DRAFT Sonoma Creek Watershed Enhancement Plan

Home , Napa Sonoma Marsh, Sacramento splittail, Sonoma Creek, Syncaris pacifica, Tolay Creek

An owner’s manual for the residents & landowners of the Sonoma Creek Watershed.

Prepared by: The Sonoma Resource Conservation District

in conjunction with the people

of the Sonoma Creek Watershed

and collaboration with the

Sonoma Ecology Center.

TABLE OF CONTENTS

ACRONYMS ...... 6 ACKNOWLEDGEMENT ...... 8 SECTION 1. INTRODUCTION AND BACKGROUND...... 9

CHAPTER 1: INTRODUCTION ...... 10

PURPOSE OF THE SONOMA CREEK WATERSHED ENHANCEMENT PLAN...... 10

PROCESS FOR DEVELOPING THE PLAN ...... 10

STAKEHOLDER GROUPS ...... 11

ORGANIZATION OF THE PLAN ...... 14

WATERSHED GOALS ...... 15 CHAPTER 2: WATERSHED DESCRIPTION AND HISTORY ...... 18

WATERSHED BOUNDARY OVERVIEW ...... 18

CLIMATE ...... 18

GEOLOGY AND SOILS ...... 19 Geologic History...... 19

Watershed Geology ...... 19

WATER RESOURCES ...... 20 Hydrology ...... 20

Surface Water Resources ...... 21

Groundwater Resources ...... 21

HABITAT TYPOLOGY AND NATURAL RESOURCES ...... 22 Oak-Dominated Forest, Woodland, and Savannah ...... 22

Chaparral ...... 23

Coniferous Forest and Redwood Grove ...... 23

Grasslands ...... 23

Wetlands and Riparian Areas...... 23

Special Status Plant Species ...... 24

Invasive Plant Species ...... 26

FISH AND WILDLIFE ...... 27 Special Status Species ...... 27

Salmonid Fish: Steelhead Trout and Chinook Salmon ...... 28

REGIONAL HISTORY AND CULTURAL RESOURCES ...... 29 Land Use ...... 31

Historic Timeline ...... 31

Summary Timeline of Changes: ...... 33

CURRENT LAND USE ...... 33

AGRICULTURE ...... 33 Developed Areas ...... 34

Unincorporated Lands ...... 35

City of Sonoma Area ...... 35

PARKS AND OPEN SPACE ...... 36

FUTURE LAND USE ...... 36 Land Use Buildout Projections ...... 37

Urban Service Boundaries ...... 38

DEMOGRAPHICS AND ECONOMICS ...... 38 SECTION 2. MANAGEMENT AND RECOMMENDATIONS ...... 40 CHAPTER 3. AGRICULTURAL AND RURAL SUSTAINABILITY ...... 41

AGRICULTURAL SUSTAINABILITY ...... 41

AGRICULTURAL BENEFICIAL MANAGEMENT PRACTICES ...... 42

AGRICULTURAL REGULATIONS ...... 42

RURAL BENEFICIAL MANAGEMENT PRACTICES ...... 46

CHAPTER 4. CLIMATE CHANGE IMPACTS AND ADAPATION ...... 48

CLIMATE CHANGE IMPACTS IN CALIFORNIA ...... 48

IMPACTS TO BIODIVERSITY AND HABITAT ...... 49

FLOODS AND SEA LEVEL RISE ...... 49

HEAT AND FIRE ...... 49

AGRICULTURE AND LOCAL ECONOMY ...... 50

SONOMA COUNTY CLIMATE INITIATIVES ...... 51

CHAPTER 5. WATER QUANTITY ...... 53

WATER DEMAND ...... 53

IMPORTED WATER ...... 53

SURFACE WATER ...... 54 GROUNDWATER...... 54

RECYCLED WATER ...... 55

FACTORS IMPACTING WATER QUANTITY ...... 55

RECOMMENDED ACTIONS ...... 56

CHAPTER 6. FLOODING ...... 58

HISTORIC AND CURRENT CONDITIONS ...... 58 Lower Sonoma Creek ...... 58

Upper Sonoma Creek...... 60

FLOOD MANAGEMENT AND ECOSYSTEM ENHANCEMENT OPPORTUTNITES ...... 60

CHAPTER 7. WATER QUALITY ...... 63

BENEFICIAL USES ...... 63 Total Maximum Daily Loads ...... 63

SEDIMENT ...... 65 Water Quality Standards ...... 65

Available Data ...... 66

Pollutant Sources ...... 66

Agriculture (livestock and cropland) ...... 68

Urban/Suburban Runoff ...... 68

Road Erosion ...... 69

Streambed and Bank Erosion ...... 69

PATHOGENS AND NUTRIENTS ...... 70

Water Quality Standards ...... 70

Available Data ...... 71

Pollutant Sources ...... 71

Agriculture (grazing land & other animal facilities) ...... 73

Urban/Suburban Runoff ...... 73

On-site sewage disposal systems ...... 73

Sanitary sewer systems & Sanitation district discharges ...... 74

PESTICIDES ...... 74

RECOMMENDED ACTIONS ...... 74 CHAPTER 8. SEDIMENT SOURCES AND IMPACTS ...... 76

EROSION PROCESSES AND CONCERNS ...... 76

SEDIMENT WATER QUALITY IMPAIRMENT AND TMDL ...... 77 Channel Incision...... 78

Surface Erosion, Gully Erosion, and Colluvial Erosion ...... 78

Landslides ...... 79

Roads ...... 80

RECOMMENDED ACTIONS ...... 83

CHAPTER 9. MARSHLANDS ...... 85

MARSHLAND DESCRIPTION AND HISTORY ...... 85

SPECIAL STATUS SPECIES ...... 86 California clapper rail ...... 87

Salt marsh harvest mouse ...... 88

RECOVERY PLANS ...... 88 Ecosystem Level Recovery Strategies...... 89

RECOMMENDED ACTIONS ...... 91 CHAPTER 10. RIPARIAN HABITAT AND SPECIES ...... 92

FOCAL SPECIES OF SONOMA CREEK WATERSHED ...... 92

INSTREAM HABITAT ...... 96

FISH PASSAGE ...... 97

RIPARIAN HABITAT ...... 97

RECOMMENDED ACTIONS ...... 99 SECTION 3. IMPLEMENTATION ...... 100 CHAPTER 11. PLAN IMPLEMENTATION ...... 101 REFERENCES ...... 108

ACRONYMS

ACOE United States Army Corps of Engineers (Corps) BCDC San Francisco Bay Conservation and Development Commission CDFW California Department of Fish and Wildlife (formerly known as CDFG: CA Department of Fish and Game) CAL FIRE California Department of Forestry and Fire Protection CCAP Community Climate Action Plan CEMAR Center for Ecosystem Management and Restoration CESA California Endangered Species Act CNDDB California Natural Diversity Database CNPS California Native Plant Society CPC Climate Protection Campaign Dbh Diameter at breast height DOC California Department of Conservation DWR California Department of Water Resources ESA Endangered Species Act FSA Farm Service Agency (USDA) GHG Greenhouse Gas emissions GIS Geographic Information Systems GMP Groundwater Management Plan LWD Large woody debris LWM Large wood material NBAA North Bay Agricultural Alliance NEPA National Environmental Policy Act NMFS National Marines Fisheries Service NOAA National Oceanic and Atmospheric Administration NRCS Natural Resources Conservation Service RCPA Regional Climate Protection Authority RWQCB Regional Water Quality Control Board SAC Stakeholder Advisory Committee SCTA Sonoma County Transportation Authority

SCWA Sonoma County Water Agency SDC Sonoma Developmental Center SEC Sonoma Ecology Center SRCD Sonoma Resource Conservation District SSC Species of Special Concern SVVGA Sonoma Valley Vintners and Growers Alliance SWRCB State Water Resources Control Board TMDL Total Maximum Daily Load TU Trout Unlimited UCCE University of California Co-operative Extension USDA United States Department of Agriculture

USEPA (EPA) US Environmental Protection Agency USFS United States Forest Service VHA viable habitat available

VOMWD Valley of the Moon Water District

ACKNOWLEDGEMENT Sonoma Resource Conservation District (RCD) gratefully acknowledges the dedication and hard work of RCD staff members and stakeholders who contributed towards the completion of the Sonoma Creek Watershed Enhancement Plan. As part of updating this watershed management plan, the Sonoma Ecology Center (SEC), Sonoma County Water Agency, Natural Resources Conservation Services, San Francisco Estuary Institute, Sonoma Valley Vintners and Growers, Sonoma County Winegrape Commission, California Department of Fish and Wildlife, and several Sonoma Creek landowners have contributed information and guidance. This process is critical to develop watershed goals that are desired and achievable by the community for the continued management of natural, cultural, and economic resources.

The RCD also acknowledges the contributions of the following funders, without which the development of this plan would not have been possible:

Sonoma County Water Agency California State Water Resources Control Board

Contributing Authors

Sonoma RCD Kara Heckert, Executive Director Valerie Minton, Program Director Christine Kuehn, Project Assistant Andy Casarez, Senior Project Manager Francesca Innocenti, Biologist

Sonoma Ecology Center Becca Lawton, Research Director, Geologist Caitlin Cornwall, Grants Director, Biologist

Consultants Vicki Hill

Funding for this project has been provided in full or in part through an agreement with the State Water Resources Control Board. The contents of this document do not necessarily reflect the views and policies of the State Water Resources Control Board, nor does mention of trade names or commercial products constitute endorsement or recommendation for use.

Sonoma Creek Watershed Enhancement Plan

SECTION 1. INTRODUCTION AND BACKGROUND

Sonoma Resource Conservation District

June 2013

CHAPTER 1: INTRODUCTION

PURPOSE OF THE SONOMA CREEK WATERSHED ENHANCEMENT PLAN

The first Sonoma Creek Watershed Enhancement Plan was developed in 1997 in order to determine how to more effectively manage the watershed. This 2013 Plan updates and replaces the 1997 Plan, with current information on the watershed and new recommendations for watershed management strategies. The Plan addresses the entire Sonoma Creek watershed, which consists of 170 square miles and drains into the San Pablo Bay.

The overall purpose of the Watershed Enhancement Plan is to identify ways in which to protect, conserve, and enhance the watershed. Draft goals were developed by the advisory committee which was composed of landowners, residents, agricultural interests, agency representatives, elected officials and community groups. Plan goals include the following:

A. Maintain long-term, local control of watershed planning and enhancement. Establish integrated watershed management.

B. Conserve and improve the natural resources of the watershed. Protect the quality and quantity of the valley’s water.

C. Maintain streams to maximize beneficial uses.

D. Encourage responsible stewardship of urban, rural residential, agricultural, and park lands.

E. Educate the community about the natural features of the watershed, its people, ecology, and economy.

F. Support diverse agriculture that responsibly manages the landscape and contributes to the valley’s economic vitality.

The objective of this Plan Update is to reflect the latest conditions, goals, and regulatory requirements associated with the watershed, to review natural resource issues concerning residents and to recommend a course of action to maintain and improve those resources. In conducting this update, the Plan reviews existing information, identifies data gaps and recommends additional data collection activities.

Several resource planning documents apply to the Sonoma Creek Watershed, including the Sonoma County and City of Sonoma General Plans, the Basin Plan, TMDL Program and Sonoma Valley Groundwater Management Plan. Most of these other plans are focused on one subject area (e.g., Groundwater Management Plan), but the Watershed Enhancement Plan (WEP) addresses all resources within the watershed. The Plan seeks to provide a comprehensive set of management strategies for multiple benefits in the watershed. As an advisory document, the WEP will be implemented by cooperative efforts among several agencies, not just one individual agency.

PROCESS FOR DEVELOPING THE PLAN

The Sonoma Resource Conservation District (SRCD) and the Sonoma Ecology Center (SEC) provided leadership and organizational support for the development and implementation of the plan. This plan was

developed using EPA recommended process guidelines for watershed planning and implementation. Although the primary focus of EPA watershed planning guidelines is on waters listed as impaired under section 303(d) of the Clean water Act, this plan addresses a multitude of stakeholder concerns and needs (beyond load reductions), and provides an analytic framework to protect and restore watershed resources.

The watershed planning process brought together a stakeholder advisory committee (SAC) in 2008, representing a broad range of interests and skills. The advisory committee was identified, recruited and led by a subcommittee of organizational and technical advisors from the SRCD and SEC. Additional technical advisors for specific issues were identified by the subcommittee and consulted as needed. The SAC met roughly every other month during the initial phase of the update effort in 2008-2010, with the assistance of a facilitator to: identify issues of concern, define the scope of the planning effort, set goals, identify management strategies, and design and implementation strategy. Issues of particular interest identified by the SAC included resource and species protection, flooding, future land uses, water supply and public outreach. The SAC committee guided stakeholders through the process and helped them to articulate their specific goals and priorities.

During the period from 2008-2010, the subcommittee worked on drafting the document and also met on a regular basis to: plan and organize stakeholder meetings, gather and analyze data for watershed characterization, identify additional technical consultants, and work with local political leadership on resource management integration. An initial plan update was drafted during that period, and it included many placeholders indicating additional data needs. Between 2010 and 2012, many efforts within the watershed yielded additional information key to completing a comprehensive watershed plan with actionable recommendations. As such, another phase of updating to the Sonoma Creek Watershed Enhancement Plan progressed between 2012-2013 with contributions from SEC, revising chapters and supplementing with up to date studies regarding water quality and quantity, flooding, sediment, riparian habitat, climate adaptation, and land use change. The plan will be sent to stakeholder groups and landowners interested in providing comment to the drafted plan update prior to completion.

STAKEHOLDER GROUPS Community outreach is an important part of the development and implementation of any watershed management plan. SRCD staff will continue to meet with the landowners and stakeholder groups to receive input on the plan through the second Phase of the planning process in 2013. Below are many of the of the stakeholder groups working on conservation concerns in the Sonoma Creek Watershed. The SRCD understands the need for agencies, watershed groups and landowners to coordinate to meet common watershed goals.

Sonoma Resource Conservation District (SRCD)

Sonoma RCD works with landowners in the watershed to provide technical, educational and financial assistance to interested landowners to protect natural resources and improve the viability of agricultural and rural lands. SRCD has been a stakeholder in the watershed dating back to the 1950s when the RCD worked with landowners on soil erosion and flooding and more recently has been helping landowners

complete rural road upgrades, assess areas for stream enhancement, providing conservation planning assistance on agricultural lands and completing water quality and flow monitoring. In 2011, the RCD was awarded a Watershed Coordinator Grant from the Department of Conservation. This three year grant will support the RCD in project identification, improving water quality, sediment reduction projects, optimizing water usage and conservation, in addition to updating the Sonoma Creek Watershed Enhancement Plan. The RCD also provides conservation planning assistance on vineyards to support compliance on the vineyard waiver. The RCD is an important entity between landowners and agencies to carryout conservation initiatives, monitoring and environmental and agricultural education.

Sonoma Ecology Center (SEC) The SEC is a community-based non-profit organization committed to working toward a condition of sustainable ecological health in Sonoma Valley. Their involvement throughout the watershed has been vital to understanding the regions biodiversity and landscape functions. SEC is a major stakeholder in the Sonoma Creek Watershed. The SEC fulfills its mission through five initiatives that are carried out through restoration projects, biotic and abiotic studies, and education, these initiatives are: community and stewardship, water, biodiversity, energy efficiency, and land. Understanding the relationship between watershed health and economic well-being through time and changes in conditions is one of their primary initiatives. The SEC offers science-based technical capabilities in the areas of fish and aquatic ecology, water quality, riparian and botanic ecology, wildlife, and geomorphology. There research interfaces with larger restoration projects and GIS modeling and data management applications. The Sonoma Valley Watershed Council, a division of the SEC, was organized to protect and enhance riparian ecosystems. They focus efforts on controlling invasive plant species, reintroducing native plant populations for erosion control efforts, and restoring creek integrity, while educating the public on stewardship of the valley’s water resources. The SEC also runs the Sonoma Valley Watershed Conservancy, a coalition of over 500 community members dedicated to the wise stewardship of the watershed. They are dedicated to exclusively the Sonoma Valley Watershed, also known as Sonoma Creek and Tributaries Watershed, using citizen science and on the ground monitoring approaches. The Conservancy promotes a grassroots methodology to watershed management by recruiting and supporting Stream Stewards, whose role is to educate themselves and others in sound watershed management practices, and to initiate and lead community efforts to implement them. California Department of Fish and Wildlife (CDFW) Historically the CDFW had conducted stream surveys in parts of the watershed in 1957. The CDFW is actively engaged in the restorative measures of native salmonid species within the watersheds of Sonoma County. They developed the Coastal Watershed Planning and Assessment Program (CWPAP) that focuses on fishery-based watershed assessments throughout the California Coast. Other plans related to salmonids are the Coho Recovery Plan and the Steelhead Recovery Plan that both aid in the selection of basins for further study. In addition CDFW supports many local entities and stakeholders with funding to carryout vital salmonid habitat recovery and habitat enhancement projects, including environmental education programming in the Sonoma Creek watershed.

Valley of the Moon Water District (VOMWD)

The Valley of the Moon Water District (VMWD) was established in 1962 after the acquisition of the Sonoma Water and Irrigation Company and the Mountain Avenue Water System. Water distribution service dates all the way back to the 1890s in the Glen Ellen region. Its long history of involvement within the Sonoma Valley makes the district an important stakeholder in the watershed. The purpose of the VMWD is to cost-effectively improve the district’s water supply to community members through conservation efforts in order to improve supply for years to come. The VMWD promotes the instillation of water-saving technology in homes and businesses within the watershed to conserve water resources not just during dry periods.

Sonoma County Water Agency (SCWA)

The SCWA oversees and manages water resources throughout the county and play a significant role in caring for the people and the environment through resource and environmental stewardship and technical innovation. They have been involved with many stakeholders and similar community members in the Sonoma Valley to incorporate the public in planning and implementation of watershed projects. In December 2007 the SCWA released the final draft of the Sonoma Valley Groundwater Management Plan for the region. The goal of the Plan was to locally manage, protect and enhance groundwater resources for all beneficial uses, in a sustainable, environmentally sound, economical, and equitable manner for generations to come. The Basin Advisory Panel develops and oversees the implementation of this plan for the Sonoma Valley. Working collaboratively with all panel members who represent groundwater use and associated interests meet to promote a common understanding current and future local water needs, their purpose is to support development of basin management objectives for sustainability.

National Oceanic and Atmospheric Administration’s National Marine Fisheries Service’s (NMFS) The NMFS is responsible for planning the recovery of threatened and endangered salmon in the U.S. The Sonoma Creek watershed is considered an ecological refuge for native aquatic species such as steelhead trout, Chinook salmon, and California freshwater shrimp. The NMFS has listed steelhead trout and chinook salmon as threatened while the U.S. Fish and Wildlife Service listed freshwater shrimp as endangered. Leading recovery planning efforts throughout California, the NMFS works diligently with several partner agencies and organizations to recover salmonid populations to sustainable levels, they have implemented projects throughout Sonoma County.

North Bay Agricultural Alliance (NBAA)

The North Bay Agricultural Alliance is an organization driven by local individuals who represent landowner concerns throughout the Sonoma Creek Watershed and a considerable number of stakeholders in the low-lying land on the shore of the San Pablo Bay. Providing alternative perspectives to issues relate agricultural production, the organization has an established voice concerning areas surrounding Highway 37, the Sonoma Creek Sediment Total Maximum Daily Load (TMDL) assessments, California Water Plans, planning for sea-level rise in the San Pablo Bay and similar restoration, conservation and development projects.

Sonoma Valley Vintners and Growers Alliance (SVVGA)

The Sonoma County Vintners and Growers Alliance (SVVGA) established in 1992 after a merging between the Sonoma Valley Vintners Association and the Sonoma Valley Grape Growers Association, making it a unique and important collaboration of vintners and growers within the watershed. Supported by hundreds of member wineries and growers alike they work together to promote the valley and its rich diverse terrain. The purpose behind the alliance is to protect the central importance of the grape and wine industry to the local economy, while assuring a healthy social and political environments. Through maximizing the quality of grapes and wines produced in the region is a dedication to also maintain the landscape and watershed. Publishing a Wine Grape Grower’s Guide for Hillside Vineyard Planting, in conjunction with the United Winegrowers for Sonoma County, the alliance established a manual of best practices for stewardship of the land and soil management techniques.

Natural Resources Conservation Service (NRCS)

The Natural Resource Conservation Service is the federal agency that distributes Farm Bill funding and helps landowners implement conservation projects on agricultural lands. Resource Conservation Districts work with NRCS to help leverage funding and implement projects throughout the County, State, and Country Through programs such as the Environmental Quality Incentives program (EQIP), NRCS works to promote agricultural production, forest management, and environmental quality as compatible goals. With funding and technical assistance through EQIP, farmers and ranchers can optimize agricultural production while meeting Federal, State, and local environmental regulations.

California Department of Forestry and Fire Protection (CAL FIRE)

Cal Fire is dedicated to the fire protection and stewardship of over 31 million acres of California's privately-owned wildlands. In addition, the Department provides varied emergency services in 36 of the State's 58 counties via contracts with local governments. CAL FIRE's mission emphasizes the management and protection of California's natural resources; a goal that is accomplished through ongoing assessment and study of the State's natural resources and an extensive CAL FIRE Resource Management Program. CAL FIRE oversees enforcement of California's forest practice regulations, which guide timber harvesting on private lands.

The Sonoma County Forest Conservation Working Group

The Sonoma County Forest Conservation Working Group was created seven years ago to help provide information and resources to private forest and woodland owners of small parcels—tools to address the threats with the goal of protecting the health and long-term tenure of forests and oak woodlands. This group is made of an interagency association of Sonoma County Agricultural Preservation and Open Space District, Sonoma Land Trust, CAL FIRE, University of California Cooperative Extension, local land trusts, Sonoma and Gold Ridge RCDs, and Landowners. ORGANIZATION OF THE PLAN The organization of this plan is based upon the US Environmental Protection Agency’s nine elements of an effective watershed management plan, as described in the “Handbook for Developing Watershed Plans

to Restore and Protect Our Waters” (2005). This Plan addresses the following descriptions of the USEPAs nine elements. a) An identification of causes of impairment and pollutant sources. b) An estimate of load reductions expected from management measures. c) A description of the nonpoint source management measures that will be implemented to achieve load reductions. d) An estimate of the amounts of technical and financial assistance needed to implement those management measures. e) An information and education component used to enhance public understanding of the project and to encourage their early and continued participation in selecting, designing, and implementing nonpoint source management measures. f) A schedule for implementing nonpoint source management measures identified in the plan. g) A description of interim measurable milestones for project implementation efforts. h) A set of criteria that can be used to determine whether load reductions are being achieved over time and substantial progress is being made toward attaining water quality standards. i) A monitoring component to evaluate the effectiveness of implementation efforts over time.

WATERSHED GOALS Table 1.1 Watershed goals and associated indicators, potential sources of impact, and management objectives for the Sonoma Creek Watershed Potential Source of Goal Indicator Management Objective Impact Agricultural run-off, lack Need for increased of rainwater Provide technical and pollinator habitat, need Improve the conservation practices, financial assistance to for bank stability to viability, health potential sediment interested landowners to protect ranch roads, and productivity of delivery from erosion implement Best Management riparian vegetation agricultural lands areas, lack of wildlife Practices and habitat management to control habitat and pollinator enhancement projects Pierces disease habitat

Low streamflow Promote Best Management observations and Lack of rain water Practices for water Improve water measurements, storage and ground water conservation and storage conservation and concerns expressed by recharge during critical implement a water reliability landowners about water low flow periods. conservation reliability and storage pilot/demonstration project. during critical periods

Develop a prioritized outreach plan based on Excessive fine Development of geomorphic surveys in sediment in steam: agricultural lands and Sonoma Creek and its buried cobbles, filled in rural residential Decrease primary tributaries and an pools, bank erosion properties, large network anthropogenic aerial photo history of resulting in stream of maintained and sediment inputs landslides and road incision, gullies, and unmaintained roads near into Sonoma development, assess high landslides developing Sonoma Creek, Creek and meet priority areas, produce and on hillslopes adjacent destabilized water quality implement sediment to creek; resulting in streambanks, removal of standards for reduction plans; in addition substandard water riparian vegetation, sediment/siltation stabilize and revegetate quality levels for modified drainage stream corridors, mitigate turbidity and total pathways, and gully erosion from gullies and rural suspended solids erosion roads, investigate and treat significant sediment sources Identify and evaluate septic system performance bringing impaired septic systems up to Septic system failures, appropriate standards of Decrease and Pollutant source sanitary sewer system function; develop a Sanitary monitor pathogen assessments completed failures, municipal Sewer Management Plan; loads associated for Sonoma Creek runoff, livestock grazing, update/amend stormwater with surface water identified it as impaired dairies, wildlife, and management plans; reduction in Sonoma Creek by pathogens per the domestic wastewater measures for runoff related to and associated Total Maximum Daily treatment facility livestock grazing; ensure tributaries Load (TMDL) discharge dairy operation compliance with applicable Waste Discharge Requirements (WDRs) or waiver of WDRs Substandard water quality levels for; High turbidity levels and Stabilize and revegetate temperature and aggradations of stream stream corridors; mitigate turbidity; channels raises water erosion from gullies and rural Support aquatic sedimentation; reaches temperature; sediment roads; conduct stream habitat life and restore with weak benthic loads alter streambed typing; remove fish passage aquatic habitat macroinvertebrate composition; removal of barriers; and increase communities; riparian riparian vegetation; fish instream habitat structure and vegetation deficiency; passage barriers complexity. lack of instream habitat structure; fish barriers

Extent & condition of Assess and wetland plant Map and assess wetland enhance riparian communities; wetland functions and conditions; Streambank and upland habitat and functional assessments; improve agricultural erosion associated flood habitat connectivity; management practices in plains bird species diversity sensitive areas; and richness

Implement watershed-scale approach to manage flood events including a stromwater Weather events detention system in the upper Assess flood zones Historic flooding influencing surface portion of the watershed; and implement events; degraded and/or water resources; tidal acquisition of easements on watershed-scale failed levee systems; effects; lack of proper lands affected by such flood mitigation loss of natural wetland infrastructure to seasonal events; acquisition measures habitat and open space accommodate increased of lands categorized as high water volume risk during current and future flooding periods in order to restore tidal wetland habitat

Spread of Sudden Oak Implement fuel reduction Levels of Sudden Oak Death pathogen; projects, help landowners Death, forests with modification of forest complete forest management even age trees and low Restore and structure and plans, assess areas for Sudden diversity, areas with protect forest composition, erosion, Oak Death and take steps to high fuel and forest fire health upland plant decreased ground water reduce the spread of the threats, levels of oak communities recharge, increased pathogen, encourage oak woodland regeneration forest fires, Doug-fir woodland regeneration and and level of invasive encroachment in oak health, reduce levels of plants woodland forests invasive plants

Prolonged drought Collaborate with events creating water Implement County level Global climate change agencies and shortages, rise in fire climate change plans to and increased stakeholders to frequency, severe reduce greenhouse gas greenhouse gas mitigate for flooding occurrences emissions, create sustainable emissions into the climate change and associated sea communities and agricultural atmosphere impacts on all land level, pressure on practices, protect biodiversity use areas species from disease and habitat and specie invasion

CHAPTER 2: WATERSHED DESCRIPTION AND HISTORY

This chapter describes the physical, climatological and biological features of the watershed, as well as its history and land uses. The chapter is intended to give a broad overview of the watershed, and many of the topics contained herein are discussed with greater detail in subsequent chapters.

WATERSHED BOUNDARY OVERVIEW

The Sonoma Creek watershed is located in southern Sonoma County and covers approximately 170 square miles (60% freshwater and 40% tidally influenced). It is bounded on the east by the Mayacamas Mountains, on the west by the Sonoma Mountains and on the north by a slight rise north of Kenwood that separates it from the Laguna de Santa Rosa watershed. The watershed drains southward and discharges into San Pablo Bay, at the southern end of the watershed. The watershed includes the City of Sonoma and the unincorporated towns (from north to south) of Kenwood, Glen Ellen, Boyes Hot Springs and Schellville. The watershed ranges in elevation from sea level to the peak of Bald Mountain at 2739 feet. (See Map 2.1).

The Sonoma Creek Watershed includes most of the land designated in the Sonoma Valley Planning Area of the Sonoma County 2020 General Plan. However, the northernmost portion of the watershed (north of Sonoma Creek near Kenwood) is not included. The Sonoma Valley Planning Area extends from Bennett Valley and Kenwood south to San Pablo Bay and from the crest of the Sonoma Mountains east to the Sonoma-Napa County line, and encompasses 91,778 acres. Though there are minor geographic differences, the terms “Sonoma Creek Watershed” and “Sonoma Valley” are used interchangeably in this plan.

[Insert Map 2.1: Watershed Overview here]

CLIMATE The Sonoma Creek Watershed has a Mediterranean climate resulting in cool to warm, dry summers and cool moist winters. The prevailing wind directions are southerly, reflecting thermal up-valley winds, in the summer and channeled, southerly winds ahead of approaching storms in the winter. Relatively frequent, light winds are a typical feature of such sheltered inland valleys. The marine influence on climate in the Sonoma Valley is most pronounced in spring and summer when daily sea breezes temper daytime temperatures and sometimes bring nighttime stratus clouds to the area. Summer maximum temperatures average in the mid-80’s with minimum temperatures in the 50’s. Winter maximum temperatures are typically in the 50’s with minimums in the 30’s. Sunshine is plentiful in all seasons.

Mean average precipitation for Sonoma Valley varies from 20 inches in the southern end of the valley to 45 inches in the north and 50 inches on Sonoma Mountain (SSCRCD, 1997). The average length of the growing season is 214 days (Sonoma Valley SCD, 1965).

Precipitation data has been collected at two sites in the Sonoma Creek Watershed, within the city of Sonoma, north of the Sonoma Historical State Park; and the Sonoma Developmental Center, at Fern

Lake. The station in the city of Sonoma has a period of record from 1893 to the present, and the station at the Sonoma Developmental Center (SDC) has a period of record from 1953 to the present.

Average precipitation at the SDC site is 47.03 inches. Average precipitation at the Sonoma site is 31.05 inches. Most of the precipitation falls as rain from October through April (the wet season) of each year. Temperature data has also been recorded at the station in the city of Sonoma since 1893 (Western Regional Climate Center, 2008 and SEC, 2008).

[Insert Map 2.2: Precipitation here]

GEOLOGY AND SOILS Geologic History

Between 8 and 5 million years ago volcanoes began erupting along a line from southern Sonoma County to Mount St. Helens. Vast flows of hot magma extruded from plates deep underground that were subducted and pulled apart along fault lines. This series of earthquakes rumbling along the valleys fault lines helped to lift up the Sonoma and Mayacamas mountains. Lava flows, and red hot ash flows blasted out a series of volcanoes and covered the area from Santa Rosa to Napa County with volcanic rocks. Water has been the principal sculptor of California’s landscape, carving, sculpting and etching Sonoma Valley. As volcanic activity built the modern coast ranges, river erosion wore them down and filled valleys between them with sand and gravel forming the plains of Santa Rosa, Cotati, and Sonoma Valley.

Around 10,000 years ago, at the end of the great ice age (Pleistocene), Sonoma Valley was vastly different. It was the end of the mass extinctions of prehistoric mammals; archeological records suggest we had species such as woolly mammoths and mastodons roaming the valley floors. It is likely that other species that co-existed with them may have also been here such as a type of pre-camel, saber tooth tigers, giant ground sloths, prehistoric horses, giant short faced bears and even the giant Pleistocene beaver, a 300 pound rodent with massive incisors. Vegetation patterns were also significantly different due to the wetter and cooler climate. Samples of fossil pollen indicate the area was heavily forested with conifers. The dominant species were cedars, alders and firs. The area resembled the current state of Alaska today, much greener, wetter and heavily forested. As time wore on there is evidence of the emergence of the more familiar plant communities. About 7000 years ago, Oak woodlands and grassland appeared. Between 7000 and 4000 years ago, expansion of Douglas Fir and Chaparral occurred. The emergence of large tracts of grassland, marshes, estuaries and wetlands occurred about 500 years ago. Historically much of the town of Kenwood in the lower elevations was marshland. Watershed Geology The dominant geology in the watershed is volcanic with the north-south trending ridges of the Sonoma Mountains to the west and the Mayacamas Mountains to the east defining the valley. Geologic units are shown in Map 2.3. As shown, the lower reaches of the watershed are composed of alluvium and alluvial fan. There is a small amount of older Franciscan complex mélange units on the margins of the watershed. (See Section 3.1.4 regarding groundwater bearing geologic units).

Many tributaries in the watershed run at their lower elevations over alluvial fans constructed of materials weathered from the Sonoma Volcanics and re-deposited by water flow. The geologic units of the Sonoma Volcanics are highly variable, with interbedded strata of hard flow rocks and highly erodible re-worked

ash deposits (Blake et al 2002, Wagner pers comm 2002, Collins and Leising 2004). Streambed material ranges in size from sand to boulders and exposed bedrock is common. Where tributaries intersect the Glen Ellen and Petaluma geologic units, formations typically composed of interbedded silts, sands, gravels, and lacustrine deposits, there appears to be a relatively high level of suspended sediment produced (Lawton pers comm., 2003).

Soil types range from clay, in the northern part of the watershed, to Bay mud in the southern section. A small amount of terrace deposits is located in the central portion. See Map 2.4. Volcanic ash mixed with Glen Ellen gravels weathers to give moderate clay content in some areas.

There are several faults in the watershed, in the northwest and southwest areas. One Alquist-Priolo zone is along the southwestern edge of the watershed. Areas of high liquefaction potential are concentrated in the southern area of the watershed near San Pablo Bay. The potential for landslides exists in several areas in the northeastern slopes of the watershed.

Sonoma County faults are part of the San Andreas Fault system which extends along the California coast. All show evidence of movement during the past 2 million years and are considered to be potentially active (Sonoma County GP, 2020).

The last major earthquake in Sonoma County was the 5.7 magnitude event on the Healdsburg fault in Santa Rosa in 1969. Analysis of seismic data indicates that 8.5 and 7.5 magnitude earthquakes can be expected for the San Andreas and the Healdsburg-Rodgers Creek faults respectively. Earthquakes of 8.0 or more on the San Andreas Fault can be expected every 50 to 200 years (Sonoma County GP, 2020). Seismic-related geologic hazards are summarized below, based on data in the Sonoma County GP 2020.

The most common type of ground failure associated with the geology of the watershed is landslides; the downslope movements of soil and/or rock materials. Landslides can be triggered by heavy rainfall, earthquakes or human activities such as road cuts, grading, construction, removal of vegetation, and changes in drainage. The Sonoma County Emergency Services Department completed a Countywide Hazards Mitigation Plan in 2006 (Sonoma County Emergency Services et al, 2006), which establishes guidelines for reducing hazards and preventing damage from seismic activities.

[Insert Map 2.3: Geology and Map 2.4: Soils here]

WATER RESOURCES

This section includes a description of the watershed’s water resources, including hydrology, surface water resources, groundwater, and flood plains. The watershed provides fresh water supply sources for the valley. According to a USGS study (2006), in 2000, 57 percent of the annual water demand was met by groundwater, 36 percent by imported water, and 7 percent from recycled water; local surface water supplies were not quantified in the study.

Hydrology Sonoma Creek drains a watershed area of approximately 100 square miles that discharges into the San Pablo Bay, which lies in the northern portion of the San Francisco Bay, California. In addition another major tributary within Sonoma Valley is Schell Creek emptying approximately 19 square miles of land in

the eastern portion of the watershed, joining Sonoma Creek downstream of tidal influence from the bay. Carneros Creek drains about 7 square miles in the southeastern portion of the valley into the Sonoma- Schell drainages. In total the Sonoma Creek watershed comprised of Sonoma-Schell-Carneros drainages makes up 465 miles of blue-line streams and roughly 40 miles of tidal sloughs (Blake et al., 1992). Tolay Creek in the southwestern area drains about 40 miles of land directly into the San Pablo Bay.

Through time channels, banks, marshes, tributaries, bay lands, and groundwater resources have been altered by human intervention in addition to natural processes influencing watershed hydrology.

[Insert Map 2.5: Watershed Sub-basins here]

Surface Water Resources Surface water resources are defined as natural water that does not penetrate the ground, thus illustrated through lakes, ponds, rivers, wetlands. These resources are significant to the overall health of the ecosystem, and are also greatly influenced by pollutants and seasonal quantity shortages. Beneficial uses of surface waters in the Sonoma Creek system that have been designated by the San Francisco Bay Regional Water Quality Control Board include: Cold and Warm Freshwater Habitat, Fish Migration and Spawning, Preservation of Rare and Endangered Species, Water Contact and Non-contact Recreation, and Wildlife Habitat.

Sonoma Creek has been listed as impaired by sediment, pathogens, and nutrients, according to section 303(d) of the federal Clean Water Act, and Total Maximum Daily Loads (TMDLs) have been completed for the former two listings, while a TMDL for the latter is in pending as of the writing of this plan (2013). The existing TMDLs set pollutant load allocations for land uses such as natural processes, roads, municipal stormwater and wastewater systems, and agriculture, and outline implementation strategies to meet these load allocations, including regulatory permits discussed in subsequent chapters of this plan.

Two United States Geological Survey (USGS) stream flow gauges, located north of Kenwood and west of Agua Caliente, routinely document flows less than 0.1 cubic feet per second (CFS) and 1 cfs, respectively, during the dry season, and flows exceeding 30 cfs and 100 cfs, respectively, during the wet season. Seasonal flows are impacted by factors such as drought, climate change, impervious surfaces within the watershed that cause higher winter flows and lower summer flows, and extraction of surface waters for human use.

Groundwater Resources

Groundwater resources play a significant role in the watershed, providing water for more than half (57%) the annual domestic and agricultural water demand. The Sonoma Valley Groundwater Management Plan (GMP) was prepared in December 2007 (SCWA, 2007), providing a comprehensive overview of the watershed groundwater resources and establishing advisory policies and recommendations for the protection of groundwater. The Plan’s goal is to: “Locally manage, protect, and enhance groundwater resources for all beneficial uses, in a sustainable, environmentally sound, economical and equitable manner for generations to come.”

The largest use of groundwater in the watershed is for agricultural irrigation, followed by rural domestic use and urban demand. Groundwater supplies approximately 25 percent of the Sonoma Valley population

and is the sole source of drinking water for rural domestic and other unincorporated areas not served by urban suppliers. In addition to private wells, there are several mutual water companies in the watershed that supply domestic water to multiple homes with groundwater. Although imported water is a major supply source in the watershed, in dry years local groundwater from the City’s and the Valley of the Moon Municipal Water District’s wells supplements imported water to meet demand. In total, groundwater provided nearly 8,500 acre-feet in 2000, based on land-cover water use estimates (USGS, 2006).

Within the watershed, groundwater in the mountains flows towards lower elevations, following the dips of geologic units toward the valley’s center. The Eastside Fault (see Section 3.1.5, Geology and Soils) may serve as a conduit for the upward circulation of deeper thermal waters in the area and may restrict groundwater flow (USGS, 2006). According to the GMP, all of the Sonoma Valley geologic formations contain groundwater, but the water bearing properties vary among the formations. The most important water bearing formations overly the Franciscan Complex basement rocks acting as a barrier to flow (USGS, 2006). Bay Mud is not considered an aquifer for water supply due to low permeability and high salinity. Groundwater monitoring takes place throughout the watershed and efforts are underway to increase well monitoring, to better understand groundwater levels, flow, and overall supply.

HABITAT TYPOLOGY AND NATURAL RESOURCES

The Sonoma Creek Watershed contains a great diversity of vegetation types. The following sections briefly describe only the most common vegetation types. Of the over 6,000 plant species in California, it is estimated that 20% occur in Sonoma Valley, in about 1% of the state’s area (Dale, 2009). Vegetation diversity drives animal diversity, and Sonoma Valley is home to many wildlife species (see wildlife section below). As of 2005, about 60% of the watershed was covered by natural or near-natural vegetation. Approximately 26% of the watershed was vegetated by closed forest or woodland, 14% by grassland, 7% by chaparral, 10% by seasonal wetland, and 1% by riparian forest (see Map 2.6).

[Insert Map 2.6: Land Cover here]

Oak-Dominated Forest, Woodland, and Savannah

Perhaps the most iconic vegetation type in Sonoma Valley, oak woodlands occur in great variety in the watershed. Shady forests with closed canopies, woodlands casting dappled shade, and oak savannahs with widely spaced trees are all often called oak woodlands. Unusual for forest or woodland types, oak forests and woodlands contain a diversity of co-dominant tree species. Forests where oaks co-exist with several co-dominant non-coniferous tree species are sometimes called mixed hardwood forests. Common tree species in this vegetation type are the deciduous oaks, such as blue oak, valley oak, Oregon oak, and black oak; evergreens, such as coast live oak and bay laurel; and other trees, such as California buckeye and California madrone.

Oaks and their associated habitats support thousands of wildlife species. “There are about 110 species of birds that breed in California's oak woodlands, although only a fraction of these are common. Another 60 or so species use oak woodlands outside the breeding season, either as winter visitors or as migrants. In

addition, 105 mammal species, 58 amphibians and reptiles, and an estimated 5,000 species of insects use oak woodlands.” (Hopkins, date unknown).

In moister areas of oak forest where fire has long been absent, Douglas fir is increasingly in frequency, raising concerns that the oak vegetation type could be displaced.

Chaparral

Chaparral is a shrub-based vegetation type that can be impassably dense. It occurs on hillsides, more extensively on west-facing slopes. Chaparral is highly fire-adapted; when fire is absent for a long period, chaparral may be replaced by woodland or forest. Dominant chaparral species are drought-tolerant, woody shrubs with leathery, stiff leaves that conserve water. Common chaparral species include scrub oak, coyote brush, chamise, buckthorn, ceanothus, toyon, mountain mahogany, and manzanita.

Coniferous Forest and Redwood Grove

Areas of evergreen conifers are relatively small in the Sonoma Creek watershed. These include Douglas fir forest patches, non-native Bishop pine patches, and redwood groves. Douglas fir forest occurs in higher, wetter areas; in many cases, these forests consist mostly of thin, closely spaced trees with little understory, reflecting regrowth after logging. Redwood groves are small, isolated patches in low-lying areas at middle elevations, such as creek confluences, where fog collects due to topography but is also enhanced by the fog-collecting architecture of redwood foliage.

Grasslands

Many types of grassland occur in the watershed, from pastures of mostly non-native annual grasses and herbs, to savannah grasslands extending under oaks, to mid-elevation meadows among forested areas, to hilltop expanses exposed to high winds. Very little acreage remains of Sonoma Valley’s native grasslands. The ecological and hydrological effects of the transformation to largely short-lived, shallow- rooted, non-native grasses are still evolving. Grasslands are the site of many invasive plant species (see next section for examples). Some of the most common non-native grassland species include wild oats, Italian ryegrass and various thistles. Some of the most common native grassland species include blue wild rye, California oatgrass, California fescue, California poppy and various lupine species.

Wetlands and Riparian Areas

Wetlands include areas where surface water pools, where groundwater lies just below surface or damp areas adjacent to ponds, among others. Vernal pools are seasonal wetlands that dry up in summer, but support unique plant and animal species during the spring. Map 2.6 depicts wetlands within the watershed. Most wetland areas are concentrated in the lower reaches of the watershed, although there are small patches of remnant wetland areas in the upper watershed (e.g., Kenwood Slough). Wetlands are important for several reasons. Not only do wetlands support many plant and wildlife species, they provide a source for groundwater recharge.

Many of the historic wetlands in the region have disappeared because of filling, siltation, channelization or other activities. Federal, state, and local regulations now set a high priority on preserving the remaining

resources and carefully managing development that has the potential to adversely affect them. Federal and state management of wetlands and water resources result from a few specific requirements that apply in a wide range of situations. These involve protection of surface and ground water from silt or pollutants, protection of wetland habitat, and preservation of endangered species.

Riparian areas are defined as relating to or inhabiting the banks of a natural course of water. Riparian zones are ecologically diverse and contribute to the health of other aquatic ecosystems by filtering out pollutants and preventing erosion.

Special Status Plant Species

The Sonoma Creek Watershed is home to several special status species, including Sonoma sunshine, Kenwood checkerbloom and Sonoma ceanothus. Special status means that the species classified, under federal or state regulations, as being rare, threatened or endangered. The California Native Plant Society (CNPS) maintains lists of plants to categorize degrees of concern for the survival of these species. The California Endangered Species Act (CESA) also allows listing of species and protection through limits of takes on those species. Species can be listed under either or both of the Endangered Species Act (ESA) of 1973 and CESA, and can have different status on each list. Additionally, the California Department of Fish and Wildlife (CDFW) possess the authority to list Species of Special Concern (SSC). These species are not listed under the ESA or the CESA, but are either declining at a rate that could result in listing, or have historically occurred in low numbers and are known to have current threats to their existence. SSC listing criteria are similar to ESA criteria, and include small, isolated populations, marked population declines, habitat decline, and conversion of land adjacent to limited and specialized habitat. Other criteria include prevalence on historic land, and limited records of recent presence in the state.

These lists include but are not limited to plants that are listed under ESA and CESA. List 1A consists of plants presumed to be extinct in California. List 1B includes plants that are rare, threatened or endangered in California and elsewhere. List 2 consists of plants that are rare, threatened or endangered in California, but more common elsewhere. It is mandatory that species on lists 1A, 1B and 2 be considered during environmental impact analyses prepared in accordance with the California Environmental Quality Act. List 3 is a review list of plants that CNPS wishes to learn more about before categorizing. List 4 is a watch list of plants that have limited distribution which cannot be considered rare, but whose status should be monitored regularly.

Table 2.1lists species that occur in Sonoma Valley that have state or federal legal protections, or that are categorized in CNPS lists 1A, 1B and 2 (California Department of Fish & Wildlife, 2013) collected from the California Natural Diversity Database (CNDDB).

Table 2.1 Sonoma Valley Special Status and Rare Plant Species Species Scientific Name Species Common Federal California Rare Plant Name listing State listing Rank

Blennosperma bakeri Sonoma Sunshine endangered endangered 1B.1

Downingia pusilla dwardf downingia none none 2.2

Legenere limosa legenere none none 1B.1

Amorpha californica Napa false indigo none none 1B.2

Leptosiphon jepsonii Jepson’s leptosiphon none none 1B.2

Creanothus sonomensis Sonoma ceanothus none none 1B.2

Fritillaria liiacea fragrant fritillary none none 1B.2

Layia septentrionalis Colusa layia none none 1B.2

Viburnum ellipticum oval-leaved viburnum none none 2.3

Arctostaphylos Rincon Ridge manzanita none none 1B.1 standfordiana

Trifolium amoenum showy Rancheria clover endangered none 1.B1

Sidalcea oregano ssp. Kenwood Marsh endangered endangered 1B.1 valida checkerbloom

Navarretia leucocephala Baker’s navarretia none none 1B.1 spp. bakeri

Ceanothus purpursus holly-leaved ceanothus none none 1b.2

Ceanothus confusus Rincon Ridge ceanothus none none 1B.1

Ceanothus divergens Calistoga ceanothus none none 1B.2

Ceanothus sonomensis Sonoma ceanothus none none 1B.2

Penstemon newberryi var. Sonoma beardtongue none none 1B.3 sonomensis

Allium peninsulare var. Franciscan onion none none 1B.2 franciscanum

Brodiaea leptandra narrow-anthered brodiaea none none 1B.2

Alopecurus aequalis var. Sonoma alopecurus endangered none 1B.1 sonomensis

Hemizonia congesta ssp. white seaside tarplant none none 1B.2 congesta

Arctostaphylos canescens Sonoma canescent none none 2.3

ssp. sonomensis manzanita

Lupinus sericatus Cobb Mountain lupine none none 1B.2

Horkelia tenuiloba thin-lobed horkelia none none 1B.2

Centromadia parryi ssp. pappose tarplant none None 1B.2 parryi

Trifolium hydrophilum saline clover none none 1B.2

Limnanthes vinculans Sebastopol meadowfoam endangered endangered 1B.1

Chloropyron molle ssp. soft bird’s-beak endangered rare 1B.2 molle

Erigeron greenei Greene’s narrow-leaved none none 1B.2 daisy

Streptanthus hesperidis green jewel-flower none none 1B.2

Astragalus claranus Clara Hunt’s milk-vetch endangered threatened 1B.1

Invasive Plant Species Invasive species are those species that have been introduced, whether brought intentionally or accidentally to an area, which once established can cause much harm to native populations. Invasive species often threaten the diversity and numbers of native species leading to competition for available resources, causing disease, preying on other wildlife, and interbreeding. Species with invasive tendencies can negatively affect the environment as a whole as they create competition in the landscape. Impacts include: overall ecosystem function, affects to agricultural and grazing lands, the delivery of ground and surface water, and flood prevention. The following species occur in Sonoma Valley and are currently listed with a “high” threat rating by the California Invasive Plant Council: barb goatgrass, giant reed (Arundo donax), red brome, spotted knapweed, yellow starthistle, jubatagrass, pampasgrass, Scotch broom, Cape-ivy, German-ivy, purple veldtgrass, water hyacinth, fennel, French broom, English ivy, Algerian ivy, perennial pepperweed, tall whitetop, Uruguay water-primrose, creeping water-primrose, parrotfeather, Eurasian watermilfoil, Scotch thistle, Himalaya blackberry, giant salvinia, red sesbania, scarlet wisteria, smooth cordgrass and hybrids, Atlantic cordgrass, dense-flowered cordgrass, Spanish broom, Medusahead.

Perhaps one of the most pervasive weeds in the watershed is Arundo donax, which is a bamboo-like rapid growing grass that prefers stream banks and other wet areas and is found in large masses in some parts of Sonoma Creek. It attains heights of 25 feet and once established tends to form large, continuous root masses. The plant reproduces vegetatively by spreading outward and from clumps broken off from an adult plant, which can happen in flood events. Both the stems and the underground parts called rhizomes have the ability to propagate.

Arundo was introduced by early Spanish settlers and was used for building materials and as a vegetation barrier (due to its rapid growth). The dense, high growing plant quickly chokes and kills everything in its path, forcing out native plant species that serve as habitat and food sources for wildlife. Because the plant did not evolve in California, the newcomer Arundo has no effective competitors in California stream beds. In addition to these adverse effects, Arundo consumes three times more water than native plants, is a fire hazard, and creates serious flood control problems. Because of the many detrimental effects of the spread of Arundo, it is one of the primary threats to the health of the streams and waterways (SEC, 2009).

FISH AND WILDLIFE

The term wildlife includes all animals—fish, mammals, birds, reptiles, amphibians, insects, etc.—that are not domesticated or tame. The animals populating Sonoma Valley before European settlement were so different from today’s wildlife that the Valley would be nearly unrecognizable to modern eyes. Large herds of elk and pronghorn grazed throughout; numerous grizzly bears competed with people for edible roots and berries; fish were thick in the streams; and a gigantic tidal marsh supported uncountable flocks of waterfowl. Very little is known about pre-European wildlife numbers and ecology. (Malcolm Margolin’s The Ohlone Way compellingly evokes Bay Area wildlife conditions before the 1800’s). Populations of large native wildlife species have decreased dramatically since European settlement. Prominent species that are now locally extinct include grizzlies, tule elk, and pronghorn.

The largest animals that regularly occur in Sonoma Valley are mountain lions and white-tailed deer. Other large species that inhabit the Sonoma Valley include beaver, black bear, gray fox, bobcat, coyote, chinook salmon, steelhead/rainbow trout, Pacific giant salamander, bald eagle, golden eagle, northern spotted owl, and pileated woodpecker. Sonoma Valley has unusual biodiversity in a small area, an estimated 20% of California’s biodiversity in 1/10th of the area of Sonoma County, which in turn is about 10% of California’s land area (Dale, 2009). Another example of the watershed’s diversity is that it is estimated to support about 23% of the 1500 bee species found in California, again within about 1% of the state’s area (LeBuhn, 2007).

Special Status Species The Sonoma Watershed provides habitat for many species that are listed as threatened, endangered, and species of special concern. The Federal Endangered Species Act of 1973 (ESA) authorizes the listing of species as threatened or endangered and provides protection for listed species through laws that limit taking of these species and allow acquisition of land and disbursement of funds for conservation of listed species’ habitats. Species eligible for listing under the ESA exhibit the following criteria: 1) Habitat is under threat of modification or destruction; 2) Species is over utilized for commercial, recreational, scientific, or educational purposes; 3) Species is subject to extreme disease or predation; 4) Existing regulatory mechanisms are inadequate to protect the species; or 5) The species continued existence is threatened by other natural or manmade factors.

Table 2.2 lists species that occur in Sonoma Valley that have state or federal legal protections (California Department of Fish & Game, 2009) and from the CNDDB for a complete list of species by quad (CNDDB, 2009).

Table 2.2 Sonoma Valley Special Status Fish & Wildlife Species Species Scientific Name Species Common Name Federal listing California state listing Reithrodontomys raviventris salt marsh harvest mouse endangered endangered

Buteo swainsoni Swainson’s Hawk none threatened

Strix occidentalis caurina nothern spotted owl threatened none

Riparia riparia bank swallow none threatened

Rallus longirostris obsoletus California clapper rail endangered endangered

Laterallus jamaicensis California black rail none threatened coturniculus

Oncorhynchus tshawytscha Chinook salmon threatened none

Oncorhynchus mykiss irideus Steelhead trout threatened none

Rana draytonii California red-legged frog threatened none

Syncaris pacifica California freshwater endangered endangered shrimp

Coccyzus americanus western yellow-billed candidate endangered occidentialis cuckoo

Haliaeetus leucocephalus bald eagle delisted endangered

Salmonid Fish: Steelhead Trout and Chinook Salmon

A great deal of research and restoration in the Sonoma Creek watershed has focused on steelhead trout. The health of the fishery can be considered an indicator of the overall health of the ecosystem. In general, what is good for native fish, such as clean, cool water, low levels of fine sediment, adequate tree cover, and channel habitat complexity, is most likely good for other native species of the stream ecosystem. In the long term, a sustainable aquatic ecosystem may be a good indicator of sustainable water supplies in the valley for generations to come.

The Sonoma Creek Watershed Limiting Factors Analysis (Micheli, 2006) found that, the high-impact, high-certainty factors limiting the steelhead population were

 Summer and winter off-channel habitat for juvenile fish. “The loss of the majority of historical off-channel rearing habitat due to direct and indirect physical alteration has reduced steelhead populations. Historical ecology mapping indicates that remaining freshwater wetlands and floodplain areas are less than approximately 10% of historical conditions.”

 Lack of instream shelter for juvenile fish. The “watershed’s shelter rating was only 13% of the maximum score. Less than one piece of woody debris per mile of stream channel. Low quality of shelter for juvenile fish has resulted in increased predation and displacement by high flows.”

 Juvenile fish being stranded by low flows in the summer. “Surveyed streams lost approximately 40% of summer rearing habitat to dewatering. Summer low flow conditions cause mortality of fry stranded in pools that go dry or lose access to food and fresh water provided by stream flow.

The Limiting Factors Analysis is discussed further in Chapter 10: Riparian Habitat and Species.

REGIONAL HISTORY AND CULTURAL RESOURCES

The Sonoma Creek Watershed has a long human history written within its landscape. Historic and cultural resources in the watershed reflect centuries of human settlement and evolution. There are several kinds of cultural resources, including historic buildings and bridges, prehistoric archaeological sites, Native American sacred sites, native plants with important cultural significance to local tribes, as well as sensitive locations where resources are likely to be identified in the future, based on existing knowledge of historic and prehistoric settlement patterns. Cultural resources are the material remains identified with either the prehistoric inhabitants of the area (any time prior to the arrival of the Spanish in the latter half of the 18th century) or with the historic inhabitants. The historic period begins with the arrival of the Spanish and continues up to 45 years ago. Historic resources are those standing structures of historic or aesthetic significance.

Prehistoric cultural resources, which include Native American structures or sites of historical or archaeological interest have been identified within the Sonoma Creek Watershed boundary. These may include districts, buildings, objects, landscape elements, sites or features that reflect human occupations of the region, such as villages and burial grounds. Centuries before the North Bay region became important in European struggles for empire and profit, Native American tribes settled in village communities and inhabited the area for several thousand years. Archeological records indicate that the Sonoma Creek Watershed has been inhabited for at least 8,000 to 10,000 years and perhaps longer by ancestors of the Pomo, Miwok, and Wappo tribes. The extensive marshes, oak woodlands, Douglas fir forests and riparian corridors provided abundant food, clothing and shelter for the first peoples who lived in the watershed.

Present day Sonoma County was occupied at the time of historic contact by peoples representing four language groups: Southern Pomo, Southwestern Pomo, Coast Miwok and Wappo. Each group was made up of numerous autonomous village communities that held a specific tract of land, often spoke a distinct dialect and was organized under one or more headmen. These tribelets followed the basic Central California hunting and gathering subsistence pattern, with acorns providing a year-round staple. They maintained permanent winter villages, and set up outlying camps during the summer to obtain seasonal resources. It is believed that the Sonoma Valley was occupied by the Coast Miwok people, a language group that also occupied present day Marin County and the Petaluma River Basin.

Typical indicators of prehistoric resources in the watershed include changes of soil color, composition, or texture which suggest the occurrence of archaeological midden (e.g., dietary debris such as bone and

shellfish); unusual ground contours or abrupt changes in vegetation patterns; the presence of prehistoric stone or shell, obsidian, or other types of lithic flaking wastes or actual chipped chert or obsidian tools; fire-fractured rock, charcoal deposits and/or charred faunal remains; and grinding implements such as mortars and pestles. Sonoma Creek and its tributaries provide a favorable environment for discovery of such prehistoric cultural deposits.

Two hundred years ago it was estimated that anywhere from 3,000 to 5,000 Native Americans were living in Sonoma Valley, however by 1823 life began to unravel for native populations when the Sonoma Mission was established. By the time General Vallejo had arrived, the Native Americans had been forced to give up their religion, to build the mission, the town of Sonoma and to work in the fields. By the 1840s most had died of the smallpox epidemic and the few remaining were taken to reservations in Mendocino.

Historical era architectural sites dating from the Spanish Period (1529-1822) through the early years of the Depression (1929-1930) are generally considered for protection if they are determined to be historically or architecturally significant. These may include missions, historic ranch lands, and structures from the Gold Rush and the region’s early industrial era. Post-Depression sites may also be considered for protection if they could gain historic significance in the future.

Although Spain and England originally claimed the land that is now California, Spain lost the title to Mexico in 1821, before the settlement of the areas within Sonoma County began. The first European travelers to enter Sonoma Valley were Padre Jose Altimira and his party, traveling north from what is now San Francisco, in 1823 (Dawson, 2008). The Mission San Francisco Solano de Sonoma, the last and northernmost mission, was established by Father Junipero Serra in 1823. It was the only California mission installed after Mexican independence from Spanish rule. Within six years, most traces of native culture rapidly disappeared, in part through the spread of disease via European settlers.

General Mariano Guadalupe Vallejo led the transformation of Sonoma into a Mexican pueblo in 1834 after the secularization of the missions. He oversaw construction of the eight-acre central Plaza (still the largest in California and the town’s focal point) and the street grid, including the 110–foot wide Broadway Avenue. In June 1845, a month after the start of the Mexican-American War, a group of Americans declared their independence from Mexico. The raising of the first California Bear Flag and Vallejo's arrest in 1846 by this band of Americans claiming to act on the orders of Col. John C. Fremont was the initial act that founded the Bear Flag Republic. The republic had no official government and was dissolved when the United States Navy took charge of Sonoma in July 1846. The war ended in 1847, and as a result of the Treaty of Guadalupe Hidalgo, California was added to the territories of the United States. California became a state in 1850 and the various counties were established in 1851. Vallejo transferred his allegiance with US statehood (1850), and with his amassed land holdings guided the development of the town and dispensed large ranches throughout the valley.

With the breakup of the ranchos after the Mexican War came the establishment of towns. The Sonoma town square originally laid out by Vallejo under his military rule was the site of great activity in the 1840s. However, the town was virtually abandoned during the gold rush of the 1850s. When California gained statehood and Sonoma County was established, the city of Santa Rosa was selected over Sonoma as the county seat. Growth and development in the Sonoma area were stimulated by agriculture, although lumbering, tanning, and quarrying also played important roles in the early economy of the valley.

The first grapes were planted in 1824 by Padre Joseph Jose Altimira at the Sonoma Mission, providing table grapes and wine for communion until 1833 when the mission was secularized. One of the first and most famous viticulturalists to recognize the grape growing potential of the region was Agoston Haraszthy, a Hungarian count, who came to California in 1849. He planted 165 varieties of grapes in his Buena Vista vineyard within two years of arriving in Sonoma. California's first wineries were established here, including Buena Vista Winery (1857) and Gundlach Bundschu (1858). Most of the construction during the first half of the nineteenth century was adobe and wood. These construction methods drew on the Mexican tradition while incorporating some of the features and floor plans of the Anglo Americans.

After statehood in 1850, cattle ranching, farming, and the early development of the wine industry supported the sparsely settled area. During this time, commercial and industrial buildings used local stone or brick, while most residences were built of wood.

The city of Sonoma contains numerous historic structures and sites associated with the mission period, the Bear Flag Republic, and the historical development of the valley. The most notable of these are the Sonoma Plaza National Historic Landmark and surrounding historic structures (e.g., the Sonoma barracks, the Sonoma Mission, etc.), and the Vallejo Estate at the corner of Spain and West 3rd Streets.

Numerous historic structures are also located within Sonoma Valley. A complete listing of historic properties in the Sonoma community, as documented by the National Register of Historic Places and the State Office of Historic Preservation, is provided in the Directory of Historic Properties data file, on file at the City of Sonoma and the Northwest Information Center.

The other communities in the valley, such as Kenwood, Glen Ellen, Schellville and Boyes Hot Springs, were founded later in the 19th century, some as resorts centered on the geothermic hot springs that still well up from deep within the earth. Boyes Hot Springs and Agua Caliente were popular health retreats for tourists from San Francisco and points beyond until the middle of the 20th century. Today the Sonoma Mission Inn in Boyes Hot Springs remains as a main destination resort, and the wineries, the historic sites, and the area's natural beauty are the main tourist attractions.

LAND USE

The Sonoma Creek Watershed supports an array of land use activities, due to its hydrology, soils and geographic location. Through time these uses have continued to develop and evolve as populations grew and demand on natural resources increased. The subsection summarizes the changes in the land cover of Sonoma Creek watershed over the last 200 years. Following this description is detailed information on current land uses within the watershed boundary.

Historic Timeline

This subsection summarizes the changes in the land cover of Sonoma Creek watershed over the last 200 years, as documented in the Sonoma Creek Oral History Project (SEC, 2002a) and Synopsis of Changes in Sonoma Valley Watershed c. 1823-2004 (SEC, 2004a):

Analysis of early surveys and other data of the Sonoma Mountain environs indicates that upland areas of the Sonoma Valley had less dense vegetation cover than exists today. Prior to modern times there was a mosaic of oak woodland, redwood forest, grassland, chaparral, and riparian vegetation uninterrupted by urbanization and development. The valley floor had expanses of oak savannah, oak woodland, grassland, and large areas of fresh and tidal marsh. The watershed was also home to large herds of elk and pronghorn, many grizzly bears, and both steelhead and salmon in the streams.

Douglas fir forests and riparian corridors provided abundant food, clothing and shelter for the first peoples who lived in the watershed. Native Sonomans lived in reciprocity with the land and research suggests that they were active participants in modifying the landscape. Indigenous people undertook pruning, coppicing (cutting vegetation to form grove-like stands), soil and weed management, tillage and plant propagation for a variety of purposes.

The most dramatic example of environmental alteration by Native Californians was the use of fire over much of the watershed to clear dense areas for easier hunting, stimulate and encourage better germination of fire-evolved species of vegetation, and control pests and plant diseases. Analysis of tree ring scars, archeological evidence and sparse lightning activity suggests fire usage every few years by aboriginal peoples in the Sonoma valley. The impact of consistently short fire intervals would have markedly influenced the vegetation creating large expanses of grasslands and lush verdant oak Savannah’s and woodlands.

With the advent of the Mexican and European settlers in the 19th century, indigenous use of landscape fire for hunting and germination was no longer practiced. Instead, fire suppression became the favored practice. Cessation of intentional burning would have allowed for denser growth of vegetation and fire suppression practices affected the distribution and composition of plant communities by converting chaparral to Douglas fir forests, encouraging invasion of oak woodlands by Douglas fir and increasing canopy density of other forest types.

Counteracting the unimpeded growth of woodlands, however, was the introduction by the settlers of grazing, farming, logging, woodcutting, wetland draining, tributary diversion, in-stream sand and gravel mining, construction of small dams, and dredging the mainstem of Sonoma Creek. These “drain and reclaim” practices generally impact a watershed’s geography and hydrology by increasing sediment delivery to creeks, reducing vegetation root strength and woody debris available to stabilize hillslopes and channels, and accelerating flood flows through the drainage system. Arrival of the railroad and an increased human population in the late 19th century likely intensified some types of land use, particularly logging and woodcutting, which reached a peak around 1900.

The mission padres also brought changes to the land, as they introduced new and exotic species of plants and animals such as sheep, cattle, fruit trees, grains, and vegetables. By the mid-1800s, the Spaniards and later Mexicans began logging the forests near the headwaters of Sonoma Creek. The major commercial enterprise in Sonoma Valley prior to 1850 was the hide and tallow trade. The bark from tan oaks was needed to cure and tan the animal hides. Other oak species were used for charcoal, fuel and building materials, and quarry mining was established to procure rocks and cobbles most of which were shipped out to pave the streets of San Francisco. Logging and quarry mining in the hilly

regions of the watershed caused major erosion problems that still exist today.

Summary Timeline of Changes:

The following timeline summarizes land use and hydrology changes over time in Sonoma Valley (Dawson, 2008):

Date Time Period Description

Before 1825 Native American Era Disconnected tributaries; soggy meadow units;15,000 acre tidal marsh; regular burning and fuel reduction processes; open landscape

1825- 1875 Mexican/Early Arrival of cattle, sheep, crops, overgrazing some areas; American Era logging; small-scale woodcutting; draining of wet areas, connection of tributaries by 1875; human and domesticated animal power implemented on landscape

1875- 1935 Watershed reaches Arrival of trains, dredges, and mechanized farm equipment; modern form commercial woodcutting; second round of logging, Sonoma Mountain deforested; dredging sloughs and diking of baylands reduces tidal marsh by 90%; diverse agriculture: prunes, walnuts, apples, pears, olives, peaches, cherries, hops, figs, grapes, dairy, chickens, hay; first flood “within living memory” in Schellville 1892; steam and gasoline power.

1935- Present Current state Agriculture mostly vineyards; flooding continues downcutting and bank loss; logging and woodcutting end and Sonoma Mountain reforested; increase of non-native species; increase acres of hardscape; runoff accelerates

Current Land Use

Existing Land Use Designations within the Sonoma Valley Planning Area include 50,622 acres of Agriculture, (56.1%); 12,185 acres ( 13.5%) of Residential uses, 537 acres ( 0.6%) of Commercial uses , 359 (0.4%) of Industrial uses, 6,420 acres ( 7.1%) of public and quasi public uses, and 1479 acres of developed city land.

Agriculture

The watershed’s land area is covered by 34% agricultural uses, which include: Grassland and Hayfield, 8.8% (9,360 acres), Vineyard, 14.7% (15,678 acres); Orchard and Row Crops, 2.5% (2,651 acres); and Pasture (including dairy pasture), 7.8% (8,346 acres). Numerous crops have been grown commercially in Sonoma Valley over the decades as later described in the history and cultural resources section of this

chapter. However, currently premium and super-premium wine grapes remain the dominant crop growing in the Sonoma Valley.

Sonoma Valley benefits from all the influences of this biologically diverse and climatically ideal region: a moderate climate with a cooling maritime influence, warm northern areas that complement the cool southern sections, and a wide range of topography. The valley's geological complexity features numerous mesoclimates and a variety of soils that lets growers select the ideal growing conditions for each grape varietal. With an average of 29 inches of rainfall a year, it is one the driest areas in Sonoma County. The mountain ranges on either side isolate the Valley, allowing in just enough coastal fog to cool the vineyards on summer nights. Predominantly southerly winds off San Pablo Bay also moderate temperatures that extend the growing season.

Lands throughout the watershed and along the Highway 37 corridor also contain agricultural lands in hay and grain, pasture for livestock grazing, and open space lands, many of which continue to support agriculture as an essential component of managing and stewarding these working landscapes that are considered emblematic of Southern Sonoma County. The high quality oat hay, grain crops, and pasture lands form a supply loop that supports livestock and food production in the North Bay region. Currently, the following grain crops are cultivated: triticale, wheat, barley, oats and oat hay, rye grass, and oat seed. Grassland pasture and grain produced in the corridor are purchased by local dairies and meat producers and as such, hay producers grow specific crops and utilize methods for highest quality grain to meet local demands for livestock and equestrian feed and for high value milk, cheese, and meat products.

Agricultural landowners farming along the southern parts of the watershed near the Highway 37 corridors face challenges as tidal marsh restoration, difficulties maintaining levees, and sea level rise threaten to take ever more acreage out of production. Protecting ever-more-vulnerable farmland from the bay is expensive. Buying title or easement over farmland to return it to a natural state is complicated by the fact that public funds are prohibited from paying more than “fair market value”, which does not value wetlands or wildland functions.

Farmers in the area, with their equipment, their cattle, and experience are critical to the success of land conservation. Therefore, ranching and grazing should be supported to the degree that people can make a living ranching and grazing. Agricultural operations require a certain economy of scale to be profitable. Oat hay supports local dairies and horses, and it’s more local, less carbon-intensive, and fresher than central valley hay.

Developed Areas

Developed areas are classified as those land uses that are composed of primarily impervious surfaces and include structures or other urban development. According to the Land Cover Map prepared by SEC (Map 2.6) developed land makes up 14% of the overall watershed and includes the following land uses: Residential, 10.1% (10,744 acres); Commercial, Facilities, and Industrial, 2.6% (2813 acres); Airport/Transportation, 1.6% (1,723 acres), and Urban Parks 0.14% (153.25 acres).

Unincorporated Lands

The hillsides east and west of the Sonoma Valley are designated in the County General Plan as Resources and Rural Development, (RRD) Rural Residential (RR), Land Intensive Agriculture (LIA) and Diverse Agriculture. The lands south of Sonoma are predominantly Land Extensive Agriculture (LEA), used for dairy and forage production. There is a large area of marshland along the San Pablo Bay, where Skaggs Island is an adjacent federal military facility. The Resources and Rural Development (RRD) designation is present to protect the county’s natural resource lands and allow only very low density residential development. Resources to be protected include watershed, fish and wildlife habitat and other biotic areas.

The two Residential Land Uses are Urban Residential (UR) and Rural Residential (RR). The Urban Residential category is used only within urban services areas. The Rural Residential designated areas provide very low density residential development on lands that have few if any urban services but have access to county maintained roads.

Based on the figures in the Sonoma County General Plan 2020 (Table LU-5, Household and Housing Projections, 2000-2020), the existing number of housing units in 2000 in the Sonoma Valley Planning Area was a total of 12,728 in the unincorporated area. Most of the 40,000 population of Sonoma Valley is concentrated in Sonoma (9,900), and in the adjacent unincorporated communities of Agua Caliente, Fetters Hot Springs, El Verano and Boyes Hot Springs. Other communities include Kenwood and Glen Ellen. The balance of the area's population is scattered in rural agricultural and hillside areas at very low densities.

City of Sonoma Area

The city of Sonoma is a working town with about 9,900 residents and a rich cultural heritage. The adjacent scenic hills and agricultural valley are protected as open space and cropland through a compact Sphere of Influence/Urban Growth Boundary that limits where future City expansion can occur. The Urban Growth Boundary helps protect quality of life for Sonoma residents by concentrating future residential, commercial and industrial growth in areas where urban services are already provided. (City Measure S, approved in 2000, prohibits the extension of City services to parcels outside the Sphere of Influence until 2020). Much of the land in Sonoma is used for residential purposes. Residential uses account for roughly half of all land in both the City and Sphere of Influence.

The city of Sonoma has a relatively compact urban area of approximately 2.32 square miles. Existing development within the city totals 1,490 acres. The predominant land use within the city is residential, with 41% single family residential, (614 acres, 2,611 parcels) and 14.4% multifamily residential (214 acres, 1,092 parcels). Commercial development covers 6.2% (93 acres, 153 parcels), Mixed Use covers 1.7% (25.2 acres, 106 parcels) and Office covers 2.2% (32.7 acres, 113 parcels). Institutional is 7.5 %( 112.2 acres, 35 parcels), Government is 7.1% (105.9 acres, 41 parcels), and Industrial is 1.8 %( 26.7 acres, 31 parcels). Vacant residential land accounts for 6.7% (99 acres, 119 parcels) and vacant non-residential land is 0.9% (13.8 acres, 19 parcels).

Existing development within the city’s adopted Sphere of Influence is 227 acres, with single- family residential at 52.2% ( 118.5 acres, 122 parcels), multi-family residential at 1.7% ( 3.8

acres, 4 parcels), parks at 29% (65.9 acres, 2 parcels), Commercial is 8.8% ( 20 acres, 14 parcels), Agriculture is 2.2% ( 5 acres, 1 parcel), mixed use is 1.0% ( 2.2 acres, 2 parcels) and office at 0.6% ( 1.3 acres , 4 parcels) . Vacant residential use is 3.5% (8 acres, 3 parcels) and vacant non-residential use is 1.0% (2.3 acres, 2 parcels.)

As of 2005, the City of Sonoma contained approximately 5,071 housing units. Approximately 2,876 of the units were single-family homes, while roughly 1,758 were multifamily units, and about 437 were mobile homes (City of Sonoma, 2006).

Parks and Open Space

Parks and open space areas are valuable areas of land which allow for the protection and conservation of both natural and cultural resources. Open space is defined as publically or privately owned land, which is in its natural state or used in agriculture, but void of intensive urban development. Open space properties allow for recreation, scenic beauty, protection and habitat requirements for rare or endangered plant and animal species, while also providing protection to water quality and supply. There are approximately 20 properties that fall within or on the watershed boundary overseen by the Sonoma County Agricultural Preservation and Open Space District (SCAPOSD). Parks offer communities an array of opportunities to learn about the environment and values of conserving such lands for future generations. One of the largest parks within the Sonoma Creek watershed is Sugarloaf Ridge State Park, which also contains the headwaters of Sonoma Creek in the Mayacamas Mountains in Kenwood. Elevations reach roughly 2,729 feet at the summit of Bald Mountain with a broad range of habitat types and plant communities throughout the park itself.

Future Land Use The Sonoma County General Plan 2020 (GP 2020) Land Use Map designates the location and intensity of potential new residential, commercial, industrial and other forms of development in the unincorporated County. The demographic and economic projections of GP 2020 represent the County’s best effort to forecast the rate and amount of growth in population, housing and employment and its geographic distribution among the nine planning areas. The agricultural industries in Sonoma County will continue to be a major factor in Sonoma County’s economy, with increased emphasis placed on the production of value added products, and agricultural tourism. Countywide, vineyard acreage has increased steadily from about 33,000 acres in 1990 to about 56,000 acres in 2000, a trend that is expected to continue to a total of about 75,000 acres by 2020. A portion of this increase in vineyards is expected to occur in the Sonoma Creek Watershed. Assuming the average production capacity of wineries remains constant, the additional grape production associated with new vineyards would increase the total number of wineries countywide from about 200 in 2000 to about 300 in 2020, with associated increases in employment. Vegetable, nursery, and other specialty crop production is generally holding steady, with increased opportunities for employment within the emerging local food processing industry.

In the Sonoma Valley Planning Area population would increase from 39,879 in 2000 to 48,990 in 2020, an increase of 9,111 residents. The number of housing units would increase from 17,520 in 2000 to 21,051 in 2020, an increase of 3,531 housing units.

In the unincorporated area, population would increase from 30,125 in 2000 to 34,400 in 2020, an increase of 4,275 residents. The number of housing units would increase from 12,728 in 2000 to 14,388 in 2020, an increase of 1,660 housing units.

Agricultural/ Commercial/ Industrial uses are projected to increase from 2,496,657 sq. ft. in 2000 to 7,128,651 sq. ft in 2020, an increase of 4,631,994 sq. ft. Agricultural processing facilities, such as wineries, are included in the square footage of agricultural, commercial and industrial development projected through 2020. (Sonoma County GP 2020 DEIR, Land Use, Population and Housing)

Land Use Buildout Projections

The Sonoma Valley Landcover Maximum Buildout Scenario Map prepared by SEC, 2004, (Map 2.7) was constructed as a maximum buildout scenario for the Sonoma Valley based on the Sonoma County and the City of Sonoma General Plans. It was constructed by assuming that all parcels would be developed to the maximum impact land-use designated in the General Plan. For example, if a parcel is currently in rural or agricultural use, but is zoned for commercial, the build-out scenario converts the future use to commercial and changes the land cover designation accordingly.

This coverage projection started with the existing LandCover coverage digitized by the Sonoma Ecology Center from a 2002 aerial photography coverage provided by the county. Coverage’s from the city of Sonoma and from Sonoma County depicting land use designations from the county general plan and the city general plan were used to estimate future conditions. Existing county and city land use designations were compared to proposed general plan land use designations.

The county and city general plan coverage’s were spliced together with the city's general plan replacing the county's general plan in the City of Sonoma's boundaries. That coverage was then intersected with the SEC LandCover data. The resulting polygons had both the city or county's future land use condition as well as the SEC existing land cover condition. The "final" condition was assigned the most intensive of the two conditions, as designated in the matrix (SEC, 2003 - Future Buildout land Use conditions Metadata).

The map divides the land coverage’s into four main categories: Natural Cover, (Barren, Chaparral, Mixed Woodland Chaparral, Grassland, Woodland, Open Woodland, Riparian, and Seasonal Wetland); Developed Cover, characterized by large amounts of constructed material, homes, etc. (Residential, Commercial, Businesss, Industrial, and Urban Park); Agricultural Cover, (Orchard, Pasture, Row Crops, Vineyard, Hay Field, and Agricultural Facilities); and Other Cover, which include Water (lakes and streams) and Airport/Transportation (roads, airport and large parking areas).

Of the 106,457.5 acres of the watershed, Natural Cover accounts for 30.3% (32,242 acres) of the maximum buildout scenario, with 26% (27,750 acres) in woodland, grassland and chapparel, and

4.2% (4492 acres) in riparian and seasonal wetland. Developed Cover accounts for 19.5% (20,770 acres) of the maximum buildout scenario. Agricultural Cover accounts for 24.5% (26,089 acres) of the maximum buildout scenario, with 2.4% (2,527 acres) orchard and row crops, 7.03% (7,481 acres) pasture, 12.03% (12,803 acres) in vineyard and 3% ( 3,276 acres) Hayfield. Other accounts for 3.5% ( 3,804.4 acres) with 1.7% ( 1,842.28 acres) in airport/ transportation and 1.8% ( 3,804 acres) in water. The LIA, LEA, DA land coverage acreages account for the remaining 22%, (23,546.88 acres).

The current City of Sonoma General Plan largely maintains the pattern of infill development established in the 1995 General Plan. The growth rate would continue to be controlled by the city’s adopted Growth Management Ordinance. Assuming that the maximum number of units allowed per year by the ordinance would continue to be 88 units, and that all of these allotments would be constructed, up to 1,320 additional units could be constructed by the year 2020.

Using ABAG’s projected year 2020 figure of 2.08 persons per household within the Sonoma Sphere of Influence, the city’s population could be expected to grow by approximately 2,745 residents by the year 2020 for a total population of approximately 12,579, an increase of approximately 28% and an annual growth rate of 1.8%. It is somewhat less than but generally consistent with ABAG estimates, which projects a population of 12,800 for Sonoma in the year 2020.

Active agricultural lands within city limits would be preserved as such in the 2020 General Plan, by maintaining the Sphere of Influence and focusing on infill development. Because it would retain the limited Sphere of Influence established in the 1995 General Plan, the 2020 General Plan update would continue to implement a compact development pattern.

[Insert Map 2.7: Land Use Buildout Scenario here]

Urban Service Boundaries

The Draft GP 2020 continues the County’s commitment to concentrate future growth in cities and urban areas with community sewer and water systems. The key to implementing this strategy is the designation of urban service boundaries (USBs) on the land use plan maps and the establishment of policies regarding extension of public sewer and water service outside these designated areas. Revisions to the USBs are recommended to reflect changes in service availability and decisions made by voters, cities and other agencies regarding growth patterns in Sonoma County.

DEMOGRAPHICS AND ECONOMICS

The Sonoma Valley subregion1 of Sonoma County, including the City of Sonoma, has a population of about 39,000. As of 2008, the City of Sonoma included a population of about

1 As described in Section 3.2.6, the Sonoma County Plan separates the county into planning areas. The Sonoma Valley Planning area covers most of the Sonoma Creek watershed with the exception of the northern Kenwood area.

9,900 (DOF, 2009). In addition, the Sonoma Development Center has a resident population of about 650. Compared to the Countywide population of 484,470 (CED, 2009), the watershed maintains a relatively low population of about 40,000.

The County is projected to increase to 535,000 by 2015, based on historic growth rates and ABAG projections. The average annual population growth in both the County and City of Sonoma has been about 1 percent, however the growth rate has slowed in the City to about .5% over the past several years (2006 to 2008) (CED, 2009).

Population density for Sonoma County was at 307.4 residents per square mile, compared to a statewide average of 244 residents per square mile. By 2015, the County’s density is expected to increase to 339 residents per square mile (CED, 2009). Assuming about 40,000 people occupy the watershed, the average density would be about 240 people per square mile.

Approximately 68 percent of Sonoma County residents in 2008 are white, compared to 43 percent in California. The white population is expected to increase 4 percent by 2015 across the county. Hispanics represented the next largest group, with 23 percent of the population, compared with 36 percent in California. The Hispanic population is projected to increase 24 percent by 2015 in Sonoma County. Asians and blacks were the next largest groups, with 21,344 and 7,422 people, respectively. The Asian population is projected to increase 24 percent, and the black population is expected to increase 19 percent within seven years. American Indians were the smallest census-classified group, with 4,660 people. That number is expected to decrease significantly by the year 2015 (CED, 2009).

The economic status of a region is characterized by indicators such as the labor force, unemployment statistics and household income. The City of Sonoma had a labor force of 4,800 in 2007, with about 200 unemployed (4 percent) compared to a countywide unemployment rate of 4.5% (CED, 2009). Median household income for the entire county was $58,000 in 2005, which was 8 percent higher than the state average. The City of Sonoma had taxable retail sales of 179,636 and total taxable sales of $208,216 in 2006, which is almost double of sales in 1990. In general, countywide sales trends are consistent with statewide trends. The largest employers in the watershed include the Sonoma Developmental Center, Sonoma Valley School District, City of Sonoma, Sonoma Mission Inn, Infineon Raceway and several large wineries.

Agriculture, particularly vineyard cultivation, wine processing, and tourism are mainstays of the area's economy. Some manufacturing and service businesses exist along Eighth Street East, east of Sonoma. Much of the local employment is in the "retail trade" and "services" sectors. Many workers commute to jobs outside the Valley.

Sonoma Creek Watershed Enhancement Plan

SECTION 2. MANAGEMENT AND RECOMMENDATIONS

Sonoma Resource Conservation District

June 2013

CHAPTER 3. AGRICULTURAL AND RURAL SUSTAINABILITY

Agricultural and rural residential land uses occupy a significant portion of the Sonoma Creek watershed’s area. (For more information on land use cover and associated activities please see Chapter 2 Watershed Description and History). As such, owners and managers of rural and agricultural lands are important stewards of the watershed and its resources. This chapter presents a background on each of these land uses, associated resource issues, and recommendations and resources for managing rural and agricultural lands. AGRICULTURAL SUSTAINABILITY Approximately 34% of the watershed is in agricultural land use (see Map 2.6: Land Cover), including vineyards, hayfields, pastures, orchards and row crops. Throughout the county, smaller farms on parcels from two to 10 acres are increasingly important economically. Grape production is one of a few crops that provide enough revenue to support small‐scale farming operations (Sonoma County PRMD, 2008). Sonoma County is a “right to farm” county and sustainable agriculture is supported by multiple agencies, public sales tax measures, regional and countywide goals and policies.

Sonoma County ranks 6th in the state and 34th in the nation in agricultural productivity; the county recognizes that agriculture is an important economic, social, and historic resource and has taken measures to protect it (Sonoma County PRMD, 2008a). The Sonoma County General Plan 2020 (Sonoma County PRMD, 2008b) contains an Agricultural Resources Element (Element) that provides “policies, programs and measures that promote and protect the current and future needs of the agricultural industry.” These provide guidelines for land use and other decisions in agricultural areas to protect existing agricultural practices. It also provides policies to assist in marketing and promotion of agricultural products and provide fair conditions for farm laborers.

The concept of sustainability is based upon the principle that management activities should meet the needs of the present without compromising future generations’ ability to meet their needs. Agricultural sustainability incorporates three main goals: preservation of environmental systems and processes, economic profitability, and social and economic equity. Stewardship of both natural and human resources is important. Stewardship of natural resources includes preservation and rehabilitation of ecological processes such as groundwater recharge, pollutant sequestration, pollination services, and nutrient sequestration.

Stewardship of human resources includes social concerns such as health and housing conditions for laborers, the needs of rural communities, and long‐term consumer health and safety. Many agricultural enterprises throughout the county practice stewardship of natural and human resources; such activities include unpaved roads maintenance and repair, riparian revegetation, erosion control, and provision of agricultural employee housing.

In Sonoma Valley, organic and biodynamic farming is a growing movement. Vineyard management practices have evolved substantially over the century and a half of Sonoma Valley viticulture. Cover crops, subsurface drains, runoff detention basins, pesticide alternatives, and drip irrigation are now part of most vineyards’ operations. Sonoma Valley Vineyard Managers and Growers are at the forefront of implementing practices and projects for water quality and environmental protection. Over the last two

decades many vineyard landowners and operators have already established management practices which improve water quality.

Conservation easements are a form of sustainability involving natural and human resources – they preserve ecological processes while supporting the area’s agricultural heritage. Private conservation easements are identified in the Sonoma County General Plan 2020 as a mechanism for natural resource and agricultural lands preservation and enhancement in several General Plan policies (Sonoma County PRMD, 2008b). Conservation easements can be acquired through Williamson Act contracts or through purchase. Williamson Act contracts involve the landowner agreeing to maintain land in agricultural or open space condition in exchange for reductions in tax obligations. About 300,000 acres of agricultural land are under Williamson Act contracts with almost 300,000 acres in fee title easements (Sonoma County PRMD, 2008a). There has also been a shift in agriculture in the watershed toward organic certification on a dairy operation, vineyards, and rangeland. Sustainability practices such as organic growing can provide financial gain. Not only do sustainable agricultural practices reap long‐term local benefit, they also contribute toward implementation of statewide goals and programs. Implementation of Beneficial Management Practices (BMPs) to control sediment, pathogens and nutrients contributes toward attainment of water quality objectives and Total Maximum Daily Load (TMDL) allocations. Sustainable agricultural practices also contribute toward achievement of goals in the San Francisco Bay Regional Water Quality Control Board Watershed Management Initiative Chapter, the California Water Plan, the California Department of Fish and Game Steelhead Restoration and Management Plan, the Bay Area Integrated Regional Water Management Plan, the Sonoma County Climate Action Plan, and other local and regional planning documents.

AGRICULTURAL BENEFICIAL MANAGEMENT PRACTICES All Agricultural BMPs support one or more aspect of agricultural sustainability. BMPs for vineyard and ranching operations such as those in the Sonoma Creek watershed include irrigation water management, spring frost protection, development and implementation of nutrient management plans, cover cropping, prescribed grazing, riparian fencing, riparian re‐vegetation (see recommendation in Chapter 10: Riparian Habitat and Species), Erosion control and road related sediment source assessment and sediment reduction projects (see recommended actions in Chapter 8: Sediment Sources and Impacts).

Agricultural Regulations

Various regulations influence management practices on agricultural lands in the watershed. The San Francisco Bay Regional Water Board’s (Regional Water Board’s) General Waste Discharge Requirements (WDRs) and General Waiver of Waste Discharge Requirements for Confined Animal Facilities regulate dairies and other facilities where cattle, calves, sheep, swine, horses, mules, goats, fowl, or other domestic animals are corralled, penned, tethered, or otherwise enclosed or held and where feeding is by means other than grazing. Both permits require animal facility operators to meet minimum requirements for manure and waste pond capacity and management, as well as requirements for land application of manure and management of animal confinement areas. Operators are required to monitor and report and water quality-related management practices, and those enrolled in the WDRs are required to prepare a waste management plan.

The Regional Water Board’s Conditional Waiver for Grazing Operations in the Napa River and Sonoma Creek Watersheds (Waiver) regulates grazing operations of 100 acres or more. The Waiver requires grazing land operators to implement management practices that minimize the delivery of sediment, pathogens, and nutrients to waterways from grazed lands and other lands used by animals or as part of the grazing operation. Operators are required to perform annual monitoring and reporting, and to complete and Ranch Water Quality Plan that documents existing conditions and management practices and schedules any additional management practices necessary to meet with requirements of the Waiver.

California’s Pesticide Use reporting program requires all agricultural users of pesticides to report their pesticide use monthly to the County Agricultural Commissioner. Pesticides listed as restricted cannot be applied without a permit from the Agricultural Commissioner. And all pesticides must be applied according to the directions on the label.

Sonoma County’s Sonoma County Grading, Drainage, and Vineyard and Orchard Site Development Ordinance, also known as VESCO, regulates growers planting or replanting vineyards and orchards. Growers are required to meet standards and implement management practices in order to prevent soil loss, protect water quality, waterbodies and public safety, and prevent flooding. VESCO requirements vary based on land slope, soil erosion hazard rating, project size, replant vs. new project, and whether or not the vineyard or orchard development project involves removal of trees. These factors are used to sort properties into categories “Level I” and “Level II.” Level II projects require engineered erosion control plans and additional information on tree removal, while Level I projects require less extensive information including aerial photos and topographic maps.

As of the writing of this plan, the Regional Water Board is developing Vineyard Program for Vineyard Facilities in the Napa River and Sonoma Creek Watersheds (Vineyard Program). At present (June 2013), the program is slated to take the form of General Waste Discharge Requirements that will apply to vineyards over a minimum size, which will depend on the slope of the vineyard facility. It is anticipated that the Vineyard Program will require growers to implement management practices that minimize erosion from vineyards and roads, attenuate stormwater runoff, support aquatic function, and prevent runoff of nutrients and pesticides into waterways. It is anticipated that growers will also be required to complete farm water quality plans and conduct annual monitoring and reporting. These activities may be undertaken with the support of third party groups that provide technical and administrative assistance to growers to comply with the Vineyard Program. The LandSmart program was developed, in part, to serve as a third party tool for Vineyard Program Compliance. Please see Table 3.1 for more information.

The table below describes several sources for BMPs that have widespread acceptance and local applicability. Many of these management activities are supported through funding assistance from agencies such as the NRCS, CDFW, SWRCB, DWR and the Sonoma County Energy Independence Program.

Table 3.1. Resources for Agricultural Management Measures. Resource Description Focus URL USDA Natural This comprehensive All aspects of http://efotg.nrcs Resources system contains agricultural .usda.gov/treem Conservation information specifically operations – extensive enuFS.aspx Service electronic developed list of

Field Office for Sonoma County. irrigation water Technical Guide Section III contains management (eFOTG) information on measures. Conservation Management Systems, which establish standards for sustained use. Detailed information about conservation practices is available in Section IV. The Vineyard Manual – A technical manual Vineyard development http://www.sscrcd.org/ A Grapegrowers Manual regarding vineyard and maintenance publications.php# for Vineyard development and vineyard_manual Development and environmentally sounds Maintenance practices LandSmart This regional All aspects of www.LandSmart.org conservation initiative agricultural operations. helps land managers and land owners meet their natural resource goals while supporting productive lands and thriving streams through LandSmart plans and on- the-ground beneficial management practice implementation. Groundwork – A A comprehensive Erosion control http://www.conservation. Handbook For Small resource detailing ca.gov/dlrp/RCD/ Scale Erosion Control in erosion control methods Documents/Erosion Coastal California, 2nd for rural and agricultural %20Control/ Edition lands. Groundwork_4-18.pdf Handbook for Forest and A comprehensive Roads http://www.krisweb.com/ Ranch Roads: A Guide resource for planning, biblio/gen_mcrcd_ for planning, designing, designing, constructing, weaveretal_1994_handbook.pdf constructing, reconstructing, reconstructing, maintaining and closing maintaining and closing wildland roads. wildland roads. US EPA National This technical guidance All aspects of http://www.epa Management Measures document contains agricultural .gov/owow/nps to information on the best operations – nutrient, /agmm/index.ht Control Nonpoint Source available, economically pesticide, grazing, and ml Pollution from achievable means of irrigation water Agriculture reducing agricultural management, erosion sources of pollution to and sediment control, surface and and animal feeding ground water. operations. US Forest Service This technical guidance BMPs that address all http://www.fs.f Pacific Southwest document provides aspects of USFS ed.us/r5/publica Region Water BMPs for timber activities in tions/water_res Quality Management for management, road and California. ources/waterqu National Forest System building construction, ality/ Lands in California mining, recreation,

vegetation, fuels management, watershed management, and range management. Written from an agency perspective. California State Water Multi‐tool website that All aspects of http://www.swr cb.ca.gov/water Resources Control Board contains a Management agricultural _issues/programs/nps/tools.sh Nonpoint Source (NPS) Practices Miner Tool, a operations including tml Pollution Control Management Measures erosion and sediment Program Encyclopedia and NPS control, animal http://www.swr Guidance in Specific waste, nutrient cb.ca.gov/water_issues/progra Interest Areas. The management, pest and ms/nps/encyclopedia/6_wtld_v Miner Tool is a weed management, ts.shtml compendium of grazing management, documented NPS irrigation water pollution management management, practices collected from groundwater protection, scientific texts, journals, and web education and outreach. sites, grant projects, and Also contains presentations. The management encyclopedia is a free practices for Riparian online reference guide Areas. designed to facilitate understanding of NPS pollution control and provide quick access to resources available on the internet.

Sonoma County This web page contains Water quality http://cesonoma University of several UC management – NPS .ucdavis.edu/W California Agriculture and Natural reduction, vegetative atershed_Mana Cooperative Resources buffer strips, gement923/Far Extension Farm & publications to reduce pesticide choice, m_&_Ranch_St Ranch Stewardship Nonpoint greenhouse and ewardship.htm Web Page source pollution from nursery management. agricultural operations. Sonoma County BMPs presented in this Control of water quality http://www.sonomacounty. Agricultural document are specific to impacts from accelerated org/agcomm/vesco.htm Division New Best Sonoma County erosion from agricultural Management Practices agricultural practices, sources. for soil types and weather Agricultural Erosion and conditions. Sediment Control Handbook Est. January 2010

RURAL RESIDENTIAL BENEFICIAL MANAGEMENT PRACTICES Rural residential development is associated with watershed impacts including sedimentation, nutrient and pesticide runoff, spread of invasive species, and water supply issues, but management practices specific to the category “rural residential land use” have not been developed for Sonoma County. Many of the issues resulting from rural residential development are experienced in a more concentrated manner by urban areas – runoff, flood control, grounds keeping/chemical control, and onsite wastewater treatment systems. Therefore, much of the information about management measures to ameliorate conditions resulting from urbanization is applicable to rural residential land use, including water conservation measures.

An aspect of rural residential development not commonly found in urban areas is the construction, use, and maintenance of unpaved access roads. Roads are widely recognized as a significant source of sedimentation (see Chapter 8: Sediment Sources and Impacts). Management practices to reduce sedimentation from roads are available from many sources. The table below lists several sources for BMPs that have widespread acceptance and relevance to local rural residential issues.

Table 3.2. Resources for Rural Residential Management Measures. Resource Description Focus URL USDA Natural Resources This comprehensive system Natural resources http://efotg.nrcs.usda. Conservation Service contains information conservation. Road and gov/treemenuFS.aspx electronic Field Office specifically developed for trail Technical Guide (eFOTG) Sonoma County. The closure, habitat information is mostly intended restoration. for large landowners. USEPA National This document provides This document provides http://www.epa.gov/ Management Measures to guidance regarding implementation actions at owow/nps/urbanmm Control Nonpoint Source management measures to the municipal scale. /index.html#06 Pollution from Urban reduce nonpoint source Areas pollution from urban activities. USEPA Protecting This web page gives an Reducing NPS pollution http://www.epa.gov/ Water Quality from overview of how individual through individual, owow/nps/urban_fac Urban Runoff dwellings impact a watershed municipal, and planning ts.html#runoff and provides actions implementation activities. individuals can take to reduce NPS pollution.

California State Water Multi‐tool website that Urban areas – most http://www.swrcb.ca. Resources Control Board contains a Management information is agency gov/water_issues/pro Nonpoint Source (NPS) Practices Miner Tool, a level, grams/nps/tools.shtml Pollution Control Program Management Measures however individual http://www.swrcb.ca. Encyclopedia and NPS homeowners will find gov/water_issues/pro Guidance in Specific Interest useful grams/nps/encyclope Areas. The Miner Tool is a information for dia/2_forest.shtml compendium of documented landscaping http://www.swrcb.ca. NPS pollution management and water management. gov/water_issues/pro practices collected from Forestry –homeowners grams/nps/encyclope scientific texts, journals, web may dia/3_3_edu.shtml sites, grant projects, and find useful information presentations. The regarding road encyclopedia is a free online construction, reference guide designed reconstruction, and to facilitate understanding of management.

NPS pollution control and provide quick access to Education and Outreach resources available on the – internet. describes specific practices on the individual household scale. FishNet 4C Roads Manual This document provides County road maintenance, http://www.fishnet4c. guidelines for county road some information org/projects_roads_m maintenance to protect aquatic applicable anual.html habitat and fisheries. to homeowners. Energy Independence A This website provides Financial incentives for http://www.sonomac Sonoma County Program suggestions for residential and individual homeowners to ountyenergy.org/ commercial improvements to implement water and conserve water and energy. energy saving measures. Marin County Stormwater This web page contains several Reducing toxins in the http://www.mcstop Pollution Prevention publications that provide environment, providing pp.org/pesticides.h Program Resources About homeowner – level information least‐toxic pest tm Pesticides about less‐toxic pesticides, management and Alternatives Web gardening, and water quality. to homeowners and Page schools. House and Garden Audit: “The House and Garden Audit Reducing toxins in the Protecting Your Family’s is for all people interested in environment through Health and Improving the learning how to protect their individual homeowner Environment, A health while effort. Guidebook to Reducing improving the environment.” Your Impacts on the Environment Less‐Toxic Pest This is an informative brochure Provides tips for http://ourwaterour Management: Pesticides about homeowner homeowner reduction of world.org/Portals/0 and contributions to water quality pesticide use. /documents/pdf/Pe Water Pollution. impairments. sticidesWQ.pdf

RECOMMENDED ACTIONS

Recommendation ARS1 – Provide education and technical services to help ranchers and growers understand and comply with applicable agricultural regulations.

Recommendation ARS2 – Develop LandSmart Farm/Ranch Water Quality Plans to document current and plan for future BMPs.

Recommendation ARS3 – Prevent and control soil erosion, and enhance soil quality. See Chapter: 8 Sediment Sources and Impacts.

Recommendation ARS4 – Improve water use efficiency of irrigation and frost protection systems. Explore alternative water sources for these uses.

Recommendation ARS5 – Manage grazing to protect and enhance soil quality, plant communities and water quality.

CHAPTER 4. CLIMATE CHANGE IMPACTS AND ADAPATION

Climate change refers to any significant change in the measures of climate, such as temperature, precipitation, or wind patterns, lasting for several decades or longer. Increases in the Earth’s temperature and associated changes to climate patterns over the past century are thought to be caused by increased levels of carbon dioxide and other greenhouse gases in the Earth’s atmosphere (EPA, 2012).

This chapter includes a description of the effects of climate change on a larger scale, more locally in Sonoma County, and adaptation recommendations.

CLIMATE CHANGE IMPACTS IN CALIFORNIA

The consequences of climate change are projected to be substantial in California and to have far-reaching impacts to many ecosystems, agriculture, and infrastructure. California is already experiencing the effects of climate change, including warming temperatures, rising sea levels, longer fire seasons and shifts in precipitation. Wetlands – coastal, riparian, seasonal, or tidal – all stand to suffer some of the greatest and most immediate and observable impacts. The projected changes of greatest concern are: sea level rise, salinity shifts, temperature increases, hydrological changes (timing, quantity and quality) and an increase in the severity of storms. On their own, each carries with it specific implications, but also of concern is the cumulative effect of any combination of these factors. Other stressors include the development and fragmentation of open spaces, water quantity and quality impairments, invasive species, pest vectors and related diseases.

Changing temperatures are already starting to impact our communities in terms of personal health and energy, water and land use. This is because climate dictates:  The quantity and quality of our water supply and patterns of water demand  Rates and patterns of commercial and residential energy use  How and where farmers can grow crops  Health risks for vulnerable populations including the very young and elderly

The impacts of climate change on biodiversity, agriculture, and infrastructure are far reaching, requiring coordinated and targeted local efforts to protect native species, their ecosystems, and ecosystem services. The Regional Climate Protection Authority (RCPA), the Climate Protection Campaign (CPC), North Bay Climate Adaptation Initiative, California Climate and Agriculture Network, and their many partners, are looking to educate and provide resources to communities in Sonoma County and beyond about the many impacts that climate change may have on our economy and our environment, and strategies to adapt to these impacts. The County has adopted a Community Climate Protection Action Plan (CCAP) and many

cities throughout the county have adopted green building programs and Land Use and Community Design Programs to address Climate Change.

IMPACTS TO BIODIVERSITY AND HABITAT

While climate change models have generated a wide range of projections, there is consensus that some ecosystems, particularly tidal wetlands, will be impacted more than others. Several factors make tidal wetlands sensitive to climate change. First, the rise in average global temperatures will influence the timing and degree of snow fall and ice melt, shifting temporal runoff patterns in watersheds supplied predominantly by mountain snowpack. Second, rates of sea-level rise are almost certain to increase over the next several decades. Sea-level rise will push sea water farther up into estuaries, increasing salinities in tidal ecosystems. Increases in sea level alone will account for losses of up to 22% of the world’s remaining tidal wetlands. Moreover, the combination of sea level rise with reclamation and development infrastructure in coastal regions may result in the loss of up to 70% of coastal wetlands (Nicholls et al., 1999; Najjar et al., 2000; but see Hughes et al. 2000). Tidal marshes are likely to be particularly vulnerable to climate change impacts through these shifts in salinity and inundation patterns (Callaway, et al, 2007). Wetlands are also important in combating climate change and its impacts. Wetlands serve as carbon sinks, storing 20-30% of the world’s soil-stored carbon (Cudmore, 2011). They also can help buffer the increased winter flooding and summer drought conditions that are predicted results of climate change by acting as sponges that trap storm water and release it slowly over time.

The predominant effects of climate change on terrestrial species will likely result from changes in vegetation communities. These changes are likely to include increases in the amount of oak, pine, chaparral, and montane hardwood vegetation, and a loss of conifer dominated vegetation. Snow-fed rivers and streams are likely to have less water, which may diminish the quantity and quality of wildlife habitat.

FLOODS AND SEA LEVEL RISE One of the projected impacts of climate change is the increased likelihood of extreme floods capable of destroying streamside land, buildings, roads, and crops. Floods can be especially severe near the coast and the bay shoreline, where higher tides caused by sea level rise can push flood levels even higher. In California, Sonoma County is already the top recipient of repetitive flood damage payments and, in fact, has losses greater than those of the next nine communities combined, making it the county with the highest number of properties suffering repetitive flood losses west of the Rockies. In 2005, the most recent year for which data is available, 30% of Sonoma County’s urban areas were in a high hazard area for flooding.

Sea level has risen approximately 7 inches over the last 100 years. Recent data from the Intergovernmental Panel on Climate Change predicts a 20-inch rise in sea level over the next 50 years and the San Francisco Estuary and Watershed Science journal predicts a sea level rise of 16-inches by mid century and 50-inches by the end of the century. The sea level rise anticipated from climate change has the potential to submerge historic wetlands and existing agricultural properties and threaten public infrastructure, including Highway 37 and the railroad unless the flood protection infrastructure (levees, ditches and pumps) is maintained.

HEAT AND FIRE

Climate Change is predicted to create more frequent and prolonged droughts; leading to water shortages for people and nature. Droughts dry up streams, stunt or kill crops, harm wildlife, and cause people to pump more groundwater near streams. As the land gets drier, streamside forests and wetlands come under more pressure to provide water, recreation, and wildlife habitat. As the land dries out, the risk of fire increases. When a rain event occurs after an area has been burned there is the threat of increased erosion hazards washing soils off hillsides into roads, ditches, and streams creating increased water quality concerns.

AGRICULTURE AND LOCAL ECONOMY Agriculture is uniquely vulnerable to climate change. Rising temperatures, constrained water resources, magnitude and persistence of droughts, and increased pest and disease pressure are among the climate change impacts that threaten to fundamentally challenge California agriculture in the coming years and decades. Models also predict pressures from weed, disease and pest shifts, and decreased crop yields, loss of chill hours for crops, and changing intensity and number of storms. Continued warming will create conditions unfavorable for production of many wine grape varieties in the future and may require farmers to change the cultivars they plant or move production further north and/or “upslope” to higher elevations.

Lands in the Southern portion of Sonoma County along the Highway 37 corridor contain agricultural lands in hay and grain, pasture for livestock grazing, and open space lands that support working landscapes. Grassland pasture and grain produced in the corridor are purchased by local dairies and meat producers and as such, hay producers grow specific crops and utilize methods for highest quality grain to meet local demands for livestock and equestrian feed and for high value milk, cheese, and meat products. This locally produced seed and grain feedstock contributes to the local agricultural economies supply loop by supporting local dairies and feed for grazing livestock. Local cultivation helps minimize the carbon and ecological footprint that would otherwise be more significant if the grain products were mostly shipped out of the region or needed to be imported. There is concern that increasing costs of doing business coupled with the challenges of maintaining levees for agricultural use and sea level rise in the vicinity will take agricultural acreage out of production.

There are a number of ways that agriculture benefits climate change and a variety of ways that farming practices could contribute to reducing future impacts. Farmland provides numerous additional benefits, including carbon sequestration, open space preservation, water absorption and filtration, and local food source. Agriculture and forestry offer the only currently available terrestrial ‘sinks’ of carbon dioxide. Among the soil management practices that have the greatest potential to sequester carbon are cover crops, perennial cropping, reduced synthetic fertilizer inputs, and conservation tillage. Composting and adding organic amendments have also resulted in increased carbon storage in soils. Increasing agricultural waste composting through anaerobic digesters and implementing methane digesters on dairies as an energy source for operation is a sustainable farming practice. Incorporating trees, shrubs or hedgerows into rangeland or farm landscapes can also sequester carbon in significant quantities. Restoring forested lands can dramatically increase carbon stocks. Cattle grazing can increase aboveground species richness and productivity of vegetation which is frequently correlated with increased soil carbon. Rotational grazing, a practice of intensively grazing and rotating livestock through paddocks, and converting from conventionally raised feedstock to perennial grasslands, has the potential to increase carbon. Lastly,

research has shown that significantly more carbon is sequestered in organic soils that are cultivated with animal manures and cover crops rather than conventional soils utilizing synthetic fertilizers.

SONOMA COUNTY CLIMATE INITIATIVES

Actions to address the current and future impacts of climate change within Sonoma County have made great progress in the last decade. The Sonoma County Board of Supervisors since 2001 has become increasingly committed to creating solutions to reduce greenhouse gases and effectively steward the environment. As a leader in climate protection, the county has invested in renewable efforts and proposed planning to curb the effects of climate change. These efforts include projects, programs and action plans to guide the goals and timelines set forth by the Board of Directors.

The Regional Climate Protection Partnership is an alliance between the County, SCWA, and the nine cities within the County to coordinate, implement and manage a series of best practices methods; which are to be administered by the Sonoma County Transportation Authority (SCTA) and Regional Climate Protection Authority (RCPA). The RCPA was established through legislation in 2009 to guide and coordinate climate change efforts between the County’s nine cities and numerous stakeholder agencies with the ultimate goal of reducing greenhouse gas emissions (GHG) throughout the region. Sonoma County partnered with the Climate Protection Campaign (CPC) in order to set an overarching greenhouse gas reduction target. This target projected the County to reduce emissions by the year 2015 to levels 25 percent below those calculated in 1990; a target which would be seen as one of the most demanding in the country (SCTA/RCPA, ). The CPC aided the County in designing and publishing the Community Climate Action Plan (CCAP); final document found here: http://www.coolplan.org/ccap-report/CCAP_Final_11- 05-08.pdf. In 2008, the document was complete offering an array of solutions to meet the challenges of climate change and provide solutions to sustain our climate and environment. The County is continues developing partnerships to increase conservation and adaptation initiatives.

Below is a list from the CCAP illustrating design:

Organized by Sector (Solutions are presented in four different sectors):

 Electricity and Natural Gas (including water, wastewater, efficiency, and new construction)

 Transportation and Land Use

 Agriculture and Forests

 Solid Waste

Assessed solutions rationally (solutions were analyzed using four criteria):

 Significant, rapid GHG emission reductions

 Cost effective

 Under local control

 Politically feasible

RECOMMENDED ACTIONS

Recommendation CA1-In riparian areas encourage native vegetation at multiple heights: groundcover, shrubs, and trees.

Recommendation CA2- In riparian areas encourage a patchwork of habitats, such as a small grassy area near a dense shrubby area near a group of tall trees.

Recommendation CA3-In riparian areas leave old and dead trees in place if they do not threaten structures.

Recommendation CA4-Allow natural processes, such as flooding and laying down new layers of sediment.

Recommendation CA5 -In forestlands look out for pest insects and disease, invasive species, and dying trees. If you have questions, contact University of California Cooperative Extension Master Gardeners or a private arborist.

Recommendation CA6- When you plant new trees or other plants, choose species that will be able to adapt to predicted future arid climate condition and from nurseries that collect, propagate, and disseminate tree species better adapted to the North Bay climate and changing environmental conditions

Recommendation CA7- Work to eradicate non-native pest insects, diseases, and invasive weeds on your property. Educate yourself on what to look for and how to avoid moving insects, diseases, and invasive species from infected areas to uninfected areas. The following websites are good places to start: www.suddenoakdeath.org and www.caforestpestcouncil.org.

Recommendation CA8-For wetlands complete large wetland restoration projects to serve as buffers to tidal flooding as well as sea level rise

Recommendation CA9 -For wetlands reduce development in low-lying areas, behind levees, or adjacent to the bay/coast and prevent or reduce other stressors that reduce the ability of the wetland ecosystem to respond.

Recommendation CA10- For wetlands identify and support projects that facilitate connectivity to marshes and wetlands prior to and as they are impacted by sea level rise

Recommendation CA11- For agriculture provide technical and financial incentives for agriculturalists to transition management practices that are affected by climate change.

Recommendation CA12-For agriculture consider transitioning to organic practice on agricultural operations.

Recommendation CA 13- For agriculture consider incorporating trees, shrubs, and hedgerows into rangeland or farm landscapes to sequester carbon

Recommendation CA14- For agriculture consider soil management practices that sequester carbon

CHAPTER 5. WATER QUANTITY

The availability of clean, freshwater is a key requirement for both human land uses and ecosystem function. In Northern Coastal California’s Mediterranean climate, water quantity can be a key limiting factor for all living things that depend on a watershed. Sonoma Valley residents are concerned about not having enough year-round water for personal use, agriculture, business, and the environment. At the same time, seasonal high flows also lead to major flooding concerns (See Chapter 6: Flooding). Water supply could be limited by drought, by the limits of the groundwater supply, and by limits on imported water. As a result of climate change the frequency and severity of droughts will likely increase in the future. Groundwater is technically a renewable resource, but on the timescale of decades it must be treated as finite.

This chapter presents a discussion of water demand and sources within the watershed, factors impacting water quantity, current conditions, and recommended actions related to water quantity.

WATER DEMAND

Quantifying the demand for water for human uses is difficult. Water conservation practices can, and already have, substantially reduced water demand per capita. Many water conservation practices are not yet in common use, although it seems likely that they may become widespread in the next decade. Some of these practices include graywater re-use, low-water landscaping, rainwater catchment, repair of leaking water and sewer pipes, re-use of treated wastewater (often called water recycling), and more efficient appliances in homes and businesses.

“In Sonoma County, a 500 square foot lawn needs about 2800 gallons of water each month, although many folks unnecessarily use up to 5000 gallons for that lawn. According to the Sonoma County Water Agency, here's how a three-person family in a single detached home uses about 150,000 gallons of water annually: 51% in the yard and mostly for lawn, 17% for toilet flushing, 15% for bathing, 11% for clothes washing, and the balance, 6% for all other household uses.” (Metzger, 2009).

Likewise, the need for water for the natural world is difficult to quantify. The California Department of Fish & Game has set mandatory streamflow rates in some streams to protect steelhead and salmon, but Sonoma Creek is not subject to any such mandate. Riparian and valley-floor trees rely on subsurface streamflow and shallow groundwater, but these requirements have not been quantified.

IMPORTED WATER

Imported water is subject to several constraints. Some 85 to 90 percent of the water used in urban homes and businesses (not including agricultural irrigation) in Sonoma Valley is imported through a pipeline from the Russian River to the Valley of the Moon Water District (VOMWD) and the City of Sonoma. The pipeline and associated transmission system are operated by the Sonoma County Water Agency (SCWA). Constraints on this supply source include water rights, transmission system limitations, potential supply limitations due to reduced diversion from the Eel River and Endangered Species Act compliance issues. In August 2009, SCWA changed its strategic trajectory, from planning to obtain and transport more water through an expanded pipeline, to either maintaining or reducing existing levels of water transported (Press Democrat, 2009). This policy change has increased the pressure on Sonoma Valley to reduce water consumption and develop sustainable ways to use local sources of water.

SURFACE WATER

The United States Geological Survey (USGS) operates two streamflow gauges in Sonoma Creek. The upstream gauge, north of Kenwood and southwest of Highway 12, between Hoff Road and Schukler Road, has been collecting data since 2008. During the period of record, flows less than 0.1 cfs were common in the low-flow season, while flows greater than 30 cfs were common in the wet season. Though the data record is shorter at this station, there is still a recorded instance of no flow for a month, during September 2009.

The downstream gauge, located west of the town of Agua Caliente at the Agua Caliente Road bridge, has been collecting data since 1955. During the period of record, flows less than 1 cfs were common in the low-flow season, while flows greater than 100 cfs were common in the wet season. Some years had no flow for many days. In 1977, the driest year on record with 15 inches of rainfall, there was no flow during July, August, and September.

The Limiting Factors Analysis for Steelhead (SEC, 2006) found that low streamflows were one of the factors most limiting the steelhead population in Sonoma Valley. Personnel surveying the streams for fish habitat encountered thousands of dead steelhead fry in dry pools.

Previous studies indicate that creek corridors have some of the highest groundwater recharge potentials of any land cover in the watershed (SEC and SCWA, 2011). Conversely, groundwater withdrawals in the vicinity of streams can reduce streamflows, depending on depth and geology of the well from which water is withdrawn.

GROUNDWATER

The goal of the Sonoma Valley Groundwater Management Plan (SCWA, 2007), a non-regulatory effort planned by a collaborative group of stakeholders. These stakeholders represent diverse groundwater interests including: local agriculture, dairies, government, local water purveyors, business, and environmental interests. The purpose of such collaboration is to locally manage, protect, and enhance groundwater resources for all beneficial uses, in a sustainable, environmentally sound, economical, and equitable manner for generations to come.

This GMP identifies a range of voluntary water management actions to sustain resources for future generations, including enhancing groundwater recharge and increasing water conservation and recycled

water use The GMP notes that groundwater pumping has resulted in a decline in groundwater levels in some parts of the watershed, based on data from the US Geological Survey (USGS, 2006). Two pumping depressions exist in the watershed: water levels southeast of the City of Sonoma are 40 feet below sea level; water levels southwest of El Verano are 20 feet above sea level. Also, groundwater level declines have occurred in the Oakmont, Kenwood and Carriger Creek areas (SCWA, 2007). Since the majority of wells with groundwater level declines have been monitored for five or fewer years, it is unclear whether this data indicates a long-term trend. According to the USGS study (USGS, 2006), most of the groundwater level declines are likely resulting from increased pumping in localized areas. The USGS study estimated that groundwater pumping in Sonoma Valley has increased from approximately 6,200 acre-feet per year in 1974 to 8,500 acre-feet per year in 2000. This represents a 37 percent increase over 25 years (USGS, 2006 and SCWA, 2007).

Numerous data gaps and limitations exist regarding water use and groundwater levels. The GMP identifies data needs for groundwater levels, pumping, streamflow, recharge and land use change.

RECYCLED WATER

The Sonoma Valley County Sanitation District, managed by the Sonoma County Water Agency, delivers tertiary treated wastewater to agricultural users to offset groundwater withdrawals for irrigation between May 1 and October 30 each year. Recycled water is used to irrigate more than 2,000 acres of winegrapes in the Carneros region, as well as local dairy pasture and silage lands (cite SCWA/SVCSD website here?). In 2005, the North Bay Water Reuse Program was established as a coordinated regional effort among a group of water and sanitation agencies in Sonoma, Marin and Napa Counties, to offset potable water demand by promoting water reuse for agriculture, urban and environmental uses (cite NBWRP website here?). Phase 1 of this program included construction of a 100 acre-foot recycled water reservoir in 2011. This project, referred to as “Reservoir 5,” increased the Sanitation District’s recycled water storage capacity to 232 million gallons (cite SCWA website again). Efforts to increase storage, distribution, and use of recycled water in Sonoma Valley are ongoing.

FACTORS IMPACTING WATER QAUNTITY

There are many factors that impact the availability of groundwater, surface water, and imported water in Sonoma Valley. They include:

 excessive groundwater extraction in some areas

 species protection mandates that limit future water exports from the Russian River

 direct withdrawal of water from streams

 climate change, increasing the frequency and severity of drought

 climate change, which may cause briefer, more intense storms with less infiltration and groundwater recharge

 paving, rooftops, and compacted surface soils, which increase runoff at the expense of infiltration and groundwater recharge; and

 inefficient water use practices

The Sonoma Ecology Center’s 2010 Sonoma Creek Watershed Water Supply Scorecard indicates the following conditions and trends in the watershed’s water supply.

Table 5.1. Water Supply Conditions and Trends Watershed Watershed Health Health Index Indicator Score Trend Precipitation Annual rainfall was extremely low relative to the Poor N/A (annual historical record. As a result, there was less water data only) flowing in creeks and rivers, and less water available to recharge the groundwater table. Natural Annual Flow Supply Because of low annual rainfall, there was less Poor N/A (annual water flowing in Sonoma Creek and its tributaries. data only) Less water in streams means less habitat for wildlife, as well as less water for urban and agricultural use. Dry Reaches Poor Not 36% of the stream miles that could support aquatic evaluated Streams life went dry during summer, reflecting over-use of water during this critical season. Groundwater - North Basin Poor Declining Groundwater storage and recharge are low relative to the historic record, and are declining in the northern part of the watershed. Storage Groundwater - South Basin Good Declining Groundwater storage and recharge are high relative to the historic record, and are declining slowly in the the sourthern part of the watershed. Impervious Area Fair Declining Impervious surfaces like pavement and roofs Landscape cover over 3% of the watershed, a level that Permeability interferes with groundwater recharge, runoff, and other critical watershed functions. Water Conservation Fair No Trend Water used per person was moderate relative to Observed Stewardship the historic record, but far from targets set by regional water planners.

Water Independence Fair Improving There is substantial room for improvement in both the re-use of treated wastewater and the reduction of water imports

RECOMMENDED ACTIONS

Recommendation WQAN1 – Continue to implement the Sonoma Valley Groundwater Management Plan

Recommendation WQAN 2 – Implement urban and rural water conservation measures such as low- water landscaping, water saving appliances and fixtures, and graywater re-use. Programs to offset costs of many of these measures are available through the City of Sonoma, Sonoma Valley County Sanitation District, and Valley of the Moon Water District.

Recommendation WQAN 3 – Implement Slow It, Spread It, Sink It! guidelines to manage stormwater for re-use and groundwater recharge.

Recommendation WQAN 4 – Increase agricultural water use efficiency. See Chapter 3: Agricultural and Rural Sustainability for more information.

Recommendation WQAN 5 – Continue to expand the storage, distribution and use of recycled water.

CHAPTER 6. FLOODING

Flooding is a serious concern in portions of the watershed. Localized flooding occurs in the towns and rural areas on the valley floor, even during relatively small winter storm events. As a result, the community of Schellville and areas downstream are inundated during heavy rains. Also, flooding has occurred in the upper reaches of the watershed, along Sonoma Creek.

This chapter discusses historic and current flooding conditions, opportunities, constraints, and recommended actions with regard to flooding.

HISTORIC AND CURRENT CONDITIONS

Historical records indicate flooding has occurred regularly along Highway 121 in Schellville for more than 50 years. Flooding in recent years has increased, sometimes backing up beyond Schellville to the City of Sonoma. Anecdotal evidence from a group of approximately 40 landowners indicates almost annual flooding since the 1950s. Recurrent flooding has caused economic loss and considerable damage to private property and roadways. The lower part of Sonoma Creek is influenced by tidal circulation, which affects the hydraulic and sediment transport characteristics of the creek. In fact, most flooding below Highway 121 is controlled by San Pablo Bay water levels, while flooding above Highway 121 is controlled by a combination of creek flood flows and high water levels downstream (ESA PWA & SSCRCD, 2012).

Historic flood events are recorded as far back as 1824, and since then in 1842, 1902, 1925, 1937, 1940, 1942, 1952, 1955, 1964, 1967, 1982, 1998, 2003. These dates were collected from historic newspaper articles, a US Army Corps of Engineers report, and landowner interviews, and compiled in a 2004 geomorphic analysis report (Collins & Leising, 2004). As of that report, the 1955 flood was the largest flood of record, inundating 6,300 acres, with overbank flow lasting about 12 hours, and flood waters remaining on the land in some places for up to 4 weeks.

Recent flooding events include an extreme flood event on New Years Eve 2005 and an intense rainfall event on January 4, 2008. The 2005 event was a 100-year storm event in which peak flows at the Agua Caliente USGS gauge reached a record high of 20,300 cubic feet per second (cfs). The storm caused extensive flooding and flood damage in the lower watershed, including several levee failures. The 2008 event (roughly a 5 year event) resulted in approximately 2 feet of storm surge in San Pablo Bay, impacting water levels up to the Sonoma Valley airport and above. Sonoma Creek overtopped its banks upstream of Highway 121, and water flowed east across Highway 12, south across Highway 121 and down Millerick Road. Peak flow at the Agua Caliente USGS gauge was 7,820 cfs.

Lower Sonoma Creek Highway37, which runs approximately east-west through the southernmost portion of Sonoma Valley, is one of the lowest-elevation highways in the Bay Area and at its lowest elevation, the roadbed is currently just below sea level. In 2012, Highway 37 was the subject of the State Highway Corridor Planning California Case Study conducted by the University of California, Davis, in partnership with the CA Department of Transportation, and local partners the Southern Sonoma and Napa RCDs, Sonoma Land

Trust, and Sonoma Ecology Center (Shilling et al, 2012). The following information is adapted from a technical memorandum prepared by the local partners in this study (SEC et al, 2012).

The Highway 37 corridor includes the lands around San Pablo Bay that are now or were historically submerged by the tides. Conversion of tidelands to farm land occurred under the Swamp Land Act of 1849 (modified in 1850 and 1860). Private individuals were offered land at no cost, provided that they would drain and develop these wetlands, which were defined as “wet and unfit for cultivation.” Landowners installed a system of levees to keep tidewater out and ditches and pumps to remove storm water making it possible to farm productively. (This Federal wetlands policy was reversed in 1988 when the “no net loss” of wetlands policy was adopted.) This resulted in establishing a robust regional agricultural economy supporting hay, grain, pasture, and vineyards. Highway 37 was constructed in the early 1900s as the primary transportation link across the North Bay and it serves local agricultural producers and connects communities and long distance travelers to the north bay.

To a large extent, these levees are still maintained today and they are the infrastructure that serves to alleviate flooding along the Highway 37 corridor and keeps Sonoma County agriculture viable and sustainable. The costs of maintaining the levee and pump infrastructure is borne by landowners in the region, including farmers, ranchers and other private landowners and federal, state and local government and nongovernmental organizations.

In order to maintain the levees, landowners are required to obtain permits the following regulatory agencies: the U.S. Army Corps of Engineers (with consultation from the National Marine Fisheries Service and U.S. Fish and Wildlife Service), Sonoma County, CA Department of Fish and Wildlife, Regional Water Quality Control Board, Bay Conservation and Development Commission and the State Lands Commission. Often, obtaining permits can be a lengthy and costly process. In order to save levee landowners time and money, and to streamline the time spent by the regulatory agencies reviewing the permit applications, the RCD administers permits issued by each regulatory agency for levee maintenance activities being completed by numerous landowners. The permits include restrictions as to when and how much levee maintenance work can be completed. It also ensures that the environment and endangered species are protected.

The effort of creating a permit program for maintaining the levees required the cooperation of many agencies, landowners, elected officials and the RCD. The first permits were issued in 1980 and the RCD applies for a renewal of permits every five years. Mitigation for this permit program was required by the regulatory agencies and included the construction of approximately 71 acres of wetlands in Southern Sonoma County. As of 2013, there are twenty-nine participating landowners from the Petaluma River and Sonoma Creek Watersheds.

The construction of Highway 37 acts as a levee in some areas, offering protection to adjacent low-lying land, but is vulnerable to flooding because its elevation is below projected sea levels. Caltrans has not experienced any major levee failures or other dramatic short-term problems, but localized flooding does occur regularly during extreme high tide (9 feet or higher) and storm events. Currently the highway is closed less than 20 hours / year. However, the likelihood, extent, and precise location of flood occurrences are unpredictable due to several factors including storm duration, intensity, timing of tides, physical constraints in conveyance and because there is no current, accurate knowledge of the location,

height, and strength of berms and levee-like structures. Climate change and its associated impacts on sea levels and storm frequency/duration/intensity, make flooding increasingly unpredictable in this area.

Upper Sonoma Creek Flood management activities in the upper Sonoma Creek watershed (north of Hwy 121), also referred to as the Zone 3A Flood Protection Zone are carried out by the Sonoma County Water Agency’s (SCWA) Stream Maintenance Program. Flood protection activities in Zone 3A are prioritized and approved by a Zone Advisory Committee, with members appointed by County Supervisors and cities whose jurisdiction overlaps with the boundaries of the Flood Protection Zone.

SCWA owns, or has easements to maintain hydraulic capacity, on approximately 75 miles of engineered flood control channels throughout Sonoma County. The Agency also has easements to maintain hydraulic capacity over approximately 100 miles of modified or natural channels (SCWA, 2013). Map 6.1 illustrates the flood control channel and stream segments maintained by SCWA within Zone 3A.

Flood protection activities carried out by SCWA, funded through tax assessments from the flood control zones include excess sediment removal, repair and stabilization of banks along engineered channels and streams, and vegetation management. In addition to flood control protection, these management practices have the added benefit of promoting improved water quality and habitat for wildlife (SCWA, 2013).

[Insert Map 6.1: Stream Maintenance Program Zone 3A here]

FLOOD MANAGEMENT AND ECOSYSTEM ENHANCEMENT OPPORTUTNITES

In 2000, the SSCRCD and Army Corps of Engineers entered into an agreement to conduct a feasibility study to indentify alternatives that would alleviate flooding and reduce flood‐related damage to public facilities, structures, roads, railroad tracks, pasture lands and crops while restoring and enhancing habitat and improving ecological and hydrological functions in lower Sonoma Creek. In 2012, the final phase of this study, titled the Lower Sonoma Creek Flood Management and Ecosystem Enhancement project (ESA PWA & SSCRCD, 2012), was completed with funding from California Coastal Conservancy and the Sonoma County Water Agency. Technical analysis and evaluation was performed by consultants ESA PWA, with the Sonoma Ecology Center providing GIS mapping data and Watershed Sciences developing baseline information. Public involvement and outreach to stakeholders was an integral component of the technical studies.

The study focuses on the southern portion of the Sonoma Creek watershed, within the reaches of Sonoma Creek and Schell Creek from immediately upstream of Highway 121 to San Pablo Bay. The primary focus of the study was to develop a project concept to accomplish flood management and habitat restoration in the Schellville area. The original study scope was expanded to include evaluation of sea level rise and identified climate adaptation opportunities in Lower Sonoma Creek that are consistent with habitat enhancement goals. The study identified the following opportunities and constraints, and evaluated the following alternative project elements.

Opportunities:

 Work with willing and engaged landowners

 Create upstream detention or retention in the watershed to reduce flood flows

 Shift to flood‐compatible land uses, including tidal wetland restoration

 Restore tidal wetlands for habitat and climate change resilience

 Enhance flood conveyance above zone of San Pablo Bay influence (potential cost‐share funding for wetland restoration for eligible agricultural producers)

Constraints:

 Topographic setting and San Pablo Bay influence on water levels

 Adjacent lands are high‐value (e.g., vineyards)

 Lack of funding support for extensive new levees or dredging

 DFG Camp 2 Unit is managed for freshwater wetlands, upland game

 Flow interactions between Sonoma and Schell Creeks can mean that “solutions” redirect flood hazards

 Fiscal constraints: minor benefits for significant costs; lack of funding mechanisms; limitations on land purchase prices if publicly funded

 Existing infrastructure: County and State roadways, railroad embankment, bridges, channels, culverts, and levees/berms

Alternative Project Elements Evaluated:

 Full‐length, wide lowered floodplain terrace or short, narrow lowered floodplain terrace

 Levee spur upstream of Highway 121 to contain and redirect flood flows

 Sonoma Creek right bank levee shift west downstream of Highway 121

 Weir connection between Sonoma Creek and Railroad Slough

 Tidal wetland restoration near Wingo

 Creek channel expansion at the Highway 121 bridge

 Floodplain lowering/reconnection at the junction of Sonoma Creek and Fowler Creek

 Schell Creek overflow channel and culvert under Highway 121

The study recommends a watershed‐wide approach, consisting of three main elements: 1) stormwater detention/retention in the upper watershed, 2) facilitation of a shift to flood‐compatible land uses along Lower Sonoma Creek, such as through the acquisition of easements on flood‐prone lands for seasonal flooding, and 3) acquisition of flood‐prone lands for restoration to tidal wetlands.

RECOMMENDED ACTIONS The following specific recommendations were identified in the Lower Sonoma Creek Flood Management & Ecosystem Enhancement study (ESA PWA & SSCRCD, 2012).

Recommendation FL1 – Implement upper watershed stormwater management to reduce flood peak flows and reduce overbank flow into Schell Creek and across Highway 121 through attenuation or diversion into storage.

Recommendation FL2 – Elevate or flood proof some buildings or construct small lengths of levee to protect remaining developments within the floodplain from most hazards.

Recommendation FL3 – Restore valuable tidal wetlands in Schellville area for endangered species habitat, managed retreat to protect some inland uses, carbon sequestration, promotion of tidal scour, and potential reduction in levee maintenance costs. There is significant potential to create valuable wetlands and expand areas on San Pablo Bay with good opportunity to create valuable mid‐ elevation, or middle, marsh habitat. Timing of such creation of middle marsh is important to initiate marsh accretion and thereby attain marshes that are sustainable in the mid‐term, given sea level rise.

Recommendation FL4 – Initiate and continue landowner outreach to conduct appraisals, solicit funds, and negotiate purchase agreements and/or flood easements.

Recommendation FL5 – Leverage infrastructure investments (highway and rail) and initiate climate change adaptation planning to benefit climate change resilience and reduce flood risks in the Schellville area.

Recommendation FL6 – Collaborate and seek funding for watershed‐wide effort to establish parameters of a multiple‐benefit project involving elements of: water quality improvement, surface and groundwater storage, rainwater harvesting, use of recycled water, wetland restoration, and seasonal flood easements to allow continued agriculture.

CHAPTER 7. WATER QUALITY

Water quality refers to the physical, chemical and biological characteristics of water. Water quality information can be used to assess the safety of surface water for a variety of beneficial uses ranging from contact recreation to aquatic fish and wildlife habitat requirements. Water quality is often framed in context of measureable concentrations of contaminants.

Water quality is determined and affected by a complex web of chemical, physical and biological processes. A wide range of human activities can contribute pollutants and affect water quality depending on the type of activity, its timing, location, duration and intensity. The concentration of pollutants varies by season, by day, and sometimes from hour to hour. This can make it difficult to measure water quality and critical to build a data record over time to assess how different conditions affect water quality.

This chapter includes a description of Sonoma Creek watershed’s water quality, including beneficial uses, pollutants and pollutant sources, the Total Maximum Daily Load (TMDL) processes conducted in the watershed, and recommended actions to protect and improve water quality.

BENEFICIAL USES

Beneficial uses, as defined by the State Water Resources Control Board of the California Environmental Protection Agency, defines beneficial uses as the resources, services, and qualities of aquatic systems that are the ultimate goals of protecting and achieving high water quality. According to the Water Quality Control Plan for the San Francisco Bay Basin (Basin Plan), the SF Bay RWQCB has identified several beneficial uses for Sonoma Creek:

 Cold Freshwater Habitat (COLD)  Fish Migration (MIGR)  Preservation of Rare and Endangered Species (RARE)  Water Contact Recreation (REC-1)  Non-contact Recreation (REC-2)  Fish Spawning (SPWN)  Warm Freshwater Habitat (WARM)  Wildlife Habitat (WILD)

In terms of rare and endangered species (RARE), Sonoma Creek supports an assemblage of native aquatic species, including a threatened run of steelhead trout, Onchorhynchus mykiss, as well as endangered California freshwater shrimp. (For a complete list of endangered or threatened species in the watershed see Chapter 2: Watershed Description and History).

Total Maximum Daily Loads

Total Maximum Daily Loads (TMDLs) are regulatory documents that identify the maximum amount of a pollutant that a waterbody can receive and still meet water quality standards, allocate that load among the various sources of that pollutant, and set forth a plan to reduce pollutant loads to target allocation levels.

Section 303(d) of the federal Clean Water Act requires that states identify water bodies that do not meet water quality standards, and develop TMDLs for those water bodies. All identified impaired water bodies are included in a list of impaired and threatened waterbodies (303(d) list), which is updated every 2 years. TMDLs are specific to each waterbody/pollutant combination, e.g. Sonoma Creek/sediment, and a TMDL must be developed for each waterbody/pollutant combination on the 303(d) list.

TMDLs account for all the sources of a pollutant, including discharges from wastewater treatment facilities; runoff from homes, agriculture, and streets or highways; "toxic hot spots;" and deposits from the air. In addition to accounting for past and current activities, TMDLs may consider projected growth that could increase pollutant levels. The San Francisco Bay Regional Water Quality Control Board (Regional Water Board) is developing more than 30 TMDL projects to address more than 160 listings for water bodies impaired by specific pollutants. For example, the TMDL project for diazinon and pesticide- related toxicity in San Francisco Bay Area urban creeks addresses more than 30 impaired urban creeks.

Table 7.1. Sonoma Creek Water Quality Objectives and Sediment-Related Beneficial Uses (SEC et al., 2006b)

Water Quality BENEFICIAL USE Numeric or Narrative Target Objective Cold Freshwater Habitat Increase from background Turbidity <10% where natural turbidity

Fish Migration is >50 NTU* Should not cause a nuisance or SEDIMENT Preservation of Rare and Endangered adversely affect beneficial uses Speciesi Settleable Should not cause a nuisance or Fish Spawning Material adversely affect beneficial uses

Warm Freshwater Habitat Should not cause a nuisance or Suspended Material adversely affect beneficial uses Wildlife Habitat Cold Freshwater Habitat The health and life history

characteristics of aquatic organisms Fish Migration Population and in water affected by controllable Community Ecology water quality factors shall not differ Preservation of Rare and Endangered significantly from those for the Species same waters on areas unaffected by

controllable water quality factors Fish Spawning

Note: Bold italics indicates water quality objective is not currently being attained. *NTU = Nephelometric turbidity unit i Preservation of rare and endangered species listed under state or federal law as rare, threatened, or endangered. Steelhead within the Central California Coast, including the Sonoma Creek and its tributaries, are listed as threatened under the federal Endangered Species Act (ESA). California freshwater shrimp have been found in the lower portion of Sonoma Creek. These shrimp are federally listed as endangered species.

Sonoma Creek is listed (in the 2010 version of the 303(d) list) as impaired for sediment, pathogens, and nutrients harmful to beneficial uses in the watershed. While the listings apply to main stem Sonoma Creek, the water quality targets, allocations, and implementation plans apply throughout the watershed in order to assure attainment of water quality standards.

TMDLs for pathogens and sediment were adopted by the Regional Water Board in 2006 and 2008, respectively. These TMDLs will be discussed further in the following sections. As of the writing of this plan (2103), a nutrient TMDL for Sonoma Creek is pending.

SEDIMENT

The Sonoma Creek Watershed Sediment TMDL and Habitat Enhancement Plan was adopted by the Regional Water Board in 2008. The TMDL defines the allowable amount of sediment that can be discharged into Sonoma Creek, expressed as a mass, and as a percentage of the natural background sediment delivery rate to channels.

Some level of suspended and bed load sediment is normal and important to the function of any stream system. In systems with excessive sediment loads, however, beneficial uses can be impaired. Excessive sediment can clog pools, limiting instream habitat for fish and other wildlife, including rare, threatened and endangered species. Clogged pools can also lead to increased water temperature and flooding. Excessive sediment can clog gravels, impairing the ability of streams to support fish spawning. And suspended sediment clouds water, leading to impacts on aquatic species, as well as aesthetic impacts that limit recreational beneficial uses.

Water Quality Standards

Water Quality Objectives from the Basin Plan and TMDL targets combine numeric and narrative targets related to sediment and beneficial uses in Sonoma Creek watershed.

Table 7.2. TMDL Sediment Targets for Sonoma Creek and its Tributaries Parameter Target Spawning gravel permeability Median value ≥ 7000 cm/hra Pool filling Decreasing trend in the volume of fine sediment deposited in pools Substrate Composition Percent of fine sediment less than 0.85 mm in diameter is less than or equal to 14 percent of the total bulk core sample (<14% fines < 0.85 mm)b

Percent Fines Percent of fine sediment less than 6.40 mm in diameter is less than or equal to 30 percent of the total bulk core sample (<30% fines < 6.40 mm)b a Target applies to all potential spawning sites for steelhead and salmon in Sonoma Creek and its tributaries.

b Target applies to wadeable streams and rivers with gradient less than 3 percent. A wadeable stream is one which an average human can safely cross on foot during the summer, low flow season while wearing chest waders.

Available Data

Datasets available to track progress in sediment load reductions in Sonoma Creek and tributaries include total suspended solids (TSS), turbidity, stream flow, and benthic macroinvertebrates (BMIs). These datasets are made public, as well as summarized in a Watershed Health Scorecard, in the Sonoma Valley Knowledge Base, at http://knowledge.sonomacreek.net/. The most recent Watershed Health Scorecard that includes water quality (2009) indicates fair watershed health scores for suspended sediment, benthic macroinvertebrates sensitive to sediment and other stream pollutants, and sediment supply as indicated by turbidity. All data are SWAMP compatible, or are being made SWAMP compatible, and were collected under state-approved Quality Assurance Project Plans and Monitoring Plans. Future data collection, analysis, and study design will benefit from knowledge and integration of these plans (also in the Knowledge Base).

Pollutant Sources Pollutant sources and load allocations are listed in Table 6 of the Sonoma Creek Watershed Sediment TMDL and Habitat Enhancement Plan, Staff Report (Low and Napolitano, 2003). The table, copied below, reflects the report’s linkage analysis: a determination of the link between sediment inputs and their impacts on habitat conditions. The staff report expressed natural background for sediment, then based load allocations on 125% of background (1.25 x 52,300 tons/year). The result, 65,375 tons/year, is rounded up to a total sediment wasteload allocation of 65,400 tons/year.

Table 7.3. Sonoma Creek Sediment Load and Wasteload Allocations (tons/years) Source Category Current (2005) Estimated Allocation Load Reductions

Needed (%) Tons/year Percent Natural Background

Natural Processes

Channel Erosion, incision 25,400 0 25,400 49

Load Allocations Load Colluvial Bank Erosion (Soil 16,600 0 16,600 32 Creep)

Surface Erosion 6,200 0 6,200 12

Landslides 4,100 0 4,100 8

Human Actions

Channel Erosion, incision 43,300 81 8,100 15

Roads and Streams Crossings 11,200 81 2,100 4

Surface Erosion, including 8,600 81 1,600 3 vineyards, grazed lands, unmanaged areas, and minor agriculture

Landslides 900 81 200 0.4

TOTAL 116,300 64,300 123

Municipal Stormwater- 600 0 600 1 NPDES Permit No. CAS000004

Construction Stormwater- 300 0 300 0.6 NPDES Permit No. CAS000002

Industrial Stormwater- 100 0 100 0.2

NPDES Permit No. CAS000001

CalTrans Stormwater- 100 0 100 0.2 NPDES Permit No. CAS000003

TOTAL 1,100 1,100 2

Wasteload Allocations Wasteload TOTAL ALLOCATIONS= TMDL=125% of 65,400 125 Natural Background

*Sediment loads and allocations are rounded to the nearest hundred. Some total may not appear to add up due to rounding.

**Table 5 also displays the estimated current (2005) sediment loads. Total current (2005) estimated sediment load= 117,400 tons/year.

***Source categories included in the wasteload allocations (e.g. municipal stormwater) are described as “urban stormwater” in Table5. The term “urban stormwater” in Table5 incorporates municipal, construction, industrial, and Caltrans stormwater

Human-caused sources of sediment—erosion of soils and bedrock due to agriculture, urban/suburban runoff, road erosion, streambed and bank erosion, and landslides—are discussed further below. All are

subject to the 82% reduction called for by the sediment TMDL, with early deadlines for implementation beginning in 2014. Chapter 8: Sediment Sources and Impacts, provides a more thorough discussion of sediment sources and management techniques.

Agriculture (livestock and cropland)

By controlling runoff from livestock areas and croplands, aquatic beneficial uses of Sonoma Creek are protected. Wasteload allocations are 1,600 tons/year, down from current estimated levels of 8,600 tons/year. Studies for TMDLs in neighboring watersheds show that the creation of Ranch Water Quality Plans and implementation of Monitoring Plans throughout watersheds help attain the following estimated reductions:  50-75% reduction in fine sediment delivery from riparian fencing and revegetation projects  80% survival for planted revegetation projects.

Chapter 3: Agricultural and Rural Sustainability provides further discussion of Ranch Water Quality Planning, agricultural sediment reduction efforts, and water quality regulations that impact agricultural management practices.

Urban/Suburban Runoff

Runoff from urban areas, specifically from hardened surfaces in neighborhoods and municipal areas flow with increased velocity when compared to runoff from non-hardened surfaces. Increased velocity erodes receiving waterways and contributes to sediment pollution. Estimates from the Staff Report indicate approximately 300 tons/year from construction stormwater, 600 tons/year from municipal stormwater, 100 tons/year from industrial stormwater, and 100 tons/year from CalTrans operations.

Urban & suburban runoff is often routed to creeks through municipal stormwater systems. These systems are regulated under the National Pollutant Discharge Elimination System (NPDES) through Municipal Separate Storm Sewer System (MS4) permits. The City of Sonoma’s MS4 permit includes the following Minimum Control Measures (City of Sonoma, 2013):

1. Public Education: The City of Sonoma must educate the public in its permitted jurisdiction about the importance of the stormwater program and the public's role in the program.

2. Public Participation: The City of Sonoma must comply with all State and local notice requirements when implementing a public involvement and participation program.

3. Illicit Discharge Detection and Elimination: The City of Sonoma must adopt and enforce ordinances or take equivalent measures that prohibit illicit discharges. The City of Sonoma must implement a program to detect illicit discharges.

4. Construction Site Stormwater Runoff Control: The City of Sonoma must develop a program to control the discharge of pollutants from construction sites greater than or equal to one acre in size within its permitted jurisdiction. The program must include inspections of construction sites and enforcement actions against violators.

5. Post Construction Stormwater Management: The City of Sonoma must require that long-term post-construction Best Management Practices which protect water quality and control runoff flow be incorporated into development and significant redevelopment projects. Post-construction programs are most efficient when they emphasize low impact design, source controls, and treatment controls.

6. Pollution Prevention and Good Housekeeping for Municipal Operations: The City of Sonoma must develop and implement a program to reduce the amount of polluted runoff resulting from municipal operations. Municipal operations include street sweeping, storm drain system cleaning, and responding to hazardous spills.

Individual homeowners who are on storm drain systems can help to prevent urban and rural stormwater pollution by keeping trash and chemicals off of streets and out of storm drains. Homeowners, both those who are on storm drain systems and those who are not, can also help with stormwater pollution by installing “Slow It, Spread It, Sink It!” practices such as rain gardens, downspout outlet protection, pervious hardscapes, and more.

Road Erosion

Increased velocity of runoff from hardened road surfaces, as well as gullying, sheetflow, and channeling of flow in inboard ditches, are all contributing factors to sediment production in Sonoma Creek watershed. Information about road erosion and sediment is made public in the Sonoma Valley Knowledge Base, at http://knowledge.sonomacreek.net/. Wasteload allocations for road and stream crossings are 2,100 tons/year, down from current estimated levels of 8,600 tons/year.

Chapter 8: Sediment Sources and Impacts provide further discussion of road-related erosion and sediment reduction efforts on rural roads.

Streambed and Bank Erosion

The TMDL Basin Plan Amendment noted that, of all human-caused sediment contributions to surface water in Sonoma Creek watershed (66,000tons/year), human-caused channel sources are estimated to contribute 66%, or 43,300 tons/year. Wasteload allocations for channel erosion and incision are 8,100 tons/year, down from current estimated levels of 43,300 tons/year. Modification of the watershed has been identified as the reason for human-caused sediment production from channel sources.

Commercial silviculture is not a substantive source of sediment in the watershed: there are not enough current forestry operations to contribute substantially to water quality problems. However, legacy effects from past silviculture, as well as unregulated tree felling in the riparian zones of Sonoma Creek and tributaries, has contributed to loss of root strength in trees that would otherwise stabilize streambanks, causing erosion and incision of streambanks and loss of dynamic equilibrium of stream channels due to tree felling too near the thalweg of Sonoma Valley streams (SEC et al., 2006).

PATHOGENS AND NUTRIENTS

The Sonoma Creek Pathogen TMDL was adopted by the Regional Water Board in 2006 and approved by US EPA in 2010. The TMDL defines the allowable amount of sediment that can be discharged into Sonoma Creek, expressed in terms of density (colony-forming units per volume of water).

Pathogens pose a threat to human health, and limit the recreational beneficial uses of a water body. While not all bacteria are pathogenic, specific types of bacteria can be used as indicators to predict the likelihood that pathogens are present.

As of the writing of this plan (2013), a nutrient TMDL for Sonoma Creek is pending. Many management activities identified in the pathogen TMDL to reduce loading of pathogens into Sonoma Creek and its tributaries also reduce the loading of nutrients.

As with sediment, some level of nutrients is natural and necessary to the functioning of any water body. Elevated levels of nutrients, however, can lead to excessive algae growth, which causes impacts aesthetics and impairs recreational beneficial uses. Additionally, excessive algal growth can lead to decreased dissolved oxygen levels in the water when the algae decompose. This phenomenon, called eutrophication, can be damaging to fish and other aquatic life, including rare, threatened and endangered species.

Water Quality Standards

Water Quality Objectives from the Basin Plan and TMDL are density-based numeric targets, as well as a zero discharge target for inadequately treated human waste.

Table 7.4. TMDL Pathogen Water Quality Targetsa for Sonoma Creek Parameter Target E. coli density Geometric mean <126 CFU/100 mLb Ninetieth percentile <409 CFU/100 mLc Fecal coliform densityd Geometric mean <200 CFU/100 mLb Ninetieth percentile <400 CFU/100 mLc Total coliform densityd Median <240 CFU/100 mLb No sample to exceed 10,000 CFU/100 mL Zero discharge of untreated or inadequately treated human waste to Sonoma Creek and its tributaries or to groundwater with direct through flow to these surface waters. a These targets are applicable year-round. b Based on a minimum of five consecutive samples collected at approximately equal intervals over a 30- day period c No more than 10 percent of total samples during any 30-day period may exceed this number d The water quality targets for total and fecal coliform shall sunset and shall no longer be effective upon the replacement of the total and fecal water quality objectives in the Basin Plan with E. coli based water quality objectives for recreation.

A TMDL for nutrients in Sonoma Creek has not yet been completed, and no numeric targets for nutrients in the watershed exist. The Basin Plan contains the following narrative objective for biostimulatory substances, which applies to nutrients:

“Waters shall not contain biostimulatory substances in concentrations that promote aquatic growths to the extent that such growths cause nuisance or adversely affect beneficial uses. Changes in chlorophyll a and associated phytoplankton communities follow complex dynamics that are sometimes associated with a discharge of biostimulatory substances. Irregular and extreme levels of chlorophyll a or phytoplankton blooms may indicate exceedance of this objective and require investigation.”

Available Data

The Regional Water Board collecting water quality data in 2002 and 2003 for the development of the pathogen TMDL. Exceedances of US EPA-recommended pathogen levels were observed at several locations: Sonoma Creek below Kenwood, at Glen Ellen, at Sonoma Developmental Center, at Highway 121; Nathanson Creek at Nathanson Creek Preserve; and Schell Creek at Highway 121 (North Coast Regional Water Board, 2013).

The Regional Water Board also conducted sampling for nutrient levels and algal growth in 2011 for the development of a TMDL for nutrients, still under development as of the writing of this plan (2013). Data is summarized as follows on the Regional Water Board’s website:

“The data collected during the 2011 dry season showed that nutrient concentrations, physical habitat quality, and algae biomass (as given by chlorophyll concentrations) were similar at sites in the Sonoma Creek watershed. Overall, few sites showed high chlorophyll levels despite some moderate nutrient concentrations. Most, but not all, sites were below the chlorophyll thresholds thought to be protective of cold water beneficial uses (100 mg chlorophyll per square meter of stream bed). Algae need both nitrogen and phosphorous to grow and, usually, algae growth is limited by one of these two nutrients. Nearly all of the sampling sites had excessive phosphorous, which means that algae growth is limited by the availability of nitrogen. The weather in 2011 was generally cool and wet, so algae growth could have been suppressed by climate.” (North Coast Regional Water Board, 2013).

Pollutant Sources Pollutant sources and load allocations are listed in Table 9 of the Sonoma Creek Watershed Pathogen TMDL, Staff Report (Low and Krottje, 2006). The table, copied below, indicates the report’s linkage analysis.

Table 7.5. Density-Based Pollutant Load and Wasteload Allocations for Discharges of Pathogens in the Sonoma Creek Watershed

Load Allocations

E. coli Fecal coliform Total coliform

Categorical Geometric 90th Geometric 90th Geometric 90th Pollutant mean percentile mean percentile mean percentile Source

On-site 0 0 0 0 0 0 sewage disposal systems

Sanitary 0 0 0 0 0 0 sewer systems

Grazing lands <113 <368 <180 <360 <216 9,000

Wildlife <113 <368 <180 <360 <216 9,000

Wasteload Allocations

Categorical E.coli Fecal coliform Total coliform Pollutant th th th Source Geometric 90 Geometric 90 Geometric 90 mean percentile mean percentile mean percentile

Sonoma <126 <409 <200 <400 <240 10,000 Valley County Sanitation District NPDES Permit No. CA0037800

Municipal <113 <368 <180 <360 <216 9,000 runoff (NPDES Permit No. CAS000004)

*These allocations are applicable year-round. Wasteload allocations apply to any sources (existing or future) subject to regulation by a NPDES permit. Load allocations and the wasteload allocation for municipal runoff reflect a 10 percent Margin of Safety.

**The allocations for total and fecal coliform shall sunset and shall no longer be effective upon the replacement of the total and fecal water quality objectives in the Basin Plan with E. coli based water quality objectives for contract recreation.

***Based on a minimum of five consecutive samples collected at approximately equal intervals over a

30-day period.

**** No more than 10% of total samples during any 30-day period may exceed this number.

*****Wildlife are not believed to be a significant source of pathogens and their contribution is considered natural background; therefore, no management measures are required.

Human-caused sources of pathogens—agricultural runoff, urban/suburban runoff, on-site sewage disposal systems, sanitary sewer systems and sanitation district discharges—are discussed further below. No source analysis has been completed, but many sources that have the potential to contribute to pathogen loading also have the potential to contribute to nutrient loading and management of these sources has the potential to reduce nutrient loads.

Agriculture (grazing land & other animal facilities)

Animal wastes contain pathogens and nutrients that may threaten aquatic beneficial uses if not managed adequately. By controlling the discharge of animal waste from grazing lands and other livestock facilities, coliform targets from these sources will be reached. Studies in the Tomales Bay watershed showed that the creation of Ranch Water Quality Plans and implementation of Monitoring Plans throughout watershed attained an estimated 60-90% reduction in pathogen and nutrient loads for all projects. Each site is different dependent on management practices installed, type of facility, and geography; however, creation of these Plans in Sonoma Creek watershed will also help attain targets.

Chapter 3: Agricultural and Rural Sustainability provides further discussion of Ranch Water Quality Planning, agricultural pollution reduction efforts, and water quality regulations that impact agricultural management practices.

Urban/Suburban Runoff

Runoff from urban and suburban areas may contain pathogens from wild animal waste, pet waste, human waste, soils and sediments. This runoff is often routed to creeks through municipal stormwater systems and regulated through MS4 permits. Minimum Control Measures required by the City of Sonoma’s MS4 permit are described above, in the section that addresses sediment sources, as are measures that can be taken by individual homeowners.

On-site sewage disposal systems Onsite sewage disposal systems, also referred to as onsite wastewater treatment systems (OWTS) or septic systems, are necessary in areas that are inhabited by humans but do not have access to centralized sanitary sewer systems. These systems can protect water quality and public health if properly sited, designed, operated and maintained. However, when these conditions are not met for an individual system, or when systems are arranged densely enough in an area that effluent cannot adequately be assimilated into the environment, pathogen and nutrient pollution can occur. The TMDL prohibits all discharge of human waste allocates a zero load to on-site sewage disposal systems. This is necessary because human fecal matter is a significant source of other pathogens, such as viruses, and attainment of coliform standards alone may not be protective of public health (Low and Krottje, 2006).

In June 2012 the State Water Resources Control Board adopted the Water Quality Control Policy for Siting, Design, Operation and Maintenance of Onsite Wastewater Treatment Systems, and the regulation went into effect in May of 2013. The policy sets standards for OWTS’s that are constructed or replaced, that are subject to a major repair, that pool or discharge waste to the surface of the ground, and that have affected, or will affect, groundwater or surface water to a degree that makes it unfit for drinking water or other uses, or cause a health or other public nuisance condition. The OWTS Policy also includes minimum operating requirements for OWTS that may include siting, construction, and performance requirements. This policy is implemented by local agencies - the Sonoma County Permit and Resource Management Department (PRMD) in the case of Sonoma Valley.

Sanitary sewer systems & Sanitation district discharges

Similar to on-site sewage systems, municipal sanitary sewer systems do not directly discharge waste except in the case of inadequate siting, design, operation and maintenance, or in the case of acute accidental discharges. The TMDL allocates a zero load to sanitary sewer systems for the same reason as the on-site sewage system zero load allocation.

Once properly treated, wastewater from a municipal sewer system may be discharged to a waterbody under the conditions of an NPDES permit. The Sonoma Valley County Sanitation District discharges tertiary treated wastewater to Schell Slough and Hudeman Slough from November through April under an NPDES permit, and a wasteload allocation for these discharges is included in the TMDL. Tertiary treated water from the Sanitation District’s plant is also used for agricultural irrigation. Further information on recycled water use is presented in Chapter 5 Water Quantity.

PESTICIDES

No data on pesticide levels in Sonoma Valley’s water or soil are known. A 1999 study (Abelli-Amen, 1999) in the adjacent Petaluma River watershed, examining concentrations of two common pesticides in streams and storm drains, is the most relevant available information. The study found that levels of chlorpyrifos and diazinon in the dry season were negligible. However, half of winter-time samples had pesticide levels potentially toxic to the standard test organism, an invertebrate called Daphnia, which is a proxy for the base of the aquatic food chain. The pesticide levels observed would not have been directly toxic to higher animals, including fish. Highest pesticide levels were in water draining from residential and commercial areas, not agricultural areas. The author states that the likely source of the pesticides was outdoor pest control.

RECOMMENDED ACTIONS

Recommendation WQ1 – Develop LandSmart Farm/Ranch Water Quality Plans and implement Management Practices to decrease sediment loads. See Chapters 3 and 8.

Recommendation WQ2 – Develop LandSmart Farm/Ranch Water Quality Plans and implement Management Practices to decrease pathogen and nutrient loads. See Chapter 3.

Recommendation WQ3 – Implement Management Practices to decrease pollutant loading from urban and suburban stormwater – those identified in NPDES permits, and those that are outlined in the “Slow It, Spread It, Sink It!” Manual that can be undertaken by individual homeowners.

Recommendation WQ4 – Maintain septic systems based on State Water Board and Sonoma County PRMD requirements and guidelines found in the “Homeowner’s Guide to Septic System Operation”.

Recommendation WQ5 – Comply with all conditions of municipal NPDES permits for stormwater and sewer systems.

CHAPTER 8. SEDIMENT SOURCES AND IMPACTS

Sediment movement is a natural part of watershed processes. However, when management activities and changes in watershed condition disrupt the sediment balance, excessive erosion and sedimentation can lead to loss of valuable soils, endangerment of structures, adverse impacts to stream channel function, and impaired water quality. This chapter discusses erosion processes, impacts to land and water quality, and recommended actions for controlling excess sediment in the watershed.

EROSION PROCESSES AND CONCERNS

Background Sonoma Valley had a long history of human activity even before the introduction of foreign settlers. Indigenous groups probably used fire as vegetation management and began to alter the landscape through plant propagation to suit their needs, beginning anthropogenic hydrologic alterations in Sonoma Valley. With the introduction of Mexican and European settlers in the early 1800s, human activities increasingly altered the natural erosion and hydrologic regimes of the Sonoma Creek watershed. By the mid 19th century, these settlers introduced grazing, farming, logging, wetland draining, stream diversion, in-stream gravel mining, and the construction of dams. These practices have a large impact on the runoff and erosion regime of a watershed and can lead to dramatic changes in the characteristics of a creek.

Since the mid 19th century, Sonoma Valley has seen the advent of a thriving agriculture industry, construction of an extensive road network, and more recent residential development. These changes have significantly altered the rate and volume of erosion and the surface hydrology of the watershed. In addition, the development of these features directly alongside the Sonoma Creek mainstem and its major tributaries have acted to further channelize (i.e., deepen and straighten) the waterways. The combination of these factors has caused dramatic changes in the types and rates of erosion in the watershed with consequences for both stream channel form and aquatic habitat quality.

The processes and rates of erosion occurring in a watershed combined with the mechanisms by which the eroded material is transported dictate the volume and rate of eroded sediment that will be delivered to a stream network. Gravel and sediment recruitment is a natural function of a stream system, but land management practices can have a great effect on erosion rates and the mechanisms that lead to sediment delivery to a stream. Historically, it is likely that Sonoma Creek delivered sediment derived from its steep upper reaches to the low-gradient alluvial plain at a slow but steady rate. Many of the streams flowing out of the mountains deposited much of their bedload in fans along the low-gradient alluvial plain that is the bottom of Sonoma Valley. The sediment transport rate of the Sonoma Creek tributary network would have been at a relative balance with the sediment inputs.

This consistent process would be accentuated by the occasional large erosion event such as a landslide or debris flow resulting from a large but infrequent storm event. Historically, these large erosion events were probably the primary catalysts to significant alterations in the morphology of the Sonoma Creek stream network.

In the last 150 years, human activity has made significant changes to the Sonoma Creek landscape in the form of altered land cover and stream channels. The upper reaches of Sonoma Creek have been logged, and the proportion of watershed area cultivated for agriculture has grown, increasing storm runoff and sedimentation. Formerly undeveloped native timber and scrublands have been converted for a variety of uses including vineyards, orchards, cattle grazing, and residential development. The altered landscape has increased the compaction of soils and the extent of impervious surfaces, such as roads and rooftops, significantly increasing runoff volumes and rates as well as erosion and transport of fine sediments. Land use development has led to the confinement and channelization of streams that would normally migrate across alluvial fans in the depositional setting of the Sonoma Valley bottom. The deepening and straightening of streams has led to shorter and steeper channels with faster connection to the mainstem Sonoma Creek (SEC, 2006). The increased runoff leads to increased peak discharge to Sonoma Creek, increased sediment inputs from incision and bank erosion, and decreased water infiltration and recharge in the valley.

SEDIMENT WATER QUALITY IMPAIRMENT AND TMDL

Sonoma Creek is listed as sediment impaired on the U.S. EPA Clean Water Act 303(d) list, and a Total Maximum Daily Load (TMDL) was completed in 2008 to address this impairment. The TMDL Problem Statement, developed by the San Francisco Bay Regional Water Quality Control Board (Regional Water Board), stated the following water quality/habitat impacts of sediment (Regional Water Board, 2011):

 Due to excess erosion and sedimentation in the Sonoma Creek Watershed, the narrative water quality objectives for sediment and settleable material are not being met and cold freshwater habitat, wildlife habitat, fish spawning, recreation, and preservation of rare and endangered species beneficial uses are impaired.  Excessive amounts of fine sediment have been deposited in the streambed at potential steelhead spawning and rearing sites. Excess fine sediment in the streambed can cause poor incubation conditions for fish eggs, resulting in high mortality prior to emergence. Fine sediment also compromises the quality of pools as rearing habitat, and reduces winter rearing habitat by filling the spaces between cobbles and boulders  Changes in physical habitat structure that appear to be caused by erosion of bed and banks (incision) in Sonoma Creek are resulting in significant adverse changes to steelhead habitat. Analysis of instream shelter in Sonoma Creek yielded a low score when considering the watershed‐wide average (38, which are 13 percent of the maximum score), indicating low quality of rearing habitat for juvenile steelhead. A steelhead census performed in 2002 indicates only 10 percent of steelhead are surviving past the juvenile

rearing stage. These conditions are limiting the success of steelhead trout in Sonoma Creek.  Stressful water temperatures, low summer flows, and migration barriers also impact the health of Sonoma Creek’s coldwater fishery. For more information on the TMDL, including water quality objectives and load allocations, please see Chapter 7: Water Quality. Channel Incision Steam channel incision is defined as the lowering of the stream bed over a period of time. A “stable” stream is in a dynamic equilibrium when, over a decadal time scale, sedimentation processes are balanced so that the channel, while changing locally, maintains the same average morphological character. The morphology of a stream depends on two independent variables: runoff and sediment yield. These act in concert to determine channel depth, cross section, and grade. Boundary conditions include the valley slope, geology, resistance, soil type, and vegetation and may also include human-made controls such as dams, bridges, and water withdrawals from the creek for agriculture or other uses. Changes in sediment load, flow regime, and boundary conditions can disrupt the balance resulting in a creek that undergoes rapid morphological changes. When long-term stream erosion exceeds sedimentation, channel incision occurs. Channel modification, including confinement and straightening of the channel, often leads to incision. Other causes for channel incision include reduced sediment transport due to upstream dams, increased peak flows caused by residential development, land cover alterations in a watershed, and the removal of wood from a stream channel. In the Sonoma Creek watershed, storm drains play a role in delivering urban runoff to the stream network and have resulted in stream incision in Sonoma Creek, Schell Creek, and Nathanson Creek (Collins, 2006).

The land use changes described in the Background section above influence sediment load, flow regime, and boundary conditions, and thus contribute to channel incision. The effects of channel incision are the disconnection of streams from their floodplain, an overall loss in pool depths, and increased sediment inputs from destabilized stream banks. The incision of a mainstem channel will also lead to the development of migrating headcuts and incision in small tributary drainages. The increased sediment input is detrimental to the habitat viability and can also lead to increased bank erosion. Bank erosion can lead to a loss of structures built along the stream channel as well as infrastructure (e.g., road culverts and bridges) within the stream.

Surface Erosion, Gully Erosion, and Colluvial Erosion Surface erosion processes are relatively small-scale erosion processes that can be broken down into rainsplash, sheet erosion, and rill erosion. These are processes that can take place over broad areas where there are bare soils or lack of cover, causing loss of valuable topsoil and delivery of sediment to streams. Rain drops that fall directly upon bare soils have a splash effect; this is called rainsplash and is defined as the impact of rain drops on the soil surface. Rainsplash only occurs if rain falls with sufficient intensity. If it does, then as the raindrops hit bare soil their kinetic energy is able to detach and move soil particles a short distance. In many cases, particles may be moved only a few centimeters; however, if rainfall begins to concentrate, these particles

are easily transported by sheet erosion. Sheet erosion is the transport of materials overland in broad, extremely shallow flows rather than in defined channels or rills. A relatively uniform layer of fine particles is removed from the entire surface of an area, often times from a disturbed area such as plowed fields or unsurfaced roads, where there is a lack of vegetative cover. As sheet flow coalesces, it will form into rills that are small channels generally categorized as measuring less than 1 ft by 1 ft in cross‐sectional area (Flosi et al., 2006). Rill erosion has the ability to transport large volumes of material delivered to them from the previous processes and can also expand as contributing flow increases, thus increasing the total amount of material in transport.

A gully is created when the process of rilling grows to larger features measuring larger than 1 ft by 1ft in cross-sectional dimension (Flosi et al., 2006). Gullies can become very large features that transport significant amounts of sediment from erosive hillslopes to a stream network. They can form from the coalescing of rills or be caused by concentrated drainage exiting a roadbed, culvert, or other drainage feature. This concentrated flow creates a new linear erosion feature where there was no drainage feature before. These features have the ability to stabilize on their own or can continue to erode and become significant features on a hillslope contributing large volumes of material to a stream depending on soils, slope gradient, and water input. These conduits act to contribute sediments to the waterway by transporting materials already in solution at the head of the gully and by expanding in size contributing its eroded materials. Gullies can also pose significant topographical land management challenges.

Colluvial erosion refers to material that has been deposited at the base of a hillslope through the process of sheetwash, rainsplash, or dry downward creep. This material is deposited in gullies and at the base of streambanks and is easily transported to mainstem streams by concentrated flows within these systems. Colluvial erosion is a significant input of naturally derived sediments within the Sonoma Creek watershed.

Vegetation is one of the primary stabilizers for these erosion types. Ground coverage prevents rainsplash from dislodging surface materials, and plant root networks help to bind soils and increase stability. Alterations to the vegetation regime can act to destabilize surface materials and make them more easily transported. The Sonoma Creek watershed has had significant alterations to the vegetation regime through timber management, agricultural development, grazing practices, land clearing, and grading activities. These practices have led to erosion becoming a large factor in the sediment regime of Sonoma Creek and its tributaries (SEC, 2006).

Landslides Landslides and slumps are major naturally occurring components of mass wasting in most watersheds of northern California. Mass wasting can be classified in several different ways. In the Cruden and Varnes system, the system preferred by the California Geological Survey, landslides and slumps fall into two categories: (1) shallow, rapid, and (2) deep seated, slow (Cruden and Varnes, 1996). Debris slides are the principal type of shallow, rapid landslide. Debris torrents or debris flows are classified as debris slides that move rapidly down the channel network and scour some length of natural stream channel or gully the hillslope down from the source area. Deep-seated landslides and slumps include rotational, translational, and composite

types. Composite types are defined as deep-seated slides and slumps that possess features or styles of two or more types of movement (e.g., rotational and translational). Landslides and slumps occur due to geologic properties of the area, steepness of slope, inputs of water, tectonic activity, and many other factors. The proliferation of these features can be increased with alterations to the landscape such as vegetation removal due to timber harvesting, grading, or fire. Stream diversions due to poor road design can lead to landsliding and slumping as well.

Landslides and slumps within the Sonoma Creek watershed vary in classification and cause. The majority of erosional volumes from landslides assessed have been identified as naturally occurring (Basin Plan, 2011). It is estimated that 20% of sediment yield from landslides in Sonoma Creek are due to land management practices. Correcting or mitigating the practices affecting these sediment sources could have a significant impact on soil stability and water quality within the watershed.

Roads Roads are major sources of erosion and sedimentation on most managed forest and ranch lands as well as on public lands and county maintained thoroughfares. Compacted road surfaces increase the rate of runoff, and roadcuts intercept and bring groundwater to the surface. Ditches concentrate storm runoff and can transport sediment to nearby stream channels. Culverted stream crossings can plug, causing fill washouts or gullies where the diverted streamflow runs down nearby roads and hillslopes. Roads built on steep or unstable slopes may trigger landsliding that deposits sediment in stream channels. Filling and sidecasting (the act of placing material on the hillslope to increase road width) increases slope weight, roadcuts remove slope support, and construction can alter groundwater pressures, all of which may trigger landsliding and slumping. Unstable road or landing sidecast materials can fail, often many years after they were constructed on steep hillslopes. Lack of inspection and maintenance of drainage structures and unstable road fills along old, abandoned roads can also result in soil movement and sediment delivery to stream channels (Weaver and Hagans, 1994).

The compacted impervious surfaces roadbeds create across a watershed actively capture and transport hillslope drainage down their lengths due to road insloping or the existence of inboard ditches that transfer flow. These conduits transport fine sediment derived from the road surface, the exposed cutbank of the road, and the inboard ditch itself, and deliver it to stream channels. Roads with a paved surface are generally stable on the driving surface but are still susceptible to surface erosion in the inboard ditches and cutbanks, and also cause concentrated runoff that may cause erosion downstream. This process is referred to as “chronic erosion” because it is a steady and on-going process.

Stream crossings on road networks require careful design and maintenance to ensure longevity. Classically, stream crossings, particularly culverted crossings, have been underdesigned and poorly constructed. Culverts are regularly too small to handle peak flows of the streams they are installed to convey; they are installed too shallow, making them subject to plugging; and the crossings are designed in a way that, in the case of the culvert being overwhelmed, the stream will flow down the roadbed rather than staying within its natural channel. This diversion of a

stream can lead to extreme erosion in the form of gullying or landsliding where the flow exits the road and finds its way back into the channel. This erosion is referred to as “episodic erosion” (Weaver and Hagans, 1994) and can lead to significant pulses of sediment being delivered to a stream system.

Unlike many watershed improvement and restoration activities, erosion prevention and "storm- proofing" of rural, ranch, and forest road systems as well as county access roads has an immediate benefit to the streams and aquatic habitat of a watershed. It helps ensure that the biological productivity of the watershed's streams is only minimally impacted by future road- related erosion and that future storm runoff can cleanse the streams of accumulated coarse and fine sediment, rather than depositing additional sediment from managed areas (Weaver and Hagans, 1994).

The purpose of a road-related sediment source assessment is to identify and quantify road-related erosion and sediment delivery to streams and to present a prioritized plan-of-action for cost- effective erosion prevention and erosion control for the road system.

In a modeled assessment of over 970 miles of county and private road within all subwatersheds of Sonoma Creek, it was estimated that about 5,250 tons of fine-grained sediments are delivered to Sonoma Creek annually (Trso, 2006). In the same assessment, it was estimated that there are nearly 1,700 stream crossings in the watershed-wide road network contributing 336 tons of fine sediments per year (Trso, 2006). These estimates are lower than the 11,200 tons per year estimate given for Sonoma Creek in the Basin Plan, but both estimates show that road-related sediment inputs are significant within the watershed.

Depending on the future land use needs a landowner or property manager may have, different techniques of drainage improvements may be utilized: upgrading or decommissioning. Upgraded roads are kept open and are inspected and maintained. Their drainage structures are designed to accommodate the 100-year peak storm flow. Conversely, properly decommissioned roads are closed and no longer require maintenance. Whether through upgrading or decommissioning, the goal of storm-proofing is to make the road as “hydrologically invisible” as possible; that is, to reduce or prevent future sediment delivery from the road to the local stream system (Weaver and Hagans 1994).

Summary of SEC Stream Reports and Current Observations for Sediment Source and Impacts: Sonoma Creek Limiting Factors: Gravel/cobble embeddedness in fine sediment Elevated stream temperatures Loss of pools/loss of pool frequency and connectivity

Instream Habitat Enhancement Opportunities: For sources of upslope and in-channel erosion utilize biotechnical approaches

Map sources of erosion on county and secondary roads and prioritize them according to present and potential sediment yield

Agua Caliente Creek Limiting Factors: Gravel/cobble embeddedness in fine sediment Elevated stream temperatures Loss of pools Loss of pool frequency and connectivity Instream Habitat Enhancement Opportunities: For sources of upslope and in-channel erosion utilize biotechnical approaches. Map sources of erosion on county and secondary roads and prioritize them according to present and potential sediment yield

Arroyo Seco Creek Limiting Factors: Gravel quality for spawning Elevated stream temperatures Loss of pools Loss of pool frequency and connectivity Decrease in pool quality and depth Instream Habitat Enhancement Opportunities: For sources of upslope and in-channel erosion utilize biotechnical approaches. Map sources of erosion on county and secondary roads and prioritize them according to present and potential sediment yield.

Carriger Creek Limiting Factors: Elevated stream temperatures

Instream Habitat Enhancement Opportunities: Look for areas where riparian vegetation development could act to increase shade alongCarriger Creek.

Hooker Creek Limiting Factors: Gravel/Cobble embeddedness in fine sediment Elevated stream temperatures

Instream Habitat Enhancement Opportunities: For sources of upslope and in-channel erosion utilize biotechnical approaches. Map sources of erosion on county and secondary roads and prioritize them according to present and potential sediment yield Mill Creek

Limiting Factors: Gravel quality for spawning Gravel/cobble embeddedness in fine sediment Elevated stream temperatures High turbidity levels Loss of pools Loss of pool frequency and connectivity Decrease in pool quality and depth

Rodgers Creek Limiting Factors: Gravel quality for spawning Gravel/cobble embeddedness in fine sediment Elevated stream temperatures

RECOMMENDED ACTIONS

Recommendation SSI1 - Utilize existing data to prioritize focus areas for road-related sediment source assessments.

Recommendation SSI2 - Conduct outreach to high-priority landowners in the Sonoma Creek watershed based on study findings.

Recommendation SSI3 - Conduct a multi-phased series of road sediment source assessments on high-priority road networks in order to develop prioritized sediment reduction plans for the watershed.

Recommendation SSI4 - Implement road sediment reduction plans resulting from the road related sediment source assessments. Conduct these in a prioritized multi-phased series based on funding availability.

Recommendation SSI5 - Utilize existing data to locate stream channel and bank erosion sites in Sonoma Creek, Schell Creek, Carriger Creek, and Carneros Creek.

Recommendation SSI6 - Make land management improvement suggestions to property managers that have current management induced stream channel and bank erosion sites. Utilize cost-effective bioengineering techniques, where feasible, to stabilize erosion. Where feasible, maintain riparian buffers to filter fine sediments before surface drainage enters streams.

Recommendation SSI7 - Utilize existing data to locate landslide sites that may be management induced in the Sonoma Creek watershed. Make land management improvement suggestions to property owners that have current management induced landslide sites. Utilize cost effective bioengineering techniques, where feasible, to stabilize erosion.

CHAPTER 9. MARSHLANDS

The Napa-Sonoma Marsh (Marsh) is a complex of tidal marshes, sloughs, rivers and reclaimed marsh used as agricultural lands. It is located at the northern edge of San Pablo Bay and covers roughly 73 square miles and an area of 48,000 acres, of which 13,000 acres are abandoned salt evaporation ponds. The Marsh is fed by Sonoma Creek, Tolay Creek, and the Napa River, and mostly only accessible by boat This chapter includes a description of the marsh habitat and historical impacts, management suggestions and a focus on special status species including recovery plan methods.

MARSHLAND DESCIPTIONAND HISTORY

The US government has designated 13,000 acres in the Marsh as the San Pablo Bay National Wildlife Refuge.. The San Pablo Bay Wildlife refuge which lies along the north shore of San Pablo Bay in Sonoma, Solano, and Napa Counties, was created in 1974 to protect migratory birds, wetland habitat, and endangered species. The refuge includes open bay/tidal marsh, mud flats, and seasonal and managed wetland habitat and supports the largest wintering population of canvasbacks on the west coast, and protects the endangered salt marsh harvest mouse and the California clapper rail. Agricultural lands occupy almost half of the Marsh and are largely reclaimed lands that support oats, hay and grains, and cattle and sheep. Salt production is the largest industrial use of the marsh, covering approximately 20% of the area.

The status of marshlands in the San Francisco Bay Delta Area has changed considerably. Conversion to agricultural and industrial/urban use, and water diversion and management (Marshall & Dedrick 1994) has changed the landscape dramatically. Nearly all of the lands within this area once were tidal salt marsh or tidal brackish marsh. There were some limited areas of moist grasslands to the north and west, along upper Sonoma Creek, and in the drainages around and below Tolay Lake. A large area of vernal pool soils existed on the western side of upper Sonoma Creek. Today, this segment is relatively undeveloped and most of the baylands are farmed. There are several managed diked wetlands along the periphery of the segment, especially near the hills to the north and adjacent to Highway 37. Tidal marsh is limited to the Bay edge near Sonoma Creek and along the outboard sides of levees along the remaining channels.

During the mid 1800s the tidelands bordering San Pablo Bay were "reclaimed" for farm land. Conversion of tidelands to farm land occurred under the Swamp Land Act of 1849 (modified in 1850 and 1860). Private individuals were offered land at no cost, provided that they would drain and develop these wetlands, which were defined as “wet and unfit for cultivation.” Landowners installed a system of levees to keep tidewater out and ditches and pumps to remove storm water making it possible to farm productively. (This Federal wetlands policy was reversed in 1988 when the “no net loss” of wetlands policy was adopted.) This resulted in establishing a robust regional agricultural economy supporting hay, grain, pasture, and vineyards. Levees were constructed to keep out the bay waters and the lands were drained and allowed to dry out, rain water flushed out the salts from the land and crops were planted. Currently, these lands are either private or publically owned and support local agricultural operations, infrastructure (i.e. roads) and important habitat and the levees require ongoing maintenance to prevent these lands from flooding. These agricultural baylands, especially portions that have seasonal ponds,

provide habitat for several species of wildlife. Farmers that continue to produce crops in the bay lands may be able to improve wildlife habitat using a variety of management practices

Sonoma Creek provides an excellent opportunity to restore large patches of tidal marsh, some as isolated marsh islands and others with natural transitions to the adjacent uplands. Marsh and tidal restoration, and preservation of important agricultural lands has been achieved by a variety of local, state, and federal agencies including Sonoma Land Trust, Sonoma County Agricultural Preservation and Open Space District, the US Fish and Wildlife Service, California Coastal Conservancy, the California Department of Fish and Game, the Point Reyes Bird Observatory. Also, there are large areas that are well suited to be managed as diked wetlands for shorebirds and waterfowl. The wetlands, waterways and grasslands surrounding the corridor are habitat for a wide variety of native fauna and flora, including several state and federally-protected species. Protected species include: the Delta smelt, green sturgeon, Sacramento splittail, steelhead trout, and Chinook salmon, California black rail, California clapper rail, and salt marsh harvest mouse.

Restoring tidal marsh in this watershed would greatly enlarge the area of shallow channel habitat for many fish species. Increased tidal prism would also enlarge existing deep channels to the benefit of fish and diving ducks. Increasing the area of tidal marsh would expand suitable tidal marsh habitat for endangered tidal marsh species such as the California clapper rail and the salt marsh harvest mouse. Restoring marsh at the periphery of the bay lands, where natural transitions to adjacent uplands could develop, would benefit several rare plants, as well as birds, mammals, and amphibians that depend on the marsh/upland transition zone. Large areas of managed diked wetlands would provide important roosting and foraging habitat for shorebirds and waterfowl.

SPECIAL STATUS SPECIES The California black rail (Laterallus jamaicensis coturniculus) is a scarce, rarely seen, year-round resident of saline, brackish, and freshwater emergent wetlands. California black rails are most commonly found in tidal emergent wetlands dominated by pickleweed (Salicornia virginica) or in brackish marshes that support bulrushes (Scirpus robustus) and pickleweed. In freshwater, they are usually found in bulrush, cattail (Typha spp.), and salt grass (Distichlis spicata) areas.

They prefer high marsh regions that have shallow, stable water levels and that seldom flood. This type of marshland features dense stands of low growing, semi-aquatic plants interspersed with areas of open water and drier upland habitat; it provides materials for nest building and cover for nests. Nests are built at ground level or elevated several inches and are concealed in dense vegetation near the upper limits of tidal flooding. Rails eat insects, crustaceans, and other arthropods, as well as aquatic plant seeds.

Information on the historical range of the California black rail is scarce. Limited numbers are known to have bred along the coast from Tomales Bay to northern Baja California in Mexico. The bird also bred inland at freshwater marshes including the Sacramento-San Joaquin River Delta. Today California black rails are found in San Francisco Bay, in Bodega Bay in Sonoma County, in Tomales Bay and Bolinas Lagoon in Marin County, and in Morro Bay in San Luis Obispo County. The black rail no longer breeds in coastal southern California. Population numbers have continued to decline since the 1970s. More than

80% of the remaining California black rails are estimated to be concentrated in the marshes of northern San Francisco Bay.

The major cause of decline and principal barrier to recovery of the California clapper rail is the loss and degradation of the wetland habitat in northern and southern California. This includes coastal and estuarine salt marshes, inland freshwater marshes, and Colorado River marshlands. Of crucial concern for the rail is loss of high marsh habitat that provides refuge areas from high tides. Lack of refuge areas has left rails exposed as easy prey for domestic and feral cats, herons, egrets, and other birds, as well as red foxes and rats. The California black rail is designated as a threatened subspecies in California. Under the federal Endangered Species Act (ESA), it is designated as a Candidate Species (C-1).

California clapper rail The California clapper rail (Rallus longirostris obsoletus) lives in coastal salt and brackish marshes and tidal sloughs. A year-round resident, the California clapper rail lives mostly in the upper to lower zones of coastal salt marshes dominated by pickleweed and cordgrass (Spartina foliosa); some birds live in coastal brackish marshes. The California clapper rail forages in the shallow water along the mudflat interface and along tidal creeks. They require adjacent higher vegetation for cover during high water. The clapper rail mostly preys on crabs, mussels, clams, snails, insects, spiders, and worms. Nesting activity occurs from mid-March through July. The birds most often nest near tidal sloughs where cordgrass is abundant. They build a nesting platform concealed by a canopy of woven cordgrass stems or pickleweed and gumweed.

Historically, California clapper rails were found in tidal salt marshes and brackish marshes from Humboldt Bay in Humboldt County to Morro Bay in San Luis Obispo County. The bird is now found in San Francisco Bay and Suisun Bay. South San Francisco Bay marshes continue to support the largest number of these rails in the state. In the Petaluma River watershed, clapper rails are resident and breed along the river as far north as Schultz Creek.

In the early 1980s, more than a decade after the California clapper rail was first listed as endangered, an estimated 1,500 birds remained, with at least 80% of the surviving population confined to the southern part of San Francisco Bay. In the mid-1980s, the population was estimated to have declined steeply. In 1992, nineteen pairs of clapper rails were estimated to be in the Petaluma Marsh, primarily found at the mouth of the Petaluma River and in nearby large portions of tidal salt marsh.

Destruction of marsh habitat for industrial, municipal, agricultural, and salt pond use, as well as over- hunting, have depleted the California clapper rail population. Habitat loss also resulted from the dying out of marsh vegetation. Rail eggs have been found to harbor elevated levels of mercury, selenium, and other contaminants, probably because sewage effluent, industrial discharges, and urban run-off have contaminated the bird’s food supply. Predators to both clapper rails and their eggs include raptors (northern harrier, red-tailed hawk, and peregrine falcon) and mammals (red foxes, rats, and cats). Predators are a serious threat to clapper rail populations, and predator management is not being regularly practiced in the North Bay. The introduced horse mussel may also inadvertently kill clapper rails by trapping the bills or feet of birds that have stepped on or probed into the shell. The California clapper rail was listed as endangered by the state of California and under the federal ESA in 1970.

Salt marsh harvest mouse Two subspecies of salt marsh harvest mouse (Reithrodontomys raviventris) are endemic to the San Francisco Bay area. The mice inhabit the middle to upper levels of dense pickleweed stands in tidal and diked coastal salt marshes. They rely on escape cover formed by dense vegetation in the higher zones of the marsh to shelter them during high tides. Grasslands adjacent to pickleweed saline emergent wetlands are used when new grass growth provides suitable cover in spring and summer months. The mice’s diet is comprised of seeds and green vegetation, and they can drink water with a relatively high salt content. Reproduction generally occurs from April through September. Salt marsh harvest mice build nests of grass and sedge on the ground; they do not burrow. Predators include hawks, owls, gulls, weasels, and other mammals.

Historically, the salt marsh harvest mouse was found throughout the extensive marshes that once bordered San Francisco, San Pablo, and Suisun Bays. It is now restricted to scattered, discontinuous, coastal salt marshes within its original range. The northern subspecies (R. r. haliocoetes) is found in the salt marshes of San Pablo and Suisun Bays in Contra Costa, Solano, Napa, and Sonoma counties. Most populations of the southern subspecies (R. r. raviventris) inhabit the southern half of San Francisco Bay in Alameda, Santa Clara, and San Mateo counties, and few occur along the eastern portion of the Marin Peninsula in Marin County and at Point Richmond in Contra Costa County.

Decline in salt marsh harvest mouse populations is linked to habitat loss, especially of escape cover, fragmentation of the remaining marshes, widespread loss of the high marsh zone as a result of backfilling, land subsidence from excessive groundwater pumping, and vegetational changes from freshwater sewage discharge, especially in the South Bay. Most of the remaining marshes are too small and too widely separated to support viable populations.

Excessive pumping of groundwater in some regions has triggered subsidence of land along the bays’ edges. This and backfilling have eliminated important escape cover in the marshland’s higher zones, making these marshes unsuited to the mice’s needs. Fragmentation of remaining marshes, as well as filling and diking of marshes for commercial salt production and urbanization, have also eliminated habitat throughout the species’ range.

Both the state and federal governments listed the salt marsh harvest mouse as an endangered species in 1970. Since populations of the mice cannot be supported long term on the small, widely separated marshes that remain the USFWS recovery plan for the species focuses on restoring and preserving existing habitat and acquiring additional habitat. Specific objectives include acquiring privately owned marshes and restoring former baylands that have been diked. The plan also calls for creating vegetative cover in the upper portions of marshes. Further objectives include studying the effects of such factors as sewage effluents, pollution, flood control, and marsh erosion on existing populations and habitat.

RECOVERY PLANS In 2010 the USFWS developed a Draft Recovery Plan for Tidal Marsh Ecosystems of Northern and Central California. The following is a list of ecosystem-level recovery methods from USFWS focused on tidal marsh conservation effort and monitoring of listed species.

Ecosystem-Level Recovery Strategies

“The following five ecosystem-level strategies are described further below:

 Acquire existing, historic, and restorable tidal marsh habitat to promote the recovery of listed species and long-term conservation of species of concern and other tidal marsh species.

 Manage, restore, and monitor tidal marsh habitat to promote the recovery of listed species and the long-term conservation of species of concern and other tidal marsh species covered in this draft recovery plan.

 Conduct range-wide species status surveys/monitoring and status reviews for species covered in this draft recovery plan.

 Conduct research necessary to the recovery of listed species and long-term conservation of species of concern and other tidal marsh species covered in this draft recovery plan.

 Improve coordination, participation, and outreach activities to achieve recovery of listed species and long-term conservation of species of concern.” (USFWS, 2010).

The USFWS also created a Draft Recovery Unit for the San Pablo Bay evaluating the watersheds and marshlands surrounding and draining into the bay. The San Pablo Bay Recovery Unit for the California Clapper rail and the Salt marsh harvest mouse evaluates the potential for a species listed under the ESA to be downlisted or delisted. Considerations to population numbers, habitat parameters and timelines are accounted for in the recovery of the Clapper rail and Salt marsh harvest mouse for this region. Actions to recover a species successfully would by definition mean that the species no longer falls in the parameters stated under the ESA as either threatened or endangered. This also demands that there is enough viable habitat available (VHA)—well-developed and complex tidal marsh habitat—to support the species existence. The following table illustrates the information taken from the Draft Recovery Plan for Tidal Marsh Ecosystems of Northern and Central California:

Table 9.1. Draft Recovery Plan for Tidal Marsh Ecosystems of Northern and Central California— San Pablo Bay Recovery Unit

Marsh CA Clapper rail- CA Clapper rail- Salt marsh harvest Salt marsh harvest Complexes Downlist Delist mouse- Downlist mouse- Delist

China Camp to Min. acreage: 2,500ac Min. acreage: 2,500ac Min. acreage: 1,000 ac Min. acreage: 1,000 ac Petaluma River Recovery Unit target Min. Density in any yr: 2 VHAs 2 VHAs (10-yr mean)= 936 birds 0.09 birds/acre 40% of VHAs with CE 75% of VHAs with Recovery Unit target of 5.0 or greater AND CE of 5.0 or greater (10-yr mean= 1,248 50% of VHAs with CE birds of 3.0 or greater Each VHA monitored twice with 2-5 yrs Each VHA monitored twice with 2-5 yrs between efforts

between efforts

Petaluma River Min. acreage: 2,500 ac Min. acreage: 2,500ac Min. acreage: 1,000 ac Min. acreage: 1,000 ac Marshes Recovery Unit target Min. Density in any yr: 3 VHAs 3 VHAs (10 yr mean) 936 birds 0.09 birds/acre 40% of VHAs with CE 75% of VHAs with Recovery Unit target of 5.0 or greater AND CE of 5.0 or greater (10-yr mean= 1,248 50% of VHAs with CE birds of 3.0 or greater Each VHA monitored twice with 2-5 yrs Each VHA monitored twice with 2-5 yrs between efforts between efforts

Petaluma River Min. acreage: 2,500ac Min. acreage: 2,500ac Min. acreage: 1,000 ac Min. acreage: 1,000 ac to Sonoma Creek Recovery Unit target Min. Density in any yr: 1 VHAs 1 VHAs (10-yr mean)= 936 birds 0.09 birds/acre 40% of VHAs with CE 75% of VHAs with Recovery Unit target of 5.0 or greater AND CE of 5.0 or greater (10-yr mean= 1,248 50% of VHAs with CE birds of 3.0 or greater Each VHA monitored twice with 2-5 yrs Each VHA monitored twice with 2-5 yrs between efforts between efforts

Napa Marshes Min. acreage: 2,500ac Min. acreage: 2,500ac Min. acreage: 1,000 ac Min. acreage: 1,000 ac

Recovery Unit target Min. Density in any yr: 12 VHAs 12 VHAs (10-yr mean)= 936 birds 0.09 birds/acre 40% of VHAs with CE 75% of VHAs with Recovery Unit target of 5.0 or greater AND CE of 5.0 or greater (10-yr mean= 1,248 50% of VHAs with CE birds of 3.0 or greater Each VHA monitored twice with 2-5 yrs Each VHA monitored twice with 2-5 yrs between efforts between efforts

RECOMMENDED ACTIONS

Recommendation MH1- Restore large patches of tidal marsh along the entire shoreline of San Pablo Bay particularly near the mouths of sloughs and major streams.

Recommendation MH2- Upstream of Highway 37; restore a broad plain of tidal marsh on both sides of Sonoma Creek. There is considerable flexibility in this area regarding the desired location of tidal and diked habitats; seasonal diked wetlands should be located in close proximity to tidal flats to provide high tide roosting habitat for shorebirds.

Recommendation MH3- With willing landowners, establish managed marsh or enhanced seasonal pond habitat (especially for shorebirds) on agricultural baylands that are not restored to tidal marsh.

Recommendation MH4 Enhance riparian habitat along Sonoma Creek in the Schellville area and upstream, and protect and restore Tolay Creek. Where possible, enhance marsh/upland transitions and provide buffers.

Recommendation MH5- Prepare and distribute information to the public about the habitat needs of these species and how watershed residents can help with recovery efforts.

Recommendation MH6- In agricultural areas allow ponding in field depressions for shorebirds and waterfowl. Recommendation MH7- In agricultural areas create small diked ponded areas adjacent to levees where possible

Recommendation MH8- In agricultural areas, encourage growth of vegetation along fence rows or field edges toprovide habitat for small birds and mammals.

Recommendation MH9 –In agricultural areas, delay spring harvest of oat-hay as late as possible to avoid nesting waterfowl.

Recommendation MH10- In agricultural areas, fence cattle from wetland areas during wet periods.

Recommendation MH11- In agricultural areas, increase the practice of rotational grazing to encourage a more diverse grassland habitat.

CHAPTER 10. RIPARIAN HABITAT AND SPECIES

Riparian habitats are essential for healthy stream systems, for aquatic species, and to help maintain the viability of surrounding communities. Riparian habitats are the plant communities growing along a stream, river or other body of water and interface with land and water. Riparian habitats also interface with upland plant communities that play an important role in the health of the stream system and associated riparian habitat. Riparian corridors are made up of the riparian habitat and associated stream, river, creek and floodplain. In this Plan riparian corridors are used to describe the specific management area to implement practices to maintain and improve riparian functions and health (USDA, 2011).

This chapter provides a description of riparian habitat conditions within the Sonoma Creek watershed, a discussion of the species that rely on these habitats, and recommended actions to protect and enhance riparian habitats and species.

FOCAL SPECIES OF SONOMA CREEK WATERSHED Fish and other wildlife are key ecosystem components of the entire watershed. Restoration of a naturally functioning ecosystem with all its elements is consistent with the Plan’s goals. A diversity of aquatic and terrestrial organisms inhabit Sonoma Creek watershed’s instream and riparian zones and include a variety of salamanders, snakes and frogs. Additionally, several listed species are found within the Sonoma Creek watershed. Previous USFWS surveys and recent studies have found the federally and state-listed endangered California freshwater shrimp (Syncaris pacifica) in Sonoma Creek. The California red-legged frog federally listed as threatened is present, as well as are several other endangered species (mostly associated with the lower drainage area) which include California clapper rail (Rallus longirostris), California black rail (Laterallus jamaicensis), and salt marsh harvest mouse (Reithrodontomys raviventris). Delisted species occurring in the watershed are California brown pelican (Pelicanus occudentalis) and Sacramento splittail (Pogonichtys macrolepidotus), although the splittail remains to be a species of a special concern.

California Golden beaver (Castor canadensis) were historically abundant along Sonoma Creek but were wiped out by trapping in the eighteenth and early nineteenth centuries. They have since returned to Sonoma Creek where they have recolonized and have even created habitat that has led to the return of the river otter (Lontra canadensis). The Chinese mitten crab, an invasive species, has also been documented in Sonoma Creek and tributaries.

Among the threatened species of fish documented in the Sonoma Creek watershed are the federally threatened Central California Coast steelhead (Oncorhynchus mykiss) and Chinook salmon (Oncorhynchus tshawytscha), which are also state listed.

In the Sonoma Creek basin, historical records of steelhead distribution indicate their presence in the mainstem and most tributaries. Important steelhead habitat has been documented in mainstem Sonoma Creek and several tributaries (Leidy et al 2003, Becker et al. 2007). In 2007, Sonoma

Creek was ranked as one of the nine streams that are “essential steelhead resources of the San Francisco Estuary” (Becker et al, 2007).

Small numbers of adult Chinook salmon have been documented recently in Sonoma Creek (SEC, 2002), but a regular, self-sustaining run of Chinook salmon is not believed to occur in the basin. NMFS believes that fall Chinook salmon found in the neighboring Napa River basin are not self- sustaining and are more likely present intermittently, during periods with favorable stream conditions (NMFS, 1999). Restoration and monitoring efforts in the Sonoma Creek watershed have focused on steelhead, although these efforts likely also benefit Chinook.

Based on late summer surveys, SEC estimates the abundance of rearing juvenile steelhead in 2002 was over 16,000 in the mainstem of Sonoma Creek and three tributaries north of Glen Ellen. Preliminary results from a steelhead population study, which is currently taking place (2013) also show thriving populations in the watershed. These are fish spawned in Sonoma Creek and its tributaries that have survived one to two seasons of juvenile rearing, despite multiple challenges, including predators, turbid winter storms, scarce summer water, hot summer temperatures, limited shelter (few places to hide), and, most likely, fierce competition for food. However, there is uncertainty as to how many of these juvenile fish reach maturity and survive to migrate to the Pacific Ocean. This fish census data indicates that only about 10% of age 0+ (0 to 12 months) steelhead in the Sonoma Creek basin survive to age 1+ (12 to 24 months). Although the consistent presence of juvenile steelhead indicates continued natural propagation, survey reports and accounts of long-time local residents have generally indicated a decline in the abundance and distribution of steelhead in the Sonoma Creek watershed (Leidy et al. 2003, SEC 2002, 2004). This trend is consistent with the substantial declines reported for steelhead stocks throughout California. For each juvenile survivor counted, there were hundreds to thousands of eggs that failed to survive. Since the census estimated that very few fish were present greater than one- year-old (age 1+), this suggests a potential bottleneck in population recovery in the juvenile rearing life phase.

Instream and riparian habitat levels for steelhead and Chinook vary throughout the Sonoma Creek watershed. Instream conditions such as variations in food availability and temperature affect growth rates of salmonid within a stream and also between different streams (USFWS, 1981). High winter flow increase salmonid emigration and may affect smolt production (Giannico & Healy, 1998). Healthy riparian corridors help reduce the adverse effects of flooding by allowing for increased changes in flow, reducing erosion, and improving stream bank protection. In addition riparian corridors improve water quality by reducing temperatures and filtering out excess nutrients from agricultural and urban runoff from entering the stream. Healthy riparian corridors, which provide key habitat to many different types of terrestrial plant and animal species, also provide a long term source of large wood material which is critical for salmonids and other aquatic species. Lastly, riparian corridors provide essential habitat linkages for wildlife movement.

The Sonoma Creek Watershed Limiting Factors Analysis (Micheli, 2006) evaluated the impacts of various physical factors on steelhead trout (Oncorhynchus mykiss) and Chinook salmon (Oncorhyncus tshawytscha), as well as California freshwater shrimp (Syncaris pacifica). The

results, as they pertain to salmonids, are listed in the table below. Limiting factors are discussed further below and in other chapters of this plan, as applicable.

Table 10.1 – Summary, Sonoma Creek Limiting Factors Rankings Life LIMITING Hypothesis Summary Statistics Potential Certainty Stage FACTOR Impact

Upstream Sufficient Late fall and early 2003 upstream Migration Flows winter are variable but migration began when generally sufficient to flow at the USGS low moderate permit upstream gauge measured 100cfs, migration of adult fish. a value exceeded most seasons.

Barriers to Artificial barriers to A total of 170 miles of Fish fish passage prevent stream length Passage upstream migration of (approximately 25% of moderate to high adult fish on a subset of the watershed) is cut off high tributaries. from fish use due to 23 full barriers.

Spawning Gravel Reduced channel Spawning-sized gravel and Egg Mobility roughness has resulted patches are relatively Incubation in reduced retention of rare and small (less moderate low spawning-sized gravel than one foot square), and increased risk of unless woody debris is redd scour. present.

Gravel Fine sediment On average, an Permeability deposited in spawning estimated 70% of gravel creates low incubating eggs will die high moderate permeability and high per year due to low rates of fry mortality. gravel permeability.

Juvenile Summer and The loss of the majority Historical ecology Rearing Winter Off- of historical off-channel mapping indicates that channel rearing habitat due to remaining freshwater Habitat direct and indirect wetland and floodplain high high physical alteration has areas are less than

reduced steelhead approximately 10% of populations. historical conditions.

Life LIMITING Hypothesis Summary Statistics Potential Certainty Stage FACTOR Impact

Pool Habitat Cumulative watershed Surveyed streams Availability effects, including average 10% pool channel incision and habitat per unit length, reductions in large vs. 30% recommended woody debris, have by CDFG. Measured high moderate reduced the extent and pool depths averaged depth of pool habitat. 1.25 ft, while rearing age 1+ fish select pools greater than 2.5 ft deep.

Pool Filling Episodic deposition of Measured pool habitat

by Sediment fine sediment in pools lost to fine sediment causes moderate averaged 8.5% of pool impacts to the quantity volume, approximately moderate moderate of available habitat. four times values measured in the Napa

basin.

In-stream Low quantity of shelter Watershed‘s shelter for juvenile fish has rating was only13% of Shelter resulted in increased the maximum score. high high rates of predation and Less than one piece of displacement by high woody debris per mile

flows. of stream channel.

Stranding Summer low flow Surveyed streams lost by Low conditions cause approximately 40% of Flows mortality of fry summer rearing habitat Juvenile stranded in pools that to dewatering. high high Rearing go dry or lose access to (cont.) food and fresh water provided by stream flow.

Riparian Low riparian tree cover Surveyed streams Cover reduces nutrients, averaged 80% riparian low shade, and bank cover, with a minimum high (localized) stability. of approximately 30% at isolated locations.

Life LIMITING Hypothesis Summary Statistics Potential Certainty Stage FACTOR Impact

Water Reduced ground water Upper watershed Temperature inputs and riparian streams exceed 68°F shade has increased only 5% of the summer, moderate moderate water temperatures. while lower elevation (localized) streams can reach lethal temperatures (>75°F).

Suspended Increased fine sediment Suspended sediment Sediment loads during storm concentrations reach events cause high levels that cause “major moderate moderate turbidity and stresses physiologic stress,” but fish. not mortality.

Water Water quality is BMI surveys indicate Quality generally sufficient to moderate impairment support ecological downstream of low low productivity. urbanized areas. (localized) Nutrient and pathogen results pending.

INSTREAM HABITAT Studies of anadromous fish movements in the mainstem of Sonoma Creek and some of the watershed tributaries have established an historical decline in spawning and habitat value for these species. Quantity of woody material and density of habitats are strongly linked to salmonid overwintering survival (Quinn & Peterson, 1996). Large wood material directly improves fish habitat. It is especially effective in pools; a pool with significant amounts of large wood is preferred by salmonids over a pool without it. Submerged large wood with a rootwad attached provides especially good cover for fish. The presence of large wood in fast water areas such as riffles and rapids creates a physical barrier around which water must flow, thus reducing water velocity. Decomposition of large wood in the stream serves as an energy source for the growth of microorganisms, which in turn are fed upon by macroinvertebrates, the main food source for salmonid fry. Many macroinvertebrate species spend part of their life cycles on large wood substrate. Large accumulations of large wood trap gravel and create new channels, especially during periods of high flow. This increases the diversity and complexity of fish habitat.

Sonoma Creek watershed and its tributaries are highly variable from one to the other. There is a definitive lack of shelter in pools and low water levels. Salmonids are present in many areas of the watershed, successfully spawning and rearing in upper tributary reaches and the mainstem.

Habitat appropriate for summer rearing occurs in both tributaries and the mainstem, but the greater number of observations of young-of-year, were made in the mainstem’s deeper pools.

FISH PASSAGE Habitat quality is influenced not only by the physical habitat available in a given reach of stream, but also the accessibility of that habitat to the aquatic species that use it. Natural stream features such as log jams, as well as man-made structures: dams, weirs, and culverts, are all instream barriers that potentially prevent or inhibit the natural movement of aquatic species. Maintaining conditions within the stream that provide hydrological and structural barriers to fish habitat are limiting their recovery. Enhancing habitat will not benefit these species without free access.

There are a few locations that become barriers during low flow conditions due to high gradient and drop offs, i.e, a natural falls and log jams. There is potential for fish passage issues in lower flows, however, adult salmonids would have little trouble passing in normal winter flows. A fish passage study throughout the watershed should be done or previous studies updated. The evaluation of potential impediments to fish passage may be based on features such as length, water velocity, slope, depth, jump height and pool depth for culverts, and features such as downstream pool depth and waterfall length for dams and weirs.

RIPARIAN HABITAT Riparian habitat is characterized by the following trees and shrubs: California Bay, (Umbellularia californica), big leaf maple (Acer macrophyllum), Black Walnut (Juglans californica ), California buckeye (Aesculus california), Maple, Oaks, Alder, California box-elder, Blue elderberry (Sambucus coerulia), willow (Salix spp.), and wild and cultivated grape (Vitis sp.). Also, there are a variety of grasses, herbs, sedges and rushes that make up the herbaceous layer of the riparian corridor. These plant assemblages integrate with upland plant comminutes that may include: mixed or closed woodlands, chaparrals, and grasslands.

For most salmonid stream bearing systems, canopy coverage of 80% or greater is considered sufficient to provide enough shade and coverage. Based on past stream surveys, much of the watershed is lacking sufficient canopy and shade along the creek. In addition to canopy coverage, the function of the riparian corridor should also be assessed based on the width and degree of adjacent floodplains, degree of regeneration and the health of the trees and understory vegetation.

A major issue in the watershed is the majority of the stream segments that are confined by either main roads or rural residential and agricultural development. This causes channelization of the stream which increases channel incision and leads to many habitat problems such as bank erosion and loss of riparian habitat (Flosi et al, 2006).

Within the lower part of the watershed there are more open areas with direct sun exposure along the mainstem. Within the upper part of the watershed Sonoma Creek and upper tributaries flow within steeper gulches that are naturally shaded. Also, the logging history and vegetation

management in Sonoma Creek has impacted the riparian corridor by limiting the establishment of larger trees along portions of the creek and within adjacent uplands areas which can contribute to erosion and the removal of riparian habitat.

There are minor to major infestations in various stream reaches in middle and upper watershed. Sections of the creek are heavily inundated with invasive plants including Himalayan blackberry and vinca (periwinkle), which both suppress natural regeneration of native riparian plans and are carriers for Pierces disease. Other major invasive riparian species include: Arundo donax, Acacia, Tree of heaven, Ivy, Annual Mediterranean grasses, however it provides some habitat value.

It is critical to provide resources to landowners on the multi-benefits of healthy riparian corridors both for habitat values and for the long term protection of adjacent agricultural and residential properties. Helping landowners understand these benefits and specific management actions that can be implemented is needed for long term habitat improvement in the watershed. The involvement of landowners is critical to implementing the needed actions recommended in this plan.

Watershed-wide, the associated riparian corridor is restricted by agricultural and residential development on both sides of the creek. There are some areas within this reach that are lacking regeneration and there are semi bare areas along the stream. More assessment and outreach is needed to determine specific zones and treatments within this reach. This needs to be done in conjunction with determining the habitat enhancement value of this work based hydrology conditions in that reach. Increased riparian cover is needed within specific reaches where the creek is exposed. There are sections where there is low regeneration and complexity. Although various areas of the channel are shaded, the riparian corridor should be expanded where it is not restricted by roads or other development. More assessment and outreach should be conducted to determine the highest priority zones and specific treatment. There are reaches with a dense establishment of Himalayan blackberry and vinca that is suppressing natural recruitment. Outreach is needed to landowners interested in Himalayan blackberry control and riparian enhancement.

To improve the riparian corridor, more assessments should be done to determine the priority and need for increasing canopy and extending the riparian corridor. Throughout the riparian corridor, there are open areas lacking in cover and regeneration. Within this area, there are evident erosion sites and bare banks. Near-stream plantings should be installed and the riparian corridor should be expanded where possible within this reach. Further assessment and outreach needs to be completed to determine priority level and specific treatments. There is an overall lack of understanding of stream conditions and low landowner participation.

Further assessment should be done to determine specific treatment zones and determine landowner interest. Outreach should be done to landowners with riparian areas to develop management plans and help landowners apply for cost share funding for those that qualify. Where needed, provide resources to landowners on invasive plant identification, the methods of invasive plant removal and connect landowners with technical and funding assistance.

RECOMMENDED ACTIONS

Recommendation RHS1 —Conduct surveys for species of concern to include but not limited to pond-breeding and stream-breeding amphibians throughout the watershed; and support instream monitoring and survey efforts of salmonid and wildlife populations.

Recommendation RHS2 –Assess all naturally occurring large wood pieces to watershed-wide large wood survey. Include assessment of decaying, or soon-to-decay, wood to determine priority reaches for additional wood to be added to the creek to supplement these decaying, or soon-to- decay, wood.

Recommendation RHS3 — Provide resources to landowners about large wood in streams, and work with landowners to maintain existing large wood in streams and develop and implement instream enhancement projects in areas with less than adequate cover and scour for anadromous species.

Recommendation RHS4—Remove major barriers to fish migration in the watershed.

Recommendation RHS5 - Coordinate with other agencies and stakeholders to assess high priority reaches and areas lacking riparian habitat information and develop site specific treatments.

Recommendation RHS6 - Conduct targeted outreach and hold small landowner meetings with neighbors along Sonoma Creek and other tributaries in the watershed. Where instream projects or other conservation projects are implemented, the stream corridor should be assessed to determine the need for increased riparian canopy throughout the watershed

Recommendation RHS7 – Secure funding and implement the highest priority, multi-purpose riparian enhancement projects

Sonoma Creek Watershed Enhancement Plan

SECTION 3. IMPLEMENTATION

Sonoma Resource Conservation District

June 2013

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CHAPTER 11: PLAN IMPLEMENTATION

The management plan is intended to be implemented over a 10-year timeframe and will be reviewed and updated as needed during that time. A complete review and update of the Plan should commence at the end of the 10-year period. The vision, goals, objectives, and policies of the Plan are well established, though the recommended actions are designed to be revised and updated as appropriate, thus providing some flexibility over the course of plan implementation. This chapter provides a framework for implementing the recommended actions defined in the previous chapters.

Table 9.1 summarizes the management actions, the timing of planned implementation, and the chapter of this plan in which the actions are described in detail. The information provided in the table can be used in conjunction with the more detailed management actions described in the previous chapters and associated appendices. Each recommended action will be included in one or more of the following:

• 5-Year Actions include many tasks that are required to build the groundwork for future on-the-ground implementation, such as monitoring and assessment.

• 10-Year Actions are follow-up on tasks or monitoring related to actions initiated in the 5-Year period. 10-year actions also include tasks that are expected to be ongoing in the long-term, such as regulatory compliance.

• As-Needed Actions will be carried out in order to achieve the goals of this plan and accomplish specific recommended actions.

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IMPLEMENTATION OF THE SONOMA CREEK WATERSHED ENHANCEMENT PLAN

Table 11.1. Schedule for Implementing Recommended Actions

Recommended Potential Actions¹ Description Chapter Date Partners As-Needed Actions Outreach and education –

Landowner participation and involvement is critical for the successful implementation of the recommended actions. The RCD understands the importance of trust between landowners and the agencies working in the watershed. Close coordination is important so that the community understands how the various agencies work together.

Additionally, this plan is a living document, and continued landowner and SEC; SCWA; stakeholder input into the plans and its recommendations is essential to keeping 2013- SVVGA; the plan current and effective. 2023 NBAA 5-Year Actions Utilize existing data to prioritize focus areas for 2013- SSI1 road-related sediment source assessments. 8 2014 SEC Conduct outreach to high-priority landowners in the Sonoma Creek watershed based on study 2014- SSI2 findings. 8 2016 Conduct a multi-phased series of road sediment source assessments on high-priority road networks in order to develop prioritized sediment reduction 2014- DFW; SCC; SSI3 plans for the watershed. 8 2017 NOAA Utilize existing data to locate stream channel and bank erosion sites in Sonoma Creek, Schell Creek, 2013- SSI5 Carriger Creek, and Carneros Creek. 8 2017 SEC Utilize existing data to locate landslide sites that may be management induced in the Sonoma Creek watershed. Make land management improvement suggestions to property owners that have current management induced landslide sites. Utilize cost effective bioengineering techniques, 2014- SSI7 where feasible, to stabilize erosion. 8 2017 SEC Conduct surveys for species of concern to include but not limited to pond-breeding and stream- breeding amphibians throughout the watershed; and support instream monitoring and survey 2013- RHS1 efforts of salmonid and wildlife populations. 10 2017 SEC; CEMAR

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Assess all naturally occurring large wood pieces to watershed-wide large wood survey. Include assessment of decaying, or soon-to-decay, wood to determine priority reaches for additional wood to be added to the creek to supplement these 2013- RHS2 decaying, or soon-to-decay, wood. 10 2017 Coordinate with other agencies and stakeholders to assess high priority reaches and areas lacking riparian habitat information and develop site 2013- DFW; NOAA; RHS5 specific treatments. 10 2017 SEC 10-Year Actions UCCE; SVVGA; Napa Provide education and technical services to help RCD; Ag ranchers and growers understand and comply with 2013- Commissioner; ARS1 applicable agricultural regulations. 3 2023 NRCS

NRCS; Napa Develop LandSmart Farm/Ranch Water Quality RCD; Ag Plans to document current and plan for future 2013- Commissioner; ARS2 BMPs. 3 2023 SVVGA Prevent and control soil erosion, and enhance soil quality. See Chapter: 8 Sediment Sources and 2013- DFW; SCC; ARS3 Impacts. 3 2023 NOAA; NRCS Improve water use efficiency of irrigation and NRCS; frost protection systems. Explore alternative water 2013- SVVGA; ARS4 sources for these uses. 3 2023 SCWA Manage grazing to protect and enhance soil 2013- ARS5 quality, plant communities and water quality. 3 2023 NRCS; UCCE In riparian areas encourage native vegetation at 2013- DFW; SCC; CA1 multiple heights: groundcover, shrubs, and trees. 4 2023 NOAA; NRCS In riparian areas encourage a patchwork of habitats, such as a small grassy area near a dense 2013- DFW; SCC; CA2 shrubby area near a group of tall trees. 4 2023 NOAA; NRCS In riparian areas leave old and dead trees in place 2013- CA3 if they do not threaten structures. 4 2023 Allow natural processes, such as flooding and 2013- CA4 laying down new layers of sediment. 4 2023 In forestlands look out for pest insects and disease, invasive species, and dying trees. If you have questions, contact University of California Cooperative Extension Master Gardeners or a 2013- CA5 private arborist. 4 2023 UCCE; NRCS

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When you plant new trees or other plants, choose species that will be able to adapt to predicted future arid climate condition and from nurseries that collect, propagate, and disseminate tree species better adapted to the North Bay climate 2013- CA6 and changing environmental conditions 4 2023 UCCE; NRCS Work to eradicate non-native pest insects, diseases, and invasive weeds on your property. Educate yourself on what to look for and how to avoid moving insects, diseases, and invasive species from infected areas to uninfected areas. The following websites are good places to start: www.suddenoakdeath.org and 2013- CA7 www.caforestpestcouncil.org. 4 2023 UCCE; NRCS For wetlands complete large wetland restoration projects to serve as buffers to tidal flooding as 2013- CA8 well as sea level rise 4 2023 SLT; DFW

For wetlands reduce development in low-lying areas, behind levees, or adjacent to the bay/coast and prevent or reduce other stressors that reduce 2013- CA9 the ability of the wetland ecosystem to respond. 4 2023 For wetlands identify and support projects that facilitate connectivity to marshes and wetlands 2013- CA10 prior to and as they are impacted by sea level rise 4 2023 SLT; DFW For agriculture provide technical and financial incentives for agriculturalists to transition management practices that are affected by climate 2013- CA11 change. 4 2023 UCCE; NRCS For agriculture consider transitioning to organic 2013- CA12 practice on agricultural operations. 4 2023 UCCE; NRCS For agriculture consider incorporating trees, shrubs, and hedgerows into rangeland or farm 2013- CA13 landscapes to sequester carbon 4 2023 UCCE; NRCS For agriculture consider soil management 2013- CA14 practices that sequester carbon 4 2023 UCCE; NRCS SCWA; Basin Advisory Continue to implement the Sonoma Valley 2013- Panel WQAN1 Groundwater Management Plan 5 2023 Members Implement urban and rural water conservation City of measures such as low-water landscaping, water Sonoma; saving appliances and fixtures, and graywater re- Sonoma use. Programs to offset costs of many of these Valley County measures are available through the City of Sanitation Sonoma, Sonoma Valley County Sanitation 2013- District; WQAN2 District, and Valley of the Moon Water District. 5 2023 VOMMWD

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Implement Slow It, Spread It, Sink It! guidelines to manage stormwater for re-use and groundwater 2013- WQAN3 recharge. 5 2023 SCWA Increase agricultural water use efficiency. See NRCS; Chapter 3: Agricultural and Rural Sustainability 2013- SVVGA; WQAN4 for more information. 5 2023 SCWA Continue to expand the storage, distribution and 2013- WQAN5 use of recycled water. 5 2023 SCWA Implement upper watershed stormwater management to reduce flood peak flows and reduce overbank flow into Schell Creek and City of across Highway 121 through attenuation or 2013- Sonoma; FL1 diversion into storage. 6 2023 SCWA Elevate or flood proof some buildings or construct small lengths of levee to protect remaining developments within the floodplain from most 2013- FL2 hazards. 6 2023 Restore valuable tidal wetlands in Schellville area for endangered species habitat, managed retreat to protect some inland uses, carbon sequestration, promotion of tidal scour, and potential reduction in levee maintenance costs. There is significant potential to create valuable wetlands and expand areas on San Pablo Bay with good opportunity to create valuable mid‐ elevation, or middle, marsh habitat. Timing of such creation of middle marsh is important to initiate marsh accretion and thereby attain marshes that are sustainable in the 2013- FL3 mid‐term, given sea level rise. 6 2023 SLT Initiate and continue landowner outreach to conduct appraisals, solicit funds, and negotiate 2013- SLT; FL4 purchase agreements and/or flood easements. 6 2023 SCAPOSD Leverage infrastructure investments (highway and rail) and initiate climate change adaptation planning to benefit climate change resilience and 2013- FL5 reduce flood risks in the Schellville area. 6 2023 CalTrans Collaborate and seek funding for watershed‐wide effort to establish parameters of a multiple‐benefit project involving elements of: water quality improvement, surface and groundwater storage, rainwater harvesting, use of recycled water, wetland restoration, and seasonal flood easements 2013- SCWA; SLT; FL6 to allow continued agriculture. 6 2023 SEC; UCCE; SVVGA; Napa Develop LandSmart Farm/Ranch Water Quality RCD; Ag Plans and implement Management Practices to 2013- Commissioner; WQ1 decrease sediment loads. See Chapters 3 and 8. 7 2023 NRCS

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UCCE; Develop LandSmart Farm/Ranch Water Quality SVVGA; Napa Plans and implement Management Practices to RCD; Ag decrease pathogen and nutrient loads. See Chapter 2013- Commissioner; WQ2 3. 7 2023 NRCS Implement Management Practices to decrease pollutant loading from urban and suburban stormwater – those identified in NPDES permits, and those that are outlined in the “Slow It, Spread City of It, Sink It!” Manual that can be undertaken by 2013- Sonoma; WQ3 individual homeowners. 7 2023 SCWA Maintain septic systems based on State Water Board and Sonoma County PRMD requirements and guidelines found in the “Homeowner’s Guide 2013- County of WQ4 to Septic System Operation”. 7 2023 Sonoma City of Sonoma; Sonoma Valley County Comply with all conditions of municipal NPDES 2013- Sanitation WQ5 permits for stormwater and sewer systems. 7 2023 District Implement road sediment reduction plans resulting from the road related sediment source assessments. Conduct these in a prioritized multi- 2013- DFW; SCC; SSI4 phased series based on funding availability. 8 2023 NOAA; NRCS Make land management improvement suggestions to property managers that have current management induced stream channel and bank erosion sites. Utilize cost-effective bioengineering techniques, where feasible, to stabilize erosion. Where feasible, maintain riparian buffers to filter fine sediments before surface drainage enters 2013- SSI6 streams. 8 2023 NRCS Restore large patches of tidal marsh along the entire shoreline of San Pablo Bay particularly near 2013- SLT; DFW; MH1 the mouths of sloughs and major streams. 9 2023 USFWS Upstream of Highway 37; restore a broad plain of tidal marsh on both sides of Sonoma Creek. There is considerable flexibility in this area regarding the desired location of tidal and diked habitats; seasonal diked wetlands should be located in close proximity to tidal flats to provide high tide 2013- SLT; DFW; MH2 roosting habitat for shorebirds. 9 2023 USFWS With willing landowners, establish managed marsh or enhanced seasonal pond habitat (especially for shorebirds) on agricultural 2013- MH3 baylands that are not restored to tidal marsh. 9 2023 DFW; USFWS

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Enhance riparian habitat along Sonoma Creek in the Schellville area and upstream, and protect and DFW; restore Tolay Creek. Where possible, enhance 2013- USFWS; MH4 marsh/upland transitions and provide buffers. 9 2023 NOAA Prepare and distribute information to the public about the habitat needs of these species and how watershed residents can help with recovery 2013- MH5 efforts. 9 2023 In agricultural areas allow ponding in field 2013- MH6 depressions for shorebirds and waterfowl. 9 2023 In agricultural areas create small diked ponded 2013- MH7 areas adjacent to levees where possible 9 2023 In agricultural areas, encourage growth of vegetation along fence rows or field edges 2013- MH8 toprovide habitat for small birds and mammals. 9 2023 NRCS In agricultural areas, delay spring harvest of oat- 2013- MH9 hay as late as possible to avoid nesting waterfowl. 9 2023 In agricultural areas, fence cattle from wetland 2013- MH10 areas during wet periods. 9 2023 NRCS In agricultural areas, increase the practice of rotational grazing to encourage a more diverse 2013- MH11 grassland habitat. 9 2023 UCCE; NRCS Provide resources to landowners about large wood in streams, and work with landowners to maintain existing large wood in streams and develop and implement instream enhancement projects in areas with less than adequate cover and scour for 2013- RHS3 anadromous species. 10 2023 Remove major barriers to fish migration in the 2013- DFW; SCC; RHS4 watershed. 10 2023 NOAA; NRCS Conduct targeted outreach and hold small landowner meetings with neighbors along Sonoma Creek and other tributaries in the watershed. Where instream projects or other conservation projects are implemented, the stream corridor should be assessed to determine the need for increased riparian canopy throughout the 2013- RHS6 watershed 10 2023 Secure funding and implement the highest priority, multi-purpose riparian enhancement 2013- DFW; NOAA; RHS7 projects 10 2023 NRCS ¹ Actions defined in Section 2 Chapters 3-10; codes correspond to listed recommended actions. ARS= Agricultural and Rural Sustainability; Climate Adaptation = CA; WQAN = Water Quantity; FL = Flooding; WQ= Water Quality; SSI = Sediment Sources and Impacts; Marshlands = MH; RHS - Riparian Habitat and Species

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