methylmercury load, and the CVRWCB goal is to reduce that amount to 3.0 grams per year. No data on total annual loads of methylmercury are available for the entire Bear Creek watershed, and there are no established targets for reducing methylmercury loads for Bear Creek below Highway 20.

Goals for Other Contaminants OEHHA has established California Public Health Goals for elements and compounds with maximum contaminant loads for MUN. These Health Goals are listed in Table G.1 in Appendix G.

5.8 Soil Contamination Some soils in Bear Creek watershed have high natural concentrations of metals. Concentrations of these metals may pose health risks to some people. Ford (2004) has developed threshold criteria used by the BLM to determine instances when concentrations in soils of eleven elements commonly associated with commercial mining may merit risk assessment. Table 5.15 presents these criteria concentrations for four types of environments for people.

The threshold concentrations for risk from metals in Table 5.15 are lower for local residents because their exposure is longer term (chronic exposure) than, say, the high thresholds for an ATV driver who may stir up and inhale dust on a riding trail but undergo a relatively short exposure time (acute exposure).

Geochemists have not yet studied the chemistry of soils extensively in Bear Creek watershed. Analyses have come from Sulphur Creek subwatershed and lower Bear Creek. Churchill and Clinkenbeard (2003) sampled several background (uncontaminated and potentially contaminated) sites in Bear Creek watershed for mercury.

The only full-spectrum analysis of soil chemistry comes from work by Morrison et al. (2008, Table 6) for six sites in the Sulphur Creek basin: one ultramafic upland soil (site S0), two sites

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Table 5.15 – Soil concentrations in parts per million for elements with potential risk to human health based on exposure Local Camper ATV Driver Worker Element Resident milligrams per kilogram Antimony 3 50 750 100 Arsenic 1 20 300 12 Cadmium 3 70 950 100 Copper 250 5,000 70,000 7,400 Lead 400 1,000 1,000 2,000 Manganese 960 19,000 250,000 28,000 Mercury 2 40 550 60 Nickel 135 2,700 38,000 4,000 Selenium 35 700 9,600 1,000 Silver 35 700 9,600 1,000 Zinc 2,000 40,000 550,000 60,000 Source: Ford (2004)

Table 5.16 summarizes data from Morrison et al. (2008) about the order of magnitude in concentrations of five elements found in watershed soils compared to the BLM threshold objectives for local residents (Table 5.15). As with water contaminants, cadmium, copper, lead, selenium, silver, and zinc did not reach potential threshold risk levels in soils. The following five elements attained concentrations exceeding risk threshold criteria for residents (Ford 2004): antimony, arsenic, manganese, mercury, and nickel.

Sampled soils had mercury concentrations as high as 605 mg/kg. For perspective, the North American average for mercury in soils is 0.06 mg/kg). High mercury, nickel, arsenic, and antimony concentrations come from the natural hydrothermal alteration of minerals deep in the ground and possibly supplemented by mining waste (J. Holloway, USGS geochemist, pers. comm.). Apart from mercury, researchers have not distinguished what share of heavy metal loads in soils originate from naturally occurring (background) concentrations of elements and which loads come from abandoned mine sites (anthropogenic).

The few data from watershed soils show the high variability of concentrations of chemical elements within a relatively small area. The data also do not indicate conclusively the extent

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The upland ultramafic Henneke soil (S0) comes from an ultramafic area on the east side of Sulphur Creek subwatershed. It differs from the hydric alluvial Arand soil (S5) along Sulphur Creek in the following ways: higher iron content, a high ratio of magnesium to calcium (10:1), a high ratio of alkali earth metals (magnesium and calcium) to alkali metals (sodium and potassium), and low total carbon. The low total carbon signals the comparatively low biomass of vegetation aboveground on ultramafic soils; the remaining features indicate soil originating from ultramafic parent rock.

The floodplain soil from Sulphur Creek (S5) originates from sediment deposited from steep hillsides during high flows (Morrison et al. 2008). These alluvial fans from the Sulphur Creek catchment are mapped as Arand Soils (Reed 2006) derived from Skyhigh and Millsholm soils upslope. Metal concentrations (e.g., nickel, lithium, and titanium) in the point bar soil from Sulphur Creek (S4) reflect adjacent stream sediment chemistry. The A-horizon of the Sulphur Creek riparian soil (S3) resembles Sulphur Creek stream sediment, but the proportion of nickel is lower, thus more typical of Skyhigh and Millsholm soils (J. Holloway, USGS geochemist, pers. comm.).

Table 5.16 – Contaminant levels for elements higher (•) and 10x higher (•) than the BLM risk management criteria for residents from soil sampling sites in Bear Creek watershed* Lower Sulphur Creek Bear Ck Element B1 S0 S1 S2 S3 S4 S5 Corval Henneke Arand

Antimony •

Arsenic • • • • • • •

Manganese • • • •

Mercury • • • • • • •

Nickel • • • • • •

*Soil series for each site are listed below the sample site number Sources: Ford (2004), Morrison et al. (2008)

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In contrast, the Bear Creek (B1) floodplain soil (Corval Series) has a more complex origin owing to its proximity to the mouth of Bear Creek, which results in the accumulation of diverse sediments from across the entire watershed upstream. The higher ratio of magnesium to calcium points to prevalence of ultramafic sediments.

Data on the chemical compositions of more extensive principal soil series in Bear Creek watershed other than the Henneke soil series are not yet available.

In conjunction with the Bear Creek Bridge reconstruction project on Highway 20, the California Department of Transportation sampled mercury concentrations in the project area (California Department of Transportation 2006). Soil samples taken from cut slopes and a roadside ditch in November 2005 showed concentrations ranging from “not detectable” to 1.5 mg/kg. A sample from sediment taken directly from Bear Creek registered 7.7 mg/kg mercury to sediment by weight, which is below the threshold for health risk to people having contact with water during recreation (Ford 2004).

Samples taken of the three endemic ultramafic soil series found on the Bear Valley floor (Bear Valley, Leesville, and Venado) had concentrations of nickel ranging from 1235 to 1658 mg/kg and chromium from 368 to 892 mg/kg (J. Alderson, pers. comm.). No adverse impacts to the environment or people have been demonstrated from these natural concentrations.

5.9 Hazardous Waste

Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Site Only one site in Bear Creek watershed falls under the category of a site targeted for hazardous waste removal under the BLM’s CERCLA authority: the Rathburn-Petray mine complex. The BLM is the project lead for completing the removal required by the CVRWQCB. This extensive site is being cleaned up because of the high volume of mercury-rich sediments. Recent estimates for the BLM find that waste piles at Rathburn and Rathburn-Petray Mines together contain approximately 101,500 cubic yards of mercury-bearing waste material. The material appears in cuts, slopes, open pits, mine waste piles, and stormwater retention ponds. Also, the ash deposited around the brick retort at the Rathburn Mine has high levels of mercury.

The major concern for water quality is surface water runoff during storm events. Especially powerful rains could erode waste and tailings piles, overflow the retention ponds, and transport mercury-laden sediment into the broad alluvial fan and into tributaries of Bear Creek on the southwest side of Bear Valley. Presently, other partners involved in the Rathburn- Petray CERCLA remediation include the CVRWQCB and the US Geological Survey-

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Geologic Division.

Action to achieve needed management and remediation piles at the Rathburn and Rathburn- Petray mines in Upper Bear Creek subwatershed began in December 2005, when the CVRWQCB issued a Cleanup and Abatement Order to the BLM Ukiah Field Office. The BLM has provided a work plan with background levels of mercury in the soil and surface water, and the vertical and lateral extent of mine waste piles, soil, and sediment contaminated with mercury. The BLM has also finalized an engineering evaluation and cost analysis (EE/CA) for the Rathburn-Petray mine complex for CERCLA response actions (Ecology and Environment, 2008). Remediation work is scheduled on the ground in 2010.

Mercury remediation has begun at the Clyde and Elgin mines as well. The latter mine is mostly on private property with a small part on the BLM lands. Otherwise, responsible parties have not begun work to remediate mercury mines on private lands. In 2009, the CVRWQCB initiated the process for cleaning up all mercury mines on private lands in Sulphur Creek subwatershed.

Brownfields "Brownfields” are potentially suitable for redevelopment or reuse, but the properties remain unused due to actual or perceived contamination on site. Generally, these sites are in urban settings or rural industrial settings such as lumber mills. No brownfields sites are designated in Bear Creek watershed.

Underground Storage Tanks Two contamination cleanups involving gasoline have taken place in Bear Creek Watershed. Gasoline contamination of soils and an aquifer potentially used for drinking water around the CALFIRE Wilbur Springs Forest Fire Station (case T0601100051) on State Highway 16 was discovered in 1998. The cleanup at the station was completed and the case closed as of September 4, 2002. Gasoline contamination of soils around the CALFIRE Leesville Forest Fire Station (case T0601100052) on Bear Valley Road was discovered in 1998. Ground water testing in 2004 and 2005 did not detect any residual petroleum. The cleanup at the Leesville station was completed and the case closed as of July 24, 2008.

Hazardous Waste Sites and Substances (Cortese List) The California Department of Toxic Substances Control does not list any hazardous waste and substances sites in Bear Creek watershed.

5.10 Air Quality Contaminants Two sources of atmospheric contamination with potential impacts to human health are asbestos and mercury. 195

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Asbestos Chrysotile and tremolite forms of serpentinite asbestos are frequently found in association with ultramafic soils and rocks occurring in Bear Creek watershed (Churchill and Hill 2000). Goff and Guthrie (1999) noted that the dominant mineral in ultramafic rock on Walker Ridge, was harzburgite, a non-asbestos form of serpentinite. O’Dell and Claassen (2006a), however, found that the asbestos content of serpenitinite minerals at a restoration sites along Highway 20 is one to five percent asbestos by mass. Data on the occurrence and density of airborne asbestos fibers are not available.

Mercury Little information is available on mercury volatilization into the atmosphere from naturally mercury-enriched soils and from mercury mine sites. Bear Creek watershed generates more volatilizing mercury than it receives from deposition from the atmosphere (refer to Table 5.2). Mercury vapor coming from springs is not well documented, but the largest percent of molar gas composition was 4.6 x 10-6 percent from Elbow Springs (Goff et al. 2001). No data are presently available concerning mercury emissions from soils in the watershed. A study of mercury volatilization in the Knoxville Mining District southwest of Bear Creek watershed showed that the highest mercury emissions occurred along the Stony Creek Fault, a major fault which also bisects Bear Creek watershed. Gustin (2002, 2003) scaled her mercury readings to estimate emissions of 37.6 kg-2 km-2 yr-1 for the Knoxville region (Gustin 2002, Gustin 2003), equal to 29.9 pounds per square mile per year. Roughly one-half of that quantity is from natural sites; the other half comes from specific mercury mines.

5.11 Identification of Critical Areas for Remediation Management of total mercury, methylmercury, and total sediment are interrelated as subjects for remediation in Bear Creek watershed. Seven principal projects are needed for targeted remediation:

1. Control and sequestering of abandoned mine sites and their mine wastes in Sulphur Creek subwatershed to reduce total mercury reaching Bear Creek and exiting downstream into Cache Creek 2. Confinement of sediments in Rathburn-Petray mine complex to prevent potential erosion into Bear Creek 3. Reduction of ultramafic sediment erosion into the lower Bear Creek riparian corridor from ultramafic soils in subwatersheds south of the confluence of Sulphur Creek with Bear Creek 4. Reduction of dissolved organic matter in Bear Valley and in lower Bear Creek south of Highway 20 to slow the rate of mercury methylation 5. Management of benthic environments in Bear Valley and lower Bear Creek to create

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conditions less conducive to methymercury production, particularly in summer months 6. Restoration of hydrologic flow and native vegetation to closed off-highway motor vehicle trails on public lands in Sulphur Creek subwatershed to reduce sediment in Sulphur Creek from ultramafic rocks and soils. 7. Removal of mercury sediment deposits along lower Bear Creek.

In addition, watershed planning and coordination within the ten-year flood zone is a necessary “best mercury management practice”. This step would avoid soil disturbances that might increase the amount of total mercury reaching creeks and tributaries or increase the production of methylmercury in stream bottoms (Cooke and Morris 2005). Care is warranted, for example, when removing invasive plants to avoid disturbing stream sediments and stream bank soils and unintentionally mobilizing mercury and methylmercury.

5.12 Information Gaps The following items are information needs critical to make improvements to the ecosystem function of Bear Creek watershed:

water quality monitoring to detect the presence of industrial organic compounds and fecal coliform bacteria water quality monitoring for ground water a study of the impacts on mercury methylation from dissolved organic matter stemming from wild animals and livestock concentrating along sections of Bear Creek, Sulphur Creek, and Mill Creek a map of mercury volatilization rates into the atmosphere from soils and geologic features in Bear Creek watershed multi-year field data collection to determine the sources, seasonality, and amounts of sediment flows from the Rathburn-Petray mine complex into Bear Valley  data on total mercury loads from cold mineral springs in Bear Valley and elsewhere more intensive soil sampling of potentially toxic chemical elements in alluvial soils along Bear, Sulphur, Trout, and Mill creeks annual monitoring at key sites in the watershed to track methylmercury amounts in fish tissues as an indicator of the effectiveness of management actions intended to reduce total mercury and methylmercury.

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CHAPTER 6

STAKEHOLDER ISSUES

Stakeholders have identified sixteen issues that pose challenges to achieving watershed goals. These issues stem from past practices or anticipated consequences of new land use practices and relate to water quality, hydrologic function, site stability, conservation biology, and economic conditions. Effective responses to these issues can improve watershed conditions and help guide future projects to safeguard natural resources and provide sustained economic productivity. Information on projects to address issues presented here are part of the accompanying document Bear Creek Stewardship Priorities, 2010 – 2014.

Some watershed issues are long-standing and have concerned residents and county advisors since at least the late 1930s (Agricultural Extension Service of Colusa County 1941). These include: creek erosion, fire control, water supply, overgrazing, weed control, and road repair. Other stakeholder issues are more recent, such as: the growing recreation demand, contaminants in the environment, a proposed wind energy development, and impacts from climate change.

This assessment does not attempt to prioritize watershed issues in a single ranking of importance as stakeholders have different outlooks about priorities. Concerned stakeholders are already actively addressing issues based on common interests, collaborative partnerships, and availability of funding.

The following sections outline stakeholder issues, their consequences in the watershed, their interactions, and strategies for resolving issues in the future.

6.1 Toxic Chemicals Chemical contaminants to soil, water, and air are a priority for many stakeholders. The principal toxic chemical of concern is mercury. Other chemical elements occur at naturally high background levels but are not known at present to contribute to environmental problems.

Mercury and Human Health Mercury found in Bear Creek watershed comes from natural sources and from sources generated by people. Naturally occurring “background” sources of mercury in Bear Creek waterways come from spring waters, the atmosphere when vaporized mercury settles on the ground or on vegetation, and normal soil erosion in the course of winter storms (Stanish and

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Cooke 2007). Some atmospheric mercury settling over the watershed may come from human sources outside the watershed as well, such as from coal-burning power plants. Abandoned mercury mines inside the watershed are the major component of human- generated mercury. Both natural and human sources contribute significantly to the total mercury load in the Sacramento-San Joaquin Delta downstream, a critical source of water for millions of Californians.

The Central Valley Regional Water Quality Control Board (CVRWQCB) oversees control of mercury from human-generated sources that increase mercury levels in streams above natural background levels. The CVRWQCB has identified Bear Creek and its tributary Sulphur Creek as impaired water bodies because of their unnaturally high amounts of total mercury (Sulphur Creek only) and methylmercury.

Mine waste at abandoned mine sites in Sulphur Creek subwatershed and potentially at the Rathburn-Petray mine complex in the foothills above Bear Valley is generating mercury- rich sediment that erodes into waterways. Soil disturbances from roads and from livestock grazing are secondary sources for increased mercury in Bear Creek and its tributaries (Cooke and Morris 2005). Together, these land uses increase the transport of mercury found in mine waste and soil into streams in Bear Creek watershed.

Mercury concentrations in fish from Bear Creek watershed also exceed State of California standards for safe human consumption of fish. The concern for people is that consuming water and fish from Bear Creek watershed would increase mercury in their bodies and damage their health. Mercury enters the body principally in the form of methylmercury. Certain naturally occurring bacteria, living in streambeds where oxygen is largely absent, convert mercury into an organic form (that is, containing carbon), methylmercury. Methylmercury can enter the food chain, passing from bacteria to algae and small invertebrates, up the food chain to large invertebrates, to fish, and then to fish-eating people and wildlife.

Boron and Agricultural Crops Bear Creek water has high concentrations of dissolved boron derived naturally from soils and spring waters. The Yolo County Flood Control and Water Conservation District continues to monitor boron in Bear Creek to track concentrations because boron in irrigation water can be toxic to crop plants. No evidence is available at present to suggest that land uses in Bear Creek watershed are increasing boron concentrations in water above background levels.

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Other Contaminant Elements The California Office of Public Health sets standards for maximum contaminant levels (MCLs) for other potentially toxic elements and compounds in California drinking water based on human health and economic concerns. Water flowing from abandoned mercury mine sites in Sulphur Creek subwatershed has higher levels than established MCLs for aluminum, antimony, arsenic, barium, fluoride, and manganese. The few data available on these elements from the California Department of Water Resources (2001 – 2006) show that levels of these potential contaminants fall to levels below MCLs permitted for drinking water standards by the time water reaches the mouth of Bear Creek.

Industrial Pesticides and Fertilizers In 2001, the last time that the Department of Water Resources monitored for industrial organic solvents, fertilizers, and pesticides in lower Bear Creek, data collected did not detect any compounds above threshold amounts that would indicate contamination.

Recent illegal cultivation of marijuana on public lands in Bear Creek watershed is creating an undetermined impact to water and soil. Since 2007, law enforcement officers have found containers of two highly toxic industrial pesticides and contaminant fertilizers at illegal marijuana growing sites in the watershed: carbofuran, used to kill native species of rodents, and methamidophos, an insecticide. On other BLM lands managed by the Ukiah Field Office, officers have found pools diverted alongside streams to mix fertilizers.

The BLM is instituting a rapid response procedure based on early alerts from the BLM and Colusa County law enforcement officers to send BLM restoration specialists to growing sites to halt environmental damage from marijuana cultivation (G. Mangan, pers. comm.). Currently, no dedicated funds are available to public land managers and private landowners to cover costs of site restoration once sites are cleared of plants and hazardous materials. Also, no program is in place to specifically test for the residues of industrial pesticides and fertilizers at sites impacted by illegal marijuana cultivation.

6.2 Sediment Delivery to Watercourses Large quantities of sediment move down Bear Creek watershed drainages annually during storm events, discharging pollutants to the waterways. Approximately 276,000 tons (or 205,000 cubic yards) of sediment was generated from large-scale erosion events (observable at a 1:20,000 map resolution) in Bear Creek watershed above Highway 20 between 1937 and 2005 (Hoorn et al. 2008). Sulphur Creek subwatershed and the canyons on lower Bear Creek leading downslope from Cortina Ridge are parts of the watershed most susceptible to sediment erosion (Figure 4.5).

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Sediment from Abandoned Mines In Sulphur Creek subwatershed, mercury-rich sediment is particularly an issue where sediment from abandoned mines routinely enters waterways during storm events. Annually, up to 72,000 tons of sediment from all sources erode from the subwatershed (Churchill and Clinkenbeard 2003), depending on winter storm frequency and intensity. Churchill and Clinkenbeard (2003) also estimated that 51,400 tons of mine waste sediments cover the ground surface in Sulphur Creek subwatershed. These sediments are highly susceptible to erosion. On average, mine sediments put 9.2 kg (20.3 lbs) of mercury into Sulphur Creek annually. Information on the mercury contribution from mine waste from the Rathburn- Petray mine complex on the southwest side of Bear Valley is less clear (Churchill and Clinkenbeard 2003). Sediment from the mine complex appears to mix with naturally mercury-rich stream sediments around cold springs found in the alluvial fan downslope from the mine complex (Slowey and Rytuba 2008).

Sediment from Roads and Trails Poorly designed roads, trails, and culverts are another source of erosion. In Leesville and Lower Bear Creek subwatersheds in particular, culverts empty water onto eroding soils, accelerating soil erosion and sedimentation into creeks. CALTRANS estimates that the two state highways in the watershed generate twelve tons of sediment that enter lower Bear Creek annually (Table 5.14).

Sediment from Illegal Dumping The extent of illegal dumping of soil and rock into Bear Creek and its tributaries is unknown. In August 2008, however, the CVRWQCB cited CALTRANS for dumping sediment next to Bear Creek along Highway 16. Dumping had been occurring at the Highway 16 site for many years.

Sediment Stemming from Domestic and Wild Animals Animals, both wild and domestic, are drawn to riparian areas for water and high-quality forage. Larger animals such as livestock and elk often concentrate at these sites, and over time they reduce vegetative cover, disturb soil, and cause banks to erode, both releasing sediment and reducing the sediment-catching function of riparian zones.

Sediment Stemming from Loss of Vegetation The interaction between fires and conversion of oak woodlands to grasslands promotes vegetation loss and soil erosion on upland sites. Conversion generates income from oak fuelwood and provides greater livestock forage on the cleared land. After deforestation and fires, rainfall strikes soils more powerfully in the absence of shrub and tree canopies and results in larger and more erosive overland water flows. These flows ultimately transfer increased sediment loads into Bear Creek tributaries. Loss of oak woodlands on steep slopes

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Unstable channel conditions also contribute sediment. Abnormally high stream flows in winter storms accumulate from overland water flow across devegetated areas and build force along lower Bear Creek next to Highway 16. At several stretches in lower Bear Creek, narrow canyons further concentrate powerful high flows. Banks along lower Bear Creek are showing signs of extensive high bank erosion that sloughs even more soil into the Creek. At the same time, periodic high stream flows are undermining the anchoring function of long- established riparian shrub and oak tree root systems, leading to further vegetation loss and soil erosion.

6.3 Creek Channel Alterations Creeks and their associated riparian zones have many important ecological functions. When properly functioning, riparian zones do the following:

provide habitat for fish and wildlife stabilize creek channels and protect banks from erosion retain rainwater and attenuate flooding filter nutrients maintain water quality provide livestock with forage and water during drought periods

People have altered waterways in Bear Creek watershed for agriculture, tourism, mining, and land reclamation. During the late 1880’s, miners moved the lower main stem of Sulphur Creek from the west side of Sulphur Creek valley to its current location on the east, adjacent to Manzanita Mine. In the late 1890’s, rechanneling at the north end of Bear Valley altered the course of Bear Creek (J. Keegan, pers. comm.), and dynamiting rock formations along Bear Creek in lower Bear Valley is said to have resulted in downcutting Bear Creek and its tributaries as the level of the streambed lowered (Reed 2006).

These modifications have altered the hydrologic function of creeks and their associated floodplains. While such alterations can benefit agriculture and other land uses, they can also lead to a loss of critical ecosystem services.

Figure 3.2 displays the human alterations to Bear Creek and its tributaries. Bear Valley, where agriculture has supported people’s livelihoods for 150 years, is the most transformed part of Bear Creek watershed. Ranchers have constructed water impoundments for stock water supplies. Many stock ponds are also found on the BLM Bear Creek Ranch and on rangeland on the east side of the watershed north of Highway 20. One challenge – especially

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Alterations to creek channels come from sources other than people. Tamarisk, a non-native invasive plant, has invaded along Bear Creek and lower Sulphur Creek. At places, it traps sediments and develops stable hummocks that can redirect creek flow and flooding patterns (Birkeland 1996). Uplift of the earth in areas characterized by shifting plates and earthquakes such as the western side of the Sacramento Valley may also reshape channels (J. Alderson, pers. comm.).

6.4 Creek and Tributary Headcuts A headcut is a sudden change in elevation or knickpoint at the leading edge of a gully. Headcuts intensify runoff, accelerate soil erosion, destabilize stream banks, and alter stream flow over time. Without remedial action to curb them, headcuts deepen over time and create a wider channel. This downcutting in the streambed can lead to a loss of floodplain function and a lower water table. Downstream from a headcut, the deepened channel disrupts natural water flow by concentrating water over a smaller area of ground surface, and the stream is less likely to flood the surrounding land at times of high rainfall (Wilder and Roberts 2002). During the summer drought, the level of shallow groundwater associated with main-stem creeks and their tributaries drops further, resulting in reduced base flow, less soil moisture, and lower annual vegetation production (Rosgen 1996).

Headcuts on Bear Creek, Sulphur Creek, upstream from Leesville, and in other small tributaries throughout the watershed are creating extensive corridors of topsoil loss. The causes of headcuts differ by site. In Leesville subwatershed, poor culvert design and placement appears to be the principal cause. In other areas, causes are less obvious and yet to be determined. Thirty-seven headcuts have been mapped thus far in Bear Valley tributaries (J. Alderson, pers. comm.). In Sulphur Creek subwatershed, headcutting has recently accelerated, resulting in extensive movement upstream in just a few years (J. Alderson, C. Thomsen, pers. obs.). The entire wetland complex in the Sulphur Creek valley is now subject to degradation from active headcuts (Hoorn et al. 2008; C. Thomsen, pers. comm.).

Another adverse impact is sediment delivery and accompanying reduction in water quality. More sediment, formerly constituting the streambed, banks and floodplain, erodes as the headcut moves upstream. The adverse impact of sediment on water quality intensifies if the increased sediment comes from mercury-rich soils or mercury-laden mine waste. Streams in ultramafic areas, mostly from the west side of the watershed, deliver naturally high

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BEAR CREEK WATERSHED ASSESSMENT background concentrations of heavy metals to watershed streams and may release even higher metal loads to waterways as headcuts become more extensive.

Ranchers are noticing a decline in forage production related to the lowered water table as streambeds deepen on account of widespread head cuts and channel incision in Bear Valley. The sunken water table is drying out rangeland and reducing the length of the growing season for forage. Options to counteract arid soil conditions are needed to restore the capacity of rangelands to support livestock.

6.5 Roads, Trails, and Firelines Roads, trails, and firelines leave an enduring imprint on Bear Creek watershed by affecting hydrologic function, water quality, site stability, vegetation cover, and wildlife habitat. Cartographers at the BLM and the US Forest Service have mapped 215 miles of existing roads and trails on public highways and on public lands in Bear Creek watershed. An unknown amount of roads and trails are on private lands. In Sulphur Creek subwatershed, Hoorn et al. (2008) mapped an additional 23 miles of trails on private lands in addition to the 100 miles on public lands.

Maintenance for Road and Trail Infrastructure Road repairs have long been an issue in the watershed. The Colusa County Agricultural Extension Service in 1941 cited the need for road improvements to Leesville and Bear Valley roads. The Colusa County General Plan (Sedway Cooke Associates 1989) notes that sufficient funding to address deferred maintenance of county roads remains an ongoing challenge. CALTRANS and the Colusa County Department of Public Works are likely to remain underfunded in the foreseeable future, so prioritization is needed for effective remedial actions that improve roads for safety and environmental benefits. Without improvements in design and maintenance, roads and trails will continue to function poorly and contribute to chronic water quality problems.

New incentives and funding could enable Colusa County to repair county roads in Bear Creek watershed known to transport sediment into Bear Creek and its tributaries (Cooke and Morris 2005). Funding is especially needed in Sulphur Creek subwatershed where more than a third of the private road mileage, most of it furnishing access to abandoned mines, is carrying mercury-rich sediments to Sulphur Creek.

Roadways in Eroding Landscapes Roads constitute the second largest source of sediment after abandoned mine waste in Sulphur Creek. In Sulphur Creek subwatershed, 67 percent of surface (non-mine) sediment (estimated at 16,158 cubic yards or 21,815 tons) comes from cutbank surfaces next to roads

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(Hoorn et al. 2008). Road maintenance is particularly needed where soils and rock on the cutbank side of roads are vulnerable to erosion, under conditions of steep slopes, high rainfall, and sparse vegetation. Both sedimentary soils (Maymen, Skyhigh, and Sleeper) and ultramafic soils (Henneke, Montara, and Okiota) along roads in the watershed are eroding locally. Severe erosion on Skyhigh and Sleeper soils where they abut Highway 16 next to lower Bear Creek creates frequent slides onto the highway that require ongoing attention. Road crews routinely place sloughed roadcut material onto fill slopes along Bear and Sulphur creeks to clear roadways following major winter storms. To avoid an eventual large-scale landslide of Henneke soil from steeps slopes on the south side of Highway 20 west of Bear Creek, CALTRANS received a right-of-way permit from the BLM to remove topsoil from a ten-acre patch of public land. The remaining exposed ultramafic rock and soils is now in need of further stabilization and revegetation to halt sediment delivery to Bear Creek (O’Dell and Claassen 2006a,b). Revegetating the site may cost up to $20,000 per acre (V. Claassen, pers. comm.).

Off-Highway Vehicle Route Designation Federal land management agencies are currently designating the off-highway vehicle (OHV) routes for public recreation and travel throughout California. Reducing erosion by closing and restoring vegetation to unneeded or poorly designed trails is one aim of route designation. The Mendocino National Forest has completed its OHV route designations, and the BLM Ukiah Field Office is beginning its second phase of designating OHV routes in Bear Creek watershed. The OHV trails on the BLM public lands in Sulphur Creek subwatershed, Bear Valley foothills, and Walker Ridge will be designated next as either open or closed to motorized use. Most of these trails are on ultramafic soils, often predisposed to landslides and soil erosion. OHV travel planning by federal agencies is also taking into account impacts to air quality from route designation on traffic volume from OHV-recreation visitors driving on unpaved county roads to reach motorized trails on federal lands.

Roads to Support Wind Energy Development Plans to develop wind energy resources on Walker Ridge in Bear Creek watershed are underway. The BLM has not issued permits for any projects, however. Eventual development would entail new road construction and widening of existing roadways and trails to support energy production and conveyance to power stations. AltaGas Income Trust, the project proponent will publish a plan of development, detailing the locations of new or modified utility roads. The BLM has in place best management practices (refer to Chapter 8) that address road design and maintenance so that wind energy production is compatible with other resource uses and protections.

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The Interaction of Roads and Trails with Non-native Invasive Plants Roads and trails alter the distribution of plant nutrients, the flow of surface and subsurface water, and soil depth along verges, often in ways that increase habitat suitability and growth for non-native invasive species (Gelbard and Belnap 2003). Vehicle corridors are also point sources for wildfires that promote multiple species of non-native fire-adapted annual grasses. Research in Bear Valley (Gelbard and Harrison 2003, 2005) indicates that roads have a negative impact on native vegetation. Native perennial bunchgrasses such as purple needlegrass (Nassella pulchra) thrive best away from roads. On the other hand, non-native invasive weed species, particularly yellow starthistle, have a lower survival rate with increasing distances from roads and their associated disturbances.

Restoration for OHV Trails and Firelines CALFIRE created more than 21 miles of new firelines across ultramafic soils on steep slopes during the 2008 Walker Fire for the purposes of containing the fire and protecting private property and public resources. Emergency stabilization for the fireline did not take place. A funding source to revegetate the fireline is not available from federal or State of California sources for public lands. Private landowners must bear the cost to curb erosion of ultramafic soils on their property from the fireline.

6.6 Fire The frequency of large wildfires has not increased in Bear Creek watershed since 1950 (California Department of Fire and Forestry Protection data), in contrast to other, more populated parts of California where conditions of fire weather (for example, Santa Ana winds) are different (Keeley et al. 2004). Until 2008, wildfires inside Bear Creek watershed were comparatively small-scale, less than 2,500 acres in extent. The 2008 Walker Fire in Bear Creek watershed burned an area nearly three times the acreage of the previous largest fire recorded since 1950.

The large extent of this fire is not attributable to a trend to larger fires. Regional circumstances at the time of the fire were extraordinary. The human-caused Walker Fire came at the same time as an unusually large number of lightning strikes ignited wildfires across northern California. Operations for suppressing wildfires were stretched beyond the normal response capacity of fire management agencies, and sufficient resources to contain the Walker Fire could not be marshaled as quickly. As a result, the fire burned more extensively.

One major concern for some stakeholders is making fire suppression more cost-effective and less expensive overall. Watershed stakeholders are rethinking strategies for fire suppression and considering the use of fuel treatments to reduce costs. Implementing

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Fire managers are now focusing on the time that a fire spends over a piece of ground (“residence time”) during a fire as a factor in designing prescribed burns and containing wildfires (B. Bahro, US Forest Service fire modeler, pers. comm.) that better meet land management goals. These considerations may be important in determining, for example, the amount of mercury vaporized into the atmosphere during fires or passing into streams during the rainy season. Scientists are just beginning to study the effects of wildfire on the release of mercury from soils and vegetation. Studies in other states indicate that mercury levels in soils drop steeply (Biswas et al. 2007, 2008) and mercury levels in streams rise significantly (Caldwell et al. 2000) after wildfire.

Another factor is the role of people as ignition sources. With more people on remote roads across public lands, the likelihood of human ignitions grows. Policies and programs to address human behavior and actions that create fire hazard and wildfire ignitions are difficult to implement and make effective.

Using Fire to Enhance Biological Diversity and Restore Native Species Many rare chaparral plant species do not germinate without periodic fire in their habitats, and their current rarity may be the result of unnaturally long intervals between fires (Safford and Harrison 2004). Harrison et al. (2003) found that a single managed fire on ultramafic soils, where most rare plant species occur in Bear Creek watershed, had a positive effect on native plant diversity. Techniques of burning under managed conditions can increase germination, growth, spread, and seedbank replenishment for rare species. But the habitat requirements for the sixteen federal sensitive plant species on public lands and the two additional CNPS Class 1B taxa on private lands in Bear Creek watershed are poorly understood. Research for long-term conservation of rare plants and other native species is needed.

Fire suppression in the past five or more decades may be shifting the composition and structure of oak woodlands and chaparral. Foothill pines are less able to survive wildfires than oaks or chaparral shrubs and are becoming more common in the absence of fires (Ledig 1999). Increasingly, pines are competing with blue oaks for water and nutrients. Greater competition among trees in denser stands may be reducing oak tree vigor as pines emerge above the oak canopy and beginning shading oaks. With a greater number of more flammable pines among less robust oaks, the stage is set for more intense wildfires and

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BEAR CREEK WATERSHED ASSESSMENT greater oak mortality (C. Thomsen, pers. obs., D. McCreary, pers. comm.).

Without periodic wildfire, chamise can form single-species chaparral stands on both ultramafic and non-ultramafic soils. As chamise gets older and larger, nutrients for plant growth become scarcer, and dead biomass (fire fuels) accumulates on and under chamise shrubs (Rundel 1982, Stohlgren et al. 1984). The surrounding area becomes more susceptible to intense fires. At the same time, the plant and animal species diversity declines. Introduction of fire on an average 20-year interval for non-ultramafic soils may reduce fuel buildups, rejuvenate chamise growth, and create a more complex and species- rich wildlife habitat.

6.7 Oak Woodlands

Oak Species at Risk Areas occupied by oak woodlands have been shrinking in many parts of California, including Colusa County. In western Colusa County, woodcutting and efforts to improve land for livestock grazing have resulted in major losses of native oak woodlands (Light and Pedroni 2002). Of particular concern in the watershed are two oak species found only in California, blue oak (Quercus douglasii) and valley oak (Q. lobata). These species may be at risk of long-term decline because of failure of the two species to regenerate sufficient seedlings and surviving saplings at many sites over the last 50 years to replace trees lost from natural mortality and land clearing (Zavaleta et al. 2007). Evidence of regeneration problems exist in the watershed, especially for valley oak.

Factors limiting regeneration of blue and valley oaks depend on biotic conditions and the land use history at a site. While many blue oaks stands investigated over the last 50 years had little or even no regeneration, the natural mortality of large blue oaks was also very low. In many places, oak seedlings rarely attain the height of saplings and small trees because ungulate animals (deer, elk, livestock) browse the young oaks unimpeded. Tule elk also use woody plants for antler rubbing and can girdle trunks of sapling trees.

Mature valley oaks remain part of the riparian community in three locations: at the south end of Bear Valley, on the BLM Bear Creek Ranch, and locally in the Leesville area. Much less common than blue oaks, valley oaks are more vulnerable to population decline and regeneration failure. Studies on valley oak elsewhere in California indicate that it has the lowest number of germinating seedlings and surviving saplings of the major oak species in California, and that germination of valley oaks may fail entirely over many years. Best regeneration, mostly under or near the canopies of full-grown trees, occurs where cattle or other large browsing animals are absent (Tyler et al. 2006).

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Public Policy and Remedies for California Oaks Losses of oaks come in part from public policies and incentives. For example, from the 1940s through the 1960s, the federal government and the State of California subsidized cutting oak woodlands as a means for increasing production of livestock forage and livestock production (Campos Palacín et al. 2002). As landowners and the public at-large have understood the multiple values from oak woodlands, the range of benefits from oak woodlands has expanded. Oak woodlands furnish both agricultural and forestry products (beef, sheep, wool, game animals, fuelwood, forage, acorns) and ecosystem services (watershed protection, soil conservation, wildlife habitat, shade for livestock, carbon storage, and landscape aesthetics) that in turn support other economic sectors (water delivery, tourism, carbon credits, recreational settings). The challenge to stakeholders is how to maintain the greatest value from oak woodlands on both private and public lands for an uncertain future.

Environmental Factors Affecting Oak Woodlands The following subsections describe and evaluate briefly the biological, hydrological, and climatic stresses to oak woodlands. Some of stress factors have their origins in human causes such as the unintentional introduction of non-native plants and fungi.

Tree Loss from Soil Erosion Medium-sized blue oaks are being lost along the Highway 16 corridor from soil erosion. At least two sources of erosion are at work: bank sloughing after stream undercutting of highly erodible soils during high winter flows in Bear Creek; and soil slides at road cuts. In each instance, oak root systems become exposed to the air and their ability to anchor the tree bole and stabilize soil is undermined.

Interactions with Non-native Plants Invasive non-native plants such as annual grasses and yellow starthistle typically grow from late fall to summer coinciding with rainfall patterns. Their abundance results in competition with oaks for available soil water. Invasive annuals have been shown to dry soils out excessively, leading to less available water for young oaks (Gerlach 2004, Gordon and Rice 1993).

Fungal Diseases The non-native fungus Phytophthera ramorum responsible for sudden oak death, has not affected oaks in Bear Creek watershed. Other native fungi such as mildews, root rots, and wood decomposers are common on oaks but do not cause large-scale epidemics of oak disease and death in the watershed.

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Plant Parasites A native plant, the Pacific mistletoe (Phoradendron villosum), germinates on live branches in the oak canopy and establishes a root system inside oak branches to draw water and nutrients. Mistletoe can greatly reduce oak growth when infestations are dense. Tending trees to remove mistletoe especially from young trees can help recover tree growth (Huntsinger et al. 1997).

Animal Predation Native insects defoliate, feed on tree sap, and burrow into acorns (Swiecki and Bernhardt 2006), and these species may depress oak tree growth and seedling germination. The long- term impact from acorn damage by insects to the capacity for species regeneration is not clear (Tyler et al. 2006). Additional predation on acorns comes from insects, rodents, deer, cattle, and people.

Rodents such as ground squirrels and voles can kill oak seedlings. Once seedlings reach sapling size, browsing by large animal browse and antler rubbing by elk has been reducing the growth and health of young valley oaks in the riparian zone of the BLM Bear Creek Ranch (C. Thomsen pers. obs.).

Drought Blue oak woodlands are the most drought-resilient of the major forest types in California (Waddell and Barrett 2005). Drought usually induces early defoliation in oaks, especially on shallow soils, to avoid prolonged water loss. Robust oak seedlings resprout from the base to produce new shoots if the previous shoot has died back from drought.

Fire and Oaks Larger oak trees are more resistant to fire – largely on account of low tree density where these trees occur. Crown fires are rare in the North Coast Range blue oak woodlands (Christensen et al. 2008). Blue oaks resprout vigorously after fire as long as burning is not frequent. A review of demography and recruitment studies of blue oaks has found that fires do not promote tree growth or increase the rate of oak seedling germination (Tyler et al. 2006).

Climate Change Climate modeling at a fine resolution for California predicts that the ranges of blue oak and valley oak will contract to 59 percent and 54 percent of their current ranges respectively and that ranges will shift northward. According to modeling, both oak species would disappear from the watershed by 2100 (Kueppers et al. 2005). The model calls into question the practicality of maintaining oak woodlands in Bear Creek watershed, if the assumptions in the climate change model are correct.

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6.8 Disturbances to Ultramafic Soils Both natural landslides and land uses disturb ultramafic soils significantly, increasing erosion and sedimentation, altering habitat value, and affecting species composition.

Potential Energy Developoment Ultramafic soils cover 41 percent of the geothermal lease area (Colusa County Soil Survey 2006, BLM lease boundaries). Care is needed in site planning to avoid eroding these ultramafic soils as they often have naturally high content of heavy metals and thus degrade water quality in streams coming from subwatersheds with ultramafic geology and soils (Morrison et al. 2008). Constructing access roads and turbine pads on ultramafic soils for wind energy may also degrade unusual vegetation communities and rare plant habitat plus destabilize ultramafic rocks and soils.

Grazing Disturbances on Ultramafic Soils Grazing has been occurring on ultramafic soils in Bear Valley, on Love Lady Ridge (now discontinued), and on the BLM Bear Creek Ranch for more than a century. Different soil series, topographic settings, and grazing practices create varied responses in vegetation on ultramafic soils. Grazing practices can do greater damage on naturally unproductive soils. For example, uplands, meadow complexes, and drainages on ultramafic (and as yet unnamed) haploxerert soils west of Cowboy Camp on the Bear Creek Ranch are characterized by steep, exposed slopes, lower than recommended levels of residual dry matter, landslips, headcuts, gullies, and degraded channel networks from grazing (field evaluations by C. Thomsen, J. Alderson, J. Weigand, 2008).

Non-native Invasive Species at Disturbed Ultramafic Sites Generally, ultramafic soils and their vegetation types are resistant to non-native invasive plants (Harrison et al. 2006). But, some non-native invasive species are now adapting to ultramafic soils where disturbances to ultramafic soils have been intense. Barb goatgrass (Aegilops triuncialis), for example, is able to grow on many ultramafic soils (Thomson 2007). Its presence may also be causing unexpected changes in soils. Batten et al. (2006, 2007), for example, found that barb goatgrass increases soil sulfate in invaded sites. The long-term significance of these changes to site productivity and species composition is not understood at present.

Under the unique soil conditions of Bear Creek watershed, intense ground disturbances resulting from bulldozer traffic at the Rathburn-Petray Mine complex now host a well- established population of yellow starthistle, barb goatgrass, and bromes. Unmanaged mine roads and OHV trails in Sulphur Creek subwatershed are fragmenting rare plant habitat on ultramafic soils and facilitating movement of non-native plants throughout Sulphur Creek (Hoorn et al. 2008).

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One source of invasive plants has been the choice of non-native species used to stabilize and reclaim highly-disturbed abandoned mine sites occurring on ultramafic soils. Williamson and Harrison (2002) found that orchardgrass (Dactylis glomerata) and tall wheatgrass (Thinopyrum ponticum) readily invaded adjacent undisturbed ultramafic soils from remediated abandoned mine sites. This finding underscores the need to use local native plant materials rather than non-native grasses in remediation projects to revegetate and stabilize abandoned mine sites.

Rare Plants Ultramafic soils have a high ratio of magnesium to calcium and contain high concentrations of nickel and manganese. The unusual soil chemistry prevents most native plant species on adjacent non-ultramafic soils from growing on them. However, some species tolerate ultramafic soils and occur only on those soils. Because ultramafic soils are rare and often appear in discontinuous habitat patches within a landscape dominated by other soils, many plant species adapted to these soils have limited ranges and are rare within those ranges.

One unique feature of the watershed is the high number of rare plant species found on Walker Ridge. One ultramafic-endemic plant, Indian Valley brodiaea (Brodiaea coronaria ssp. rosea), is listed as a State of California endangered species and has less than twenty separate populations, two of which are known for Bear Creek watershed. Disturbances to soils in the limited habitats of rare plant species such as the brodiaea pose threats to their populations and to native species diversity.

6.9 Non-native Invasive Species Non-native invasive species have been intentionally introduced by watershed residents, while others arrived by wind, water, wildlife, domestic animals, vehicles, or as hay contaminants. Invasive plants displace native species, alter wildlife habitat, and impair agricultural production. They alter fire and flood regimes, change erosion and sedimentation patterns and nutrient cycling, and reduce water and light availability (di Tommaso and Johnson 2006). Plants such as yellow starthistle and many grasses from the Mediterranean Basin plague hikers and animals with spines and seeds that detach and cling to clothing and fur. Yellow starthistle depletes soil moisture, sometimes equivalent to as much as nine inches of rainfall in infested soils (Gerlach 2004). On the BLM Bear Creek Ranch, invasive plant control is a major land stewardship activity, taking a substantial share of staff time and financial resources.

At least 47 invasive species occur in the watershed, 12 of which are designated as “noxious” by the California Department of Food and Agriculture (CDFA), and 35 that are listed by the California Invasive Plant Council (Cal-IPC) as “invasive plants of greatest ecological

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Yellow starthistle, medusahead, and barb goatgrass are the most widespread noxious weeds in grassland communities. These and other Mediterranean Basin annual grasses and forbs comprise the dominant vegetation. Many of these same non-native grassland species dominate the understory of blue oak woodlands and compete with oak seedlings for moisture, nutrients, and light. Field collections in 1999 (C. Thomsen, pers. obs.) found smilograss (Piptatherum mileaceum) growing profusely on burned over chamise stands on the BLM Bear Creek Ranch. Smilograss is also well adapted to riparian zones and is occurring with greater frequency along Sulphur Creek.

Along Bear Creek, weeds such tamarisk, perennial pepperweed, and tall wheatgrass are now the dominant vegetation in many areas, displacing native riparian plants and preventing native plant establishment (C. Thomsen, pers. obs.). Although they provide some habitat benefits to wildlife, the dense thickets of these three species are altering riparian plant species composition and hydrologic function.

Ranchers and grazing operators in the watershed are concerned that increasingly arid soils are favoring the most widespread and unpalatable invasive plant species. These species are effectively outcompeting desired livestock forage species. The spread of perennial pepperweed, in particular, is damaging forage productivity in Bear Valley floodplains (J. Alderson, pers. comm.).

6.10 Impacts from Certain Grazing Practices and Browsing and Gnawing Animals Animals can have beneficial as well as adverse impacts on vegetation conditions desired by land managers and landowners. Research in Bear Valley has shown that livestock grazing helps to maintain the high diversity of native wildflower species there (Gelbard and Harrison 2003). Many areas in the watershed, however, are characterized by low levels of residual dry matter, soil compaction, upland terracettes, streambank and channel degradation, and active headcutting, some of which may be in response to overgrazing in the past. Similarly for wildlife, Johnson and Cushman (2007) studied the impacts of reintroduced tule elk in Marin County and found that elk have both positive and negative effects on native vegetation.

A study conducted just north of Bear Creek watershed found that livestock compacted soil around blue oak saplings. This fact may contribute to blue oak saplings in grazed plots having smaller stem diameters and heights than saplings in ungrazed plots (Jansen et al.

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1997). Tyler et al. (2006) have noted that livestock grazing may have a positive impact for oak seedling and sapling growth if oak seedlings and saplings are protected from grazing with tubes around their stems. Livestock grazing on non-native grasses surrounding the protected oaks promotes oak growth over grass growth by reducing the competitiveness of grasses for water.

With few exceptions, unprotected young valley oaks along Bear Creek are not regenerating to replace old trees. Seedlings are abundant in some locations, but saplings are rare and appear to only be surviving in one location where tule elk are less frequent (C. Thomsen, pers. comm.). Elk browsing tends to reduce native woody plant cover and may shift vegetation composition to grass-dominated vegetation (Johnson and Cushman 2007). Beaver also play a role in suppressing regeneration of willows and cottonwoods along Bear Creek (G. Mangan and C. Thomsen, pers. obs.).

Ranchers in the watershed and elsewhere in the region are finding that the harm attributed to livestock grazing is exaggerated or misplaced. Modern techniques and multiple-use considerations, often identified as “holistic grazing” (Butterfield et al. 2006), interweave livestock grazing into detailed planning for forage cropping, protection for wildlife habitat, and water and soil conservation. Widespread attitudes about the unsuitability of livestock grazing on public lands appear to drive a trend to more grazing closures and reduced numbers of animals on allotments that ranchers have traditionally relied on.

6.11 Low Recruitment of Native Woody Riparian Plants Riparian zones are among the most productive terrestrial environments and are critical to the hydrologic function of the watershed. Multiple ecosystem services come from riparian zones, for example: wildlife habitat, water sources for animals, flood protection, and drought alleviation. When native riparian woody plants are lacking or in poor condition, these services become degraded, affecting recreation, agriculture, and water delivery. Low recruitment of native woody plants in riparian zones usually results from one or more of the previously cited issues that interact in the riparian zone: sediment delivery to watercourses; creek channel alterations; creek and tributary headcuts; non-native invasive species; and impacts from grazing, browsing, and gnawing animals (beaver, cattle, tule elk). Together, these five factors are preventing successful regeneration and sustained habitat for native shrubs and trees along streams.

Over the last century, loss of riparian habitat quality in Bear Creek watershed has resulted from disturbances to riparian areas. Soil loss on streambanks from excessive animal or vehicle use has meant smaller areas for riparian species to germinate and grow. Downcutting in stream beds means that stream levels drop, stream banks are left higher and

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Without adequate cover of trees and shrubs in riparian zones, the strike force of rain on soil and soil erosion from stream flow is intensified. The result can be a spiral downward in the productivity of riparian sites that undermines land managers’ and landowners’ objectives to draw maximum sustainable benefits from riparian lands. After native species disappear, non-native plants such as tamarisk, perennial pepperweed, and tall wheatgrass invade riparian sites and outcompete native species for water and nutrients.

Animal Browse on Native Riparian Woody Plants Browsing animals prefer riparian species such as willows for their high nutrient value, especially nitrogen (Shoenecker et al. 2004). In northern California, elk and deer have been found to thwart regeneration in riparian zones significantly if browsing is not controlled, but exclosures to prevent entry of deer into restoration sites have been effective in promoting rapid growth of willows (Opperman and Merenlender 2001). Baker et al. (2005) showed that beaver cutting and elk browsing occurring jointly can stunt riparian vegetation even more intensively than if only one browsing species is present.

Where livestock have had uncontrolled access to riparian vegetation in Bear Creek watershed, woody plants are mostly absent. The browsing intensity over many decades appears too intense to allow regrowth and sustain vigor of woody species. Annual surveys by the BLM and CDFG between 1970 and 2000 describe severely degraded conditions along lower Bear Creek resulting from excessive livestock grazing on the Bear Creek Ranch prior to acquisition by the BLM. Some ranchers, however, in the watershed prefer not to encourage woody species to establish along their streams (J. Alderson, pers. comm.).

6.12 Growing Demand for Recreation and Tourism Open space on public lands and the network of public roads and trails in Bear Creek watershed afford opportunities for many kinds of recreation but also create challenges for recreation management. Some areas are accumulating refuse from shot-gun shells, excessive soil compaction and erosion from equestrian riding and foot traffic, and inappropriate OHV use on Walker Ridge.

Increasing Regional Population Populations of the three counties surrounding Bear Creek watershed (Colusa, Lake, and Yolo) are projected to grow by an additional 60 percent between 2010 and 2050 (California Department of Finance 2007). The value of the watershed for recreation will rise as urbanization expands and open space contracts with the increased population. Understanding the carrying capacity for recreation for Bear Creek watershed will be critical

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New Jobs in the Recreation and Tourism Industry Nearby cities such as Williams and Clear Lake have been suggested as “gateways” for recreation and tourism for the proposed Berryessa Snow Mountain National Conservation Area, which includes the public lands within the Bear Creek watershed. One focus is how to have recreation contribute more significantly to the local economies of gateway cities in Colusa and Lake counties and in the Capay Valley of Yolo County.

Personal Safety Criminal marijuana cultivation on public lands by heavily armed growers is a concern. Contact between growers and recreational users who unwittingly enter illegal marijuana gardens could have unfortunate results. A program to close down illegal operations on public lands is essential to healthy and safe recreation.

6.13 Potential Environmental Impacts of Energy Developments As the newest land use to arrive in Bear Creek watershed, commercial energy production must fit in with other pre-existing land uses, particularly on public lands committed to multiple uses. The constraints to energy development are greater today that in the past for several reasons discussed below. Proponents of energy developments must consider environmental impacts, including cumulative impacts, in their designs for alternative energy projects.

Energy Development and Protection of Biological Diversity CDFG species of special concern (equivalent to BLM and USFS sensitive species) with ranges inside the present energy lease areas include foothill yellow-legged frog, western pond turtle, pallid bat, and Townsend’s big-eared bat and at least eight BLM and US Forest Service sensitive plant species (GIS data from the Department of Fish and Game’s California Natural Diversity Database 2009). Concern for the fate of bats and raptor birds in the vicinity of wind turbine projects may require special operations and mitigations. No information is currently available on bat and raptor populations and their habitat use patterns on Walker Ridge that can serve as a baseline for detecting eventual impacts from geothermal and wind energy development projects in the watershed.

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Energy Development and Ground Disturbance on Sensitive Soils Installation of energy projects would incur an as yet unspecified amount of disturbance on the ultramafic soils which predominate in the energy lease areas. Large amounts of earth moving for project development would have the potential to further impair water quality and undermine hydrologic function. The portion of the Geysers KGRA in Bear Creek watershed encompasses 36 percent of the remaining 188 acres of rare hydric soils, critical for hydrologic function in Sulphur Creek subwatershed (Reed 2006). Extra measures will be necessary to prevent sediment delivery from energy sites to streams in Bear Creek watershed. Ground disturbance and increased vehicle traffic may promote the spread of noxious weeds such as barbed goatgrass and yellow starthistle.

At the same time that the BLM will be closing undesignated OHV trails in energy lease areas, the leaseholder for the wind project may be constructing new access roads to support construction and infrastructure maintenance at energy production sites. Energy projects may require a widened Walker Ridge Road. Increasing the surface area taken up by roads might also increase sediment erosion from ultramafic soils. Vehicle travel will likely generate larger amounts of dust, which naturally contains asbestos and heavy metals. The health impacts to exposed workers and recreation visitors in the area are not presently known.

Interactions between Energy Production and Recreation Energy developments may affect scenic values that draw visitors to Wilbur Hot Springs, Walker Ridge, and Bear Valley. Design and installation of energy projects need to protect the visual quality of the surrounding landscape upon which recreation and tourism depend. With the growing demand for both energy and recreation opportunities, the two uses may come into conflict. Increasing traffic and noise may lower the recreation value of public lands in the vicinity of energy installations. In some areas, public lands will be closed to public access to secure energy facilities.

Energy Development and Climate Change At a global scale, projects to capture energy from sustainable sources such as wind and sunlight have a positive impact for the environment. Shifting energy production and use away from fossil fuels (petroleum, natural gas, coal) to wind, solar, and geothermal energy can reduce emissions of carbon dioxide and other greenhouse gases into the atmosphere and hopefully moderate climate change. Energy development potentially at the expense of the local environment to improve the global environment may make some stakeholders uncomfortable.

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6.14 Fiscal and Policy Obstacles for Landowners to Meet Regulatory Targets Regulatory agencies establish targets and timelines to accomplish restoration of water quality, air quality, and wildlife habitat. Projects to restore ecosystem services and economic productivity for land uses can be costly, as evidenced from the cost estimates to clean up abandoned mines in the Bear Creek watershed and restore impaired water quality (TetraTech 2003, Ecology and Environment 2008). Finding funds to meet targets and timelines is challenging in difficult economic times. Regulatory agencies are not always clear about where the money is to come from to reach restoration goals.

Abandoned Mine Cleanups Pragmatic regulatory policies can accelerate people’s involvement in mercury mine cleanups. A major issue for watershed stakeholders is the slow pace of progress being made toward fairly assigning costs to parties responsible for abandoned mines and their mine waste. Despite scientific documentation of the mercury problems, recommended prescriptions for technical solutions, clear regulatory targets to reduce mercury and methylmercury in Bear Creek watershed, and the public desire to cleanup abandoned mines since at least 2003, cleanups are proceeding slowly. The CVRWQCB is now addressing mercury at abandoned mine sites on private lands in the watershed by involving the public at every step to develop cleanup and abatement orders for the Central, Cherry Hill, Empire, Manzanita, West End, and Wide Awake mines. All of these mines are on private property. The CVRWQCB Clean Up and Abatement Orders are already in place for the mines entirely or partially on federal public lands.

Costs for compliance with cleanup regulations are daunting to landowners. These landowners have inherited impaired conditions from previous landowners or mining companies who caused the damage decades ago. Many landowners are reluctant to clean up abandoned mercury mines because of ambiguity about who should pay. Ambiguity comes from the fact that the so-called “potentially responsible parties” for mine abandonment and subsequent mercury contamination are not always known immediately and require time to identify and locate. The landowner is responsible for underwriting the search for the parties (whether persons or corporations) responsible for the mercury contamination. If no other potentially responsible party can be located during the search, the current landowner is by default the party liable for the cost of the abandoned mine cleanup.

In cleanups of the abandoned Abbot and Turkey Run mercury mines in the adjacent North Fork Cache Creek watershed, none of the private landowners paid for the costs of mine remediation and site restoration. In the case of these mines, the corporate responsible parties were identified, located, and required to pay for the needed mine cleanups.

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Restrictions on Ranching Operations Increasingly, ranchers feel an economic burden on their operations from restrictions designed to protect air quality and water quality. Measures in place are obstacles to basic management needs for forage production and water for livestock. Using fire as a tool to improve forage and control the spread of invasive plants is greatly limited because other lands uses and vehicle emissions outside the watershed have put air quality at risk for the Sacramento Valley region.

Maintaining water flows for water quality in Bear Creek is a major priority for water agencies. In recent drought years, permitting for construction of stock ponds and other off- stream watering systems has become more difficult. Water has been scarce for all beneficial uses of Bear Creek. Many ranchers, however, see an imbalance in water agency decisions in allocating water for ranchers, who have only water from the watershed to draw upon, and for consumers outside the watershed, who have multiple options for obtaining water.

6.15 Climate Change The State of California is taking a leading role nationally to address the impacts to society and the environment from climate change. Six working groups are jointly developing from different perspectives the Climate Adaptation Strategy (CAS) for California. The Strategy consists of a synthesis of current information about expected impacts from climate change, explicit strategies to promote societal and environmental resiliency in response to climate change, and steps in the short term and long term to offset adverse impacts from climate change. The discussion draft is available for public review (California Energy Commission 2009) online.

The CAS is being formulated at a political and geographic scope larger than individual watersheds. Proposed actions in Bear Creek watershed in support of the CAS are beyond the scope of this watershed assessment until the Strategy is completed. This watershed assessment, however, is useful as a source of information for implementing the forthcoming CAS at the watershed scale. Climate change is likely to modify land uses and management practices designed to maintain or increase land use productivity. Many land uses of key importance to the State of California’s response to climate change are present or could be present in Bear Creek watershed in the future, namely: agriculture, energy, recreation, water delivery, and ecosystem services (for example, carbon sequestration and conservation of biological diversity). In addition, many stakeholder issues identified in Bear Creek watershed assessment are also key issues for the CAS. Those common issues include: fire, oak woodlands, increasing demand for recreation, and toxic chemicals. Efforts to enhance the productivity of these land uses and to resolve related stakeholders’ issues in the watershed can fulfill watershed goals while providing support for statewide actions for

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Many land management practices possible today for good watershed stewardship are also practices that can facilitate the watershed and California as a whole to adapt and respond effectively to climate change. Stakeholders’ issues concerning sustainability in Bear Creek watershed link directly to wider issues of climate change in an uncertain future. Table 6.1 provides a summary of the crossover issues between the Bear Creek watershed assessment and the California Climate Adaptation Strategy.

Table 6.1 – Crosswalk of issues covered in both the California Climate Adaptation Strategy and the Bear Creek watershed assessment Land Use or Climate Adaptation Bear Creek Watershed Ecosystem Service Strategy Issues Stakeholder Issues Oak Woodlands Reduce loss and increase area of oak Avoid cutting woodlands for woodlands to maintain woodlands for Carbon Sequestration fuelwood to maintain carbon storage erosion control, carbon storage in soils in soils and trees and reduce carbon and trees, soil fertility, and wildlife dioxide (a “greenhouse” gas) habitat Creek and Tributary Headcuts Soil loss from stream downcutting lowers the water table, and creates longer periods of soil drought on Drought from climate change is more Agriculture agricultural lands and wildlands in the intense and reduces agricultural summer. Loss of forage production and productivity available water for livestock during long drought cycles puts the economic viability of ranches at risk. Potential Environmental Impacts of Energy Developments Alternative energy projects may Without careful planning and cause losses to sensitive, rare, and mitigation measures, alternative Energy Development state and federally listed species and energy projects may causes losses to may fragment habitats in the process sensitive, rare, and state listed species, of reducing use of carbon fuels and and will fragment habitats mitigating climate change Growing Demand for Recreation and Tourism Population growth within driving Climate change may reduce distance of Bear Creek is creating Recreation aesthetic, educational, health, and growing demand for aesthetic, economic benefits from outdoor educational, health, and economic recreation benefits from outdoor recreation Toxic Chemicals and Sediment Delivery to Watercourses Powerful winter storms and floods Fewer but more powerful winter generate the largest inputs of mercury- storms and floods may increase the Water Delivery laden sediments from mine waste into amount of soil erosion, pollutants and the main stem of Bear Creek which has contaminants in water designated for a beneficial use as a municipal and municipal and domestic uses domestic water supply

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Land Use or Climate Adaptation Bear Creek Watershed Ecosystem Service Strategy Issues Stakeholder Issues Fire and Non-native Invasive Species Catastrophic fire sometimes leads to … increased … sedimentation, and More intensive management of increased opportunities for invasions prescribed burning can help prevent Biological Diversity of non-native species that could catastrophic fires that alter vegetation and compromise management efforts to cover, increase sedimentation in Water Delivery protect native species in the face of waterways, and shift soil nutrient climate change … Maximizing balances to favor invasions of non- prescribed burning … needs to be native species, particularly annual done with … climate change scenarios grasses. in mind.

6.16 Information Gaps This section does not discuss specific information gaps about resources already taken up in previous chapters. Instead, this section steps back to consider gaps in information about how stakeholders can work best to resolve stakeholder issues and achieve real improvements for Bear Creek watershed and for their own lives.

One significant information gap in Bear Creek watershed concerns the gap in communicating information among stakeholders in Bear Creek watershed – about stakeholder desires, needs, or expectations – and connecting stakeholders in productive ways to jointly make progress on stakeholder issues, especially issues that a single stakeholder cannot resolve alone. Lack of communication can be a major source of information gaps.

Stakeholders interested in watershed issues may want to make progress on issues but may not know how to go about resolving these issues. How can stakeholders acquire the technical information and the interpersonal skills to collaborate on resolving issues collectively? People can shape their roles in watershed stewardship to include active learning and purposeful sharing of information. Nevertheless, the commitment to acquiring and sharing information can be time consuming, and time may be in short supply for stakeholders with many other commitments.

Another gap in information concerns information about methods that stakeholders can collaboratively apply to overcome impasses with one another in the process of forging solutions to watershed issues of common concern. Impasses may consist of personality differences, seemingly intractable political or economic barriers to progress, or overwhelming uncertainty about the correct action to take. Information about techniques to improve interpersonal skills, negotiate solutions, and handle complexity and uncertainty comfortably are tools from which some stakeholders, and certainly the authors of this

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Finally, agency efforts to overcome information gaps occur irregularly and are often short- lived, especially as agencies have many priorities and limited funding. New technical information and advances in knowledge comes in spurts. Seldom do the best intentions of land management agencies to establish adaptive management anticipate, much less fund, watershed monitoring. Without monitoring, however, learning from the outcomes of stewardship actions is less likely and the risk increases of making the same mistake repeatedly.

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CHAPTER 7

SYNTHESIS OF WATERSHED CONDITIONS AND FOCAL AREAS FOR MANAGEMENT RESPONSES

This chapter summarizes information on stakeholder issues, land use, soils, water resources, natural disturbances, and options for resource management organized into thirteen “analysis areas”. Analysis areas consist of one or more subwatersheds in Bear Creek watershed following the delineation by Jack Alderson at the NRCS office in Colusa County (Figure 2.3). Each of the following chapter sections discusses one of the analysis areas in terms of important features, issues, potential projects, and job opportunities. Table 7.1 summarizes by analysis area the major issues identified in this assessment. The accompanying document Bear Creek Watershed Stewardship Priorities 2010 – 2014 provides more in-depth information on the highest priority projects.

7.1 Brophy Canyon

Land Uses livestock grazing, recreation and tourism (backpacking, camping, equestrian riding, game hunting, hiking), water delivery

Major Soils This watershed has non-ultramfic soils; Skyhigh, Sleeper, Millsholm, and Boar series are the most common. Water permeates these soils slowly, and runoff and soil erosion can be very high because of the steep topography. Sleeper and Millsholm soils are slightly alkaline soils, whereas Skyhigh soils are the most acidic of the major soil types in the watershed.

Major Stakeholder Issues Climate change Impacts from certain grazing practices and Creek channel alterations browsing and gnawing animals Fire Invasive non-native species Growing demand for recreation and tourism

Analysis Brophy Canyon may play an important role in water quality for Bear Creek watershed. As the last large drainage before the mouth of Bear Creek, Brophy Canyon supplies water to dilute the naturally high boron and salinity concentrations in Bear Creek water before it enters Cache Creek.

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Table 7.1 – Summary of the distribution of major issues by subwatershed analysis area

of of

& to to

& Tributary Tributary

Wildlife

nnel nnel

Analysis Area &

Policy Policy

Projects Projects Woody Woody and

& native Invasive -

Toxic Chemicals Toxic DeliverySediment Watercourses to Creek C Alterations Creek Headcuts Trails, Roads, Firelines Fire Oak Woodlands Disturbances Soils Ultramafic Non Species from Impacts Grazing Native Plants Riparian Recreation Tourism Impacts Potential Energy Fiscal Obstacles Change Climate Gaps Information Brophy Canyon X X X X X X Craig Canyon / Eula Canyon X X X X X X X Deadshot Canyon / Trout X X X X X X X X Creek Doyle Canyon / Gaither X X X X X X Canyon Hamilton Area / Warnick X X X X X Canyon Leesville X X X X X X X X Robbers Flat / Stinchfield X X X X X X X X Canyon Thomson Canyon X X X X X X X West of Cortina Ridge X X X X X X Mill Creek Subwatershed X X X X X X X X Sulphur Creek X X X X X X X X X X X X X X X Subwatershed Upper Bear Creek X X X X X X X X X X X X X Lower Bear Creek X X X X X X X X X X X X X X X

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Creek channel alterations: At least six water impoundments, originally constructed as stock ponds, may be reducing the water flow from the Canyon into Bear Creek. Restoring natural flows to waterways by carefully breaching the impoundments may keep water flowing in Brophy Canyon for a longer period during the dry season. An analysis of the advantages and disadvantages of removing some of the impoundments is needed, in view of the reduction in livestock grazing on public lands.

Growing demand for recreation and tourism: Brophy Canyon is a popular setting for dispersed recreation. The trail along Cache Creek Ridge on the southwest edge of the subwatershed is a destination for visitors with overlooks into the Middle Cache Creek canyon, impressive vistas, and solitude. Erosion is particularly a concern along the steep north side of lower Brophy Canyon. Unstable slopes there are impacting hunter and hiker trails. Trail repair or re-routing is necessary in some areas.

Impacts from certain grazing practices and browsing and gnawing animals + Invasive non- native species: Grazing practices to suppress medusahead is a focus of land management. Current practices are unintentionally releasing yellow starthistle from competition with medusahead.

Fire: The eastern half of the subwatershed burned in 1999 during an arson fire originating along Highway 16. South-facing slopes, which are drier, more sparsely vegetated, and have more flammable chaparral vegetation, are at greater risk of erosion after fires.

Climate change: In the past, chaparral and oak woodland habitats were converted to grassland, particularly in the northwest quarter of the subwatershed. Reestablishment of native chaparral and woodland habitats may become more difficult, however, if wildfires become more frequent under the hotter, drier conditions forecast by climate change modeling.

Potential Projects and Job Opportunities  Restoration of oak woodlands and chaparral vegetation on lands previously converted to grasslands  Guided tours for environmental education for youth from Colusa, Lake, and Yolo counties  Re-examination of management practices to determine whether multiple ecosystem goals are being achieved, especially in regard to managing targeted invasive plants, controlling erosion, improving hydrologic function, and enhancing native vegetation

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7.2 Craig Canyon / Eula Canyon

Land Uses livestock grazing, recreation and tourism (hunting, hiking, equestrian sport, mountain biking, wildflower viewing), scientific research and monitoring, water delivery, woodland management

Major Soils Three soils predominate in these canyons: from west to east, Contra Costa on successive narrowly spaced ridges, ultramafic haploxerert soils on barren hills, and Hillgate on lower hills and ending in a floodplain at the edge of lower Bear Creek. The individual soils support marked bands of vegetation: chaparral, ultramafic barrens, and oak woodland from west to east.

Major Stakeholder Issues Climate change Information gaps Disturbances to ultramafic soils Non-native invasive species Growing demand for recreation and tourism Oak woodlands Impacts from certain grazing practices and browsing and gnawing animals

Analysis Eula Canyon lies north of Craig Canyon. These small watersheds share similar topography and vegetation. The canyons are notable for the absence of recorded wildfire over the last 60 years.

Impacts from certain grazing practices: Previous land conversion of blue oak woodland to grassland and subsequent overgrazing appear widespread on the east end of Eula Canyon. Current livestock practices are compromising stream bank stability and water quality. Insufficient residual dry matter, livestock trails, soil compaction, and trampling characterize some grazing areas.

Oak woodlands: Valley oaks persist in the pasture created on the terrace at the base of Craig Canyon above Bear Creek. Increasing oak stand cover would increase watershed protection and provide thermal cover for game species.

Disturbance to ultramafic soils + Non-native invasive species: Plant surveys on the ultramafic barrens have discovered rare plant populations. An infestation of non-native barb goatgrass threatens these rare plant populations. Another invasive plant concern for riparian areas has been the presence of ravenna grass, an outlier infestation that

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Recreation: This portion of the BLM Bear Creek Ranch does not have an extensive network of recreation trails. Monitoring livestock grazing and recreation trail use along the creek and adjacent upland in Craig Canyon is necessary to ensure the functioning of the riparian zone.

Climate change: The north-south orientation of the vegetation and soils may function as corridors for genetic and species migration during adaptation to climate change. Opportunities for reforestation close to Bear Creek at the base of Craig Canyon may provide greater carbon storage.

Information gaps: The three bands of differing soils and corresponding different vegetation close by in these canyons are useful research sites for tracking and understanding comparative responses of vegetation associations to climate change.

Potential Projects and Job Opportunities  Restoration of blue and valley oak woodlands on lands previously converted to grasslands for livestock grazing  Management of non-native plants, principally documented infestations of perennial pepperweed in riparian zones and barb goatgrass on ultramafic barrens  Management for oak woodlands to produce traditional cultural resources  Scientific research on rare and little-known plant communities on the barrens and their development under climate change  Re-examination of management practices to determine whether multiple ecosystem goals are being achieved, especially in regard to managing targeted invasive plants, controlling erosion, improving hydrologic function, and enhancing native vegetation

7.3 Deadshot Canyon / Trout Creek

Land Uses development (residential), energy production, livestock grazing, mining, recreation and tourism (hiking, hunting, wildlife and wildflower viewing), scientific research and monitoring, water delivery

Major Soils Henneke and Okiota ultramafic soils predominate on the highest elevations along Walker Ridge as well as eastward (down slope) across two-thirds of the distance to the Bear Valley

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Major Stakeholder Issues Climate change Non-native invasive species Disturbances to ultramafic soils Potential impacts of energy development Fire Roads, trails, and firelines Growing demand for recreation and tourism Sediment delivery to watercourses Information gaps

Analysis Trout Creek subwatershed lies to the north of Deadshot Canyon subwatershed. The array of uses or potential uses in the two canyons makes this analysis area important for coordinated watershed management. A discussion of the issues that pertain to the Bear Valley portion of these subwatersheds is found in section 7.12 Upper Bear Creek Subwatershed.

Disturbance to ultramafic soils + Sediment delivery to watercourses: The ultramafic soils and rock in both Deadshot Canyon and Trout Creek have been subject to natural avalanches, indicating unstable ground over the foothill portions of the two subwatersheds. The ravine in Deadshot Canyon appears particularly prone to large slides. It is unclear at present how much sediment from these slides currently reaches Bear Valley.

Several areas of extensive human disturbance to ultramafic soils have occurred. A mine prospect straddles the ridge on the north side of Trout Creek subwatershed. This site may be valuable as a reference site to better understand the composition and rate of natural regeneration on highly-disturbed ultramafic rock and soils. Information from the site would be useful in informing the remediation and revegetation designs at the Rathburn-Petray mine complex found on the same soil type just to the south of Deadshot Canyon.

A ranch development on private land has removed a considerable area of chaparral in the center of Trout Creek watershed. Given that the development area is large and next to a stream, higher than background levels of debris and other sediment may be entering a tributary of Trout Creek. Just below the development are the remnants of a landslide.

Fire: Deadshot Canyon subwatershed partially burned in 2008, but an evaluation of impacts has not been undertaken to determine what kind of restoration or protection measures are needed. The post-fire response from vegetation, especially shrubs and rare endemic plants has yet to be documented.

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Non-native invasive plants: Arundo, or giant reed, is found along lower Trout Creek. More recent updates on the extent of non-native invasive plants in the subwatershed are not available.

Potential impacts of energy development: A wind project leasing area covers the Walker Ridge part of the analysis area. The BLM is reviewing a proposal for development from AltaGas Income Trust to construct a wind energy development on a small percentage of the lands inside the wind energy lease area on the Ridge. The wind lease area lies above steeper slopes where landslides occur. The known ranges of rare plants in these subwatersheds as delineated by the California Natural Diversity Database largely lie largely within the wind lease area. Protecting the scenic, biological, and watershed values will require excellent engineering and ecological design standards for the wind project if wind turbines are constructed in this analysis area.

In the event of a wind energy project being installed, raptor birds and bats are likely to die during the course of turbine operations. Monitoring mortalities of raptor birds and bats and studying the impacts to other wildlife species such as black bear and native cats will be necessary to determine compensation for habitat enhancements for these species elsewhere. The impact of energy development on the BLM lands to bat colonies in nearby abandoned mines, especially colonies of pallid and Townsend’s big-eared bats, is presently unknown.

Geothermal development is unlikely to occur because of limited access and questionable viability of geothermal production at this edge of the Geysers-Clear Lake volcanic field.

Roads, trails, and firelines + Growing demand for recreation and tourism: Cross-country trails are extensive in Trout Creek subwatershed. In response to the need for fire protection during the Walker Fire, the California Department of Forestry and Fire Protection bulldozed part of a 21-mile fireline across public and private lands across these subwatersheds. The fireline is a long scar on the landscape and efforts to rehabilitate the land have not been undertaken yet. No decision and funding for mitigation appear to be on the horizon.

The only designated OHV trail in the analysis area is Walker Ridge Road. Within the next five-years, the BLM Ukiah Field Office will be determining the final design for its OHV route network in the Walker Ridge / Indian Valley planning area. Considerations of land stability and sensitive ecological environments will be part of the planning effort. Accommodating both motorized recreation visitors and employees and contractors for energy leaseholders on Walker Ridge Road will require travel management on account of environmental constraints and sensitive resources. New roads may be required as well, and these would further disturb ultramafic soils and fragment native vegetation.

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Climate change: One important question is how best to mitigate adverse impacts of climate change. The Federal government and the State of California both advocate energy production from renewal resources as one mitigating step. Dedicating some public lands to renewable energy projects can contribute to alleviating climate change impacts globally, but on a regional scale other considerations arise. Walker Ridge, a higher-elevation site and a north- south corridor, may be an important location for species to shift their ranges as they adapt to a changing climate. Rare plants dependent on ultramafic soils may be particularly at risk. An inclusive public discussion among stakeholders of the tradeoffs and mitigation measures to avoid losses to biological diversity and watershed values is needed.

Information gaps: Natural resource inventories of the largely unexplored public lands in these subwatersheds are necessary for determining sites for wind turbines in low-impact, energy- efficient locations. Information on the soil and vegetation conditions of the 2008 fireline is not available. An evaluation of altered hydrologic function and impaired water flow and quality is not possible without more information.

Potential Projects and Job Opportunities Baseline biological surveys of animals (invertebrate and vertebrate) and plants Employment in energy-related construction and wind farm operations Plant ecological and physiological studies at the mine prospect site on the ridge dividing Trout Creek and Gaither Canyon subwatershed to guide revegetation elsewhere Site analysis for determining which, if any, revegetation and soil erosion control projects are necessary for the Walker Fire fireline

7.4 Doyle Canyon / Gaither Canyon

Land Uses energy production, livestock grazing, recreation and tourism (car touring, hiking, hunting, OHV riding, wildlife and wildflower viewing), scientific research and monitoring, transportation, water delivery

Major Soils Henneke and Okiota ultramafic soils predominate at the highest elevations along Walker Ridge as well as eastward (down slope) across two-thirds of the distance to the Bear Valley floor. A band of Millsholm soils connects the canyons with Bear Valley. Soils on the floor of Bear Valley consist of partially hydric Venado soils and the unique Leesville soil series, both of which are of alluvial and ultramafic.

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Major Stakeholder Issues Climate change Information gaps Disturbances to ultramafic soils Potential impacts of energy development Growing demand for recreation and tourism Roads, trails, and firelines

Analysis A discussion of the issues that pertain to the Bear Valley portion of these subwatersheds is found in section 7.12 Upper Bear Creek. This analysis area historically has had fewer land use impacts. As a result, stakeholder issues are not as numerous.

Disturbances to ultramafic soils: Landslides are virtually absent from the analysis in contrast to the Deadshot Canyon / Trout Creek analysis area. Pre-2008 trails in these subwatersheds may have limited utility for either recreation or possible future wind energy production and need evaluation to know whether they are posing erosion problems. The 2008 fireline discussed in Section 7.3 also traverses this area.

Roads, trails, and firelines + Growing demand for recreation and tourism: Conditions are similar to those described in Section 7.3. In addition, an isolated sedge wetland on ultramafic soil is present along Walker Ridge Road. Some OHV tracks are visible at the perimeter of the wetland. Management to secure the wetland from OHV intrusions and dust deposition is in order, especially if vehicle traffic along Walker Ridge Road increases to meet recreation demand or to facilitate access to wind energy project sites.

Potential impacts of energy development: Refer to Section 7.3.

Climate change: Refer to Section 7.3.

Information gaps: Refer to Section 7.3.

Potential Projects and Job Opportunities Refer to Section 7.3.

7.5 Hamilton Area / Warnick Canyon

Land Uses energy production (potential), livestock grazing, recreation (car touring, hunting), transportation, water delivery, woodland management

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Major Soils This analysis area is a transition zone between ultramafic soils (Henneke – Okiota) in the southwest part and the more widespread sedimentary-derived Millsholm, Contra Costa, and Hillgate soils elsewhere in the analysis area. A small finger of an ultramafic barren enters the area at the south edge.

Stakeholder Issues Impacts from certain grazing and browsing Oak woodlands and gnawing animals Roads, trails, and fire suppression lines Non-native invasive species Sediment delivery to watercourses

Analysis This analysis area consists almost entirely of private lands. Information about the region is limited. Rare plants are present in a small area covered by an ultramafic barren.

Impacts from certain grazing and browsing and gnawing animals: Livestock grazing is the mainstay economic livelihood in this analysis area. At least fifteen stock ponds are present, with most concentrated in the southeast. No information is available about animal impacts.

Oak woodlands + Sediment delivery to watercourses: Large tracts of blue oak woodlands have been converted to grassland. A statewide program of carbon credits could give incentives to landowners to conserve and replant oak woodlands. The ecological benefits of oak woodland management could enhance oak woodland-dependent wildlife. Reforestation can moderate rainfall impact on soils and reduce sediment delivery to intermittent streams.

Roads: Part of Highway 20 crosses the analysis area and mostly parallels a Bear Creek tributary. Wet meadows are adjacent to the highway. Culverts are functioning well and do not appear to be causing excessive sedimentation, but the tributary streambed is filling with sediment in places and creating bars.

Non-native invasive species: In meadow wetlands, annual grasses and teasel are widespread. The creek along Highway 20 has a diverse complement of native aquatic and riparian species (cattails, sedges). However, at several locations arundo has invaded.

Information gaps: In general, little public information is available for this analysis area because it consists of private lands.

Potential Projects and Job Opportunities  Reforestation jobs to promote germination, planting, and sapling survival of oaks  Control for non-native plant species in the CALTRANS right-of-way along, streams, and

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7.6 Leesville

Land Uses development (residential), crop agriculture and livestock grazing, recreation and tourism (car touring, hunting, long-distance running, bicycle racing), transportation, water delivery, woodland management

Predominant Soil Series Contra Costa and Millsholm soils are present on hillslopes, and Hillgate soil predominates in valleys.

Stakeholder Issues Creek and tributary headcuts Low recruitment of native woody riparian Creek channel alterations plants Fiscal and Policy Obstacles to Meet Targets Oak woodlands Impacts from certain grazing practices and Roads, trails, and firelines browing and gnawing animals Sediment delivery to watercourses

Analysis Leesville subwatershed has a small residential population and is the second most populous area in Bear Creek watershed. Livestock grazing is the principal land use. Private landowners are concerned by the effects of soil loss on the productivity of their lands. The lowered water table, headcuts, and channel incision are reducing land productivity for quality forage.

Creek channel alterations: At least four man-made ponds were developed to provide water for livestock, game animals, forage crops, and home gardens. A hydrological analysis of the Leesville subwatershed is not available to know how the impacts of creek alterations affect water flows and riparian areas.

Creek and tributary headcuts + Sediment delivery to watercourses: A large network of headcuts and gulleys covers much of the south valley and has caused considerable soil loss. In the small valley at the north end of the subwatershed, some streams are downcutting.

Roads: Severe headcuts originate in part from twelve poorly designed and placed road culverts at eleven locations along Leesville Road. Some gullying across Huffmeister Road is occurring, particularly near the intersection with Leesville Road. Roads have low vehicle traffic but need extensive maintenance to halt damage to private property.

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Low recruitment of native woody riparian plants + Impacts from certain grazing practices: Loss of upland and riparian vegetation from past overgrazing is a factor contributing to unstable stream banks, channel incision, and soil erosion. The floor of Long Valley has remnants of woody riparian vegetation consisting of old cottonwood, willow, and valley oak trees along the main drainages. These remnant trees do not provide high-quality habitat for wildlife dependent on riparian woodlands. Stream banks would benefit from habitat restoration.

Oak woodlands: The greatest value for wildlife, particularly game species, is the extensive blue oak woodland in upland areas. Large areas of oak woodlands on the west side of the south valley have been cleared, resulting in increased sediment fanning out onto the Long Valley floor.

Fiscal and policy obstacles to meet targets: Adequate funding to maintain more remote roads is not readily available.

Potential Stewardship Projects and Job Opportunities  Road repair and culvert redesign / replacement along Leesville Road  Restoration of riparian vegetation in Long Valley to slow water flow, maintain soil moisture longer, reduce soil erosion, and provide more forage to benefit livestock  Development of recreational hunting, marathon runs, and tourism centered in the historic Leesville settlement  Oak woodland reforestation to supply an even flow of oak fuelwood, improve wildlife habitat, reduce overland erosion, and store atmospheric carbon

7.7 Robbers Flat / Stinchfield Canyon

Land Uses agricultural crops and livestock grazing, recreation and tourism (car touring, game hunting, nature study), scientific research and monitoring, telecommunications, transportation, water delivery, woodland management

Major Soils Ultramafic Henneke and Montara soils predominate at the top of the headwaters on Walker Ridge. Some metavolcanic rocks are present along part of Walker Ridge. Henneke soils run through mid-elevations. The lowest foothills are interspersed with Millsholm soils. Leesville soils and a sliver of Venado soils comprise the Bear Valley portion of the subwatersheds. Rock outcrops are more frequent here than in other parts of Walker Ridge; a few rock pinnacles are present.

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Stakeholder Issues Climate change Low recruitment of native woody riparian Creek channel alterations plants Impacts from certain grazing and browsing Non-native invasive species and gnawing animals Oak woodlands Information gaps Roads, trails, and firelines

Analysis Creek channel alterations: On the Bear Valley floor, parts of the creek through Robbers Flat subwatershed have been straightened and channelized en route to Mill Creek. These actions appear to have dried the wetlands and hydric soils that were once extensive at the base of Mill Creek.

Climate change: Because of the known high number of rare plants on public lands, this area can serve as a long-term conservation area and monitoring site to see how plants dependent on ultramafic soils are responding to climate change.

Low recruitment of native woody riparian plants + Non-native invasive species: Riparian habitats on ultramafic soils in the foothills along Brim Road are in good condition, with abundant and diverse trees, shrubs, and forbs. However, further down slope into Bear Valley all riparian vegetation has disappeared. Channeling and lack of riparian shrubs or trees have devegetated and dewatered the land. Crops are not grown at present. The grasslands and riparian areas are dominated by non-native grasses.

Oak woodlands + Impacts from certain grazing practices: In lowland portions of the Robbers Flat subwatershed, oak woodlands on Millsholm soils appear to have been partially cleared to create grassland.

Roads, trails, firelines: Both Brim Road and Walker Ridge Road are important routes for visitors to the Indian Valley Recreation Area and to the Mendocino National Forest. Robbers Flat subwatershed would likely become more frequently traveled if OHV recreation expanded on public lands in Bear Creek watershed and in the adjacent North Fork Cache Creek watershed. Integrated travel management, recreation, and ecosystem planning is necessary for accommodating increased road use. Considerations include air quality, dust, traffic noise and safety, impacts of road widening on riparian vegetation and water quality, and available funding for county road maintenance.

Information gaps: Botanists have explored the ultramafic chaparral habitat along the upper portion of Walker Ridge Road and along Brim Road down to the Bear Valley Floor for rare

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Potential Projects and Job Opportunities  Botanical surveys, vegetation mapping, and long-term monitoring for responses of vegetation to climate change  Oak woodland reforestation for carbon sequestration and moderating climate conditions on Millsholm soils  Improvements to Brim Road and Walker Ridge Road to mitigate impacts from increased vehicle travel to nearby recreation areas and, potentially, to wind energy turbine sites.

7.8 Thompson Canyon

Land Uses development (residential), livestock grazing, recreation and tourism (hiking, backpacking, equestrian riding, mountain biking, game hunting), scientific research and monitoring, water delivery, woodland management

Major Soils Four non-ultramafic loamy soils predominate in Thompson Canyon: Boar, Skyhigh, Millsholm, and Sleeper. All but Millsholm are deep soils. Because of their topographic positions, soils may erode after strong storms. A finger of haploxerert barren soil extends into the subwatershed at the northern boundary, where ultramafic soils reach their southernmost extent in Bear Creek watershed.

Stakeholder Issues Climate change Information gaps Disturbances to ultramafic soils Non-native invasive species Fire Oak woodlands Growing demand for recreation and tourism Sediment delivery to watercourses Impacts from certain grazing and browsing and gnawing animals

Analysis Impacts from certain grazing practices: Long-term livestock grazing has transformed the western part of the watershed. Much chaparral vegetation has been cleared. A network of trails crisscrosses the terrain. Evaluation of these trails for any needed repairs and erosion controls would be useful, particularly where recreation trails parallel ephemeral streams.

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Fire: Wildfires have only rarely burned in the subwatershed over the last sixty years, but the prescribed burning has been conducted regularly since the 1980s. Investigating the outcomes for soils, vegetation, and wildlife from prescribed burning would help managers determine whether the burns accomplished objectives for invasive weed control and production of forage for game species such as elk and deer.

Disturbances to ultramafic soils + Non-native invasive species: Habitats of rare plants in the subwatershed occur on the ultramafic soils. Barb goatgrass is spreading on the ultramafic barren. A complete survey of non-native invasive species is not yet available for the rest of the subwatershed.

Growing demand for recreation and tourism: The BLM has established a recreation trail network across Thompson Canyon watershed. These trails set the stage for opportunities for environmental science education and outdoor recreation experiences for youth. Other recreation opportunities for the public may be available.

Sediment delivery to watercourses: Many recreation trails follow the courses of streams. With a greater emphasis for recreation and environmental education, trails may receive greater use. Attention to trail design and repair to prevent soil erosion into streams is increasingly important for maintaining watershed health and visitor safety.

Information gaps: Most of Thompson Canyon subwatershed is rugged backcountry. Information about the subwatershed is limited because of lack of public access in the past and remoteness from paved roads. Rare plant habitat occurs in the northwest corner of the subwatershed where ultramafic soils are present.

The mouth of the canyon is habitat for foothill yellow-legged frogs. Effects of prescribed burning on aquatic habitat for western pond turtle are not known. Monitoring for turtles and frogs is needed to ensure that populations of these sensitive species are faring well.

Potential Projects and Job Opportunities  Revegetating chaparral to lands previously converted to grasslands and testing the effectiveness of revegetation practices for increasing carbon storage  Jobs for recreation guides, interpretive specialists, and environmental educators in organizing recreational and outdoor education events  Jobs for youth groups to monitor and repair recreation trails, control erosion, and assist with revegetation projects in the subwatershed  Developing a plan for environmental education and public outreach for the subwatershed

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7.9 West of Cortina Ridge

Land Uses livestock recreation, recreation and tourism (backcountry hiking and camping on public lands), water delivery, woodland management

Major Soils Nearly the entire analysis area consists of Millsholm and Contra Costa soils. On steep slopes, these soils are susceptible to erosion.

Stakeholder Issues Climate change Oak woodlands Fire Sediment delivery to watercourses Non-native invasive species Information gaps

Analysis This analysis area consists of a series of seven small canyons on the east side of lower Bear Creek below Highway 20. The northern part of the analysis area is private land; in the south the BLM manages public lands. Grazing has been the most important land use, but the area has extensive open spaces available for livestock grazing, wildlife conservation, and recreation opportunities.

Fire + Climate change + Sediment delivery to watercourses: The southern portion of the analysis area west of Cortina Ridge has remote, steep, and highly dissected terrain. This terrain makes controlling wildfires a logistical challenge. Natural ignitions are rare in the analysis area, but wildfires spreading from human ignitions originating east of Cortina Ridge, in Cache Creek Canyon, or along Highway 16 put the landscape at repeated risk.

Steep, south-facing slopes are especially susceptible to increases in temperature and drought thought to be associated with climate change. If the pace of regeneration of plant cover slows after wildfires, predicted increasingly intense winter storms could generate more slope erosion in this analysis area. Increased erosion on south-facing slopes would increase sediment loads in stormwater flows to Bear Creek.

Oak woodlands + Non-native invasive species: A large block of oak woodland has been cleared on private land at the north end of the analysis area. Other lands near ranch roads also appear to have reduced canopy cover of oak woodlands. The presence of non-native grasses and forbs, such as barb goatgrass and yellow starthistle, may make natural oak germination and sapling growth difficult to achieve.

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Information gaps: Little information is available on biological resources in the analysis area. Techniques for cost-efficient silviculture to reforest blue oak woodlands are needed.

Potential Projects and Job Opportunities Reforestation of blue oak woodlands Water quality monitoring for sediment loads in streams in the analysis area and throughout the watershed

7.10 Mill Creek Subwatershed

Land Uses crop agriculture and livestock grazing, mining, recreation and tourism (OHV riding, wildlife viewing, backcountry camping and hiking), scientific research and monitoring, water delivery, woodland management

Major Soils Ultramafic Henneke, Okiota, and Montara soils are dominant in most of Mill Creek subwatershed. Runoff is high to very high with these soils because of widespread steep terrain. The lowest elevations on the east side of the subwatershed have sedimentary Millsholm and ultramafic alluvial Leesville and Venado soils. Both soils are unique to Bear Creek watershed. Hydric soils are present along the lower course of the main stem of Mill Creek.

Stakeholder Issues Creek channel alterations Impacts from certain grazing and browsing Disturbances to ultramafic soils and gnawing animals Fire Information gaps Growing demand for recreation and Low recruitment of native woody plants tourism Sediment delivery to watercourses

Analysis Mill Creek subwatershed is the most remote and least known part of Bear Creek watershed. Rock outcrops and ultramafic barrens are major visual features in the diverse terrain of Mill Creek subwatershed. The low-elevation southeast portion of the subwatershed comprises the northwest section of Bear Valley.

Creek channel alterations: On agricultural land on the floor of Bear Valley, Mill Creek has several channelized sections that depart from the natural sinuosity expected in a stream that flows over terrain with very low slope. Channels from Robbers Flat subwatershed also flow to

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Mill Creek. Section 7.12 expands on the effects of channelization on the hydrology of Bear Valley.

Impacts from certain livestock grazing practices + Low recruitment of native woody riparian species: Expected recruitment of native woody riparian species along streams on the southeast flank of the subwatershed is lacking. Despite loss of riparian vegetation and downcutting along lower Mill Creek, the aquatic environment remains sufficient to support foothill yellow- legged frogs.

Fire: Mill Creek subwatershed is the only part of Bear Creek watershed with two fire management jurisdictions: the Mendocino National Forest and the California Department of Forestry and Fire Protection. The two jurisdictions abut at the boundary between the National Forest and the BLM public lands. Fire suppression in the subwatershed would require aerial operations because of its remoteness. Development of practices and strategies to manage fire and control erosion in this remote area is a challenge for public land managers. In the past six decades, only two fires have burned in the subwatershed, having entered from outside the subwatershed at the north perimeter of the Bear Creek watershed boundary.

Growing demand for recreation and tourism: Public access is only at the top of the watershed on Love Lady Ridge. The ridge is accessible by way of OHV trails designated by the Mendocino National Forest. The trail coming from the north requires advanced motorcycle riding skills, and careful 4-wheel driving is necessary when coming from the south. Remoteness and ruggedness of the landscape are excellent for backcountry camping.

Disturbances to ultramafic soils + Sediment delivery to watercourses: The large area of ultramafic soils in the subwatershed is susceptible to landslides from natural causes. Between 1984 and 2005, one large landslide released 29,000 cubic yards of rock and debris (Hoorn et al. 2008). These events might increase if wild fires were to remove large areas of vegetation from the steepest parts of the watershed and expose soil and rock to the elements.

Small-scale mining for chromite has resulted in one abandoned mine site, the Black Bird mine. Previous efforts at the site to limit watershed impacts appear to prevent significant sediment from flowing into tributaries of Mill Creek from the mine site. The mine is scheduled for full remediation in 2010-2011 (R. Mowery, Mendocino National Forest hydrologist, pers. comm.).

The remoteness of Mill Creek subwatershed is attractive for illegal marijuana cultivation, which already occurs north and west of Love Lady Ridge. Covert cultivation leads to disturbances on ultramafic soils and possible site contamination from herbicides and rodenticides.

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Information gaps: Mill Creek ultramafic habitats lie at their eastern limit in the Inner Coast Range (R. O’Dell, BLM botanist, pers. comm.; Cheung 2004). Inventories of biotic resources in the subwatershed are lacking and would contribute to knowledge about responses of plants and animals to climate change along the steep elevation gradient. Rare plant occurrences are probably more extensive than indicated in Figure 7.10. Surveys in a similar setting in the Frenzel Creek Research Natural Area just outside Bear Creek watershed indicate that plant surveys of Mill Creek ultramafic soil sites would provide new information on the distribution of little-known rare plant species.

Data on Mill Creek water flow and quality do not currently exist. Installation of a water quality monitoring station in lower Mill Creek would provide information about the flow and chemical composition of Mill Creek water.

Potential Projects and Job Opportunities  Biological inventories, especially for rare plant species adapted to ultramafic soils  Clean up and remediation at the Black Bird mine  Surveying for rare plants and mapping plant communities on public lands  Water quality and flow monitoring just above the confluence of Mill Creek with Bear Creek  Recovery of riparian vegetation along lower Mill Creek to help reduce soil erosion and slow water flow away from the subwatershed, providing a longer wet season for soils  Opportunities for guides to lead backcountry hiking and camping trips on National Forest and BLM public lands  Research opportunities for rare plant conservation and habitat enhancement on public lands in the National Forest and BLM public lands

7.11 Sulphur Creek Subwatershed

Land Uses development (residential, spa resort), energy production and conveyance, crop agriculture, mining, recreation and tourism (wildlife and wildflower viewing, hiking, OHV riding, spa services, lodging), scientific research and monitoring, telecommunications, water delivery, woodland management

Major Soils Reflecting the underlying complex geology, soils in Sulphur Creek subwatershed are a complex mosaic from volcanic, ultramafic, and sedimentary sources. The diversity of soil types creates varied vegetation communities. Soils metamorphosed from volcanic rocks are present on Walker Ridge in the northwest and southwest corners of the subwatershed.

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Henneke and Okiota ultramafic soils characterize the northern uplands and cross the subwatershed diagonally to the southeast of Walker Ridge. Many springs and seeps with unusual waters are present. In the northeast and the south third of the watershed sedimentary Skyhigh and Millsholm soils predominate.

Stakeholder Issues Climate change Information gaps Creek channel alterations Low recruitment of native woody plants Creek and tributary headcuts Non-native invasive species Disturbances to ultramafic soils Oak woodlands Fire Potential impacts of energy development Fiscal and policy obstacles to meet Roads, trails, and fire suppression lines regulatory targets Sediment delivery to watercourses Growing demand for recreation and tourism Toxic Chemical

Analysis Land uses have in large measure transformed the subwatershed. Past mining has created significant costs for environmental cleanup. Issues of natural resource management and land uses in the subwatershed are complex, and multiple stakeholders are scrutinizing the subwatershed to make improvements to its environmental quality.

Sediment delivery to watercourses: Natural landslides are numerous in areas with ultramafic soil and rock. In addition, mine waste adds sediment to Sulphur Creek tributaries. Unstable banks and headcuts in Sulphur Creek valley in the central part of the subwatershed produce tons of soil erosion annually (Hoorn et al. 2008). All such areas are inventoried and mapped.

The Colusa County Resource Conservation District has focused on progress in stabilizing or removing these sediments to reduce their flow into streams in the subwatershed. The CVRWQCB had awarded the District funding for the work to halt erosion from roads as a model project for sediment control for watersheds in the Inner Coast Ranges. Funding cuts and projected high costs forced the CVRWQCB to withdraw funding. Site characterization and planning for sediment control structures in the subwatershed remain critical on both public and private lands.

Toxic chemicals: The mercury minerals in mine and retort waste are much higher than background levels. Sediments with high mercury content enter Sulphur Creek and its tributaries, especially in the lower half of the subwatershed where mercury mines are concentrated. Currently, Sulphur Creek has two TMDLs, for mercury and methylmercury. The TMDLs are based on findings over the last decade about the quantity and movement of mercury-laden sediments and scientists’ better understanding of the biochemical processes

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that drive the formation of methylmercury, the mercury compound that poses the greatest risk to the health of people and wildlife. Recent data from Morrison et al. (2008) and Holloway et al. (2009a,b) show that mercury has contaminated soils well away from the abandoned mercury mines as well, notably in the floodplain areas in the subwatershed. In the coming years, multiple mine remediation and site restoration projects are anticipated. The BLM has already initiated cleanups at the Clyde and Elgin mines.

Fiscal and policy obstacles to meet regulatory targets: The public has known about the magnitude of mercury contamination in Sulphur Creek watershed since the reports by Suchanek et al. (2002) and Churchill and Clinkenbeard (2003), funded as part of the CalFed Bay-Delta Mercury Project. Response actions have taken years to initiate because the scope and complexity of the mercury problem affecting the Sacramento River Basin and the Sacramento-San Joaquin River Delta is immense. Procedures for regulatory agencies to address mercury contamination are stringent to safeguard the public interest. The State of California requires that the public be involved at every stage of actions to address mercury pollution from abandoned mines. The regulatory agencies involved in Bay-Delta issues have not always had sufficient staff to address mercury contamination in all the affected watersheds flowing into the Sacramento River and Delta. Prioritization of efforts has been necessary. Bear Creek watershed as part of the larger Cache Creek Basin has been a high priority for reducing mercury contamination in the Delta. The CVRWQCB accelerated the process of issuing cleanup orders in 2009 to address the mercury mines on private lands in Sulphur Creek subwatershed.

The federal Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) process directs clean up for hazardous contaminant materials such as mercury mine wastes on public lands. CERCLA permits the agency that cleans up a site with contaminants to obtain compensation for cleanup costs from the one or more parties who were responsible for the contamination. Private landowners with abandoned mine sites for which they are not responsible for resulting contamination are liable for the cleanup costs unless they are able to identify another potentially responsible party (PRP). Current landowners are required to bear the costs for their searches and documentation of liability of an earlier PRP. Time-consuming negotiation and litigation may ensue to settle final responsibility for cleanup costs. Landowners may also incur legal costs to clarify responsibility as well. Perceptions of unfairness in the process can hamper the cooperation of landowners and create delays in dealing with mercury contamination.

Creek channel alterations: The course of Sulphur Creek has shifted as the result of engineering to the Creek during the peak of mercury mining. To stabilize the a portion of Sulphur Creek next to the Wilbur Springs Road, the Colusa County Public Works Department lined the creek bank with riprap in 2007. In addition, rerouting of streamflows from natural

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springs has occurred around many of the commercially important hot springs. Effects of these diversions and bank alterations on stream flow are not known.

Fire: Despite the long presence of human communities in the Sulphur Creek subwatershed, wildfires have not started in the area in past decades. However, in 2008, two-thirds of the subwatershed burned during the Walker Fire. To date, no information is available about soil erosion resulting from the fire and the composition and extent of vegetation regeneration since the fire.

Road, trails, and firelines: The narrow track of Wilbur Springs Road is vulnerable to erosion and flood damage. The cutbank along the road exposes rock faces and bare soil profiles in several places. During winter floods, washouts in the road can occur.

Numerous ranch routes and OHV trails are present across the watershed at all elevations. Closing and revegetating redundant routes coupled with redesign and repair of essential routes would contribute to decreasing the amount of soil and mine sediment reaching Sulphur Creek. Trail closures in the vicinity of abandoned mercury mines are a high priority in the lower half of the watershed.

At higher elevations on ultramafic soils in Sulphur Creek subwatershed, the BLM has thus far designated two OHV trails in its Resource Management Plan (2006): Walker Ridge Road and the OHV trail that runs from Walker Ridge Road downslope and eastward to the Rathburn- Petray mine complex. Both routes cross the major block of BLM public land in the subwatershed designated as part of the Indian Valley ACEC. The purpose of the ACEC is to secure undisturbed rare plant habitat. Keeping this road open has encouraged OHV riders to use the mercury mine pits (just outside Sulphur Creek subwatershed) for sport riding. The OHV trail is problematic because it runs through a rare spring-fed wetland on ultramafic soils. The mine trail and unauthorized spur routes are impacting wetland vegetation. Disturbance from the OHV route is likely to increase to accommodate vehicle access during remediation and revegetation of the Rathburn-Petray mine complex.

In the next few years, the BLM will finalize the OHV route designations for Walker Ridge. BLM will close and restore those routes not designated for OHV travel. Closure and restoration of these trails will reduce ultramafic soils erosion down slope into Sulphur Creek.

In 2008, part of the 21-mile long fireline to halt the Walker Fire crossed through the subwatershed. No repair to the habitat fragmentation from the fireline is underway. The Walker Fire fireline can provide avenues for illegal vehicle traffic if no controls to access are in place.

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Creek and tributary headcuts: Headcuts in the Sulphur Creek valley are reducing the surface area of the valley, leading to a lower water table, loss of wetland habitat, soil erosion, and sedimentation. Very large volumes of topsoil have been lost in Sulphur Creek valley as headcuts have rapidly moved upstream through the valley in recent years. Soil loss related to headcuts may be releasing more mercury previously stored in soils.

Oak woodlands: During the era of mercury mining, oak woodlands in Sulphur Creek subwatershed furnished the fuelwood for firing mercury retorts. Photographs of the Wilbur Spring area at the turn of the 20th century show the surrounding hillsides nearly void of oak trees. Since that time, significant even-aged blue oak stands have regenerated naturally.

Growing demand for recreation and tourism: Temporary loss of access to the Sulphur Creek subwatershed by way of Wilbur Springs Road occurs occasionally on account of storm damage and erosion. The Colusa County Department of Public Works responds quickly. Loss of road access for an extended period would greatly hamper tourism to the lower part of the subwatershed.

In the upper part of the watershed, designation of OHV access across fragile ultramafic soils with high numbers of rare plants deserves careful consideration. The slow rate of revegetation and growth of plants on ultramafic soils makes these ecosystems vulnerable to vehicular disturbance and wildfire. To date, no designated non-motorized trails are in place for visitors who come to appreciate the unique flora, an unusual ultramafic landscape, solitude, and scenic vistas.

Potential impacts of energy development + Disturbances to ultramafic soils: The western one- third of Sulphur Creek subwatershed is part of a wind energy lease and corresponds to the ultramafic soil zone where landslides have been frequent since 1937. Also, the wind energy lease area encompasses the entire portion of the Indian Valley ACEC within the subwatershed. Wind turbine sites in the ACEC and elsewhere in the ultramafic zone of the subwatershed would add to soil disturbances.

Non-native invasive plants: The firelines related to the Walker Fire may be providing avenues for non-native invasive plants. Arundo is present at Wilbur Springs where it is used as a screen and ornamental purposes at the resort. Fortunately, growing away from its preferred soil and moisture conditions and possibly on account of water chemistry in the area, arundo has not spread downstream. The source infestation of tamarisk in the watershed was at Wilbur Springs, but a four-year effort has controlled the once extensive infestations there. Downstream of Wilbur Springs, tamarisk is still thriving. A small infestation of barb goatgrass occurs in the Sulphur Creek valley, but it is not under control. In recent years, perennial pepperweed has taken hold

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in the valley; in 2007 over 50 patches were mapped. Pepperweed has the potential to become a dominant plant throughout the valley wherever moist soils occur. Similar to most other grassland areas in the watershed that occur on non-ultramafic soils, medusahead and yellow starthistle are abundant.

Climate change: One feature projected for climate change in California is winters with fewer but more powerful storms. The trend toward increased peak storm flows would alter stream courses, flush more mercury-rich soils and sediment from the subwatershed, further deepen stream channels, widen the banks of Sulphur Creek, and pose a greater threat to the integrity of Wilbur Springs Road.

Information gaps: In the last decade, CalFed has invested in many studies to clarify the sources, amounts, and pathways of mercury in Sulphur Creek subwatershed. Applying this information toward containing mercury contamination will lead to significant progress in resolving watershed issues that extend downstream well beyond Bear Creek. The large number of present and potential land uses in the subwatershed, combined with unique and sensitive natural resources, warrant well-considered planning for resource protection.

Eight CNPS List 1b and BLM sensitive plant species are known from Sulphur Creek subwatershed. This high number of species indicates the importance of the subwatershed for rare plant conservation. The California Native Plant Society has recommended to the BLM that the Indian Valley ACEC be expanded to include more of the rare plant habitat found here and in the other subwatersheds on Walker Ridge. Virtually no information is available about the ecology of these rare species or about steps to effective management to increase their populations in the subwatershed. In the absence of botanical surveys, resource managers need predictive models of the distributions of rare plant species. Progress in conservation planning for rare plants and their habitats has been slow in the subwatershed. Also, three locally endemic insect species depend on the unusual water chemistry of Sulphur Creek for their life cycle. Documented sightings are needed to ascertain their population status.

Landowners and land managers will need to know whether their management actions to resolve issues are successful and are not creating new problems. A well-designed monitoring system for the subwatershed can validate outcomes and alert stakeholders to unintended consequences from projects in the subwatershed. For example, water quality monitoring can track progress toward achieving the Sulphur Creek TMDL for total mercury and determine where abandoned mine cleanups are working effectively.

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Researchers at the University of California at Davis are beginning to study responses by vegetation on ultramafic soils to the Walker Fire. Information from these studies will give resource managers insights into the rates of shrub regeneration, populations and ranges of rare plants, and the invasibility of burned sites on ultramafic soils by non-native invasive species.

Potential Projects and Job Opportunities Mine remediation, involving teams of engineers, machine operators, laborers Inventories of rare species, especially bats, plants, aquatic insects, and frogs Plant ecologists and field crews to revegetate redundant roads and trails, reclaimed mine surfaces, riparian zones, and firelines Road redesign of Wilbur Springs Road to reduce soil erosion and sedimentation into Sulphur Creek Engineers, maintenance staff, and construction crews for developing industrial and domestic sources of solar, geothermal, and wind energy Hydrologic restoration of wetlands and streams impacted by land uses, particularly in regard to headcutting and loss of riparian vegetation Multi-year studies of the flora and fauna of the region to better document the overall biological value of public lands in this subwatershed, as well as its link to surrounding areas Long-term monitoring of total mercury and methyl mercury in Sulphur Creek stream water Mapping the extent and concentration of heavy metals, and especially mercury, in the subwatershed soils

7.12 Upper Bear Creek

Land Uses development (residential), livestock grazing, crop agriculture, beekeeping, mining, recreation and tourism (car touring, hunting, long-distance running, wildlife and wildflower viewing), scientific research and monitoring, transportation, water delivery, woodland management

Major Soils The floor of Bear Valley contains the Bear Valley, Leesville, and Venado soils, unique to this watershed on account of the unusual blending of alluvial soils from both ultramafic and sedimentary rock sources. Venado soils cover a substantial part of the valley, particularly along Bear Creek itself. These soils are in part hydric and could be important to conserving water in the Valley. Ultramafic soils, especially Henneke and Okiota, predominate in the foothills on the west side of the Valley while Millsholm soils coincide with the band of hillsides and oak woodlands on the east side of Bear Valley. The portion of the Bear Valley

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Buttes within the subwatershed contains intermixed Buttes and Millsholm soils. The unique Buttes soils occur only on the Bear Valley Buttes.

Stakeholder Issues Climate change Information gaps Creek channel alterations Low recruitment of native woody riparian Creek and tributary headcuts plants Disturbances to ultramafic soils Non-native invasive species Fiscal and policy obstacles to meet regulatory Oak woodlands targets Sediment delivery to watercourses Growing demand for recreation and tourism Toxic chemicals Impacts from certain grazing and browsing and gnawing animals

Analysis Upper Bear Creek subwatershed is the most agricultural of the Bear Creek subwatersheds. Continuous agricultural land use for more than 150 years has maintained notable natural resources of statewide significance along Upper Bear Creek. Bear Valley has the only prime farmland in the watershed as designated by the State Department of Conservation. This analysis also encompasses similar issues from the parts of Bear Valley that form the eastern ends of multiple subwatersheds previously discussed (that is, from north to south: Mill Creek, Robbers Flat, Stinchfield Canyon, Doyle Canyon, Gaither Canyon, Trout Creek, and Deadshot Canyon).

Toxic chemicals: Environmental problems relating to water quality are locally acute. In the southwest corner of the subwatershed, the abandoned Rathburn-Petray mine complex has been in need of remediation since mining ended in the early 1970s. Currently, the BLM Ukiah Field Office is remediating the mine complex and sampling the quality of water leaving the mine complex site. Water quality sampling upslope from Bear Valley is critical to understanding how much the mine complex is exporting mercury in runoff to the Valley. Concerns stem from the recent discovery of high amounts of mercury and methylmercury in the soil and in cold springs in the southernmost alluvial fan in the Valley. It is uncertain still whether the mercury from the cold springs stems solely from natural “background sources” or whether surface and subsurface water flow from the mine complex upslope contributes a man- caused source of mercury contamination on the valley floor.

Creek channel alterations + Creek and tributary headcuts: People have modified, both intentionally and unintentionally, the hydrologic function of this stretch of Bear Creek over the last 120 years. These developments have led to a suite of issues that concern hydrologists, natural resource managers, and landowners.

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The presence of remnant hydric soils on the broad valley bottom indicates the potential for reestablishing or expanding existing wetlands and recreating marshes (National Riparian Service Team 2001). Knowledge of the past condition of wetlands in Bear Valley is incomplete, but the low gradient of the valley floor, stream sinuosity, and naturally wide and shallow undisturbed channels indicate that water once flowed through the Valley more slowly than at present. An excerpt from an undated letter quoted by Green (1950) describes Bear Valley in the late 19th century as follows:

“The banks of Bear creek are, along the valley, rather low, and the land on either side subject to overflow. The springs on the hill-sides keep the ground moist and the valley is nearly always covered with green grass and flowers.”

Longer residence time of water once kept native vegetation green longer by keeping soils moist during more of the year. Rates of stream bank erosion were likely very low and riparian vegetation was widespread in the past.

As people impounded tributary water to Bear Creek, the supply of water to Bear Creek may have diminished. Modifications to Bear Creek such as dynamiting channels may have also accelerated water flow rate out of the valley. Soils on the valley are now in general more arid and less productive due to the lowered water table and loss of topsoil. Bear Creek and its tributaries downcut their banks and lowered the streambed and water table. Riparian vegetation is establishing along Bear Creek at the level to which the streambed has dropped. Examining historical photographs would help to clarify how these changes to hydrologic functioning and riparian habitat occurred.

Sediment delivery + Disturbances to ultramafic soils: Sediment is a particular concern in upper Bear Creek because of the ongoing loss of soil from diverse sources: headcuts, culverts, stream downcutting, and loss of stream bank stability resulting from missing riparian vegetation. Improvements to the pattern of water flow in Bear Valley would have benefits downstream. Reducing the winter rate of water flow leaving the Valley and making water flow more evenly throughout the year would reduce soil loss in the Valley and curb bank erosion along lower Bear Creek.

Most soils in Bear Valley are unusual alluvial ultramafic soils in that they consist of a blend of ultramafic and sedimentary soil sources mostly washed down slope from opposite sides of Bear Valley. Venado soils and riverwash soils along Bear Creek and its valley tributaries now have considerably reduced hydric function as a result of creek channel alterations, downcutting, and headcuts. These resulting local human-caused disturbances to topography in Bear Valley have led to a functional loss in the water holding (“sponge”) capacity of hydric soils to retain water longer throughout the year. Restoring water storage capacity would be an important goal for reestablishing a more natural water flow system in Bear Valley.

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Oak woodlands + Low recruitment of native woody riparian plants: The extensive valley oak woodland at the south end of the subwatershed provides an image of what riparian vegetation might have looked like in Bear Valley before 1850. Woody riparian habitat is now mostly absent on the valley floor.

Impacts from certain grazing practices: To revegetate riparian corridors and protect banks from eroding further, the NRCS has worked with landowners in the Valley to fence stream banks to allow them to revegetate with native plants and prevent further bank erosion.

Removing livestock from the Bear Creek channel may be important to water quality. The unexpectedly high ratio of methylmercury to mercury found in water at the north end of Bear Valley away from mercury mine sources occurs in streams with high amounts of dissolved organic matter (DOM). DOM contributes the methyl portion to methylmercury. The role of livestock in increasing DOM and the resulting comparatively high methylmercury production is currently under study in the Putah Creek watershed nearby.

From their research work in Bear Valley, Gelbard and Harrison (2003) have demonstrated that livestock grazing on the valley floor benefits the spring wildflower bloom that draws visitors to Bear Valley. Livestock grazing may be critical for controlling non-native invasive annual grasses that compete for water and growing space with wildflower populations in Bear Valley.

Growing demand for recreation and tourism: Bear Valley offers magnificent views of strikingly different scenery around its perimeter. The wildflower fields in the spring are remarkable and draw many visitors. Incorporating Bear Valley into automobile touring routes of the backroads in western Colusa County could provide business opportunities for landowners. Opportunities for game hunting exist on private ranches where game species are less intensively hunted than on public lands.

Non-native invasive plants: The CDFG has delineated the wildflower field at the southern end of the Valley (found on Bear Valley and Venado soils) as an outstanding biological area for its plant species diversity. Three rare plant species ranked by the California Native Plant Society as meriting the highest conservation concern are found in the Valley. However, the wildflower field and other areas of the Valley are under threat from non-native invasive plants. Major invasive species in Bear Valley are barb goatgrass, tall wheatgrass, medusahead, perennial pepperweed, and yellow starthistle. They are displacing native vegetation in both upland and riparian parts of the Valley.

Fiscal and policy obstacles to meet regulatory targets: Current landowners have largely prospered despite the altered hydrologic condition and reduced soil moisture in Bear Valley. They may not have a strong incentive to replace current conditions at great expense with a

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wetland and stream system that resembles more the original valley of the mid-1800s. Regulators and beneficiaries of Bear Creek water downstream need to consider their role in furnishing incentives for private landowner participation in a landscape-scale effort to restore the Valley.

Further funding from state water and wildlife agencies or tax breaks for landowner incentives could support project work. Current economic conditions and state revenues for water restoration projects may be insufficient to address all of the Upper Bear Creek hydrology and habitat restoration at this time. The State of California faces critical choices in developing water policy and projects that meet the future demand for water by Californians. Restoring the whole of the wetland system of Bear Valley in one large project may rank as a lower priority statewide.

An alternative strategy to improve hydrology in Bear Valley is to work as opportunities arise, incrementally on a small scale and in a patchwork fashion. This “small projects” approach relies on interest in stewardship on the part of individual landowners. In time, the cumulative benefits of smaller projects can restore hydrologic function and native habitats in Bear Valley. Currently, the Colusa County Resource Conservation District is proposing such a smaller- scale project with a Valley landowner to the State of California Wildlife Conservation Board.

Climate change: Restoring the hydrology of Bear Valley may not be easy in a time of climate change. People interested in improving hydrology and the stream and wetland habitats for holistic livestock management there may have to resort to a program of partial recovery. If the water supply in the watershed declines as the result of more severe droughts, replicating past conditions may be difficult. Design of an adapted hydrologic system that functions under changing climate conditions can still foster desired habitat and ecosystem improvements. Climate change requires re-thinking the usefulness of the term “restoration”. Adaptation and mitigation of climate impacts may be more apt goals upon which to base improvements to the hydrology of Upper Bear Creek.

Information gaps: A feasibility study would clarify the scope of work needed to repair and improve hydrologic function in Bear Valley. Knowing what practical engineering and ecological solutions are available plus the consideration of associated costs and benefits would provide stakeholders with basic information for good decisions.

The possibilities for improving the hydrologic system require a better understanding of how the present system works. A computer model of the existing hydrology in Bear Valley and the Bear Creek tributaries flowing into the Valley would familiarize stakeholders, planners, and engineers with Bear Valley watershed function. To understand what conditions were like before people modified Bear Valley, a simulation model could create the best picture of how

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people think the Valley originally functioned. Stakeholders could then use models of current and past conditions to consider a range of alternatives for future hydrological improvements.

Wildlife note: Upper Bear Creek subwatershed contains known nesting habitat for the following uncommon or declining raptor birds: prairie falcon, golden eagle, burrowing owl, and potentially Swainson’s hawk. Existing land use practices in the subwatershed are sustaining populations of these species. More information on raptor population dynamics under climate change effects would support habitat management decisions to sustain raptor birds in the subwatershed.

Potential Projects and Job Opportunities Projects to improve hydrologic function, wetlands, native plant populations, and game populations on ranchlands in Bear Valley Tourism promotion for Bear Valley as a wildflower and wildlife destination Valley oak woodland restoration Expansion of off-stream watering systems for livestock under the current assistance program with the Colusa County Resource Conservation District Recovery of woody riparian vegetation Development of a watershed model for Bear Valley that depicts current conditions, approximates historical conditions, and simulates outcomes of proposed alternatives to improve hydrologic function in the Valley

7.13 Lower Bear Creek, including Lynch Canyon

Land Uses livestock grazing, crop agriculture, energy conveyance, recreation and tourism (bicycling, car touring, equestrian riding, hunting, kayaking, mountain biking), development (governmental, residential), scientific research and monitoring, telecommunications, transportation, water delivery, woodland management

Major Soils Millsholm soils are the most widespread of the sedimentary soils and occur in the eastern and southern parts of the subwatershed. Skyhigh and Sleeper soils form mosaics with Millsholm soils particularly on the west side of Bear Creek. These soils erode easily on several steep banks along Bear Creek and at roadcuts along Highway 16. Henneke soils predominate at higher elevations on the west side of Bear Creek in a band stretching both north and south of Highway 20. Ultramafic barrens occur in the area immediately to the west of Cowboy Camp on the BLM Bear Creek Ranch and along Bear Valley Road near Highway 20.

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Stakeholder Issues Climate change Information gaps Creek and tributary headcuts Low recruitment of native woody plants Creek channel alterations Non-native invasive species Disturbances to ultramafic soils Oak woodlands Growing demand for recreation and tourism Roads, trails, and fire suppression lines Fire Sediment delivery to watercourses Fiscal and policy obstacles to meet regulatory Toxic chemicals targets Impacts from certain grazing practices and browsing and gnawing animals

Analysis Lower Bear Creek subwatershed drains from the south end of Bear Valley to the confluence with Cache Creek at the Colusa-Yolo county line. This part of Bear Creek watershed experiences the greatest human travel and visitation.

Roads: Transportation is a major land use in this subwatershed. Most of the length of state highway corridors that traverse Bear Creek watershed passes through this subwatershed. The intersection of Highways 16 and 20 is the busiest traffic point. Because Highway 16 parallels lower Bear Creek and its adjacent steep terrain to the mouth of Bear Creek, the highway has the potential to impact Bear Creek adversely. Engineering for the highway requires intensive maintenance to keep the road in good working order over its narrow course. The large number of culverts along Highway 16 is necessary to direct overland flows to Bear Creek with the least impact to soils and water quality. Deferred maintenance is a problem because sediment fills and buries many culverts along the highway. Other culverts are damaged and do not direct water to Bear Creek as intended. In some places, riprap has been the solution used for bank stabilization. Three large eroding slopes are failing along the highway just north of the mouth of Bear Creek.

Initial estimates of sediment-laden runoff from state highways in the watershed are considerable (>12 tons solid sediment and > 12 tons dissolved material annually). Trash and dumping have been a problem in the travel corridor. The BLM and CALTRANS have taken steps make sure that dumping does not continue.

CALTRANS has taken precautions to prevent landslides on steep terrain along Highway 20 west of the intersection with Highway 16. Drainage pipes are installed in several locations, and long culverts and ducts convey water into Bear Creek with minimal soil disturbance to side slopes. CALTRANS has removed soil from a ten-acre parcel on BLM public lands. The scraped site now exposes ultramafic rocks that fracture easily. Rock sediments and remnants

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of soil now erode from the site. The parcel is unsightly from the highway and from viewsheds on public lands. CALTRANS had initiated a well-conceived revegetation project but has abandoned that effort.

Several wetlands lie along Highway 20 and some are at risk of compromised biological integrity. For example, Destinella Flat at the Colusa County line, which contains a seasonal wetland, is at risk from infestations of barb goatgrass in upland areas, extensive pepperweed patches, and grazing practices that are degrading the wetland. Widening of the parking strip along the highway is a problem as sediment drains from the road verge into the adjacent wetland.

Over the years, volunteers have controlled weed infestations to maintain the diversity of native wildflowers and grasses found in the Bear Creek Botanical Management Area established by CALTRANS along Highway 20. Recent realignment of the Highway 20 bridge over Bear Creek has required extensive disturbance of the Management Area north of Highway 20, although the core prairie complex on the south side of Highway 20 next to BLM land has remained mostly protected from earthworks. Volunteer activity has ceased, and barb goatgrass and yellow starthistle infestations are likely to spread.

Growing demand for recreation and tourism: Another major land use for this subwatershed is recreation. Lower Bear Creek subwatershed is a gateway via Highway 16 from Yolo County to recreation and tourism opportunities on the BLM Bear Creek Ranch, Walker Ridge, and the county roads in Bear Valley. Stopping along Highway 16 can be hazardous since the narrow canyon terrain does not have room for many road shoulders and easy pullouts. Signs for safe places to park vehicles are not in place. Unauthorized recreational shooting is creating problems, especially where people litter the landscape with cartridges and shells. Increasing popularity of the Ranch and the range of outdoor recreation available suggest that a comprehensive recreation plan is in order to accommodate diverse recreation groups and minimize conflicts among user groups.

Toxic chemicals: The CVRWQCB has requested that the BLM and private landowners curtail developments along the lower Bear Creek riparian zone because of the likelihood of dislodging mercury bound in stream and bank sediments. Recent findings by the CVRWQCB staff (Bosworth and Morris 2009) have shown that an estimated 91 kg (200 lbs) of total mercury are present in sediment deposition zones on banks along lower Bear Creek.

One challenge to stakeholders is how to manage sites known or suspected of being hot spots for mercury methylation. Researchers have not yet investigated to what extent lower Bear Creek below the confluence of Sulphur Creek (the major source of mercury) functions as an incubator for methylating mercury. Methylation production from streamside pools during low

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summer flows, for example, deserves research. With this information, resource managers can map levels of methylation production for lower Bear Creek and then focus on managing the aquatic ecology at mercury hot spots to suppress mercury methylation.

Oak woodlands: Oak harvesters have removed blue oak woodlands over much of Bear Creek Ranch and elsewhere in portions of the subwatershed for fuelwood and short-term increases for forage production. Large gaps appear in the continuity of woodlands. Given the change in emphasis for land uses on Bear Creek Ranch, the benefits of past vegetation management may not apply to future management needs. Rangelands are often difficult sites to revegetate as oak woodlands. Drought, weeds, multiple browsing by animals, securing an adequate supply of acorns at the right time, loss of soil fertility, and imperfect silvicultural practices all come in to play. Some large-scale natural oak woodland regeneration has occurred.

Low recruitment of native woody riparian plants: Steps to reduce animal browsing are underway along lower Bear Creek, and signs of recovery are apparent near the confluence with Cache Creek. Where valley oaks have persisted in the Bear Creek riparian zone, seedlings are present but survival to saplings and older tree stages is rare.

Non-native invasive species + Disturbance to ultramafic soils: Perennial peppergrass, tall wheatgrass, and tamarisk are the most dominant invasive plant species in the lower Bear Creek riparian zone, especially at sites with deeper soils. They are transforming the appearance and function of riparian zones. Barb goatgrass invasion on ultramafic soils is also extensive.

Sediment delivery to watercourses + Impacts from certain livestock practices and browsing and gnawing animals: Livestock grazing occurs occasionally on private land on the east side of Bear Creek and annually on the BLM Bear Creek Ranch. Stakeholders involved with the Ranch are concerned about the effects of intensive livestock grazing on hydrologic function, site stability, and water quality in lower Bear Creek riparian areas. Current grazing practices are causing riparian vegetation loss, livestock trampling, and animal waste to get in the water. For example, west of Cowboy Camp, headcuts and gullies are widespread, and sufficient vegetation to curb erosion is missing on upland and riparian zones. These conditions would benefit from changes to the timing, location, and intensity of grazing.

Fiscal and policy obstacles to meet targets: Public and regulatory expectations for resource management issues in the Lower Bear Creek subwatershed require ongoing stakeholder collaboration. Stakeholder agreement on goals, specific issues, priorities, and management pathways is for necessary steps to plan, identify bottlenecks and stewardship solutions, locate funding, and implement and monitor projects for watershed improvements.

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Fire: Arson fires have been a problem along Highway 16 in the past. A concern is that with the increase of visitors to public lands the risk of wildfires will increase. If climate change affects fire behavior and frequency, the composition and amount of required revegetation may be unprecedented. Multiple prescribed fires have occurred on the BLM Bear Creek Ranch since 1993, but no one has documented or quantified the benefits of prescribed burning for the Ranch.

Climate change: Forecasts of a warmer, drier climate for the region, however, point to longer droughts that might cause Bear Creek to cease flowing more often than in the past. Impacts of more frequent and longer disruptions of stream flow in Bear Creek are likely to threaten populations of foothill yellow-legged frogs. There is a need to prepare for future changes for specific vulnerable sites using best available information.

Information needs: A model of the depositional processes and methylation rates of mercury in sediment accumulations and summer season pools along Bear Creek can better predict locations where mercury management is most critical to reduce mercury and methylmercury exports to Cache Creek.

Note on biological diversity: Under the direction of Dr. Ellen Dean, with the Center for Plant Diversity at UC-Davis, the BLM Bear Creek Ranch has been the focus of intensive botanical inventories. Over 450 species of plants have been documented, six of which are BLM sensitive plant species. Five of these species are endemic to ultramafic soils.

The riparian corridor is also important to foothill yellow-legged frogs and western pond turtles, both BLM sensitive animal species. The frogs are especially common in Bear Creek above the confluence with Sulphur Creek. Bald eagles are common along the Creek, especially during the winter. One small tributary just north of the confluence with Sulphur Creek has historically maintained a population of the Wilbur Springs Shorebug, but the species has not been recorded there since 1979.

Potential Projects and Job Opportunities Revegetation of the BLM land along Highway 20 where CALTRANS scalped soil to avoid landslides covering the highway Planning and implementing removal of mercury-rich sediment piles in deposition zones along lower Bear Creek Stewardship and research to increase the extent of blue oak and valley woodlands as mitigation for climate change impacts, carbon sequestration, and wildlife habitat improvement

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Increased outdoor recreational, interpretative, and scientific programs for children and young adults sponsored by schools, recreation groups, and educational foundations, patterned on events such as the Cache Creek Watershed Discovery Day Conservation planning and project implementation to protect and enhance habitat for sensitive and special status aquatic species Management of aquatic habitats identified as hot spots for mercury methylation to reduce net methylation in lower Bear Creek Monitoring for aquatic and terrestrial wildlife along lower Bear Creek as indicators of stream proper functioning condition Studies of the effectiveness of past prescribed burns

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CHAPTER 8

NEXT STEPS

This chapter outlines next steps for addressing stakeholder issues to attain watershed goals. In preparing the Bear Creek watershed assessment, we gathered and evaluated multiple sources of information: historical facts, research data, geographic information, reviews of new science and technology, and judgments of experts familiar with the watershed. Although many aspects of the watershed are still not well understood, the overall intent of this work has been to provide information on the current state of knowledge as a guide for future decision making and to identify what we need to be learning. Watershed assessment does not suffice by itself; it must be coupled to actions on the ground in the watershed and to learning on the part of stakeholders.

This chapter focuses on three general action areas for progress:

 determining and implementing voluntary best management practices (BMPs) for concerted actions  learning for better decision making in natural resource stewardship, consisting of four components: inventories, technical evaluations, scientific research, and monitoring  recovering diminished ecosystem services and natural resources through remediation and restoration projects, as prioritized by stakeholders.

8.1 Best Management Practices for Watershed Stewardship Best management practices (BMPs) refer to controls, procedures, and operations designed to protect and improve environmental conditions. The original context for BMPs concerned water quality, but the term is used more broadly now to include conservation measures to protect other resources such as soils and wildlife and to halt the spread of invasive plants or pathogens, for example. BMPs for Bear Creek watershed would cover stakeholder issues including, among others: controls for mercury pollution and sediment control; standards to restore creek channels and recover native vegetation of riparian areas; road and trail maintenance for erosion control; prescribed fire treatments; oak woodland conservation; limits to disturbances on ultramafic soils; integrated weed management practices; reductions of impacts from energy developments; and responses to mitigate or adapt to impacts from climate change.

Some sets of BMPs are already in place for public lands in Bear Creek watershed. They do not refer to any other lands than to the BLM and US Forest Service lands. However, they may serve as points of departure for broader stakeholder discussions of BMPs for application watershed wide.

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The BLM Ukiah Field Office Resource Management Plan (RMP) (2006) contains two sets of BMPs that relate to two stakeholder issues in Bear Creek watershed: impacts to other resources from energy resource development and demand for recreation. The references for these BMPs appear below.

Appendix I - Wind Energy Best Management Practices, available online at: http://www.blm.gov/ca/pdfs/ukiah_pdfs/rmp-eis/Appendices/Appendix_I.pdf

Wind energy BMPs cover site monitoring and testing in advance of development, preparing the plan of development, construction procedures for an approved project, subsequent project operation, and site decommissioning. Natural resources addressed by BMPs include: wildlife (bats and birds especially), unique habitats, and special-status plant species.

Appendix J – Recommended Off-Highway Vehicle Management Guidelines from the BLM Northwest California Resource Advisory Council, available online at: http://www.blm.gov/ca/pdfs/ukiah_pdfs/rmp-eis/Appendices/Appendix_J.pdf

The BMPs (“guidelines”) for motorized recreation deal with planning and management to protect, water quality, riparian and wetland habitats, biological diversity, and soils.

The Pacific Southwest Region (Region 5) of the US Forest Service has established BMPs for water quality management, a major stakeholder issue in Bear Creek watershed. These BMPs are currently in effect for the Mendocino National Forest portion of the watershed. The document Water Quality Management for National Forest System Lands in California (2000) is available online at:http://www.fs.fed.us/r5/publications/water_resources/waterquality/water-best-mgmt.pdf

The range of topics for water quality management covers forestry, mining impacts, recreation effects, livestock grazing, and road and trail construction. As technical knowledge grows, the Pacific Southwest Region plans to refine its water quality BMPs.

The California Department of Transportation (CALTRANS) addresses the stakeholders’ transportation issue in part with its Construction Site BMP Manual (2003). The document is available online at: http://www.dot.ca.gov/hq/construc/stormwater/CSBMPM_303_Final.pdf.

The applicability of the BMP Manual extends beyond transportation construction. Sections cover soil stabilization and stockpile management, sediment control measures, and handling of contaminated soils and hazardous waste. These BMPs also assist stakeholders in managing abandoned mine reclamation, stabilizing stream banks, and revegetating disturbed lands. The Landscape Architecture Program at CALTRANS provides further BMPs for erosion and methods for implementing BMPs using the Caltrans Erosion Control Toolbox, available on-line

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Other important BMPs for Bear Creek watershed may deal with fire management. The California Department of Forestry and Fire Protection is an important stakeholder and source for information in this regard. Topics for BMPs could cover: (1) protecting sensitive vegetation types, especially on ultramafic soils; (2) controlling non-native invasive species spread after prescribed burns and wildfires; (3) reducing emissions of mercury generated from wildfires; (4) avoiding landslide hazards, especially on ultramafic soils after fires; and (5) protecting aquatic and riparian ecosystems during and after fires.

8.2 Information Needs for Resource Management This section summarizes assessment findings about information needs in four tables: Table 8.1 Resource Inventories; Table 8.2 Technical Evaluations; Table 8.3 Science Research; Table 8.4 Monitoring. All projects proposed to meet information needs address the stakeholders’ overarching goal for maintaining economic livelihoods and creating jobs. The new jobs generated to fill information needs are a source of employment for skilled workers. But the information generated is designed to increase the productivity of soil and water resources for sustaining ranching in Bear Creek watershed and for delivering water for agriculture and municipalities downstream. Because the cost to acquire desired information in Bear Creek watershed exceeds the limit of realistic funding, stakeholders will be prioritizing those information needs that promise the greatest return toward attaining watershed goals and addressing stakeholder issues.

To keep the size of the tables small, the following list displays abbreviated terms for the stakeholders’ issues and goals as originally stated in Chapter 1:

Goal Abbreviation Watershed Goal Biological Diversity Protect and enhance biological diversity Catastrophic Events Reduce the likelihood and impacts of catastrophic events Employment Maintain economic livelihoods and create jobs Energy Development Develop energy resources Hydrologic Function Restore hydrologic Recreation Enhance recreation Soil Conservation Conserve topsoil and stabilize erosion-prone areas Water Quality Improve water quality

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Issue Abbreviation Stakeholder Issue Animal Grazing / Browsing Impacts from certain livestock grazing practices and browsing and gnawing animals Channel Alterations Creek channel alterations Climate Change Climate change Energy Resources Potential environmental impacts of energy developments Fire Fire Headcuts Creek and tributary headcuts Information Gap Information gaps Invasive Species Non-native native species Oak Woodlands Oak woodlands Policy Obstacles Fiscal and policy obstacles for landowners to meet regulatory targets Recreation Demand Growing demand for recreation and tourism Roads Roads, trails, and fire suppression lines Sediment Sediment delivery to watercourses Toxics Toxic chemicals Ultramafic Soils Disturbances to ultramafic soils Woody Riparian Plants Low recruitment of native woody riparian plants

Resource Inventories (Table 8.1) Managing natural resources is difficult if resource managers and landowners do not have a complete inventory of the resources over which they exercise stewardship. Table 8.1 summarizes the resource inventories identified in previous chapters of the watershed assessment and their relevance to stakeholders’ issues and goals. Tasks include field work, aerial photo interpretation, and GIS mapping.

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Table 8.1 – Resource inventories to improve management decisions for Bear Creek watershed Resource Work Done Principal Stakeholder Issue(s) Watershed Goal(s) Focal Area(s) Inventory to Date Anthropogenic Prescribed burns: field work, Fire, Invasive Species Biological Diversity BLM Public Lands none photo Interpretation Stream alterations: field site Bear Valley and Leesville, Lower Bear Creek, Channel Alterations Hydrologic Function some descriptions, mapping and Sulphur Creek subwatersheds Vegetation conversion to Climate Change, Invasive Biological Diversity, Soil grassland: field work, Watershed-wide none Species, Oak Woodlands Conservation mapping Biologic Baseline for vascular plants Biological Diversity, Energy Resources, Information and vertebrate animals: field Employment, Energy Walker Ridge, Mill Creek subwatershed some Gap, Ultramafic Soils, work Development Channel Alterations, Fire, Native invertebrates: field Biological Diversity, Walker Ridge and Lower Bear Creek, Mill Information Gap, Woody none recently work Hydrologic Function Creek, and Sulphur Creek subwatersheds Riparian Plants Non-native plant invasions: Animal Grazing / Browsing, Biological Diversity field work, remote sensing, Invasive Species, Oak Recreation, Soil Watershed-wide some photo Interpretation Woodlands Conservation, Ranges of sensitive species: Fire, Invasive Species, Biological Diversity, BLM and US Forest Service Public Lands some field work Ultramafic Soils Catastrophic Events Geoscientific Hydrologic Function, Headcut characterization: Bear Valley and Leesville, Lower Bear Creek, Headcuts, Sediment Water Quality, Soil some field work and Sulphur Creek subwatersheds Conservation Landslides and mass wasting: Energy Development, Fire, Catastrophic Events, Lower Bear Creek and West of Cortina Ridge field work, photo Roads, Sediment, Ultramafic Energy Development, some subwatersheds interpretation Soils Soil Conservation Longitudinal and cross- Animal Grazing / Browsing, Bear Valley and Lower Bear Creek and Hydrologic Function some sectional stream profiles Channel Alterations, Sediment Sulphur Creek subwatersheds

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Technical Evaluations (Table 8.2) In some cases, before stakeholders can undertake projects to recover impaired ecosystem services and restore productivity of specific environments in Bear Creek watershed, they may need technical evaluations upon which to base decisions. Table 8.2 summarizes the key technical evaluations identified in previous chapters of the Bear Creek watershed assessment. They are intended as decision support tools based on best available information. Technical evaluations may be expensive, and hiring consulting experts can be cost-prohibitive. Stakeholders from government agencies can sometimes provide in-house expertise to assist in technical evaluations and offset costs.

Science Research (Table 8.3) Science research has transformed our understanding of Bear Creek watershed. For example, the CalFed-sponsored research and subsequent studies by scientists from the US Geological Survey have helped stakeholders understand the magnitude of mercury contamination in the watershed and the impacts to aquatic ecosystems and wildlife.

The efficiency of scientific research ensures that just enough information is gathered to attain a desired level of confidence (often 95%) that the scientific findings are accurate. The high probability of accuracy furnishes new information that landowners and resource managers can rely on for decision making. Table 8.3 lists the major topics identified as needed research in the preceding chapters and the issues and goals that the research addresses. Scientists have already initiated some of these research topics.

Achieving continuity in a program of science research is seldom possible without substantive commitments of funding from stakeholders in government, industry, or non-profit foundations as well as the support of landowners and land managers. Watershed stakeholders can build on existing relations with government agencies in Sacramento and research institutions such as the University of California at Davis, both of whom have longstanding involvement in research in the watershed.

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Table 8.2 – Technical evaluations, syntheses, or modeling to improve management decisions for Bear Creek watershed Evaluation, Synthesis, or Work Done Stakeholder Issue(s) Watershed Goal(s) Focal Area(s) Modeling to Date Anthropogenic Air quality risks to people from Energy Resources, Recreation Subwatersheds asbestos, mercury, and dust Demand, Roads, Toxics, Ultramafic Energy Development, Recreation originating on Walker none Inhalation Soils Ridge Bear Valley, Leesville Economic benefits from channel Employment, Hydrologic Function, Channel Alterations and Sulphur Creek none alterations to landowners Quality subwatersheds Options to repair headcuts, Channel Alterations, Headcuts, Hydrologic Function Watershed-wide some culverts, and stream alterations Roads, Sediment Biologic

Map of vegetation alliances per Animal Grazing / Browsing, Climate Biological Diversity, Energy Sawyer et al. (2009) and Change, Energy Resources, Fire, Oak Development, Hydrologic Function, Watershed-wide some ecological site descriptions tied Woodlands, Ultramafic Soils, Woody Soil Conservation to soils Riparian Plants Animal Grazing / Browsing, Climate Predictive habitat models for rare Change, Energy Resources, Fire, and sensitive species and game Biological Diversity, Catastrophic Invasive Species, Oak Woodlands, Watershed-wide some species under current and Events Recreation, Ultramafic Soils, Woody climate change conditions Riparian Plants Climatic Climate Change, Fire, Oak Potential for reforestation to Woodlands, Policy Obstacles, Catastrophic Events Watershed-wide none store carbon Woody Riparian Plants Geoscientific Energy Resources, Information Gap, Watershed-wide, as Geological hazard mapping Catastrophic Events, Employment some Sediment, Ultramafic Soils needed for projects More detailed soil mapping at Energy Resources, Fire, Roads, Energy Development, Recreation, Watershed-wide, as none sensitive sites Sediment, Ultramafic Soils Soil Conservation needed for projects Hydrologic Model of historical wetlands and Biological Diversity, Employment, Channel Alterations, Headcuts, hydric soils in Bear Creek Hydrologic Function, Soil Watershed-wide none Roads, Sediment watershed Conservation, Water Quality

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Table 8.3 – Research to improve management decisions for Bear Creek watershed Work Done Research Topic Stakeholder Issue(s) Watershed Goal(s) Focal Area(s) to Date Biologic Animal Grazing / Browsing, Fire, Bear Valley and Biological Diversity, Employment, Information Gap, Invasive Species, Leesville, Lower Bear Invasive plant control Hydrologic Function, Soil some Ultramafic Soils, Woody Riparian Creek, and Sulphur Conservation Plants Creek subwatersheds Climate Change, Fire, Information Optimal fire regimes for Biological Diversity, Catastrophic Gap, Invasive Species, Ultramafic Watershed-wide some vegetation alliances Events, Soil Conservation Soils, Woody Riparian Plants Identification of native pollinators of rare plant species Climate Change, Invasive Species, Biological Diversity, Catastrophic Watershed-wide some and potential native pollinators Ultramafic Soils Events, Employment for agricultural crops Ecology and range of pallid and Subwatersheds Biological Diversity, Employment, Townsend’s big-eared bats using Energy Resources, Toxics originating on Walker none recently Energy Development abandoned mercury mines Ridge Geoscientific Background and contamination Sulphur Creek and Animal Grazing / Browsing, amounts of mercury and other Soil Conservation Upper Bear Creek some Recreation, Toxics, Ultramafic Soils elements with MCLs in soils subwatersheds Mercury transport from Rathburn Animal Grazing / Browsing, Toxics, Upper Bear Creek Petray mine complex to the floor Soil Conservation, Water Quality some Ultramafic Soils subwatershed of Bear Valley Hydrologic Sulphur Creek and Relation between animal waste Animal Grazing / Browsing, Toxics Water Quality Upper Bear Creek some and mercury methylation subwatersheds Bear Valley and Lower Aquatic hot spots for mercury Sediment, Toxics Water Quality Bear Creek and Sulphur none methylation Creek subwatersheds

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Environmental Monitoring (Table 8.4) In the feedback system for adaptive management, monitoring provides the information to landowners and resource managers about the effectiveness of the management actions thus far undertaken to meet watershed goals. Key features of a robust monitoring system are:

development and adoption of statistically well-designed, peer-reviewed, and practical protocols attention to quality assurance for continuous training and checking that people follow protocols production of quality-controlled data high standards for processing, management, storage, and sharing of monitoring data electronically.

Monitoring is sometimes costly. Land and resource management agencies, generally underfunded and understaffed, rarely adopt extensive monitoring programs. When funding is insufficient, agency monitoring staff is cut back. Therefore, the fifth element in a robust monitoring system is an active fund-raising effort to secure continuous funding for monitoring. Collaborative partnerships among stakeholders can contribute greatly to making monitoring fiscally sustainable.

Table 8.4 displays the monitoring topics required by regulatory agencies and additional monitoring needs for watershed stakeholders to consider. Details of specific monitoring are discussed below.

Water Quality in Streams Monitoring required by regulatory agencies covers principally water and its contaminants with respect to numeric maximum contaminant levels (MCLs) established by the State of California. For reference, Appendix G outlines water regulations in California. The major MCL of concern is mercury. The TMDLs for methylmercury and total mercury established the CVRWQCB are the governing MCLs for mercury and mercury compounds in the Bear Creek watershed. The US Geological Survey has recently completed a protocol, statistical design, and plan for monitoring mercury at strategic sites throughout Bear Creek watershed (Suchanek et al. 2010).

Sulfate, sulfide, and dissolved organic matter in water relate to mercury because they facilitate conversion of molecular mercury to methylmercury. High levels of these ions together in water may indicate that methylmercury is forming in significant amounts. Boron is the other element of concern. The Yolo County Flood Control and Water Conservation District monitors boron in Bear Creek water regularly.

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The California Department of Water Resources tracks water quality from one station on lower Bear Creek. At present, monitoring for fecal coliform bacteria rarely takes place, and monitoring for industrial organic compounds (e.g., herbicides, rodenticides) has not occurred since 2001.

Water Flow The US Geological Survey maintains one station in lower Bear Creek. Other stations have operated in the past. Water flow data are needed especially at the mouth of Sulphur Creek, on Mill Creek at Brim Road, and at the south end of Bear Valley for estimating total amounts of mercury or methylmercury in daily and annual flows at these critical points in the watershed. The Yolo County Flood Control and Water Conservation District could use these data as an alert to high flows that might put communities downstream such as Rumsey and Woodland at risk of flooding.

Other Water-Related Monitoring Three other areas of water monitoring are needed. Little is known about groundwater in Bear Creek watershed. Baseline information about groundwater in Bear Valley and the Sulphur Creek subwatershed is important to understand the water quality, existing consumption, and potential uses for groundwater.

Springs in Bear Creek watershed are major background sources of unusual chemical elements, other than mercury. Monitoring loads of these elements at springs and at sites just downstream from abandoned mines can determine which elements are exceeding their established MCLs because of human-caused sources related to abandoned mines. Data on flows from springs may also signal changes in groundwater recharge or loss of connections between springs and geologic water deep in the earth as the result of seismic shifts.

Some of the rarest and most vulnerable habitats are wetlands on ultramafic soils, including those outside of Bear Valley. A designated OHV trail presently passes through the Eaton Springs wetland in Sulphur Creek subwatershed, and Highway 20 runs next to the seasonally wet Destinella Flat.

Population Trends for Special Status Species Little monitoring is in place to track populations of special status species. Monitoring is needed especially for Indian Valley brodiaea, a plant species listed as endangered by the State of California. Sections 2.9 and 2.10 provide basic information on these species.

Climate Change Weather and climate stations strategically placed in the watershed can provide information on changing climate. RAWS and SCAN stations are not present in Bear Creek watershed; one RAWS stations lies just outside the watershed boundary. Stations on Walker Ridge, in Bear

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Table 8.4 – Monitoring for regulatory requirements and for feedback to stakeholders about management actions Work Done Monitoring Topic Stakeholder Issue(s) Watershed Goal(s) Focal Area(s) to Date Anthropogenic Outcomes over time to Animal Grazing / Browsing, Fire, Biological Diversity, Soil vegetation and wildlife after BLM Public Lands none Invasive Species, Ultramafic Soils Conservation prescribed burns All state highways, county Energy Development, Hydrologic roads, BLM and US Forest Sediment loads coming from Recreation Demand, Roads, Function, Soil Conservation, Service designated OHV none roads and trails Sediment, Ultramafic Soils Water Quality routes, and eventual energy project rights-of-way Biologic Animal Grazing / Browsing, Fire, Extent of non-native invasive Biological Diversity, Recreation, Recreation Demand, Roads, Watershed-wide ongoing plant infestations Soil Conservation Ultramafic Soils Animal Grazing / Browsing, Fire, Population trends of important Oak Woodlands, Recreation Biological Diversity, Recreation Watershed-wide ongoing game species Demand, Woody Riparian Plants Channel Alterations, Climate Change, Energy Resources, Fire, Population trends of sensitive Invasive Species, Oak Woodlands, Biological Diversity Public lands watershed-wide some species Recreation Demand, Ultramafic Soils, Woody Riparian Plants Climatic Vegetation reference sites to Climate Change, Fire, Invasive detect and observe effects of none Species, Oak Woodlands, Biological Diversity, Catastrophic climate change Watershed-wide Ultramafic Soils, Woody Riparian Events, Soil Conservation Data from RAWS and SCAN Plants none weather stations Hydrologic Bear Valley and Leesville, Animal Grazing / Browsing, Bacterial contaminants Recreation, Water Quality Lower Bear Creek, and none recently Demand for Recreation Sulphur Creek subwatersheds Lower Bear Creek and Sulphur Boron Sediment Water Quality ongoing Creek subwatershed 281

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Work Done Monitoring Topic Stakeholder Issue(s) Watershed Goal(s) Focal Area(s) to Date Elemental contaminants with Roads, Sediment, Toxics Water Quality Watershed-wide some MCLs, other than mercury Bear Valley and Leesville and Groundwater Information Gap, Policy Obstacle Water Quality none Sulphur Creek subwatersheds Industrial organic compounds Information Gap, Toxics Water Quality Watershed-wide none recently Methylmercury for TMDL Water Quality Watershed-wide ready to start standards in stream loads Toxics when funding Total mercury for TMDL Water Quality Sulphur Creek subwatershed is available standards in stream loads Springs Climate Change, Toxics Recreation, Water Quality Watershed-wide none recently Channel Alterations, Climate ongoing Stream flow Hydrologic Function Watershed-wide Change, Headcuts locally Biological Diversity, Energy Energy Resources, Fire, Sediment, Walker Ridge and Sulphur Development, Hydrologic Wetlands on ultramafic soils Recreation Demand, Roads, Creek and Upper Bear Creek none Function, Recreation, Water Ultramafic Soils subwatersheds Quality RAWS – Remote Automated Weather Station at the USDA Forest Service in partnership with other federal land management agencies SCAN - Soil Climate Analysis Network at the USDA Natural Resource Conservation Service

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Valley, and in the Brophy Canyon, Leesville, Mill Creek, and Sulphur Creek subwatersheds would clarify how environmental conditions are varying across the watershed. SCAN stations are particularly useful for tracking changes to soil moisture. Bear Valley stations could track changes in soil moisture as projects to restore hydrologic function in the Valley are implemented.

8.3 Stewardship Priorities for Remediation and Restoration At its best, a watershed assessment leads to implementation of projects that benefit the land and people connected to the watershed. In this regard, the assessment and a separate document titled Bear Creek Stewardship Priorities, 2010-2014, have identified projects needed to repair or protect the natural capital of the watershed. The projects aim to sustain ecosystem services, goods, benefits, and livelihoods for stakeholders. These projects also produce new jobs. For implementation, projects will require good design, thoughtful application, monitoring, and long- term collaborative stewardship efforts. Assessment information can provide background for watershed project planning and for completing the environmental documentation required under the National Environmental Protection Act (NEPA) and the California Environmental Quality Act (CEQA) to ensure that projects are successful. New watershed projects are already moving forward in 2010 for abandoned mine site remediation at the Rathburn-Petray mine complex and revegetation of ultramafic sites along Highway 20.

8.4 Updating the Bear Creek Watershed Assessment Watershed assessment is an ongoing process among stakeholders. New information about Bear Creek watershed is appearing continually as researchers, resource managers, landowners, and other stakeholders learn more about Bear Creek watershed. Reassessing to reflect changing conditions on the ground and new knowledge is necessary over time as part of adaptive management. Incorporating new information about the watershed as it becomes available and then updating analyses and evaluations then becomes a recurring process. In this way, the assessment develops in response to changes in watershed conditions, stakeholders’ priorities, regulatory requirements, and government policies. One option for stakeholder consideration is to update the assessment every five years and to time the revision with a new version of the Bear Creek Stewardship Priorities for the period, 2015 to 2019.

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APPENDICES

APPENDIX A SUMMARY OF AGENCY MANAGEMENT PLANS FOR LANDS AND RESOURCES IN BEAR CREEK WATERSHED

Land and resource management plans, prepared by government agencies and non- governmental organizations for Bear Creek watershed, are important to this watershed assessment because they identify issues that bear on the entire watershed. The existing plans also outline land management activities currently underway on lands in the watershed.

Colusa County General Plan The most recent Colusa County General Plan was completed in January 1989 and has a planning range extending to 2010. The Plan‟s Housing Element was updated 2004. The General Plan provides the basis for county decisions regarding growth and land development in Bear Creek watershed and elsewhere in Colusa County, with the intent of “encouraging economic development while managing growth, conserving agricultural lands, protecting the environment, and preserving the qualities that make Colusa County unique” (Plan pg 17). Continuity of current land uses and protection of the landscape quality are the principal focus of the General Plan for Bear Creek watershed. The County Plan assumes that population growth will be ten percent or less in the watershed for the plan period, with greater population growth, however, occurring just north of the watershed in the Stonyford- Lodoga area. The limited availability of water constrains economic and residential development. Dryland farming and grazing continue to be the most extensive land uses in Bear Valley. Elsewhere in the watershed, steeper rangeland and hillside areas are to remain undeveloped as well. Mineral extraction and geothermal developments are to be permitted if environmental studies conclude that projects pose no harm to other resources or may be mitigated.

The General Plan calls attention to current or likely issues in the watershed. Two issues are especially prominent in the Plan: (1) the need to maintain the existing county road structure in the face of ongoing fiscal limitations and associated safety issues; and (2) the potential for mining operations to alter the visual quality of the scenic Coast Range slopes in Bear Creek watershed. Increases in the prices of precious metals such as gold could spur reconsideration of the economic feasibility of mining at existing mine sites as well as exploration for new sites in the watershed. The Plan cites Bear Valley Buttes as meriting conservation for its significant habitat for raptor birds.

The County of Colusa Department of Building and Planning is currently preparing a new version of the General Plan.

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Colusa County Resource Conservation District Long-Range Plan, 2008-2013 Colusa County Resource Conservation District (CCRCD) is a non-governmental organization that assists local landowners in the Bear Valley watershed and elsewhere in Colusa County to protect, conserve, and restore natural resources on their lands. In its mission to provide information and technical assistance to local landowners, CCRCD advocates for landowners to protect individual landowner‟s rights and supports local decision making for conservation planning that promotes social and economic sustainability for local communities. The CCRCD‟s current Plan (2008) addresses the following topics directly related to issues in Bear Creek watershed:

1. limiting sediment discharges into streams to protect water quality 2. protecting stream banks and establishing riparian buffer strips 3. eradicating and managing invasive species 4. promoting sound grazing practices 5. developing off-stream watering systems for livestock and wildlife 6. bringing together stakeholders to advance locally led conservation stewardship 7. facilitating creation of conservation easements on agricultural lands 8. assisting stakeholders in securing funding for conservation projects

The CCRCD actively promotes excellent resource management and improvement projects in Bear Creek watershed.

California State Lands Commission Management Plans A management plan for the lands in Bear Creek watershed under jurisdiction of the California State Lands Commission is not currently in place. Management for these lands is based on individual environmental impact reports that govern changes in uses for Commission lands.

Land Management of Federal Public Lands Federal laws commit the two federal agencies that manage public lands in Bear Creek watershed to multiple uses for the public lands. The direction for planning for multiple uses on federal public lands is set forth in the National Forest Management Act of 1976 for the US Forest Service and the Federal Land Policy and Management Act (FLPMA) of 1976 for the BLM. Striking the appropriate balance of land uses on public lands for the benefit of local and regional stakeholders and the American people as a whole is a core task for the federal land management agencies.

Mendocino National Forest Plan (1995, as amended in 2007) The portion of the Mendocino National Forest within Bear Creek watershed lies entirely within the Sullivan Management Area (Area #4). Timber management for commercial

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The Mendocino National Forest uses three key processes to implement its Forest Plan: interagency coordination, adaptive management, and watershed analysis (page V-1 of the Plan). Watershed analysis/assessment is the analytical process used as the technical basis for implementing ecosystem management.

Management activity for the area involves at present completion of an inventory of the existing trail system, designation of permanent off-highway vehicle (OHV) trails, rehabilitation of unauthorized trails to natural conditions, and closure of abandoned mines. Rehabilitation of closed OHV trails is a lower priority now because closed trails closer to roads at lower-elevation trails to the north and west merit attention first.

BLM Ukiah Field Office Resource Management Plan (2006) The public lands in Bear Creek watershed managed by the Ukiah BLM Field Office belong to two management units: the Cache Creek Management Unit which includes all BLM lands south of or immediately adjacent to State Route 20; and the Indian Valley Management Unit which covers the public lands on the east side of Walker Ridge and on the west and north slopes of Bear Valley. The BLM Ukiah Field Office manages public lands under its Resource Management Plan (RMP) to balance recreational opportunities and environmentally responsible commercial activities with the conservation of natural and cultural resources. Overarching management goals that apply to Bear Creek watershed are (1) maintaining scenic quality and visual integrity of the diverse natural landscapes and ecosystems characteristic of the watershed and (2) inclusion of local communities and residents in conservation and sustainable uses of the BLM public lands appropriate to the landscapes and watersheds where the lands occur. Commercial timber harvesting and

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BEAR CREEK WATERSHED ASSESSMENT livestock grazing, except to promote native vegetation, are not currently part of management on lands in both management units. Habitat management for special status species, game and non-game species in upland and riparian areas, and non-motorized recreation opportunities are the major emphases for current management. Actions planned for the management units are described below.

Cache Creek Management Unit 1. Restoration of the Bear Creek riparian corridor south of Highway 20. The area does not currently meet BLM standards for proper functioning condition of riparian ecosystems as the result of infestations of non-native tamarisk (Tamarix spp.) shrubs that have altered the natural stream course and distribution of stream sediments. 2. Inventory and site documentation of cultural resources on newly acquired BLM Bear Creek Ranch. 3. Prescribed burning on a rotational basis to approximate natural fire intervals. 4. Closure to wind energy development and to fluid mineral leasing and other minerals- related economic activity, with a proposal for withdrawal from all future mining. 5. A comprehensive trail plan to integrate multiple types of dispersed, low-density recreation, including equestrian and mechanical recreation. 6. Further development of the Cowboy Camp trailhead for multiple-use public access. 7. Stabilization of headcuts and other erosion sites on Bear Creek and its tributaries. 8. Restoration of native fisheries in lower Bear Creek.

Indian Valley Management Unit 1. Identify areas with naturally occurring asbestos and any trails and roads that generate sediment and dust likely to contain asbestos. 2. Restrict infrastructure for telecommunications. 3. Collaborate with federal and state agencies to halt soil and water contamination from mercury created from human activities. 4. Prescribed fire on a small-scale for chamise and other chaparral species with high fuel loads.

In keeping with national energy priorities, the Field Office is considering all of the energy development potential on the public lands in the Indian Valley Management Unit. The RMP underscores that the Indian Valley Management Unit lands in the northern half of Bear Creek watershed are potentially available to energy and mining development in coming years. Geothermal energy is a possibility in the subwatersheds that drain to the east from Walker Ridge, at the eastern margin of the Geysers Known Geothermal Resource Area (KGRA). Oil and gas resources on BLM lands east of the Stony Creek Fault are classified as highly valuable and therefore potentially having future economic importance. Walker Ridge

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BLM Cache Creek Coordinated Resource Management Plan (2004) The Cache Creek Coordinated Resource Management Plan (CRMP) covers the Cache Creek Natural Area that spans Colusa, Lake, and Yolo counties. Specifically, for Bear Creek watershed, the CRMP covers the BLM Bear Creek Ranch. The CRMP lays the foundation for the management for the BLM public lands in the southern half of the watershed comprising the Cache Creek Management Unit Zones D and E (roughly equivalent to the Cache Creek Management Unit and a portion of the Indian Valley Management Unit in the 2006 BLM Ukiah Field Office RMP). The management prescriptions for the BLM Cache Creek Natural Area in the CRMP are incorporated as part of the BLM Ukiah Field Office RMP and are summarized in Appendix N of the RMP.

Work described in detail in the CRMP for the Bear Creek Ranch involves: final details of a non-motorized trail network design for multiple sport recreation activities; integrated pest management for control of upland weed species; elk herd management; prohibiting non- hunting shooting; creation or repair of permanent water sources; development of research sites to study weed control methods; and protection measures for rare plant species and Townsend's big-eared bat.

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APPENDIX B

SUMMARY OF PLANS FROM REGULATORY AGENCIES FOR PUBLIC RESOURCES IN BEAR CREEK WATERSHED

Regulations are complex and often confusing for stakeholders. Landowners, land managers, and other stakeholders involved in Bear Creek watershed must comply with regulatory requirements established by Federal, State of California, and County of Colusa agencies. The regulations of interest in this watershed assessment govern protection and enhancement of water and air resources.

Water Resources The impetus for preparing the watershed assessment for Bear Creek and its tributaries is the regulatory requirement for the watershed to meet water quality standards established by the US Environmental Protection Agency (US EPA), the California State Water Resources Control Board, and the Central Valley Regional Water Quality Control Board (CVRWQCB). This section discusses the laws and regulations regarding water from these agencies that apply to Bear Creek watershed.

Federal Clean Water Act The Federal Clean Water Act of 1972, as amended, regulates the discharge of pollutants into surface waters. Under the Act, the US EPA:

1. sets national policies regarding control of industrial wastewater; 2. establishes minimum national standards for maximum allowable concentrations of contaminants in water (water quality standards); and 3. implements programs to control pollution caused by industrial wastewater.

The Clean Water Act delegates the authority for regulation and enforcement of water quality to the states. Clean Water Act sections that affect Bear Creek watershed are discussed in the following paragraphs.

Section 303(d) Section 303(d) requires the State of California to identify “impaired” water bodies that do not meet water quality objectives and do not support uses of the water bodies. Every two years, the State of California submits an updated 303(d) list of Water Quality Limited Segments to the US EPA, citing the pollutant or stressor causing the impairment. The State also prioritizes and plans projects to address the impairment of water quality in these water bodies. In 2004, California promulgated its Water Quality Control Policy to provide a

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In cases where water quality objectives are not being met, the 303(d) List also identifies where a Total Maximum Daily Load (TMDL), established by the State and approved by US EPA, is required for a water body not now meeting water quality standards. A TMDL is defined as the largest concentration (load) of a pollutant allowed in a water body that still does not violate state water quality standards. California follows a five-step process to produce a regulatory TMDL:

1. Stakeholder involvement: all interested parties, including individual citizens, contribute input concerning TMDL development 2. Assessment of the water body to identify pollution sources, amounts, and overall effects 3. Determination of total allowable amounts and allocations of allowed amounts among pollutant sources 4. Development of an implementation plan to achieve total allowable amounts and allocations 5. Amendments to the Water Quality Plan for the Sacramento and San Joaquin River Basins.

Two TMDLs, one for Bear Creek as a whole and one specifically for Sulphur Creek, are in place. The TMDL for the entire Bear Creek watershed refers to controlling the concentration of methylmercury. A second TMDL for lower Sulphur Creek alone covers total mercury.

Section 404 The US Army Corps of Engineers issues permits under the Clean Water Act Section 404 for dredging and filling in water bodies, including wetlands. These permits, however, must conform to the State of California State Water Quality Control Board objectives for water quality and the California EPA Office of Environmental Health Hazard Assessment public health drinking water standards, to protect isolated wetlands, riparian areas, and stream headwaters. The California Department of Transportation has Section 404 permits for its bridge construction work on Highway 20 at Bear Creek.

The Porter-Cologne Water Quality Control Act The Porter-Cologne Water Quality Control Act (California Water Code Division 7: Water Quality Section 13000 et seq.) governs water quality in the State of California. Further, the Act assigns responsibility for water rights and water quality to the California State Water Resource Control Board, and it delegates authority to nine statewide Regional Water Quality Control Boards (RWQCBs) to develop and enforce water quality standards within

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California water quality standards consist of three elements: beneficial uses; water quality objectives, consisting of both numeric and narrative criteria; and policies and procedures to counteract degradation of water quality. These standards apply to “waters of the state”, which are defined by the Water Quality Control Act as “any surface water or ground water, including saline waters, within the boundaries of the state.” The Act covers both surface water and ground water. The CVRWQCB has delegated authority over water quality on federal public lands as well, including lands managed by the US Forest Service and the BLM in Bear Creek watershed. Chapter 5 of this assessment discusses the three elements in depth.

To achieve water quality objectives in Bear Creek watershed, the CVRWQCB carries out the following steps:

1. identifies potential water quality problems in the watershed; 2. confirms and characterizes water quality problems through assessments for source, frequency, duration, extent, fate, and severity of a pollutant causing water contamination; 3. remedies water quality problems by enforcing appropriate response measures; and 4. monitors known problem areas in Bear Creek watershed to assess effectiveness of remedial measures.

The Water Quality Plan for the Sacramento and San Joaquin River Basins (October 2007) The CVRWQCB has concerns about water quality that bear on the beneficial and potential beneficial uses for Bear Creek watershed. The principal impairment to the watershed is the high concentrations of mercury found in water, sediments, and tissues of aquatic animals in Bear Creek watershed. Non-point discharges from abandoned mercury mine sites are the principal sources for levels of ambient mercury above natural background levels in the watershed. These concerns are expressed in the Water Quality Plan. The CVRWQCB has amended the Water Quality Plan for the Sacramento River and San Joaquin River Basins twice, in 2005 and 2007 to deal with TMDLs for methylmercury and total mercury in Bear Creek watershed.

Agreements between the State Water Quality Control Board and Federal Land Management Agencies A 1981 Management Agency Agreement (MAA) with the US Forest Service waives discharge requirements from the State Water Quality Control Board for certain nonpoint source discharges over all US Forest Service lands in California, provided that the US

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Forest Service implements Board-approved best management practices (BMPs) and procedures along with the provisions of the MAA. Implementation of the BMPs, monitoring, and performance review requirements approved by the State and Regional Water Boards, is the primary method of meeting the Basin Plan water quality objectives. The MAA in no way limits the authority of a RWQCB to carry out its legal responsibilities for management or regulation of water quality.

In September 1985, the CVRWQCB Executive Officer signed Memoranda of Understanding (MOUs) with the three BLM Districts that at the time oversaw federal public lands in parts of the Central Valley (the Ukiah District, the Susanville District, and the Bakersfield District). The MOUs, which are identical for each District, expanded coordination between the two agencies for the control of water quality problems resulting from mineral extraction activities on BLM administered lands. On 27 January 1993, the State Water Board signed a MOU to address water quality issues from nonpoint sources on public lands managed by BLM.

Cache Creek Watershed Mercury Program The Cache Creek Watershed Mercury Program for methylmercury and total mercury applies to the Cache Creek Basin, defined as the main stem of Cache Creek from Clear Lake to the Yolo Settling Basin outflow; North Fork Cache Creek from Indian Valley Reservoir Dam to the main stem Cache Creek; Bear Creek (including Sulphur Creek); and Harley Gulch. This implementation program is intended to reduce loads of methylmercury and total mercury to achieve all applicable water quality objectives for mercury and methylmercury. The program includes monitoring mercury in fish, water, and sediment.

Mercury Program Actions to achieve water quality objectives and the methylmercury allocations in the Bear Creek methylmercury and Sulphur Creek mercury TMDLs are:

1. reduce loads of total mercury at inactive mines 2. implement projects to reduce total mercury loads in creek channels and creek banks downstream of discharges from historic mines 3. reduce erosion of soils with enriched total mercury concentrations 4. limit land use activities in the watershed that increase methylmercury in creeks and, where feasible, reduce discharges of methylmercury from existing sources 5. evaluate other remediation actions that are not directly linked to activities of a discharger.

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Sacramento Valley Integrated Regional Water Management Plan (Preliminary Final Version November 2006) Although this document is not in its final form, the direction of the Regional Water Management Plan is clear from the preliminary final document. Impending management actions that are relevant to Bear Creek watershed include:

1. Completion of a Colusa County Groundwater Management Plan Colusa County has completed its groundwater management plan. The plan will permit management for economic uses of groundwater resources in Colusa County. The management plan covers conjunctive use, groundwater assessment, options for groundwater recharge, protection of groundwater quality, control of non-point source pollutants that contaminate groundwater, and a systematic monitoring program.

2. Control and reduction of high loads of mercury in Bear Creek that may put people in the Lower Cache Creek and the Delta at risk if they consume large quantities of fish and fish-eating wildlife.

3. Measures for preventing extreme flood events from winter storms to avoid worsening downstream flooding in the Western Yolo Floodplain and in the City of Woodland, which the Federal Emergency Management Agency has found to have protection only for a ten-year flood event.

Northern Sacramento Valley (Four County) Drinking Water Quality Strategy Document (June 2005) Butte, Tehama, Glenn, and Colusa counties have jointly prepared a policy and action document that provides an integrated approach to water quality management in the four- county region.

Sacramento River Basinwide Water Management Plan (2004) This document covers the Sacramento River Subregion and includes an in-depth discussion of the Cache Creek Basin of which Bear Creek watershed is a part. Bear Creek is not specifically mentioned in the document. Although this management plan contains current and future projections of water supply and water use for many Colusa County water districts, Bear Creek watershed is not part of the analysis and planning because no water district covers the watershed.

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Air Resources

Federal Clean Air Act The Federal Clean Air Act (FCAA) requires that the State of California determine whether an entire air basin or a part of an air basin is meeting the National Ambient Air Quality Standards established in the Clean Air Act. The National Standards consist of maximum amounts set by the FCAA for key air pollutants. In the event that an air basin does meet the National Standards, the State of California is responsible for preparing and enacting an air quality plan for the air basin. The air basin plan lays out a management framework and specific actions to reduce the concentrations of emitted pollutants in the air basin.

Presently, Colusa County has rankings of attainment or unclassified for all FCAA standards.

California Clean Air Act The federal government has delegated to the California Air Resources Board (ARB) the authority to manage air quality in the state of California. The ARB regulates sources of mobile emitted pollutants and provides guidance to county Air Pollution Control Districts (APCDs) and regional Air Quality Management Districts (AQMDs). In many instances, the ARB has instituted air quality standards applicable to California that are stricter than the federal standards for criteria air pollutants. Evaluation of attainment of these standards is a process parallel to determining attainment of National Ambient Air Quality Standards.

Bear Creek Watershed is under the jurisdiction of the Colusa County APCD and the Sacramento Valley AQMD (and included as part of the Northern Sacramento Valley Air Basin for planning purposes). Colusa County and its watersheds collectively are considered to be in attainment or unclassified for all state standards except those for ozone and PM10.

The Districts adopt and enforce controls on stationary sources of air pollutants through permit and inspection. They also regulate agricultural burning. Other District responsibilities include monitoring air quality, preparing clean air plans, and responding to air quality complaints from citizens.

The AQMDs of the Northern Sacramento Air Basin (2003) have jointly prepared and adopted a uniform air quality attainment plan addressing ozone and PM10.

Details of air quality standards are presented in Appendix F.

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APPENDIX C PRINCIPAL ROCK TYPES FOUND IN BEAR CREEK WATERSHED

Great Valley Geomorphic Province Rock Types Rock Type Associated Minerals Notes Great Valley Sequence Sedimentary Rocks dark gray, derived from clay and silt mudstones sediments, jumbled Stony Creek petrofacies often red, brown, black, or gray; orderly shale contain fossil hydrocarbons (oil and layering of sediments gas) siltstone silt and some clay; not easily fractured quartz, feldspar, sodium chlorite, gray to dark gray; sand cemented with graywacke magnesium chlorite; storing smaller sediment particles, poorly sandstone underground water sorted by sediment size angular rocks and minerals of different sizes in a cement of sediments; formed breccias by submarine avalanches and mud flows gravels, pebbles, and cobbles in a conglomerates cemented matrix of other smaller sediments; rocks in matrix are rounded

Great Valley Sequence Metasedimentary Rocks silica as the cementing crystal; weakly metamorphosed from clay argillite sericite, chlorite; aluminum mudstones and shale, jumbled derived from shale, easily cleaved into slate quartz, chlorite, sericite flat plates gray or gray-black; wavy and phyllite quartz, sericite, chlorite corrugated with a sheen, not easily cleaved derived form siltstones under high metasiltstone pressure derived from graywackes under high metagraywacke pressure usually red or green conglomerates quartz, moganite, often with gold derived from multiple rock types chalcedony deposits embedded in cemented sand or clay sediments; frequent fossils

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Coast Ranges Geomorphic Province Rocks Rock Type Associated Minerals Notes Tehama-Colusa Serpentinite Mélange (TCSM) Sedimentary Rock Types sedimentary; red; local; sediment radiolarian chert rock that overlay mid-Pacific ophiolite originating under the Stony Creek petrofacies in the Sulphur Creek copper, silver, gold ores from subwatershed from geothermal water magma under high pressure causing rock hydrothermal fractures into which liquid magma breccias (“epithermal”) ore deposits pour Tehama-Colusa Serpentinite Mélange (TCSM) Igneous Rock Types gray or dark gray; volcanic origin but calcic feldspar and pyroxene with basalt breaching the ocean crust to form 50% silicon dioxide minerals(SiO ) 2 pillow-shaped rocks; non-mafic feldspars (62%) most common volcanic origin, in submarine mantle; diabase minerals, often in a finer matrix of ultramafic; rare; appear as sliver- clinopyroxene and olivine shaped rock bodies clinopyroxene, feldspar, and coarser grained than diabases; gabbro olivine; often containing precious ultramafic; intermittent north of metals Sulphur Creek lowest in the ophiolite layer; 90% olivine; 10% orthopyroxene - peridotite ultramafic; most dominant rock type mostly harzburgite in TCSM pyroxenites 90% orthopyroxene Principal source of serpentinite Tehama-Colusa Serpentinite Mélange (TCSM) Metamorphic Rock Types metamorphosed under low heat and serpentinite lizardite, brucite low pressure; formed by addition of water; increases rock volume clinopyroxene, feldspar, analcite, mafic or ultramafic; green; derived greenschist chlorite, epidote from basalt and gabbro blue, green-blue, or gray; Non-mafic; blueschist glaucophane, epidote, albite derived from basalt deep in the earth Franciscan Volcanic and Metavolcanic Rocks poorly known; silicic minerals erupt andesite amid basaltic lava flow Franciscan Sedimentary and Metasedimentary Rocks graywacke albite (feldspar), chlorite light green to gray; clay mortar formed from degraded graywacke phyllosilicates, often coated with phyllonite sediments, on crest and east flank of chlorites Walker Ridge Other Sedimentary Rocks Quaternary Alluvial and Terrace Sedimentary Rocks young rocks consisting of poorly breccias sorted, diverse clay, silt, sand, and gravel, in Bear Valley Sources: Barnes et al. 1973a, b; Bergfeld et al. 2001; Goff and Guthrie 1999; Moiseyev 1968; McLauglin et al. 1989; Sherlock 2005

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APPENDIX D COMPARATIVE SYNOPSIS OF FEATURES OF THE PRINCIPAL SOIL SERIES IN BEAR CREEK WATERSHED

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Comparative synopsis of features of the principal soil series in Bear Creek watershed, part 1 Surface Soil Topographic Percent Soil Series Depth Drainage Permeability Runoff Rate Watershed Location Texture Class Position Slope medium to north part of Bear Creek Ranch near the Lake County Boar very deep well-drained slow loam hill toe slopes 15 – 50 very high line low to very foothills and widespread east of Bear Valley (northern watershed) Contra Costa moderately deep well-drained slow loam 9 – 75 high mountains and on the east side of lower Bear Creek moderate to very shallow or somewhat gravelly sandy mountain side locally along Walker Ridge and in the Mendocino Etsel moderately low to high 30 – 75 shallow excessively drained loam slopes National Forest rapid well to moderately very slow to hydric zones in lower Bear Valley and central Sulphur Hillgate very deep medium loam old terraces 0 – 9 well-drained slow Creek

somewhat moderately very gravelly Livermore very deep low alluvial fans 5 – 9 Leesville area excessively drained rapid loam moderate to somewhat high to very mountain side locally along Walker Ridge and in the Mendocino

Magnesic Maymen shallow moderately sandy loam 30 – 75 - excessively drained high slopes National Forest rapid Non low to very widespread on either side above Bear Valley floor; NE Millsholm shallow well-drained moderate loam hills 5 – 75 high and southern third of southern watershed; calcareous moderately very slow to eastern foothill-Bear Valley edge and locally in lower Salt Canyon very deep well-drained loam alluvial fans 1 - 9 slow medium Bear Creek along Highway 16 low to very as a minor component on the eastern boundary of the Sehorn moderately deep well-drained slow silty clay Foothills 9 – 50 high watershed medium to Sulphur Creek subwatershed, Bear Creek Ranch and Skyhigh moderately deep well-drained slow loam Hills 15 – 50 very high just south of Bear Valley medium to Sulphur Creek subwatershed, Bear Creek Ranch and Sleeper deep well-drained slow loam Hills 15 – 50 very high just south of Bear Valley somewhat moderately gravelly sand Bear Valley very deep very low alluvial fans 2 - 5 south end of Bear Valley excessively drained rapid loam medium to locally on Walker Ridge and headwaters of Mill Creek

Dubakella moderately deep well-drained slow very high stony loam Mountains 15 - 50 subwatershed Haploxerts, moderate to high Unidentified deep to very deep well-drained slow clay loam mountain sides 30-50 along Highway 20 west of intersection with Highway 16 moderately high to very Henneke shallow well-drained slow to slow high sandy loam mountain sides 15 - 75 Mill Creek subwatershed and locally on Walker Ridge moderate to very low clay loam alluvial fans lower west side of Bear Valley Leesville very deep well-drained slow 0 – 5 moderately gravelly sandy Ultramafic (Magnesic) Ultramafic high mountain sides Mill Creek subwatershed Montara shallow well-drained rapid loam 15 – 50 moderately high to very gravelly loam mountain sides Walker Ridge crest and eastern slope Okiota shallow well-drained slow high 15 – 75 Venado very deep poorly drained slow very low Clay basin floor 0 - 2 Bear Valley floor , including riparian areas

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Comparative Synopsis of Features of the Principal Soil Series in Bear Creek watershed, part 2 Soil pH at Aver Aver surface Mg:Ca annual Soil Series Soil Genesis Parent Rock ppt Vegetation Noteworthy Characteristics and ratio temp mm y-1 1-m depth ºC from sandstone, wild oats, annual grasses, filaree,, blue oak a very deep soil compared to associated Boar residuum no data -- 76 14 shale and siltstone and live oak Sleeper and Millsholm soils fine-grained shale a widespread soil derived from the Central Contra Costa weathered 6.9 - 6.5 -- 18 annual grasses sandstone Valley formation chaparral with chamise and species of presence of an ochric epipedon; no cambic Etsel weathered sandstone or shale 6.0 - 6.3 -- 114 14 manzanita, ceanothus, and scrub oak horizon scattered manganese accumulations; ochric annual grasses and forbs with open stands Hillgate alluvium mixed sources 6.2 - 6.2 -- 41 18 epipedon; smectitic, superactive; slightly of valley and blue oaks sodic sedimentary and blue oak with annual grasses, foothill pine, mollic epipedon, fertile CEC/clay > 0.80 at all Livermore alluvium 6.1 - 6.6 -- 43 17 metasedimentary and ceanothus levels Magnesic - sandstone, shale and Maymen weathered 6.0 - 6.0 -- 107 14 chamise and other chaparral shrubs shallow soil (<45 cm deep)

Non conglomerate Millsholm residuum sandstone, and shale 7.0 - 7.5 -- 64 17 oak savannah with annual grasses 20 -30% clay Salt Canyon alluvium mixed sources 7.0 - 7.5 -- 51 16 annual grasses and forbs clay 25 - 35% intermixed with Contra Costa and Millsholm Sehorn residuum sandstone and shale 7.0 - 7.0 -- 64 18 blue oak and annual grasses soils smectic, dry soil crack to 1.0 cm and down to Skyhigh residuum sandstone and shale 5.7 - 5.7 -- 89 14 blue oak and annual grasses 25 cm depth blue oak, annual grasses, foothill pine, and Sleeper residuum sandstone and shale 7.5 - 7.8 -- 81 16 smectic, deeper than Skyhigh ceanothus unique soil found only in Bear Creek Bear Valley alluvium serpentinite 6.6 - 7.5 3 to 6:1 48 17 sparse annual grasses and forbs watershed; high gravel content manzanita, leather oak, McNab cypress, capable of timber production; ochric Dubakella residuum peridotite 7.0 - 7.0 -- 76 11 foothill pine epipedon to 27 cm Haploxerts, residuum serpentinite 7.4 - 8.0 -- -- 16 annual grasses and forbs require more detailed classification Unidentified manzanita, leather oak, McNab cypress, Henneke residuum peridotite 6.7 - 7.0 -- 76 13 shallow soil (<50 cm deep) foothill pine Leesville alluvium serpentinite 7.2 - 8.2 3 to 6:1 48 15 annual grasses and forbs deep soil (> 150 cm deep) manzanita, leather oak, McNab cypress, Montara residuum serpentinite 8.0 - 8.0 >1:1 71 14 shallow soil (<50 cm deep) foothill pine

Ultramafic (Magnesic) Ultramafic hard-ftractured manzanita, leather oak, McNab cypress, highest organic matter in the surface horizon Okiota residuum 6.3 - 6.1 Na 94 16 peridotite foothill pine (3%) of all ultramafic soils found locally > 35% clay; polygonal cracking pattern; much Venado alluvium serpentinite 7.2 - 8.6 5 to 11:1 48 15 annual grasses and forbs erosion from downcutting as the result of channel dynamiting in the late 19th century

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APPENDIX E LIST OF PLANT ALLIANCES KNOWN OR SUSPECTED TO OCCUR IN BEAR CREEK WATERSHED

Globally rare plant alliances are highlighted in red. Major Species Common Scientific Names Alliance Soil Categories Soil Types Notes Name(s) Chaparral (37.000.00) > 60 percent chamise Mafic, Chamise Adenostoma fasciculatum 37.101 Henneke Okiota cover, on dry slopes and Ultramafic ridges Henneke, Montara, Mostly north-facing slopes Wedgeleaf Ceanothus Ceanothus cuneatus 37.211 Ultramafic Okiota and ridges, sandy soils Described by Rivas Jepson's Ceanothus Ceanothus jepsonii 37.212 Ultramafic Henneke, Okiota Martinez (1997) from Bear Creek watershed Described by McCarten and Rogers (1991); Whiteleaf Manzanita Arctostaphylos viscida 37.305 Ultramafic Henneke, Okiota dominant in Bear Creek watershed Occurs in a mosaic with Henneke, Montara, other chaparral alliances; Leather Oak Quercus durata 37.306 Ultramafic Okiota often with chamise, toyon, foothill pine, and cypresses Widespread in Bear Creek watershed gentle to very Scrub Oak Quercus berberdifolia 37.407 Non-Ultramafic Millsholm, Skyhigh steep northwest- and northeast-facing slopes Scrub Oak Quercus berberidifolia Suspected but not Alderleaf Mountain- 37.408 Non-Ultramafic ? Cercocarpus montanus identified in the watershed mahogony Scrub Oak Quercus berberdifolia Suspected but not 37.409 Non-Ultramafic Contra Costa, Millsholm Chamise Adenostoma fasciculatum identified in the watershed Locally on shallow, Contra Costa, Millsholm, Interior Live Oak Quercus wislizeni 37.420 Non-Ultramafic moderately to excessively Skyhigh drained soils

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Suspected but not Toyon Heteromeles arbutifolia 37.911 Non-Ultramafic Contra Costa, Millsholm identified in the watershed Non-Ultramafic, Suspected but not Pacific Poison Oak Toxicodendron diversilobum 37.940 unknown Ultramafic identified in the watershed Native Grasslands (41.000) In ephemerally moist to hydric soils at springs, in Mafic, Non- Meadow Barley Hordeum brachyantherum 41.052 ? meadows and swales in Ultramafic Bear Valley; clayey, silty, or fine loamy soil On clay or clay loam soils at edges of hydric zones Arand, Millsholm, Beardless Wildrye Leymus triticoides 41.080 Non-Ultramafic Dominant in Bear Creek Skyhigh and Sulphur Creek floodplains, now rare On Love Lady Ridge per Mc Carten and Rogers (1991); formerly extensive, occurs Etsel, Maymen, Purple Needlegrass Nassella pulchra 41.150 Non-Ultramafic in many settings and often Millsholm, Skyhigh with many other native and non-native grass species Widespread but rarely Sandburg's Bluegrass Poa secunda 41.180 Mafic Leesville, Venado dominant in the watershed Widespread dominant in Sulphur Creek and Bear Saltgrass Distichlis spicata 41.200 Saline Arand Creek floodplains; also found in alkaline seeps Rare; found at one Tufted Hairgrass Deschampsia caespitosa 41.220 Saline ? wetland site on Walker Ridge On Love Lady Ridge per Mc Carten and Rogers (1991) Squirreltail Elymus elymoides 41.230 Ultramafic ? and elsewhere in small patches

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Rarely if ever in large Blue Wildrye Elymus glaucus 41.640 Ultramafic ? patches

Big Squirreltail Elymus multisetus 41.650 ? ? Found in small patches

Non-Native Grasslands (42.000) Widespread in many Non-Ultramafic Barb Goatgrass Aegilops triuncialis 42.003 All except saline soils settings, adapted to severe Ultramafic disturbances Bromus diandrus, B. Non-Ultramafic, Poorly characterized Annual Bromes hordaceus, B. madritensis, 42.026 Many soils Ultramafic alliance B. rubens Contra Costa, Milholm, Aira caryophylla, Bromus Non-Ultramafic Poorly characterized California Annual Grasslands 42.040 Skyhigh, Sleeper; hordeaceus, Erodium botrys Ultramafic alliance Henneke, Okiota Widespread including Non-Ultramafic Yellow Starthistle Centaurea solstitialis 42.042 All except saline soils severely disturbed Ultramafic mercury mine sites Found in roadsides and in Tall Wheatgrass Thinopyrum ponticum 42.100 Non-Ultramafic Many soils riparian zones Meadows and Seeps (45.000) Occurs in alkali meadows Hydric soils including Baltic Sedge Juncus balticus 45.562 Not known and at seeps and springs; saline soils often indicates overgrazing Marshes (52.000) Found locally along Bear Broadleaved Cattail Typha latifolia 52.040 Non-Ultramafic Hydric soils, submerged Creek Found along lower Bear Broadleaved Pepperweed Lepidium latifolium 52.205 Non-Ultramafic Riparian and hydric soils Creek and its tributaries; not native

Riparian Forest and Bottomland (61.000) and Riparian Scrub (63.000) Remnant riparian Fremont Cottonwood Populus fremontii 61.111 Non-Ultramafic Hillgate woodland in Little Valley in the Leesville subwatershed

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Occurs in and along Bear Non-Ultramafic, Sandbar Willow Salix exigua 61.209 ? Creek, Mill Creek, and the Hydric Leesville subwatershed Ultramafic, Brewer's Willow Salix breweri 61.213 ? ? Hydric Ultramafic, Possibly occurs in Mill Western Azalea Rhododendron occidentale 63.310 Henneke, Okiota Hydric Creek subwatershed Widespread in riparian Non-Ultramafic, Tamarisk Tamarix sp. 63.810 Riverwash zones along Bear Creek Hydric and Sulphur Creek Oak Woodland (71.000) Non-Ultramafic, Widespread at the eastern Boar, Contra Costa, sometimes edge and in lower Bear Blue Oak Quercus douglasii 71.020 Millsholm, Skyhigh, overlying Creek watershed, often on Sleeper Ultramafic infertile, fast draining soils Unique stand at the south Boar, Contra Costa, end of Bear Valley plus Non-Ultramafic, Corval, Millsholm, Salt several clusters along Valley Oak Quercus lobata 71.040 Riparian Canyon, Skyhigh, Lower Bear Creek and in Sleeper the upper part of the Leesville subwatershed Boar, Contra Costa, Small patches are found Interior Live Oak Quercus wislizeni 71.080 Non-Ultramafic Millsholm, Skyhigh, locally in the watershed Sleeper Coniferous Upland Forest and Woodland (80.000) Found on infertile soils, Gabbro, Henneke, Montara, especially on ridges, McNab Cypress Cupressus macnabiana 81.300 Ultramafic Okiota usually in single-species stands of the same age Found on infertile soils, not in the same areas as Sargent Cypress Cupressus sargentii 81.500 Ultramafic Henneke, Okiota McNab cypress, in moister canyon sites Etsel, Henneke, Occurs on ridges and Non-Ultramafic, Knobcone Pine Pinus attenuata 87.100 Maymen, Montara, upper slopes on infertile, Ultramafic Okiota droughty soils, usually in

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single-species stands of the same age Widespread on upland

Non-Ultramafic slopes, usually on infertile, Foothill Pine Pinus sabiniana 87.130 Contra Costa, Henneke, Ultramafic on chaparral sites it is a Millsholm, Okiota canopy emergent Multiple woodland conifer Pinus lambertiana, P. communities that require Mixed Conifer ponderosa, Pseudotsuga ? ? Henneke, Montara closer study east of Love menziesii Lady Ridge ? = not known or undescribed Sources: Colusa County Soil Survey (Reed, 2006), NatureServe Explorer (2009), USDA Forest Service Region 5 (multiple years) obtained from CalFlora (2008), Biogeographic Data Branch (2003, 2007)

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APPENDIX F AIR QUALITY REGULATIONS

Federal and State of California Standards for Air Quality The US Environmental Protection Agency (US EPA) and the California Air Resources Board each set standards air quality standards for major or “criteria” pollutants based on known thresholds for adverse health effects for people. These ambient air quality standards are levels of contaminants that represent safe limits to avoid specific adverse health effects associated with each pollutant. Table F.1 provides a compares the standards currently in effect under each agency. California Air Resources Board standards are more stringent to provide a wider margin of safety.

US EPA regulations consist of national primary standards and national secondary standards. Primary standards are the measures of air quality that provide an adequate safety margin to protect the public‟s health. Secondary standards for air quality protect the public from any known or anticipated adverse effect of a criteria pollutant.

California ambient air quality standards are listed in the Table of Standards in Section 70200 of Title 17 of the California Code of Regulations.

Table F.1 – State and national ambient air quality standards for criteria pollutants California Standards Federal Standards not to equal or exceed unless noted Averaging not to be exceeded more than once a year except as noted Pollutant otherwise Time Concentration(1) Method Primary (1) Secondary(1) Method

0.09 ppm 1 Hour - (180 μg/m3) Same as Ozone Ultraviolet Ultraviolet Primary (O ) Photometry Photometry 3 0.07 ppm 0.075 ppm Standard 8 Hour (137 μg/m3) (147 μg/m3) (2)

3 3 (3) 24 Hour 50 μg/m 150 μg/m Inertial Respirable Gravimetric or Same as Separation Particulate Beta Primary and Matter Annual Attenuation Standard Gravimetric (PM ) Arithmetic 20 μg/m3 - 10 Analysis Mean

3 (4) Inertial Fine 24 Hour No Separate State Standard 35 μg/m Same as Separation Particulate Primary and Matter Annual Gravimetric or Standard Gravimetric (PM ) Arithmetic 12 μg/m3 Beta 15 μg/m3 2.5 Analysis Mean Attenuation

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California Standards Federal Standards not to equal or exceed unless noted Averaging not to be exceeded more than once a year except as noted Pollutant otherwise Time Concentration(1) Method Primary (1) Secondary(1) Method

9.0 ppm 9 ppm Non- 8 Hour 3 Non-dispersive 3 Carbon (10 mg/m ) (10 mg/m ) dispersive Infrared None Monoxide 20 ppm 35 ppm Infrared 1 Hour Photometry (CO) (23 mg/m3) (40 mg/m3) Photometry Annual 0.030 ppm 0.053 ppm Arithmetic 3 Nitrogen (57 μg/m ) Gas Phase (100 μg/m3) Same as Gas Phase Mean Dioxide Chemi- Primary Chemi- (NO ) 0.18 ppm luminescence Standard luminescence 2 1 Hour - (339 μg/m3)

30 days 1.5 μg/m3 - - - average Lead Atomic (Pb) Absorption High Volume Same as Calendar Sampler and - 1.5 μg/m3 Primary Quarter Atomic Standard Absorption Annual 0.030 ppm Arithmetic - - (80 μg/m3) Mean not to exceed 0.14 ppm Sulfur 24 Hour 0.04 ppm Ultraviolet 3 - Spectro- 3 (365 μg/m ) photometry Dioxide (105 μg/m ) Fluorescence (Pararosaniline (SO2) 0.5 ppm Method) 3 Hour - - (1300 μg/m3) 0.25 ppm (655 1 Hour - - μg/m3) In sufficient amount to produce an extinction coefficient of 0.23 per Visibility 8 Hour kilometer-visibility of ten miles or Reducing (10 am to more due to particles when the Particles 6 pm, PST) relative humidity is less than 70 No percent. Federal Standards Sulfates 24 Hour 25 μg/m3 Ion Chromatography

Hydrogen 0.03 ppm Ultraviolet 1 Hour Sulfide (42 μg/m3) Fluorescence Source: California Air Resources Board (2008); US Enviornmental Protection Agency (2008) Notes: 1. Equivalent units given in parentheses are based upon a reference temperature of 25° C and a reference pressure of 760 mm of mercury. 2. The ozone standard is attained when the fourth highest eight hour concentration in a year, averaged over three years, is equal to or less than the standard.

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3. For PM10, the 24 hour standard is attained when 99 percent of the daily concentrations, averaged over three years, are equal to or less than the standard. 4. For PM2.5 the 24 hour standard is attained when 98 percent of the daily concentrations, averaged over three years, are equal to or less than the standard.

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APPENDIX G DRINKING WATER OBJECTIVES APPLICABLE TO BEAR CREEK WATERSHED

Primary maximum contaminant levels are legal requirements for toxic chemical elements and compounds in drinking water. Secondary maximum contaminant levels are recommended thresholds, not enforceable by law, for chemicals or visual and odor characteristics in water that make the water unpleasant to use as drinking water.

Table G.1 – Water quality numeric criteria for chemical elements in California Maximum Contaminant California Dissolved Concentration Notification Response Beneficial -1 Public Constituent (mg liter ) Level Level Use Health Goal (mg liter-1) (mg liter-1) Primary Secondary (ppb) Chemical Elements MUN Aluminum 1.000 0.600 600 - - MUN Antimony 0.006 - 0.020* - - MUN Arsenic 0.010 - 0.004 - - MUN Barium 1.000 - 2,000 - - MUN Beryllium 0.004 - 1 - - AGR Boron - - - 1.000 10.000 MUN Cadmium 0.005 - 0.04 - - MUN Chloride - 250.0 - - - MUN Chromium (total) 0.050 - - - - MUN Copper† 1.300 1.000 300 - - MUN Fluoride‡ 1.400-2.400 - 1,000 - - Iron - 0.300 - - - MUN Lead 0.015 - 0.2 - - Manganese - 0.050 0.500 5.000 MUN Mercury 0.002 - 1.2 - - MUN Nickel 0.100 - 12 - - MUN Selenium 0.050 - - - - Silver - 0.100 - - - MUN Thallium 0.002 - 0.1 - - Vanadium - - - 0.050 0.500 Zinc - 5.000 - - - COLD Dissolved Oxygen 7.000 - - - - SPWN Dissolved Oxygen 7.000 - - - - WARM Dissolved Oxygen 5.000 - - - - Source: Water Quality Control Plan for the Sacramento and San Joaquin River Basin, as amended 2007 and the Department of Environmental Health Hazard Assessment (current as of September 2009) *currently under review †The copper concentration occurs in>10 percent of tap water samples collected.

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‡The acceptable contaminate level for fluoride varies inversely with increasing temperature from 2.4 mg liter-1 at temperatures less than 53.7°F to 1.4 mg liter-1at 90.5°F.

Table G.2 – Water quality numeric criteria for ionic compounds applicable in California

Maximum Contaminant California Dissolved Concentration Notification Response Beneficial -1 Public Constituent (mg liter ) Level Level Use Health Goal (mg liter-1) (mg liter-1) Primary Secondary (ppb)

Chemical Ions All Bene- Nitrogen: Ammonia (as 0.025 ficial Uses NH3) MUN Nitrogen: Nitrate (as 45 10,000 TITLE22 NO3) MUN Nitrogen: Nitrate + 10 10,000 TITLE22 Nitrite sum MUN Nitrogen: Nitrite (as 1 1,000 TITLE22 NO2) MUN Sulfate 250.0 Source: Water Quality Control Plan for the Sacramento and San Joaquin River Basin, as amended 2007 and the Department of Environmental Health Hazard Assessment (current as of September 2009)

Mercury The Basin Plan calls for a 95 percent reduction in the amount of total mercury discharging from abandoned mines.

Table G.3 – Target reductions of mercury discharges at abandoned mercury mines

Current Load Target Load Mine or Mine Complex Ownership kg yr-1 kg yr-1 Central, Cherry Hill, Empire, private 5.0 0.25 Manzanita, West End Clyde BLM 0.4 0.02 Elgin private 3.0 0.15 Rathburn Petray BLM, private 25.0 1.25 Wide Awake Mine private 0.8 0.04 Total 34.2 1.71 Sources: California Geological Survey for estimate for the Ratburn Petray mine complex; other estimates come from the staff of the Central Valley Water Board

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Table G.4 – Total daily maximum loads for mercury and methylmercury (MeHg) established by the CVRWQCB for Bear Creek and its tributary Sulphur Creek

MeHg in Water MeHg in Fish Basin Plan TMDL Fish Trophic Level Bear Creek TMDL MeHg Target MeHg, unfiltered 3 4 ng liter-1, g yr-1, averaged mg per kg of Wet Fish Wt instaneous maximum Mouth of Sulphur 0.8 Creek Bear Creek 0.9 @ Bear Valley Road Bear Creek 3.0 0.06 0.12 0.23 @ Highway 20 Total Mercury, instantaneous maximum Flow ≤ 3 cfs Flow > 3cfs Sulphur Creek TMDL mg per kg of suspended ng liter-1 solids Mouth of Sulphur 1,800 35 Creek Sources: CVRWQCB (2007), Central Valley Water Board Resolutions R5-2005-0146 and R5-2007-0021

Table G.5 – Standards for maximum amounts of fecal coliform bacteria for safe drinking water in the region covered by the CVRWQCB Beneficial Bacteria Count Basis for Count Maximum Limit Use per 100 ml Geometric Mean 400 Using five or more samples for any 30-day period AND ≤ 10 percent of samples with > REC-1 400 bacteria Geometric Mean 200 Using five or more samples for any 30-day period Samples for any 30-day period AND ≤ 10 Average 4000 REC-2 percent of samples with > 400 bacteria Average 2000 Samples for any 30-day period Source: CVRWQCB (2007)

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Table G.6 – CVRWQCB limits for agricultural water quality Limit Limit Element Element mg liter-1 mg liter-1 Aluminum 5.000 Iron 5.000 Arsenic 0.100 Lead 5.000 Boron 0.700 – 0.750* Manganese 0.200 Cadmium 0.010 Molybdemum 0.010 Chloride 106.000 Nickel 0.200 Chromium 0.100 Selenium 0.020 (VI) Sodium 69.000 Cobalt 0.050 Vanadium 0.100 Copper 0.200 Zinc 2.000 Fluoride 1.000 pH 6.5 – 8.4 Source: Ayers and Westcott (1985) *upper value from the US EPA (1986)

Table G.7– California Toxics Rule criteria for protection of freshwater aquatic life protection in inland surface waters Continuous Maximum Concentration Concentration Constituent (4-day Average) (1-hour Average) Notes total recoverable, mg liter-1 Arsenic 0.150 0.340 Cadmium 0.00083 - 0.0073 0.00095 - 0.022 exact values depend on water Chromium (III) 0.067 – 0.640 0.560 – 5.400 alkalinity Chromium (VI) 0.011 0.016 Copper 0.0029 – 0.030 0.0038 – 0.052 exact values depend on water Lead 0.00054 – 0.019 0.014 – 0.480 alkalinity Nickel 0.016 – 0.170 0.150 – 1.500 Selenium 0.005 0.020 Silver -- 0.0037 – 0.440 exact values depend on water Zinc 0.037 – 0.390 0.0037 – 0.390 alkalinity

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APPENDIX H

NARRATIVES OF WATER QUALITY OBJECTIVES FOR SURFACE WATER AND GROUND WATER

The CVRWQCB uses narratives for water quality objectives for both surface water and ground water. Table H.1 refers to constituents and characteristics in surface water; table H.2 lists and describes the narratives referring to ground water.

Table H.1: Narrative water quality objectives for constituents and characteristics of surface water in Bear Creek watershed

Constituent or Descriptive Water Quality Objectives Characteristic Bacteria MUN: For drinking water from surface water sources, the fecal coliform counts based on a minimum of not less than five samples for any 30-day period shall not exceed a geometric mean of 20 per 100 ml. The total coliform counts under the same sampling conditions shall not exceed a geometric mean of 100 per 100 ml. REC-1: In waters designated for contact recreation, the fecal coliform counts based on a minimum of not less than five samples for any 30-day period shall not exceed a geometric mean of 200 per 100 ml, nor shall in more than ten percent of the total number of samples taken during any 30-day period exceed 400 per 100 ml of water. The total coliform values shall exceed a median of 240 per 100 ml, nor shall any sample exceed 10,000 per 100 ml. Biostimulatory Water shall not contain biostimulatory substances (fertilizers) which promote aquatic growths Substances in concentrations that cause nuisance or adversely affect beneficial uses. Color Water shall be free of discoloration that causes nuisance or adversely affects beneficial uses. Dissolved For surface water bodies outside the legal boundaries of the Delta, the monthly median of the Oxygen mean daily dissolved oxygen concentration shall not fall below 85 percent of saturation in the main water mass, and 95 percentile concentration shall not fall below 75 percent of saturation. The dissolved oxygen concentrations shall not be reduced below the following minimum levels at any time: waters designated WARM 5.0 mg liter-1; waters designated COLD 7.0 mg liter-1; waters designated SPWN 7.0 mg liter-1. Floating Water shall not contain floating material in amounts that cause nuisance or adversely affect Material beneficial uses. Methylmercury Refer to Table G.3 and the related TMDL documents from the CVRWQCB. Oil and Grease Waters shall not contain oils, greases, waxes, or other materials in concentrations that cause nuisance, result in a visible film or coating on the surface of the water or on objects in the water, or otherwise adversely affect beneficial uses. pH (percent The pH shall not be depressed below 6.5 nor raised above 8.5. Changes in normal ambient pH hydrogen ions levels shall not exceed 0.5 in fresh waters with designated COLD or WARM beneficial uses. In in solution) determining compliance with the water quality objective for pH, appropriate averaging periods may be applied provided that beneficial uses will be fully protected. Pesticides No individual pesticide or combination of pesticides shall be present in concentrations that adversely affect beneficial uses. Discharges shall not result in pesticide concentrations in bottom sediments or aquatic life that adversely affect beneficial uses. Total identifiable persistent chlorinated hydrocarbon pesticides shall not be present in the water column at concentrations detectable within the accuracy of analytical methods approved by the Environmental Protection Agency or the executive Officer. Pesticide concentrations shall not

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Constituent or Descriptive Water Quality Objectives Characteristic exceed those allowable by applicable antidegradation policies (see State Water Resources Control Board Resolution No. 68-16 and 40 C.F.R. Section 131.12). Pesticide concentrations shall not exceed the lowest levels technically and economically achievable. Waters designated for domestic or municipal supply (MUN) shall not contain concentrations of pesticides in excess of the Maximum Contaminant Levels set forth in California Code of Regulations, Title 22, Division 4, Chapter 15. Waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of thiobencarb in excess of 1.0 μg liter-1. Radioactivity Radionuclides shall not be present in concentrations that are harmful to human, plant, animal or aquatic life nor that result in the accumulation of radionuclides in the food web to an extent that presents a hazard to human, plant, animal or aquatic life. At a minimum, waters designated for use as domestic or municipal supply (MUN) shall not contain concentrations of radionuclides in excess of the maximum contaminant levels (MCLs) specified in Table 4 (MCL Radioactivity) of Section 64443 ofTitle 22 of the California Code of Regulations. Sediment The suspended sediment load and suspended sediment discharge rate of surface waters shall not be altered in such a manner as to cause nuisance or adversely affect beneficial uses. Settleable Waters shall not contain substances in concentrations that result in the deposition of material Material that causes nuisance or adversely affects beneficial uses. Suspended Waters shall not contain suspended material in concentrations that cause nuisance or Material adversely affect beneficial uses. Tastes and Water shall not contain taste- or odor-producing substances in concentrations that impart Odors undesirable tastes or odors to domestic or municipal water supplies or to fish flesh or other edible products of aquatic origin, or that cause nuisance, or otherwise adversely affect beneficial uses. Temperature The natural receiving water temperature of intrastate waters shall not be altered unless it can be demonstrated to the satisfaction of the Regional Water Board that such alteration in temperature does not adversely affect beneficial uses. At no time or place shall the temperature of COLD or WARM intrastate waters be increased more than 5°F above natural receiving water temperature. Toxicity All waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life. This objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances. Compliance with this objective will be determined by analyses of indicator organisms, species diversity, population density, growth anomalies, and biotoxicity tests of appropriate duration or other methods as specified by the Regional Water Board. The survival of aquatic life in surface waters subjected to a waste discharge or other controllable water quality factors shall not be less than that for the same water body in areas unaffected by the waste discharge, or, when necessary, for other control water that is consistent with the requirements for "experimental water" as described in Standard Methods for the Examination of Water and Wastewater, latest edition. Turbidity Waters shall be free of changes in turbidity that cause nuisance or adversely affect beneficial uses. Increases in turbidity attributable to controllable water quality factors shall not exceed the following limits: (1) Where natural turbidity is between 0 and 5 Nephelometric Turbidity Units (NTUs), increases shall not exceed 1 NTU. (2) Where natural turbidity is between 5 and 50 NTUs, increases shall not exceed 20 percent. Where natural turbidity is between 50 and 100 NTUs, increases shall not exceed 10 NTUs. Where natural turgidity is greater than 100 NTUs, increases shall not exceed 10 percent. In determining compliance with the above limits, appropriate averaging periods may be applied provided that beneficial uses will be fully

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Constituent or Descriptive Water Quality Objectives Characteristic protected. Exceptions to the above limits will be considered when a dredging operation can cause an increase in turbidity. In those cases, an allowable zone of dilution within which turbidity in excess of the limits may be tolerated will be defined for the operation and prescribed in a discharge permit. Source: CVRWQCB (2007)

Table H.2 – Narrative water quality objectives for constituents and characteristics of ground water in Bear Creek watershed

Constituent or Descriptive Water Quality Objectives Characteristic Bacteria In ground waters used for domestic or municipal supply (MUN) the most number of coliform organisms based on a minimum of not less than five samples for any 30-day period shall be less than 1.1 per 100 ml. Radioactivity At a minimum, ground waters designated for use as domestic or municipal suppy (MUN) shall not contain concentrations of radionuclides in excess of the MCLs specified in Table 4 (MCL Radioactivity) of Section 64443 of Title 22 of the California Code of Regulations. Tastes and Ground waters shall not contain taste- or odor-producing substances in concentrations that Odors cause nuisance or adversely affect beneficial uses. Toxicity Ground waters shall be maintained free of toxic substances in concentrations that produce detrimental physiological responses in human, plant, animal, or aquatic life associated with designated beneficial use(s). This objective applies regardless of whether the toxicity is caused by a single substance or the interactive effect of multiple substances. Source: CVRWQCB (2007) and State Water Quality Control Board standards as of November, 2009

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APPENDIX I

BACKGROUND TO THE CHEMICAL AND BIOLOGICAL SIGNIFICANCE OF MERCURY IN BEAR CREEK WATERSHED

The CalFed Program to research and restore ecosystems of the Sacramento-San Joaquin Delta and San Francisco Bay has invested in ecological studies in Bear Creek watershed and elsewhere in the Cache Creek Basin.

Mercury Dispersal Mercury mining and processing around the world have released previously inert stocks of mercury into the soil, water, and air from multiple points. The increasing availability and dispersal of mercury occurs through physical, chemical, and biotic pathways: physically in stream flows and the atmospheric currents; in chemical reactions facilitated by aquatic bacteria; and by movements of organisms that contain mercury in their cells, tissue, or organs. Controlling this dispersal to reduce the exposure of mercury to people and other species challenges resource managers worldwide. The problem of mercury dispersal is especially acute at the original sources of the dispersion, such as Bear Creek watershed (Domalgaski et al. 2004b). Dilution of mercury unfortunately is not the solution to mercury pollution exiting the watershed because the process of bio-accumulation of toxic forms of mercury in estuaries, bays, and deltas concentrates mercury in bacteria, plants, and animals throughout aquatic ecosystems. Containment of mercury at its source is an essential part of mercury management.

Effects of Mercury Mercury can impair the cognitive, neurological, motor, reproductive, and immunosuppressant abilities of people (Batten and Scow 2003). Fetuses and small children are particularly vulnerable on account of their relatively small size and still developing bodies. The major agent of mercury toxicity to people is methylmercury. The human body absorbs methylmercury more readily into tissue and organs than it can absorb elemental mercury. Methylmercury concentrations from 0.3 microgram to 1 microgram are toxic, even deadly. Most mercury exposure for people stems from consumption of fish or shellfish. Harnly et al. (1997), for example, found that Native Americans living at Clear Lake (Lake County) and consuming fish from Clear Lake had levels of inorganic mercury in their urine equivalent to background levels of mercury in the soil. On the other hand, average concentrations of organic mercury (methylmercury) in their blood samples averaged 15.6 micrograms liter-1, a high amount compared to average levels reported in people who do not consume fish, i.e., 2 micrograms liter-1 (Brunne et al. 1991).

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Fish and wildlife are also vulnerable to the toxicity of environmental mercury. In aquatic and riparian food web, the percentage amount of mercury in animal tissues increases (“biomagnifies”) at each higher level of predation. Being at the highest trophic (food consumption) level in aquatic or riparian ecosystems, fish-eating fishes, birds, and mammals accumulate methylmercury in their bodies at higher concentrations than their prey. This “bio-magnification of mercury levels” in animal tissues can negatively impact growth, reproduction, and survival of species. Fish-eating birds and mammals resident in Bear Creek watershed at risk include bald eagle (Haliaeetus leucocephalus), osprey (Pandion haliaetus), and river otter (Lontra canadensis).

Mercury Chemistry Mercury exists in several different forms, each having distinctive properties for reactivity and mode of transport through Bear Creek watershed and downstream.

Elemental Mercury Elemental mercury (chemical symbol Hg0) is a liquid and can be found naturally as droplets in mercury mines. It is unusual among in that it can vaporize into the atmosphere. This form of mercury is the most common form of mercury (98 percent) found in the atmosphere at concentrations of 1 to 2 nanograms per cubic meter (Gray 2003). People can inhale elemental mercury in the air, which then passes into the blood stream and spreads throughout the body. Red blood cells, the liver, and the central nervous system transform 0 2+ + Hg to mercuric mercury (Hg ) and methylmercury (CH3Hg ) (Björg 2003). Light energy transforms a small percentage of quicksilver to mercuric ions.

Mercuric Ions The mercuric (Hg2+) form of mercury is reactive chemically and, of all forms of inorganic mercury, most readily reacts to form methylmercury. In the human body, ionic mercury can bind to sulfur atoms on essential cell proteins and thus disturb vital functions of cells causing damage to the central nervous system, neuromuscular malfunction as well as damage people‟s kidneys and intestines (Björg 2003). Most mercury deposited back to the earth surface from the atmosphere arrives in this form (Gray 2003) and readily methylates once it reaches suitable conditions in an aquatic environment.

Mercurous Ions Mercurous ions (Hg+) like quicksilver react only to form inorganic compounds and are not methylated. The role of mercurous ions in the mercury cycle worldwide is poorly known.

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Organic Compounds of Mercury Organic compounds of mercury are the most toxic forms of mercury as they accumulate in people as well as fish and wildlife. Sediments in aquatic benthic environments provide the conditions for transforming elemental and ionic mercury into organic compounds. These compounds are readily soluble in lipids (blood fats) and easily move through the body and across the blood/brain barrier.

Methylmercury Once inside the body, methylmercury slowly breaks down to Hg2+, triggering delayed cumulative poisoning. In oxygen-deprived („anoxic”) conditions as in waterlogged or hydric soils, methylmercury can accumulate high concentrations. Mercuric ions (Hg2+) combine - + with a methyl radical (CH3 ) to form methylmercury (CH3Hg ). In Bear Creek watershed, methylmercury tends to reach its highest amount in January, when powerful storms transport large sediment loads overland and into streams (high flow – high load); in April and May; and in late-summer when the stream flows are the lowest of the year and methylmercury concentrations in these low flows are highest of the year.

Dimethylmercury

Dimethylmercury ((CH3)2Hg) is rare in nature (Barkay and Wagner-Döbler 2005) and is particularly toxic, with just a drop or two in contact with the skin can cause death after ten months (Björg 2003). Because of its volatility to gas, dimethylmercury is less apt to enter the food web of an aquatic environment.

Major Mercury-Containing Minerals in Bear Creek watershed Cinnabar Cinnabar (α-HgS), or mercury sulfide, is a red solid compound of mercury naturally found in ores and stream sediments in Bear Creek watershed. Most mercury from Bear Creek watershed exists as cinnabar and is associated with serpentinite, altered sedimentary rock near serpentinite, and the vent zones of hot springs (Studemeister 1984). It is not toxic to animals and people because cinnabar cannot be absorbed into blood. Cinnabar is the source of the pigment vermilion. Under natural conditions, cinnabar weathers and alters chemically only very slowly. When transported into aquatic ecosystems as a suspended solid, it may ionize slowly to a mercuric ion, which then may transform to methylmercury (Domalgaski et al. 2004a). The reaction rates from cinnabar to mercuric ion to methylmercury are not presently known.

Metacinnabar Metacinnabar (ß-HgS) has a black color and consists of a complex of linked cinnabar molecules formed during retorting (heating to about 600°C) of cinnabar in the industrial

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process to extract pure elemental mercury from cinnabar ore. It is found in the “calcines” (waste rock and sediment piles) at mercury production sites and it is highly insoluble in water. The presence of metacinnabar is an indicator of the presence of human-caused mercury contamination.

Other Mercury Compounds as By-Products When producers retorted cinnabar to extract elemental mercury, they also generated unnaturally high concentrations of other mercury minerals, in addition to metacinnabar as by-products in the calcines left in the Sulphur Creek subwatershed. At nearby mercury mining and retorting sites in Napa and Lake counties, the following mercury compounds, more soluble that cinnabar and metacinnabar, were present in unnaturally high percentages: corderoite (Hg3S2Cl2), schuetterite (HgSO4), terlinguite (Hg2OCl), and mercuric chloride 2+ (HgCl2). These by-products can release Hg more readily to start the process of methylation (Kim et al 2000). The composition of calcines from retort sites in the Sulphur Creek subwatershed has not been studied in depth.

Key Chemical Processes with Forms of Mercury Sulfide Reactions Sulfur-containing ionic compounds and gases are prominent constituents of thermal spring waters in the Sulphur Creek subwatershed. The proximity of sulfur to large stores of mercury controls mercury chemistry, particularly in anerobic (oxygen-less) conditions found in stream sediments. Increasing concentrations of sulfide ions, particularly from dissolved hydrogen sulfide (H2S), a common gas in Sulphur Creek thermal springs, creates acidic conditions where cinnabar becomes more soluble. Under these conditions, cinnabar forms - 2- soluble mono- and bisulfide ions, HgS2H2, Hg2S2H , and HgS2 . Iron sulfide or pyrite (FeS2) also makes the sediment environment more acidic and thus activates cinnabar to form sulfides (Boszke et al. 2003). Other iron compounds called oxyhydroxides provide bonding sites in stream sediments for the mercury bisulfides that then wash downstream, particularly during winter highwater flows.

Methylation Bacteria are responsible for methylation of mercury mono- and bisulfides to mono- and dimethylmercury. The rate of bacteria-mediated methylation depends on temperature, water pH, amount of soluble mercury ions, and the type and amount and type of organic matter lodged in the soil sediment just below the water/sediment interface. The greatest methylation by bacteria takes place in late summer when low-flow conditions cause Bear Creek water to be low in oxygen and thus make aquatic habitats more conducive to methylating bacteria. The species believed to contribute most to methylmercury production in Bear Creek are Desulfobacter and Desulfovibrio, based on findings at the Abbott Mine in

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the North Fork Cache Creek watershed adjacent to Bear Creek watershed (Batten and Scow 2003). Ambient concentrations of dissolved calcium (Ca2+), magnesium (Mg2+) and high salinity (Cl-) act to inhibit Hg methylation.

Demethylation Bacteria also demethylate mercury with enzymes to precipitate solid cinnabar (mercury sulfide) under both anaerobic and aerobic conditions in stream water, depending on the species of bacteria. These reactions are now intensively studied for applications in environmental remediation to remove methylmercury and mercury from mercury- contaminated water and sediments.

Mercury in Soils Churchill and Clinkenbeard (2003) undertook extensive sampling of local background conditions of soils in the Sulphur Creek subwatershed for mercury concentrations. These data cover a more extensive area and include samples from Skyhigh and Millsholm soils on the floor of the Sulphur Creek valley floor northwest of Wilbur Springs as well as Henneke soil sites near the Elgin and Rathburn-Petray mine works at higher elevations. The range of mercury concentrations differed greatly among sites: from low values of 0.79 and 1.72 up to 280 ppm near the Cherry Hill Mine alone. The highest concentrations locally exceed the threshold for very high risk to human health. Mapping of naturally occurring mercury concentrations in soils of Bear Creek watershed is not available and is less well understood than the distribution of mercury in sediments in Sulphur Creek and in mine wastes at abandoned mines in the Sulphur Creek subwatershed.

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APPENDIX J

SUMMARY OF THE STATUS OF CHEMICAL ELEMENTS WITH MCLS IN BEAR CREEK WATERSHED

Aluminum Ultramafic soils usually have low concentrations of aluminum compared to non-ultramafic soils. Despite this pattern, water flow from abandoned mines, and to a lesser extent from spring waters, causes concentrations of total aluminum to exceed the primary aluminum MCL in Sulphur Creek. The recommended lower concentration from the secondary MCL is exceeded in virtually all water samples from the Sulphur Creek subwatershed collected in February 2001 (Suchanek et al. 2002). Time of year or water flow may affect concentrations. For example, data from Sulphur Creek in May 1994 were lower by at least a factor of four than the February 2001 data. Data from the lower main stem of Bear Creek show, however, diluted concentrations well below the primary MCL at all times (Department of Water Resources data, 2003-2006).

Antimony Data on antimony are few and differ greatly over time and among springs. Highest reliable readings of antimony concentrations in water come from the Jones Fountain of Life and Wilbur Spring - up to 0.085 mg liter-1 (Suchanek et al. 2002), in the immediate floodplain of Sulphur Creek. Water in creeks flowing from Cherry Hill Mine into Sulphur Creek had ten times the concentration of the antimony MCL. Concentrations of antimony in lower Sulphur Creek and Bear Creek indicate very low concentrations, well below the MCL.

Antimony usually occurs at concentrations of < 1 mg kg-1 in soils and frequently in association with arsenic (Lehr et al. 2007). The locally high concentration of antimony found in Soboba soil in Sulphur Creek valley had an antimony concentration > 9 mg kg-1. (Morrison et al. 2008) This high concentration is greater than any found in a national survey of soils by the US Geological Survey (Shacklette and Boerngen 1984). The high antimony concentrations were in the C soil horizon, at > 4 cm depth. Most other soil samples taken from Sulphur Creek show an evenly distributed and low concentration of antimony throughout the soil horizon. Given the immobility of antimony, absence of antimony in the Soboba A soil horizon is odd if the source of antimony were anthropogenic mining products. Antimony concentrations are high (> 35 ppm) in two Sulphur Creek sediment samples taken downstream of mine sites (Morrison et al. 2008).

Knowledge about how antimony behaves at these higher concentrations is poorly known in hydric soils (Tighe et al. 2005). Bacteria can methylate antimony and chemically reduce antimony (V) to antimony (III) in anaerobic sediments to form water-soluble and toxic

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antimony acids. Initial study of antimony methylation indicates that soil pH, water content, and temperature do not correlate with the rate of antimony biomethylation observed with antimony (Duester et al. 2005).

Arsenic Most arsenic enters water supplies from natural deposits or springs in the earth or from leaching from mine waste rock and sediment. Concentrations of arsenic measured at Blanck Spring, Jones Fountain of Life, and Wilbur Spring are above the arsenic MCL (0.010 mg liter-1) for drinking water (Suchanek et al. 2002). Dilution effects in Sulphur Creek put the concentration well below the MCL. Levels of arsenic measured by the Department of Water Resources between 2001 and 2006 near the mouth of Bear Creek approached but never exceeded the MCL for arsenic.

The source of arsenic in soils may in part be the result of flooding and drainage of water laden with arsenic (principally arsenite, the arsenic ion form As(III)) that comes from geothermal springs and commercial mining (Manning and Suarez 2000). Arsenic adsorbs to clay minerals in soil where oxidation of arsenic (III) to arsenic (V) occurs, especially with increasing pH (Lin and Puls 2000). Oxidation can also take place by methylation, which may reduce arsenic toxicity (Bentley and Chasteen 2002).

Barium Goff et al. (2001) and Suchanek et al. (2002) provide consistent data for barium. All thermal springs measured in the Sulphur Creek watershed had barium concentrations higher than the barium MCL. Most concentrations were slightly above the MCL except for Blanck and Elgin springs, which had concentrations three times higher. Stream flow and perhaps seasonality may affect barium concentrations. Suchanek et al. (2002) readings in Sulphur Creek during February 2001 were roughly one-eighth of the readings during May 1994 (Goff et al. 2001), with most Sulphur Creek readings being below the MCL for barium. Readings from Bear Creek from May 1994 were about a third of the concentrations found in Sulphur Creek at the same time.

Chloride Chloride, the dissolved ionic form of chlorine, is an indicator of salinity. It is present in thermal springs at concentrations higher than any other element. High values of chloride indicate the ancient marine environment of the region. Readings taken at all seasons have shown that chloride concentrations in Sulphur Creek subwatershed springs range consistently from 36 to 39 percent of total dissolved solids by weight. Amounts range as high as 13.39 grams per liter at Elbow Spring (Goff et al. 2001). These amounts are more than 100 times higher that the secondary MCL for chloride.

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Chloride and sodium ions contribute a significant proportion to the dissolved solids in stream water. Data from the California Department of Water Resources water quality station in lower Bear Creek show seasonal patterns in the concentrations of chloride similar to those of sodium. Concentrations of chloride are highest in the driest months when water in thermal springs contributes a larger share of water flow.

In Sulphur Creek, chloride as a percentage by weight of total dissolved solids is the same as for springs but the concentrations of chloride are about half those of Sulphur Creek springs. Even with dilution from Bear Creek water, the concentrations of chloride and total dissolved solids in lower Bear Creek exceed the secondary recommended MCLs for chloride (250 mg 1-1) and total dissolved solids (500 mg 1-1) from May through October (USGS data from gage station 11451720 collected from 1969 to 1979; Department of Water Resources data from gage station A1825000 collected from 2000 to 2006). Percent of chloride by weight of total dissolved solids ranges widely from 16 to 33 percent in lower Bear Creek.

Chromium Currently the California Department of Public Health has an MCL for total chromium (element symbol Cr). From the standpoint of drinking water and human health, the concern is for Cr(VI), a known cancer-causing contaminant made famous by the film Erin Brockovich. The California Office of Environmental Health Hazard Assessment issued a draft public health goal for Cr(VI) in advance for setting a separate MCL for Cr(VI).

Total chromium concentrations in Sulphur Creek springs and stream water in data from Suchanek et al. (2002) do not exceed the MCL. Data collected by the California Department of Water Resources close to the mouth of Bear Creek (2000-2006) confirm that chromium does not exceed the MCL; concentrations at the mouth of Bear Creek are as high as or higher than readings from Sulphur Creek subwatershed.

Gough et al. (1989) first noted the natural occurrence of Cr(VI) in very small amounts at a thermal spring in an ultramafic area of Tehama County; previously, Cr(VI) was thought exist only as an industrial product.

Fluoride Fluoride, the dissolved ionic form of fluorine, is present in all thermal springs in the Sulphur Creek subwatershed at concentrations up to five times greater than the fluoride MCL. Apart from water streaming from mines, concentrations of fluoride are about 30 percent more than the MCL. Few data come from Bear Creek, but they indicate that Bear Creek has fluoride concentrations well below the MCL.

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Iron Iron (chemical symbol Fe) is a not a toxic pollutant of concern but does affect color and taste of water destined for drinking water. It has a secondary MCL of 0.3 mg liter-1. Ultramafic rocks naturally have high iron content in their minerals. Fe(II) precipitates and accumulates at discharge points from high-salinity springs in Sulphur Creek subwatershed. Elgin Mine and Jones Fountain of Life are the two springs with consistent values for iron concentrations above the MCL. The total iron in Sulphur Creek water is very high (Suchanek et al. 2002), but creeks flowing into Sulphur Creek from the Wide Awake Mine and the Cherry Hill mine have dissolved-only iron concentrations three times higher than the MCL. These concentrations are diluted to amounts well under the MCL near the mouth of Bear Creek (Department of Water Resource data, 2001-2006). Other subwatersheds north of Sulphur Creek are likely not major sources of iron.

Manganese Manganese (chemical symbol Mn) has a secondary MCL of 0.05 mg liter-1, a notification level of 0.50 mg liter-1, and a response level of 5.0 mg liter-1. Manganese is a widespread metal in ultramafic rocks in Bear Creek watershed. Measurements from Elbow Spring and the Jones Fountain of Life, the creeks originating from mines, and Sulphur Creek stream water exceeded the MCL for manganese. Concentrations for manganese in Sulphur Creek in May 1994 (Goff et al. 2001) were three to four times higher than readings taken in February 2001 (Suchanek et al. 2002). Manganese concentrations near the mouth of Bear Creek, however, are well below the MCL (California Department of Water Resources data, 2000- 2006).

Non-toxic concentrations of manganese in soil range from 40 to 900 ppm (Agency for Toxic Substances and Disease Registry (ATSDR) 2008). Manganese forms cation-exchange bonds and ligand exchanges for its retention in soil, and natural accumulations (without constant inputs) occur in subsurface soil horizons. When the cation ion exchange capacity and organic matter content of soils are high, manganese concentrations are higher in the soils. Bacteria play an as yet poorly defined role in manganese toxicity; for example, bacteria may make manganese more mobile and bio-available by converting Mn(IV) to Mn(II) (Gadd 2004). Like boron, manganese is a plant micronutrient that can become toxic to plant growth when concentrations in soils become too high. Concentrations in the watershed present moderate risk to local residents. Skin contact with manganese compounds in soil is usually not toxic as soil manganese is usually somewhat inert with only about 3 to 5 percent of the soil amount in contact being absorbed internally (ATSDR 2008).

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Nickel Nickel is commonly found in large amounts in areas of ultramafic rocks and soils. Plants, notably in the cabbage family (Brassicaceae), have adapted to soils with high nickel concentrations and can accumulate nickel internally. All data for nickel concentrations in water from Sulphur Creek watershed were more than 50 percent below the nickel MCL. Nickel compounds appear not to accumulate in the food chain. In general, nickel does not accumulate to toxic levels in animals or in humans (Barceloux 2000) except in unusual situations such as in the proximity of nickel mines.

Sulfur Ions containing sulfur, particularly sulfate and sulfide, are present in high amounts in all geothermal springs found in the Sulphur Creek subwatershed. The odor of hydrogen sulfide gas permeates the air around several springs in the subwatershed and lower Sulphur Creek itself. Churchill and Clinkenbeard (2002) estimate that between seven and sixteen metric tons of sulfate ions enter Sulphur Creek annually from abandoned mines and hot springs. An as yet unknown amount of sulphate originates as well from the cold springs in the southwest corner of Bear Valley (Slowey and Rytuba 2008). The co-occurrence of sulfur and mercury at abandoned mine sites is critical in magnifying the impact from mercury to biota and the stream ecosystems of Sulphur Creek and lower Bear Creek (Rytuba 2000). High concentrations of sulfate are important because sulfates bind readily to mercury in cinnabar to form water-soluble mercury sulfate. Solubility mobilizes the diffusion of mercury from sediments into stream water. Subsquently, bacteria are able to methylate mercury in the presence of dissolved organic matter in fluvial and wetland environments. Methylation converts mercury into methylmercury, the form of mercury most easily incorporated into human and wildlife bodily tissues, and result in mercury accumulation and sometimes to mercury toxicity. Churchhill and Clinkenbeard (2002) also point out that managing stream concentrations of sulfate is indispensible step to controlling mercury and methylmercury in Sulphur Creek and lower Bear Creek.

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APPENDIX K

PROPERTIES OF HYDROTHERMAL SPRINGS IN SULPHUR CREEK SUB-WATERSHED IN REGARD TO CONTAMINANTS AND WATER PROPERTIES

The following table summarizes work undertaken by the US Department of Energy (Goff et al. 2001), a team from the US Geological Survey and the University of California - Davis (Suchanek et al. 2002), and the Central Valley Water Board (Cooke and Stanish 2007) to characterize spring waters. Concentrations in excess of primary maximum contaminant levels are highlighted in yellow; concentrations in excess of secondary maximum contaminant levels are highlighted in blue; and concentrations in excess of notification levels are highlighted in green. The largest value recorded for a particular chemical constituent or water property is in red type. Unless otherwise specified, concentrations of elements are in parts per million.

The MUN standards used here for reference apply only to watersheds or subwatersheds that have MUN as a designated beneficial use. Lower Sulphur Creek does not have MUN as a designated beneficial use. Thus, these data provide an overview about how natural spring sources in the Sulphur Creek subwatershed depart from characteristics for suitable municipal water.

Table K.1 – Characteristics of major hydrothermal springs in the Sulphur Creek subwatershed Barium Temp Mercury Water Sources Field pH Aluminum Antimony Arsenic mg liter-1 Boron º C Raw total Wilbur Spring Don <0.010 – 54 – 58 7.2 – 8.0 0.0064 <0.200 <0.010 1.12 – 1.43 255 - 278 White’s 0.021 0.0035 - 0.003 – <0.010 – Wilbur Spring Main 50 – 57 6.87 – 7.9 <1.000 1.34 – 1.39 283 - 295 0.0073 0.023 1.200 Jones Fountain of 0.0220 – <0.010 – 53 – 62 7.28 - 8.2 <1.000 <1.000 1.32 – 1.53 265 – 300 Life 0.0336 1.200 0.003 – 0.010 – Blanck Spring 36 – 45 7.0 – 7.5 0.0069 <0.100 3.21 – 3.86 158 - 196 0.310 0.063 <0.010 – <0.001 – Elbow Spring 70 – 74 8.0 - 8.5 0.0610 <0.010 1.16 – 1.22 315 – 355 1.800 0.010 Elgin Spring Main 67 – 70 7.4 - 8.3 0.0110 <0.010 0.010 <0.010 2.96 – 3.14 220 – 223 Elgin Spring Orange 63 8.2 0.0007 <0.005 0.010 <0.010 3.44 223 Tub Unnamed Hot Spring 52 7.0 0.0043 <0.100 <0.010 <0.010 1.11 319

Water Sources Cadmium Cloride Chromium Copper Flouride Iron Lead Manganese Wilbur Spring Don 9720 - <0.010 <0.020 <0.020 2.11 – 2.36 80 <0.010 0.020 White’s 11080 8810 - <0.002 - <0.020 – <0.004 – 0.010 – Wilbur Spring Main <0.005 <0.010 2.10 – 3.32 11100 0.010 0.265 0.010 0.060 Jones Fountain of 9130 - <0.002 – 0.040 – 0.005 – 0.010 – <0.005 <0.010 2.54 – 5.15 Life 11260 0.030 0.410 0.060 0.080 7519 - <0.010 – 0.050 – <0.010 – Blanck Spring <0.010 <0.010 2.47- 0 3,57 <0.020 8765 0.023 0.180 0.020

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Water Sources Cadmium Cloride Chromium Copper Flouride Iron Lead Manganese 12530 - <0.010 – 0.070 – 0.010 – Elbow Spring <0.010 <0.020 4.36 – 5.76 <0.020 13390 0.030 0.09 0.110 11170 - 0.300 – <0.010 – Elgin Spring Main <0.010 <0.010 0.020 2.43 – 3.48 <0.020 11390 0.700 0.040 Elgin Spring Orange <0.005 11480 <0.010 0.020 2.56 0.500 <0.010 0.020 Tub Unnamed Hot Spring <0.010 12550 <0.010 <0.010 4.61 0.060 <0.010 <0.020

Water Sources Nickel Nitrate Nitrite Selenium Silver Sulfate Thallium Vanadium Zinc Wilbur Spring Don <0.010 – <0.020 <0.200 <10.000 n.d. <0.005 141 –420 n.d. n.d. White’s 0.070 72.7 – Wilbur Spring Main <0.010 <2.000 <0.500 n.d. <0.005 <0.00002 n.d. <0.100 187 Jones Fountain of <0.010 <0.200 <0.500 0.040 <0.005 109 - 220 <0.00020 <0.002 <0.100 Life <0.005 – <0.200 – Blanck Spring <10.000 n.d. <0.010 292 - 506 n.d. n.d. <0.050 0.030 5.96 <0.005 – 56.6 - <0.010 – Elbow Spring <0.200 <10.000 <0.001 <0.010 n.d. n.d. 0.060 455 0.070 Elgin Spring Main <0.010 <0.200 <1.000 n.d. <0.010 104 - 221 n.d. n.d. <0.050 Elgin Spring Orange <0.010 <0.200 <0.200 n.d. <0.005 262 n.d. n.d. 0.050 Tub Unnamed Hot Spring <0.010 <0.200 <0.200 n.d. <0.005 194 n.d. n.d. <0.050

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GLOSSARY OF TERMS

A abandoned mine any excavation, under the surface of the earth, formerly used to extract metallic ores, coal, or other minerals abandoned mine lands areas adjacent to or affected by abandoned mines, often containing materials that contaminate the surrounding watershed and its associated ecosystem acre-foot the amount of water to cover one acre to a depth of one foot, equivalent to 43,560 cubic feet or 325,851 gallons of water adaptive management a structured, iterative process for decision making about land and resource management in the face of uncertainty, aiming to reduce uncertainty and improve decision making through environmental monitoring and scientific investigation adit a nearly horizontal passage from the surface into a mine alkaline referring to water that contains dissolved ions of an alkali metal (lithium, sodium, potassium) that give the water a pH value greater than 7 and where the concentration of hydrogen ions from water is correspondingly low alluvial fan a fan-shaped accumulation of sediment deposited by water at the mouth of a ravine or at the juncture of a tributary stream with the main stream amenity a thing or circumstance that makes life easier or more pleasant anaerobic living, active, occurring, or existing in the absence of molecular oxygen (O2) anthropogenic originating as the result of human activities aquatic vegetation plants that have adapted to living in or on aquatic environments artesian referring to water held belowground in rock formations that subsequently rises to the surface under pressure asbestos a naturally occurring magnesium silicate mineral with fibrous crystals that cause risks to human health when the fibers lodge in people’s lungs aspect the geographic direction toward which a slope faces

B background naturally occurring in the environment, independent of any human cause

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BEAR CREEK WATERSHED ASSESSMENT bankfull water volume the amount of water that fills a stream up to the height of its banks, the maximum amount of water before flooding occurs basalt a dense dark gray, fine-grained igneous rock formed from lava and composed chiefly of feldspar and silica compounds rich in iron and magnesium, forming rounded pillow-like rocks as lava cools on the ocean floor bedrock unweathered rock lying beneath surface soil bench a level shelf of land with steep slopes above and below it, a terrace benchmark a standard by which something can be measured or judged beneficial use one of 20 uses of water that comprise the basis for establishing water quality objectives in California benthic relating to the bed (e.g., streambed) of a body of water benthos the assemblage of organisms living at the bottom of a body of water biological diversity (biodiversity) the variety and variability among living organisms and the ecosystems where they occur biological integrity the joint capacity of all species at a site, both above and below ground or in water, to support ecological processes within the normal range of variability expected for the site, to resist damages to this capacity, and to recover the capacity when damages to ecological processes occur biomass the weight of living or dead biological organisms in a given area or ecosystem at a given time breccia a rock composed of smaller angular rock and mineral fragments held within a matrix of clay and sand that cement the mixture together brome a grass species in the genus Bromus, several of which are major weed species brownfield abandoned or underused industrial or commercial land that is available for another land use browse parts of shrubs and trees eaten by animals

CALFED Bay-Delta Program a cooperative effort of more than 20 State of California and federal agencies to improve the quality and reliability of California's water supplies and restore the San Francisco Bay-Delta ecosystem carbon emissions gases and particulate matter containing carbon that originate from both natural (e.g., wildfires) and man-made (e.g., automobiles) sources and are released to the atmosphere carbon sequestration the process of collecting and storing carbon dioxide or other forms of carbon for the long term to offset adverse effects from global warming

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2- carbonate an ion consisting of carbon and oxygen, with the chemical formula CO3 , that combines with calcium to form limestone carnivore a flesh-eating animal chalcedony a form of quartz that is nearly transparent or has a milky appearance chamise a shrub in the rose family that is a major component of chaparral vegetation in California (scientific name: Adenostoma fasciculatum) channel incision a cut into a stream bank caused from water eroding exposed soil chaparral shrubland vegetation with thick stiff leaves and branches, found in southwestern Oregon, California, and Baja California where the climate has mild wet winters and dry hot summers chemical element one of the more than 100 known substances that cannot be separated into simpler substances and that singly or in combination constitute all matter chert a fine-grained, dense sedimentary rock with very small crystals formed in ancient ocean sediments climate change statistically significant change in measurements of either the mean state or variability of the temperature, precipation, wind, etc., for a particular place, region, or planet cold spring a source of water from inside the earth that is not heated by the earth’s core confluence the place where two rivers merge and flow together connate water seawater trapped in sedimentary rocks as they formed under pressure from sediments deposited on the ocean floor conservation easement a legal agreement between a landowner and a conservation organization or a government agency that limits permanently or for a specified time the land uses on a property so that the values of the property for wildlife habitat, biological diversity, watershed protection, etc., are sustained consumptive resource a natural resource that people physically alter to meet their needs; the resource may be renewable (food) or non-renewable (petroleum), depending on whether the total supply of the resource can increase sustainably contaminant a substance not naturally present in the environment or present in unnatural concentrations that can, in sufficient concentration, adversely alter an environment and cause harm to organisms, including people creek mile the length in miles that a creek runs, taking into account the turns and curves in the streambed criteria pollutant one of a group of air and water contaminants regulated by the US EPA under the Clean Air Act and the Clean Water Act on account of scientific information about adverse impacts from the contaminant on human health and the natural environment crosswalk a table that combines two datasets to develop more information crust the solid outer layer of the earth

351

BEAR CREEK WATERSHED ASSESSMENT cultural heritage the legacy of physical artifacts and intangible attributes of a group or society that are inherited from past generations, maintained in the present, and bestowed for the benefit of future generations

D debris dam a barrier caused by a landslide after an earthquake; floating woody debris and rock material that accumulates across a river channel debris flow a landslide of unconsolidated, water-saturated debris, often appearing like flowing concrete and including boulders and occasionally a large amount of logs or tree stumps defoliator an insect or other organism that strips the leaves from plants deformation (rock) a change in the shape or size of an object due to an applied force from tension, compression, shear, or twisting delineation the process of determining the outline of a natural feature such as a rock formation, body of water, or habitat of a species of interest dendritic characterized by having a branched structure, treelike detritivore an organism that feeds on and breaks down dead plant or animal matter, thereby returning essential nutrients to the food cycle of an ecosystem devegetated characterized by the absence of plants drought a lack of water, particularly in the soil when the rate of evapotranspiration from plants and the soil exceeds the replenishment of water from rainfall, groundwater or irrigation

E ecosystem a recognizable, relatively homogeneous unit of the earth that includes organisms, their environment, and all the interactions among organisms and between organisms and their environment ecosystem service a natural process in the environment that enhances human life and maintains the quality and quantity of goods and services produced by land uses

El Niño a warm ocean current that flows along the equator from the International Date Line to the coast of Ecuador at Christmas time, leading to heavier than normal rainfall in California during the winter endemic being unique to a particular geographic location or habitat, being found nowhere else equestrian related to riding on horseback eradication elimination, complete destruction erosion removal of soil, sediment, or rock by wearing down or grinding through the force of wind or water

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BEAR CREEK WATERSHED ASSESSMENT evapotranspiration the sum of the movement of water to the atmosphere from the soil, wet surfaces on vegetation, and bodies of water (evaporation) AND the loss of water as vapor by plants through small openings (stomata) in their leaves

F fecal coliform bacteria bacteria present in the digestive tract of mammals and birds that are transmitted to water through defecation – these bacteria serve as indicators of the presence of harmful disease-causing bacteria fire line a gap in vegetation with exposed soil or rock that acts as a barrier to halt or slow the progress of a wildfire fissure a long narrow opening or depression in a surface, a crevice flood plain capacity the ability of a flood plain to slow the force of water during high flows and reduce rate of soil erosion and volume of sediment transported off site fluvial relating to or happening in a river, referring especially to the processes of the erosion, transport, and sediment deposition and to the resulting land forms created by these processes foothill a larger hill at the base of a mountain range forb a non-woody flowering plant that is not a grass species friable crumbly, easily broken into small fragments or reduced to powder fugitive dust small particles of soil suspended in the air by wind action or human activities (farming operations, motor vehicles, etc.)

G genetic stock a variety of a species possessing a specific set of genes that provide the organisms of that variety with identifiable traits geochemistry the science of chemistry applied to rocks and minerals geohazard features in the rocks and geological faults of a region that have the potential to create to uncontrollable risk and damage, for example an earthquake or landslide geologic water water formed from chemical reactions in rocks and subsequently embedded in rocks for thousands or even millions of years geologic fault a crack in the earth's crust resulting from the displacement of one side with respect to the other, often resulting in sudden movements of great force such as earthquakes geomorphology the branch of geology that studies the characteristics, shapes, and evolution of rocks and land forms

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BEAR CREEK WATERSHED ASSESSMENT geothermal of or relating to the heat in the interior of the earth geothermometer a thermometer designed to measure temperatures in deep-sea deposits or in bore holes deep below the surface of the earth geyser a hot spring characterized by intermittent discharge of water ejected turbulently and accompanied by steam greenhouse gas a gas in the atmosphere that absorbs and emits radiation within the thermal infrared range, contributing to global warming because it reduces the loss of heat into space ground water water that collects or flows belowground, filling porous spaces in soil, sediment, and rocks, often supplying aquifers, springs, and wells groundwater recharge the downward and sideway flow of surface water that increases the amount of water stored underground gully a narrow channel cut by water running down a slope

H habitat the specific area or environment in which a particular type of species lives and which provides all the basic requirements for survival of that species habitat fragmentation the breakup of natural environments into smaller, often more isolated sections haploxert a soil generally with >30% clay content in the fine-grained fraction of a soil to a depth of >50 cm, or < 50 cm if the bedrock is closer than 50 cm to the soil surface, with seasonally wet soils, and with cracks developing in the soil surface > 5 mm wide and >25 cm deep for >60 days during the three months after the summer solstice hazardous waste (HAZMAT) material that poses a threat to public health or the natural environment headcut a knick point in a streambed where a steep drop in bed elevation causes water to build up force and erode soil above the nick point, gradually resulting in a lower channel and a lowered water table heavy metal one of a group of chemical elements, including mercury and arsenic, that can produce toxic effects on organisms herbaceous referring to a plant that is not woody, i.e., lacking lignin herbicide a chemical that kills plants or inhibits their growth and reproduction hierarchical characterized by multiple levels or layers in a specific order hydric soil a soil that formed under conditions of saturation, flooding or ponding, often poorly drained and having a water table at ground level during the growing season hydrocarbon an organic compound (e.g., methane) that contains only carbon and hydrogen, often used as a source of energy

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BEAR CREEK WATERSHED ASSESSMENT hydrography the science of measuring, describing, and mapping surface waters hydrologic basin a landscape area characterized by all runoff being conveyed to the same outlet hydrologic function the capacity of a watershed to capture, store, and safely release water from rainfall and to resist and recover from disturbances that diminish this capacity hydrologic unit a geographic area representing part or all of a surface drainage basin as delineated on State Hydrologic Unit Maps; each hydrologic unit is identified by an eight-digit number hydrology the branch of geology that studies water on the earth and in the atmosphere, including its distribution, uses, and conservation hydrothermal relating to hot water, particularly coming from below the earth’s crust hydrothermal alteration a chemical change in rocks and minerals caused by super-heated water dissolving metals in rocks and creating fluids that transport and precipitate metals into mineral deposits at concentrations that are often important for commercial extraction hypothesis an unverified proposal that intends to explain certain facts or observations

I igneous produced under conditions involving intense heat such as fire or cooling magma impaired water a water body that does not meet water quality standards established by the federal government or the State of California because of the presence of contaminants impermeable preventing to pass or diffuse through infrastructure the basic physical elements of human-made services, including roads, energy utilities, water, sewage, and telecommunications, considered essential for human productivity and well-being intermittent stream a watercourse that flows in a well-defined channel only in direct response to a precipitation event or seasonal flow from a spring inversion an abnormal condition occurring when air temperature increases with height, often leading to air pollution when pollutant chemicals build up their concentrations in the colder air close to the ground and cannot disperse invertebrate an animal lacking a spine or an internal skeleton ion a particle of one or more atoms that has an electrical charge (positive or negative) because one or more of the atoms have lost (positive charge) or gained (negative charge) one or more electrons

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L langley a unit of solar radiation equal to one gram-calorie per square centimeter. A gram-calorie is the amount of heat required to raise the temperature of one gram of water one degree Celsius. lithic consisting of or relating to stone or rock longitudinal section a diagram of the lengthwise shape of a stream

M mafic referring to a silicate mineral or rock that has high content of magnesium and iron, e.g. basalt magma molten rock in the mantle below the earth’s crust mass wasting a geomorphic process of rock or soil sliding downslope under the force of gravity material culture the collection of physical objects or artifacts used by a society maximum contaminant load the largest concentration permitted in the State of California for a pollutant in water mechanized trail a recreation pathway that permits foot traffic and vehicles that travel only under the power of the vehicle rider (e.g., a mountain bike)

Mediterranean climate a climate characterized by moist, mild winters and hot, dry summers mélange a large-scale mass of rocks characterized by discontinuous layers and rock fragments of all sizes appearing as a complex jumble metamorphosed changed in form or nature, referring to rock that pressure and heat have altered metasedimentary referring to rock created from ocean sediments that transformed physically or chemically under pressure or heat metavolcanic referring to rock created from magma that pressure or heat later transformed physically or chemically meteoric water water on the surface, in the ground, and in the atmosphere that originates from rainfall methylation the chemical process of attaching or substituting a methyl group (-CH3) in a molecule, e.g., when an atom of mercury bonds chemically to a methyl group

+ methylmercury an ion containing carbon in a methyl group plus mercury (CH3Hg ) that is readily absorbed into organisms and is highly toxic metropolitan statistical area a geographic area with a significant core urban population, along with other smaller adjacent communities that are economically and socially integrated with the core population

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BEAR CREEK WATERSHED ASSESSMENT microclimate localized climate conditions, e.g., in a valley or under a forest canopy micropolitan statistical area an area with an urban core that contains between 10,000 and 49,999 residents mine complex a group of mines located close together and treated as a single unit when remediation for abandoned mines is planned or underway mine waste the rock removed to get to the valued ore deposits at a mine site molar referring the percent of molecules or atoms of a particular gas in a volume containing different gases mollusk an invertebrate having a soft unsegmented body, often enclosed by a shell motorized trail a recreation pathway that permits foot traffic, vehicles that travel only under the power of the vehicle rider (e.g., a mountain bike), and vehicles powered by motors (e.g., a 4-wheel drive automobile)

N natural disturbance a naturally occurring event that alters ecosystem processes temporarily or permanently (e.g., flood, hurricane, earthquake, fire) neotropical referring to tropical areas in the Americas nephelometric turbidity a quantitative measure of suspended sediment and dissolved particles in water using the extent to which light passing through the water is deflected (or “scattered”) non-consumptive resource a natural resource that people do not alter in their response to or interaction with it, e.g., a recreation experience or a landscape vista non-governmental organization a legally chartered non-profit group created by people or corporations and not associated with any government non-renewable energy energy from a finite source that cannot be replenished

O ophiolite a sequence of igneous rocks in the earth’s crust or upper mantle, characterized by ultramafic rocks at the base and, in ascending order, gabbro, basalt, and an overlay of deep-sea sediments organic matter residues of dead organisms in a state of decomposition overland flow the movement of water downslope across a land surface, also known as surface runoff overthrust a rock layer pushed up by pressure until one side of the layer folds over onto the other side, resulting in younger rock layers being situated above older rock layers

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BEAR CREEK WATERSHED ASSESSMENT ozone a colorless gas consisting of three oxygen atoms, occurring as a pollutant at ground level but acting as a shield against solar energy in the upper atmosphere

P parent rock the mineral material from which a soil has formed particulate matter tiny amounts of solids or liquids suspended in a solid, liquid, or gas pathogen any organism, such as a bacterium or virus, that causes disease percolate to leach, spread gradually peridotite an ultramafic rock composed principally of the iron-magnesium silicate olivine and with a silica content of less than 40 percent petrofacies one or more attributes of a rock type based on its composition and structure pH a measure of the acidity of a solution given as the logarithm of the reciprocal of the hydrogen-ion concentration in a solution photosynthesis the process by which plants and other organisms produce carbohydrates and oxygen from carbon dioxide, water, and light energy in their cells plagioclase a feldspar mineral consisting of silicon, aluminum, calcium, and sodium and originating in magma plant alliance vegetation with one or more diagnostic dominant species found on sites with similar climate, soils, moisture, and disturbance regimes ponding standing water in closed depressions on the ground surface where percolation into the soil is the only source for outflow potentially responsible party a possible polluter who may eventually be liable for the costs of response actions to clean up a contaminated site public trust the responsibility that the public places with government to care for its interests; the responsibility of the government to preserve resources for public use

R raptor a bird of prey; a bird that hunts and kills other animals recruitment the process of propagating new plants naturally at a site redox potential a measure in volts of the ability of a chemical to acquire electrons, a higher value indicating a greater affinity for electrons

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BEAR CREEK WATERSHED ASSESSMENT regeneration the process of reestablishing vegetation at a site after a disturbance on site regulatory agency a public authority responsible for overseeing the status of a natural resource and empowered with the ability to permit or deny an action that affects the natural resource remediation the process of cleaning up toxic or hazardous materials from disturbed sites such as abandoned mines renewable energy energy generated from natural resources such as sunlight, wind, tides, and geothermal heat that are capable of replenishing themselves naturally resilience the ability of an ecosystem to function intact despite disturbances AND to return to its previous condition after excessive disturbances alters the structure and function of the ecosystem restoration the process of recovering ecological processes and species components to a site after a disturbance retort a closed chamber or vessel with an outlet tube retort furnace a vertical furnace fitted with a cylindrical metal retort into which cinnabar ore is placed and heated to extract mercury from cinnabar decomposition riparian of or referring to the bank of a stream or river rodenticide chemicals intended to kill rodent pests runoff the part of precipitation that travels overland to reach surface streams or other water bodies

S saline having a high content of salts salt an ionic compound produced from the reaction of an acid with a base, the most common being sodium chloride or table salt savanna a grassland characterized by widely spaced trees and a discontinuous tree canopy cover sediment particulate matter that is transported by a fluid, wind, or ice and eventually deposited sedimentary referring to rocks formed by the deposition and subsequent compression of small mineral particles seep a fracture in rock through which a liquid such as groundwater or petroleum discharges intermittently serpentinite rock containing ultramafic minerals transformed by the addition of water and the application of pressure or heat sinuosity a measure of the deviation of a stream course from the shortest possible distance between two points in the stream course; a bending or curving shape to a stream

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BEAR CREEK WATERSHED ASSESSMENT slate a fine-grained rock formed from the metamorphosis of clay or shale that splits into thin, smooth- surfaced layers soil moisture deficit the difference in moisture between the maximum amount of water that a soil can hold and the amount of moisture in the soil at a given time, specifically in the rooting zone of plants soil series the basic unit of soil classification used by the USDA National Cooperative Soil Survey consisting of soils originating from similar parent rock and sharing chemical and physical properties soil stability the capacity of a site to limit redistribution and loss of soil and its resources such as mineral nutrients and organic matter due to erosion by wind or water solar radiation the total spectrum of electromagnetic energy (including sunlight) given off by the sun solute a chemical substance uniformly mixed into another chemical substance and usually splitting apart to form ions stagnation lack of movement in air layers so that pollutants from fires, industrial emissions, or motor vehicles accumulate stakeholder an individual or group with an interest in delivering solutions to issues and sustaining the ecological services and economic production of a watershed for common goals stewardship the careful and responsible management of something entrusted to one’s care stomata pores on the surface of leaves that allows for the exchanges of gases, including water vapor, between plants and the atmosphere; a single pore is called a stoma stream channel a streambed and its banks stream morphology the pattern and shapes of a stream channel and the changes to the channel over time as affected by sediment erosion, transport, and deposition stewardship the careful and responsible management of something entrusted to one’s care strike-slip fault one rock formation slips past one another subduct to move under another plate in the earth’s crust, often down into the earth’s mantle to become molten subsistence hunting or gathering of wild foods or other natural resources for personal or family use substrate a surface on which an organism grows or is attached subwatershed a division of a watershed that defines the drainage area of a tributary to the main stream of the watershed swale a natural or man-made low-lying area that holds water during and after storms and permits the water to infiltrate the soil

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T tailings crushed rock left from processing ore deposits at a mine site talus a mass of loose rocks at the base of a steep slope or cliff tectonic plate a part of the earth’s crust that shifts against or away from another plate and at whose boundaries earthquakes, volcanic eruptions, trench formation, and mountain building occur tectonics movement and deformation of the earth’s crust terracette a small step-like terrain feature developed on the surface of a slumped soil mass along a steep, often grassy, hillside thermal spring see hot spring thrust fault one rock layer pushes up and over another layer in a different rock formation topography the configuration of the earth’s surface features total daily maximum load a calculation of the maximum amount of a pollutant that a stream or other water body can receive and still safely meet the water quality standards established by a governmental water management agency total mercury the sum of molecular mercury, mercury in chemical compounds, and mercury in ionic forms found in a defined volume of soil, water, or air transpire to exude water vapor through plant stomata tributary a stream that flows into a larger stream trophic pertaining to nutrition for a species; describing the relationships among organisms in a food web tuff rock composed of compacted volcanic ash

U ultramafic referring to igneous rocks and derived soils with a very low silica content (<45 percent) and a high iron and magnesium (“mafic”) content ultramafic barren an ultramafic rock outcrop with limited soil formation, low fertility, and scant vegetation; also known as serpentine barren upland land at a higher elevation outside a flood plain

V vegetation alliance see plant alliance

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BEAR CREEK WATERSHED ASSESSMENT vertebrate an animal that has a backbone or spinal column volatile organic compound a chemical compound that contains carbon and vaporizes at ambient temperature volcanic field a region of the earth’s crust characterized by numerous active volcanoes volcanic rock igneous rock form from cooling lava on or near the earth’s surface

W water quality the physical, chemical, and biological features of a water body water table depth in the soil below which the ground is saturated with water watershed an area, usually bounded on its sides by a natural divide such as a hill, ridge, or mountain, from which water drains ultimately to a single channel or river weathered altered in color, texture, chemical composition, or form from exposure to the weather, usually over a long time wetland habitat where the presence of surface water or groundwater has resulted in the development of plant or animal communities adapted to aquatic or intermittently wet conditions

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