2008 Willow Creek Watershed Assessment

WILLOW CREEK WATERSHED ASSESSMENT AND MANAGEMENT PLAN

Final Report

Submitted by Watershed Consulting, LLC P.O. Box 1701 Kalispell, MT 59903

Submitted to Blackfeet Environmental Office 457 Hospital Road Browning, MT 59417

September, 2010

This project was conducted in cooperation with the Blackfeet Tribe Environmental Office and the EPA Region 8

Table of Contents Table of Contents...... i List of Tables ...... ii List of Figures...... iii List of Maps ...... iii List of Appendices ...... iv 1. Executive Summary...... 1 1.1 Summary of Accomplishments...... 1 1.2 Summary of Results...... 2 2.0 Standards...... 4 3.0 Site Description and Project Overview...... 6 3.1 Project Description...... 8 3.2 Objectives ...... 8 3.2 Site and Source Description...... 9 3.2.1 Primary Pollution Sources in the Watershed ...... 9 3.2.2 Description of Listed Segments and Sources...... 9 3.2.4 Listed Segment Summary...... 13 4.0 Methods...... 15 4.1 Aerial photo interpretation and GIS analysis...... 15 4.2 Field Data Collection ...... 15 4.2.1 Sediment ...... 18 4.2.2 Physical Stream Characteristics...... 19 4.2.2 Nutrients...... 21 4.3 Community Outreach and Restoration Planning ...... 21 5.0 Results and Analysis ...... 22 5.1 Aerial Photo Interpretation Results...... 22 5.2 Field Results: Sediment ...... 22 5.2.1 Stream Condition Assessment ...... 22 5.2.1 Road Inventory Assessment...... 24 5.2.2 Channel Morphology ...... 25 5.2.3 Streambank Erosion...... 26 5.2.4 Total Suspended Solids...... 28 5.2.5 Turbidity ...... 29 5.4 Field Results: Nutrients...... 32 5.4.1 Nitrogen ...... 32 5.4.2 Total Phosphorous ...... 36 5.4.3 Dissolved Oxygen...... 37 5.5 Field Results: Temperature...... 39 5.6 Field Results: Pathogens...... 40 5.6.1 Total Coliform ...... 40 5.7 Water Quality Data Analysis Summary...... 41 5.7.1 Pollutant Reduction Targets...... 44 5.8 Temporal Analysis...... 47 5.9 Data Gaps...... 48 6.0 Discussion and Management Recommendations ...... 49 6.1 Influences on Stream Segment Condition...... 49 6.2 Restoration Priorities and Recommendations...... 51 i

6.3 Monitoring Recommendations...... 54 6.3.1 Filling data gaps...... 54 6.3.2 Effectiveness Monitoring...... 55 6.3.3 Monitoring to support additional efforts...... 58 6.3.4 Budget for Proposed Monitoring Approach ...... 59 6.4 Adaptive Management...... 60 7.0 References...... 61

List of Tables

Table 1. Pollutant Standards ...... 4 Table 2. Dissolved Oxygen Criteria Fisheries and Associated Aquatic Life ...... 5 Table 3. Land Use and Pollution Source Assessment...... 13 Table 4. Willow Creek Watershed Listed Segments and Designated Uses*...... 13 Table 5. Data collected by Watershed Consulting and BEO (05/2008 – 08/2008) ...... 16 Table 6. Existing BEO Water Quality Sites and Years of Existing Data ...... 17 Table 7. Potential pollution sources from aerial photo interpretation ...... 22 Table 8. RAF scores...... 23 Table 9. Road-related Sediment Sources with Highest Sediment Contributions ...... 24 Table 10. Culverts displaying at least one indicator of higher risk of failure...... 25 Table 11. Stream Type and Morphology ...... 26 Table 12. Eroding area of streambank for each reach, normalized to rate/1000ft...... 27 Table 13. Total Suspended Solids Summary Data...... 28 Table 14. Upper Willow Creek Total Suspended Solids Results by Reach...... 28 Table 15. Lower Willow Creek Total Suspended Solids by Reach...... 29 Table 16. Depot Creek Total Suspended Solids by Reach ...... 29 Table 17. Turbidity Summary Data ...... 29 Table 18. Upper Willow Creek Turbidity by Reach...... 30 Table 19. Depot Creek Turbidity by Reach...... 31 Table 20. Lower Willow Turbidity by Reach...... 32 Table 21. Total Nitrogen by Listed Segment...... 32 Table 22. Upper Willow Creek Total Nitrogen by Site...... 33 Table 23. Lower Willow Creek Total Nitrogen by Site...... 33 Table 24. Depot Creek Total Nitrogen by Site ...... 33 Table 25. TKN Summary Data by Listed Segment...... 34 Table 26. NO2+NO3 Summary Data...... 35 Table 27. Total Ammonia Summary Data...... 35 Table 28. Ammonia (NH3) Summary Data...... 36 Table 29. Phosphorous Summary Data...... 36 Table 30. Dissolved Oxygen Summary Data...... 37 Table 31. Upper Willow Creek Dissolved Oxygen Summary data by Reach...... 38 Table 32. Lower Willow Creek Dissolved Oxygen Summary data by Reach...... 38 Table 33. Depot Creek Dissolved Oxygen Summary Data by Reach ...... 38 Table 34. Temperature Summary Data...... 39 Table 35. Maximum Water Temperature Readings...... 40 Table 36. Total Coliform Summary Data ...... 41 Table 37. Lower Willow Creek Total Coliform Summary data by Reach ...... 41 Table 38. Depot Creek Total Coliform Summary Data by Reach...... 41

Table 39. Assessment Sites with Indicators of Degradation: Depot Creek ...... 42 Table 40. Assessment Sites with Indicators of Degradation: Lower Willow Creek ...... 42 Table 41. Assessment Sites With Indicators of Degradation: Upper Willow Creek...... 43 Table 42. Stream condition improvement targets...... 44 Table 43. Dissolved oxygen improvement targets...... 45 Table 44. Phosphorous improvement targets...... 45 Table 45. TSS improvement targets...... 45 Table 46. NO2+NO3 improvement targets...... 46 Table 47. TKN improvement targets ...... 46 Table 48. Total Nitrogen improvement targets...... 47 Table 49. NH3 stream reach target levels...... 47 Table 50. Total Ammonia stream reach target levels ...... 47 Table 51. Percent Land Use and Percent Pollution Source ...... 50 Table 52. Restoration Priorities Matrix ...... 51 Table 53. Detail of Priority Restoration Projects included on Maps 11 and 12, Appendix A...... 52 Table 54. Summary of Monitoring Recommendations and Estimated Budget ...... 59

List of Figures Figure 1. Stream Reach Assessment Scores ...... 24 Figure 2. Eroding Bank Area Source Types and Total Contribution ...... 27 Figure 3. Upper Willow Turbidity Range and Median value by Reach ...... 30 Figure 4. Depot Creek Turbidity Range by Reach ...... 31 Figure 5. Lower Willow Turbidity Range by Reach ...... 31 Figure 6. Upper Willow Creek Dissolved Oxygen Ranges by Reach ...... 37 Figure 7. Lower Willow Creek Dissolved Oxygen Range by Reach ...... 38 Figure 8. Depot Creek Dissolved Oxygen Range by Reach...... 38

List of Maps Map 1. Willow Creek and surrounding watersheds...... 7 Map 1a. Willow Creek Drainage Listed Segments...... 10

Maps in Appendix A Map 1. Temperature and Monitoring Sites Map2a. Land Use Map Map 2. Stream Condition Ratings Map 3. Culverts at risk Map 4. TSS Results Map 5. TN Results Map 6. Nitrates and Nitrites Results Map 7. Ammonia Results Map 8. Total Phosphorous Results Map 9. Temperature Influences Map 10. Priority Restoration Sites: West Half Map 11. Priority Restoration Sites: East Half

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List of Appendices

Appendix A Maps Appendix B List of criteria for aerial survey; Road data Appendix C Narrative standards for coliform; Ammonia calculations Appendix D Data summaries by segment

1. EXECUTIVE SUMMARY

Project Title: Willow Creek Watershed: 2008 Water Quality and Watershed Condition Assessment

Grant Number: C9-98852701-01 Grant Source: Environmental Protect Agency

Watershed Consulting assisted the Blackfeet Environmental Office in assessing the condition of the Willow Creek watershed and summarizing existing data to support future restoration and monitoring activities in the Willow Creek watershed. Water quality data collected from sites throughout the watershed were analyzed to help define current biological, physical, and chemical water quality conditions within the watershed. This report includes summaries of water quality trends, applicable water quality standards, and data gaps, priority restoration sites and activities, and monitoring recommendations to strengthen the dataset and support future restoration.

1.1 Summary of Accomplishments

This report summarizes available water quality data in the Willow Creek Watershed for three listed stream segments and synthesized results in such a way as to provide the Blackfeet Environmental Office with a foundational document from which a comprehensive watershed management plan can be established. The structure of this report is based on requirements of watershed plans following EPA’s Nine Elements of Watershed Plans (EPA 2008).

This report satisfies the following objectives: 1. Defines water quality standards applicable to listed stream segments in the Willow Creek watershed 2. Identifies and describe current conditions, causes and sources of pollution in the watershed by listed segment 3. Compares water quality conditions to standards to determine impairment 4. Attributes and quantifies water quality impairments to sources of pollution 4. Calculates pollutant level reductions needed to meet water quality standards (as data allow) 5. Provides management, restoration, and monitoring recommendations to achieve needed pollutant reductions over a 5 to 10 year timeframe 6. Map and provide cost estimates for priority projects and related monitoring 7. Define acceptance criteria for restoration activities

This analysis defined spatial and temporal trends in water quality data where possible. Analysis included identifying the causes and sources of pollutants by listed sub-watershed, relating water quality conditions to land uses and recommending management measures to achieve pollutant reductions. As important as data results, the report highlights data gaps that currently limit the precision of determinations of exact land uses and intensities (particularly grazing) and thus site- specific contributions to pollutant levels. For example, ammonia data can not be compared accurately to water quality standards because temperature and pH readings were not taken in the same sampling event. Some areas need more monitoring to pinpoint sources of pollution more closely. Metadata associated with land uses, particularly grazing, were not readily available for 1

precise calculations of pollution influences and are discussed in the Data Gaps. Analysis of water quality over time was not feasible due to lack of consistency among sampling events and the small existing dataset for sampling. This dataset and monitoring protocol have recently become more standardized by the BEO. This report includes recommendations for further monitoring and restoration activities.

1.2 Summary of Results Water quality is analyzed and summarized by listed segments, identified by EPA and BEO. Through a site and source assessment, current conditions in the Willow Creek watershed were attributed to the land uses in the project area. Data analysis and mapping further defined some spatial trends in water quality for nutrients, sediment indicators, and habitat condition, and determined the sources of pollutants. The most significant source of nutrients were associated with the sewage lagoon and likely associated with sewer overflow on Depot Creek, and to a lesser extent, urban run-off. Specific sources of sediment pollution identified were related to agricultural return flow, riparian grazing and to a lesser degree road crossings, including potential sources at culverts with high risk of failure. Stream habitat condition scores were lowest on upper and lower willow creek in heavily grazed areas, but varied throughout the watershed. These data allowed for some of the limited pathogen and temperature data set to be associated with habitat conditions, which also informed restoration recommendations. These recommendations focus on reducing sediment and nutrient inputs to streams and also address some sources of pathogens, elevated temperatures and solid waste.

Too few comparable data were available for stream temperature and pathogens to determine water quality trends, though data mapping did locate the sites of most concern for these variables and their potential influences on water quality. Too few comparable data also did not allow for precise determinations of the exact pollution amount attributable to each source. However, data did allow for pollution reduction goals to be established per listed segment as well as the identification of site-specific projects.

Grazing is the largest land use activity in all four listed segments by acreage. Data for precise grazing intensities were not available. Recommendations relative to grazing land uses are centered on decreasing the duration and intensity of grazing in riparian areas. The establishment of off-site water and hardened crossings in heavily used areas and relocating corrals further from surface waters can decrease the sediment contribution of grazing to all three sub-watersheds. Increasing the quantity and width of riparian vegetated buffers and conducting shoreline restoration at Kipp Lake can increase the sediment-catching capacity of riparian areas throughout the watershed.

Closer to Browning, nutrient pollution is the most pressing issue and is associated for the most part with the sewage treatment lagoons on Depot Creek, and to a lesser extent urban run-off and sewer overflow. User-created stream crossings contribute some sediment to the stream and are recommended to be restored, not only for pollution reduction but for aesthetic values within the town of Browning and overall stream ecologic function, particularly sediment capture and storage. Community outreach activities and pollution-prevention campaigns to lower the occurrence of user-created stream crossings and garbage dumping in drainageways and elsewhere on the landscape are recommended, as well as community workshops and educational efforts to teach students and other residents about the characteristics and importance of good water quality and stream habitat.

Monitoring recommendations are designed to fill gaps in water quality data, locate pollution sources more precisely and monitor the effectiveness of restoration activities. Monitoring includes additional water quality sampling, assessing stream habitat and geomorphic condition at restoration sites and establishing additional monitoring sites. Additional monitoring includes road crossing inventories and sediment source survey at repaired crossings, vegetation inventory at restoration sites, monitoring at dumping sites, and community surveys to track the effectiveness of outreach programs.

2.0 STANDARDS

The conditions of the Willow Creek watershed, as shown by the available data in this report, are gauged relative to standards set by the BEO for water quality, including nutrients, pollutants and sediments. These standards determine the thresholds within which designated uses of the streams can be maintained.

The Willow Creek Watershed is within the EPA’s aggregated nutrient eco-region V, South- Central Cultivated Great Plains, sub-eco region 42, Northwestern Glaciated Plains (EPA 2000). Where narrative standards apply, DEQ and EPA reference stream parameters, Best Professional Judgment, and field observations were used to determine the relative standards for a reference reach in the area. Results were compared to these relative conditions to provide a sense of the relative health of stream segments relative to natural conditions.

The following table summarizes standards for aquatic life classes and human health consumption, against which field results were measured. Pollutants listed in Tables 1 and 2 are those for which data were available after 2000. EPA reference conditions for this ecoregion are also provided for comparison and cross-reference.

Table 1. Pollutant Standards USEPA Ecoregion Nutrient BEO Standards Criteria Pollutant Sub Region 42# Ecoregion V! Tribal Narrative Tribal Aquatic Standards## Standards† 25th percentile- 25th percentile- Acute (CMC) Chronic all seasons all seasons (CCC)

Ammonia* (mg/L) pH and temperature- dependent * NH3+NH4 (mg/L) pH and temperature- dependent Dissolved Oxygen** 1 day minimum 8.0 (mg/L) mg/L for salmonid; 5.0 mg/L for non-salmonid Total Nitrogen = TKN 0.610 0.880 “all waters be free from + N02, N03 (mg/L) the deposition of contaminated sediments in amounts that impair any of the designated uses of Tribal waters” Nitrates + Nitrites 0.060 0.260 “all waters be free from (NO2+NO3) (mg/L) the deposition of contaminated sediments in amounts that impair any of the designated uses of Tribal waters” Phosphorous (mg/L) 0.041 0.067 “all waters be free from the deposition of contaminated sediments in amounts that impair any of the designated uses of Tribal waters” 4

Sediment a) 20% of pool depths filled by sediment b) salmonid spawning areas contain >15% fine sed. (.25 cm or less). Temperature Narrative standards also 20° Max apply (salmonid) 25° Max (non- salmonid) Fecal Coliform Narrative standards a), d), e), f). See Appendix C Total Coliform Narrative standards a), d), e), f) See Appendix C Total Suspended Solids Not to exceed 120% of (TSS) natural, except by permit. Turbidity (NTU) 30 7.83

* Ammonia and NH3 + NH4 standards are pH and temperature-dependent – see Tables 82, 84, and 86 in Appendix D. ** Refer to Table 5, below. Values are similar for DEQ and BEO. † Refer to BEO Narrative Standards in Appendix C. # Nutrient Calculations for Ecoregion V, Sub-Region 42, from EPA, 2001 ! Nutrient Calculations for Ecoregion V, from EPA, 2001 ## From BEO, 2005

Table 2. Dissolved Oxygen Criteria Fisheries and Associated Aquatic Life Time Period Salmonid Non – Salmonid (mg/L)* (mg/L)*

30 – day average NA* NA 7 – day average 9.5 (6.5) 6.0 95% saturation 7 – day average minimum NA NA 1 – day minimum 8.0 (5.0) 5.0 95% saturation * These are water columns concentrations recommended to achieve the required intergravel DO concentrations shown in parenthesis. For species that have early life stages exposed directly to the water column, the figures in parenthesis apply.

Narrative standards of the BEO indicate that streams will be “free from” pollutants and substances harmful or injurious to public health/safety and welfare. In cases where no numeric standards are available, the narrative standards are applied.

3.0 SITE DESCRIPTION AND PROJECT OVERVIEW

The Blackfeet Nation is located in Northwestern Montana and covers an area of 1,525,712 acres. The reservation covers most of Glacier County and extends southward into Pondera County. The reservation lies on the east slope of the Lewis Range of the Rocky Mountains. It is bordered by Canada to the north, the Lewis and Clark national forest to the south, and Glacier National Park to the west. There are an estimated 11,000 stream miles and over 5000 linear miles of riparian habitat (BEO 2007). Waters from the areas on the east side of the Continental Divide eventually flow into the Gulf of Mexico and Hudson Bay. The Watersheds on the reservation are St. Mary River drainage, Milk River Drainage, Cut Bank Creek drainage, Two Medicine Drainage and the Birch Creek Drainage. These drainages carry a bulk of the estimated 1.5 million acre/feet of water that flow across the reservation each year.

The Willow Creek drainage flows west to east from its headwaters in the foothills east of Glacier National Park, between the Cut Bank and Milk River Drainages (See Map 1 below). The watershed is entirely within the Marias River Basin and the Northwestern Glaciated Plains EcoRegion (DEQ 2006). The watershed drains an area of 92,600 acres (BEO 2007) and its three main water bodies are Willow Creek, Depot Creek and Flatiron Creek. Depot and Flatiron Creeks flow into Willow Creek just east of Browning, from the south and north, respectively. Willow Creek flows through Browning and then northeast into Cut Bank Creek. These streams originate in the foothills east of Glacier National Park and are first, second and third order streams. Primary land uses in the watershed vary from recreational and low density cattle grazing in the upstream reaches and headwaters to residential, commercial, and wastewater treatment closer to Browning. Downstream of Browning, land use is dominated by ranching and agriculture. Two paved highways, State Highway 89 and US Highway 2, meet in Browning. A network of dirt and gravel roads traverses the watershed and a railroad line runs from southwest to northeast.

The BEO determined that three streams in the watershed were impaired, namely Depot Creek, Flatiron Creek and Willow Creek. Water quality concerns are related primarily to nutrients, coliform and sediment as influenced by agriculture, urban runoff and wastewater treatment in the watershed (BEO 2006). This project was implemented as part of the EPA and Blackfeet Environmental Office (BEO) efforts to define and quantify the impairment of these streams within the Blackfeet Reservation. Both agencies are currently working together to develop a water quality restoration plan for the Reservation. This report, addressing the 9 steps of an EPA watershed restoration plan (EPA 2008), summarizes available data for the Willow Creek Watershed and provides initial recommendations for steps forward.

Map 12. Willow Creek and surrounding watersheds

3.1 Project Description The project assessed the conditions of the Willow Creek watershed, between the Cut Bank and Two Medicine drainages in order to provide the BEO with accurate and current data as to the conditions of the watershed and to determine sediment-related impairment and water quality as they relate to Blackfeet standards and designated uses. Thirteen water quality monitoring stations are currently distributed throughout the watershed and monitored by the Blackfeet Office of the Environment. Project sites include existing BEO water quality monitoring sites and 2008 assessment sites. Project sites are located on Willow Creek, Depot Creek, and Flatiron Creek.

The overall goal of this assessment is to provide the BEO with comprehensive data and analysis that can help the agency move toward a watershed restoration and management plan that will enhance the ecological services of the surface waters on the Blackfeet Reservation, thus providing multiple benefits to the population of the Reservation. 3.2 Objectives The primary goal of this initial watershed-wide effort is to ensure the full recovery of aquatic life and human activity beneficial uses. To achieve these goals, data were collected in order to identify specific sources of nutrient or sediment contributions within the watersheds of the three listed stream segments. Data came from multiple sources, including:

 Publicly available aerial photographs and GIS data  Sediment source inventory data collected in 2008  Current and past water quality data  Riparian vegetation condition data (existing tribal data and additional data collected in 2008)  Channel morphology measurements collected in 2008  Information from residents, landowners and BEO officials as to historical and current uses and trends

This assessment provides the BEO with a document consistent with the 9 components of a watershed restoration plan, with the goal of providing a founding document from which an effective and targeted watershed restoration plan can be developed. The report includes data analysis to:

 Identify the land uses associated with the three listed segments of the Willow Creek Watershed and the causes and sources of pollutants to those systems  Establish targets for estimated reductions of source pollutants necessary to achieve desired water quality standards and beneficial uses for listed segments  Recommend management measures to be implemented to achieve pollutant reductions  Estimate the needed technical and financial resources to achieve management objectives  Identify public outreach and education strategies to enhance the public’s understanding of individual projects and the overall objectives of the watershed management plan  Establish criteria to determine effectiveness of management measures  Recommend monitoring criteria to evaluate the effectiveness of implementation efforts

A detailed schedule and measureable milestones to be achieved will be dependent upon BDO management and restoration priorities and funding. 8

3.2 Site and Source Description

3.2.1 Primary Pollution Sources in the Watershed The predominant land uses around each listed segment vary considerably and are the primary influences on stream quality and pollution inputs. Each land use tends to contribute specific pollutants to streams. Livestock operations, when concentrated in a feedlot or other structure near a stream, can often produce large inputs of nitrogen, phosphorous and pathogens, as much as 6-800 mg/L of total nitrogen (TN) and 4-5 mg/L of total phosphorous (TP). Open grazing, where cattle have free access to streams, often leads to trampling of streambanks, a lack of adequate vegetation and often sediment contributions to the stream. The latter land use tends to affect stream morphology, habitat and stream ecological functions. Agricultural activities, often in the form of pesticides, have been reported to contribute .77- 5.04 mg/L of TN, and .085- .104 mg/L of TP in other areas (FISR, no date).

Land uses associated with urban areas are a significantly smaller source of pollutants by area in this watershed. Impervious surfaces, litter, stream crossings and recreation activities are potential sources of pollutants in an urban setting. Nutrient contributions from wastewater have been reported in other areas to contribute 30 mg/L of TN and 10 mg/L if treated and 35 mg/L of TN and 10 mg/L TP if untreated (FISR, no date). A concentrated water treatment pond can be an even larger source of nitrogen, phosphorous, other nutrients and coliform. The wastewater treatment facility and the stormwater conveyance system in Browning are known pollutant sources, and are a priority for upgrade to reduce pollutant contributions from urban sources. These urban pollutant sources are also point-source in nature and will be addressed in efforts beyond the scope of this non-point source assessment.

3.2.2 Description of Listed Segments and Sources

The following section describes each listed segment, and a general characterization of land uses in each, including sources of pollutants as determined prior to the 2008 field work The beneficial uses of the Willow Creek listed segment are different above and below its confluence with Depot Creek. For the purposes of this report, Willow Creek is divided into an Upper and Lower listed segment, sometimes referred to as subwatersheds. The segments assessed throughout this report are shown in Map 1a below.

Map 1a. Willow Creek Drainage Listed Segments

Depot Creek Hydrological Unit Code: 100302020201

The Depot Creek stream segment includes the entirety of Depot Creek, which runs approximately 6 miles from its tributaries in the foothills south and west of Browning to its confluence with Willow Creek just east of town. The BEO 2008 Management Plan listed Depot Creek as impaired for nutrients, coliform and solid waste (BEO, 2006). The sewage lagoons along Depot Creek and “illegal dumping” were cited by BEO as the specific source for these contaminants. Animal holdings were also cited as a source subcategory and have been the object of previous efforts by the BEO (BEO, 2006). To increase the available data set around this critical pollution source, two monitoring sites were added to existing BEO sites, one above (01) and one below (02) the ponds.

Though an important source of pollutants in this listed segment, the ponds, by area, are less than 1% of the 7,446 acres of the segment. The primary land use is rangeland, covering 3,961 acres of the overall area. Based on WSC re-digitized stream layers, there are 19.5 stream miles on Depot Creek and its tributaries, 13.8 miles of which run through grazing allotments. Though the stream maintains a non-urban character throughout its length, as it approaches Browning urban development becomes a source of pollutants, particularly in the form of stormwater runoff from impervious surfaces, an outdated sewer system and litter blown or thrown into the creek. There are 38.9 miles of road surface in the watershed, predominantly classified as “local road/city street” by BEO road layers. The “Urban” land use around Depot Creek accounts for <1% of the land area of the sub-watershed, including 0.33 stream miles.

Flatiron Creek Hydrological Unit Code: -100302020203

Flatiron Creek is the northern-most tributary of Willow Creek, flowing over 7 miles and draining an area of approximately 20, 235 acres. An irrigation diversion has rendered most of the stream dry. Regardless, the stream was listed as impaired for nutrients (BEO, 2006). The BEO used best professional judgment in attributing the source of the impairment to grazing. The dominant land use around the entire stream segment is rangeland, with grazing activities comprising 39% of the segments land area. There are 29.4 stream miles in the segment, though precise determination of the length of actual flowing stream was not calculated. Nearly 40% of these stream miles flow through rangeland. A network of roads crosses the subwatershed, comprising approximately 61.6 miles, primarily local roads and city streets.

Willow Creek Hydrological Unit Codes: 100302020202 and 100302020204

Willow Creek flows for 25 stream miles from the foothills to Cut Bank Creek. The stream was considered impaired by the BEO for nutrients, pesticides and sediment (BEO, 2006). The BEO determined rangeland, particularly grazing impacts, as the primary pollutant source and stormwater runoff as a contributing source (BEO 2006). Range management along Willow Creek is described by the BEO as summer and winter-long grazing with “free access to streams and riparian areas.” Bank trampling, de-vegetation of banks and nutrient loading were determined to be consequences of these practices, which increase where feeding, calving or other grazing operations are concentrated near streams (Berthelson, 2007). Designated uses for the 11

stream differ upstream and downstream of the Depot Creek confluence and for purposes of this report will be referred to as “upper” and “lower” Willow Creek.

Upper Willow Creek Based on the redigitized stream layer in GIS (see Methods, Section 4), the Upper Willow Creek segment is approximately 38 stream miles long and includes the stream’s tributaries in the southwestern foothills and the main channel as it flows north and west along the valley floor to its confluence with Depot Creek. This segment drains an area of approximately 17,303 acres, with 53.9% of this land area in rangeland. Rangeland in Montana have been found, to varying degrees, to negatively affect riparian habitat and vegetative cover, stream erosion and nutrient and bacterial discharge (FISRWG, no date).

A network of dirt roads and cattle trails transect this watershed, totaling approximately 66.9 miles. Along with their associated culverts, these roads are also seen as potential sources of sediment delivery. Photos and ground observation show that many stream crossing areas were lacking in riparian vegetated buffer strips. Riparian vegetation with deep, binding root mass, such as shrubs and native sedges, functions to catch sediment, filter nutrients and reduce overall pollution loads in streams (FISRWG, no date).

For approximately 0.9 stream miles, Upper Willow Creek passes through the urban center of Browning. Stormwater return, litter and motorized recreation and travel were thought to be probable pollution sources. In this short section the stream crosses under a network of paved roads and highly used areas including the North American Indian Days Pow-Wow Grounds, a baseball diamond and city park areas. The urban land use along this section of Upper Willow Creek comprises approximately <1% of this sub-watershed’s total land use.

Lower Willow Creek The Lower Willow Creek segment is the largest in the project area and includes all of Willow Creek downstream of the Depot Creek confluence, draining an area of approximately 45,909 acres. Land use on Lower Willow Creek is predominantly agricultural, with nearly 36,939 acres dedicated to rangeland activities, or 34% of the segments total area.

This segment contains fewer tributaries and feeder streams, in total running 76 stream miles to its mouth at Cut Bank Creek north and west of Browning, as calculated from the re-digitized stream layer in GIS at a scale of 1:7000. Although by area grazing activities only comprise a third of land use, nearly 84% of stream miles in the segment run through rangeland.

Networks of dirt roads and culverts are present in the area and have the potential to deliver sediment to the stream system. Roads consist in less than 1% of the total area of the watershed, including paved and gravel roads as well as native surface roads.

3.2.4 Listed Segment Summary

In Table 3 below, we summarize the major land uses around each listed segment. These approximate areas, derived from spatial analysis of GIS layers form the baseline to which we apply data analysis and toward which we apply our recommendations and conclusions (see Methods and Data Gaps sections for further discussion).

Table 3. Land Use and Pollution Source Assessment Listed Segment Total Grazing Area Stream Stream Stream Road Watershed (Acres) Miles Miles in Miles Miles Area Rangeland in (Acres) Urban Depot 7,446.2 3961.3 19.5 19.5 .33 38.9 Flatiron 20,235.8 7904.1 29.4 29.4 1.2 61.6 Upper Willow 17,303.4 9330.2 38.3 38.3 .88 66.9 Lower Willow 45, 908.9 15743.3 75.6 75.6 0 101.7 Watershed Total 90,894.2 36,938.8 162.8 110.0 2.4 269.1

Within these reaches, the BEO has a body of historical water quality data from stream sampling locations throughout the watershed. Analysis of existing data and GIS-based source assessment identified key areas where new data sets would help narrow in on specific pollutant sources. A total of 14 new sample sites were established in 2008 field season.

Table 4 below summarizes the stations for which data were analyzed for this report. Listed segments and their designated uses were established by BEO. Aerial maps and GPS locations of reaches were used to determine their corresponding listed segment.

Table 4. Willow Creek Watershed Listed Segments and Designated Uses* Listed Sample site ID Drinki Aquatic Life Recreational Listed Segment ng For: Water Depot Creek 122A, 122B, D-02, D-01, Class II Salmonid all life Class I Nutrients, 59, 58, 719, 723 stages; Non-salmonid coliform full life stages, Partial and solid life stages waste

Upper Willow 83A, 83B, W-83 DS, 57, Class II Salmonid all life Class I Nutrients, Creek 130A, 130B, W-12US, W- stages pesticides 12, W-12DS, and W-131A, 131A, W-05, sediment 131AB, W-06,131SP, 131B, 13, 721 Lower Willow W-01, W-02, 03W, W-03, Class II Non-salmonid full life Class I Nutrients, W-04, W-01.5, 14, 720, 722 stages pesticides and sediment

Flatiron Creek 54, 03 Class II Salmonid all life Class I Nutrients stages; Non-salmonid full life stages * All streams are designated for Wildlife growth and propagation, Agricultural, Navigation and Industrial and Cultural uses. Reaches in Italics indicate 2008 temperature monitoring sites.

Temperature and monitoring sites are shown in Map 2 in Appendix A, as well as in Map 1a above. Map 2a shows the same sites along with BEO rangeland layers, roads and sewage ponds, the major land use influences in the watershed.

4.0 METHODS

4.1 Aerial photo interpretation and GIS analysis The overall approach to determining sources of impairment in the watershed was first to characterize the land uses around the listed segments being investigated. Tribal grazing data, road densities and urban influences from digital map layers were used to calculate these influences as a proportional area and length of stream for each listed segment. Further aerial photo interpretation and GIS analysis were completed to plan additional environmental sampling within the watershed. ArcGIS v. 8.3 was used to map significant likely sources of pollution.

The GIS project included color aerial photos from 2005, roads, streams, and public data for points of diversion, towns, point source discharges, landfills, mines, and railroads. The stream layer was re-digitized to a larger scale (1:5000 to 1:7000 scale) to allow much more accurate measurement of stream miles relative to land use influences. Redigitizing the stream to the closer scale was necessary because the 1:24,000 scale existing stream layer does not include enough detail to allow good estimations of stream feature lengths, often being short by over 200% in sinuous reaches. In addition, re-digitizing allowed our analysis and recommendations to focus on primary perennial streams and discount potential distortions from ephemeral and intermittent streams. Though these can contribute some pollution to the system in flash events, their overall contribution to the watershed pollution picture is relatively small.

Potential sources of pollutants were digitized as needed onto the aerial photo and stream layer. Riparian cover, road and trail crossings, sewage lagoons, corrals, irrigation returns and several other factors were digitized into the GIS project and used in the source assessment for this report. A list of criteria for potential pollutant sources in the aerial photo interpretation and GIS-based initial assessment is included in Appendix B.

Potential assessment reaches and survey sites were selected and mapped in GIS to facilitate field monitoring. Potential field assessment sites and additional water quality monitoring stations were plotted in GIS for review with the Blackfeet Environmental Office prior to sampling. Pollutant sources mapped in aerial photo interpretation are included in maps of water quality sampling sites and pollutant concentrations in Appendix A.

4.2 Field Data Collection Between May 5, 2008 and August 31, 2008, a variety of data was collected from existing and newly established sample sites in the watershed. These data included water quality, stream morphology, habitat and riparian conditions and are provided in Table 5. The methods for each assessment are described in the following sections, organized by the pollutant to which the assessments pertained.

Table 5. Data collected by Watershed Consulting and BEO (05/2008 – 08/2008)

Reach Lat./Long. Riparian Channel Pebble Water Water Physical Stream ID @ cross- Condition Morphology Count Biology Chemistry Temp section or Assess. water quality site W-83 DS 48.508075 X 113.137546 W-12U 48.55047 X X X 113.09591 W-12DS 48.55948 X X X X 113.06324 W-131A 48.56194 X X X 113.02486 W-05 48.56154 X 113.01929 Upper Willow W-06 48.56182 X 113.01654 131SP 48.56053 X X X 113.01086 721 48.57116 X 112.87545

W-01.5 48.62635 X X X 112.78129

W-01 48.5792 X X X X X X 112.81892

W-02 48.61835 X X X X X X 112.80541

03W 48.566525 X 112.907189

W-03 48.571234 X X X 112.874634 Lower Willow W-04 48.55471 X X 112.98818

720 48.65871 X 112.75886

722 48.62589 X 112.78888

D-02 48.53507 X X X X X X 113.02765

Depot Depot D-01 48.54929 X X X X 113.00479

719 48.54590 X 113.00887 723 48.55428 X 112.98775

03 48.54664 X X X 113.15622 Flatiron

BEO water quality monitoring sites have been established in the watershed for years (some since the late 1970s). Existing data from these sites were provided to WSC and were analyzed with data collected in Table 5 above. The date ranges and sample sizes of existing BEO data vary and were evaluated by pollutant category in the analysis provided in this report, summarized in Table 6. In order to provide the most accurate picture of stream conditions currently, and due to low frequency and comparable datasets prior to 2000, only data between 2000 and 2008 were used in comparison to standard and criteria targets. Older data were summarized and used for comparison and temporal analysis.

Table 6. Existing BEO Water Quality Sites and Years of Existing Data Reach Lat./Long. Existing Data @ WQ site BEO Habitat Water Biology Water Chemistry Physical Assessment 83A 48.50709 ‘01 ’04, ’06, ‘08 ’04, ’06, ‘08 ’02, ’04, ’05, ’06, 113.14109 ‘08 83B 48.50784 ’04, ‘08 ’04, ’06, ‘08 ’01, ’02, ’04, ’05, 113.13715 ’06, ‘08

57 48.51210 ‘01 ’00, ’01, ’05, ’07, 113.12812 ‘08 130A 48.5188 ’07, ‘08 113.1189 130B 48.51992 ‘08 ‘08 ’07, ‘08 113.11815 W-12 48.55552 ‘01 ‘05 ’78, 95, ’96, ’97, ’78, ’94, ’96, ‘97 113.08875 ‘05 ’99, ’00, ’01, ’04, ’05, ’07, 08 Upper Willow W-131A 48.56165 ‘08 ‘08 ’07, ’08 113.02616 131AB 48.56163 ‘08 ’07, ‘08 113.01703 131B 48.56147 ‘08 ‘08 ’07, ‘08 113.00586 13 48.55440 ‘05 ’78, ’94, ’96, ’00, ’78, ’94, ’96, ’97, 112.98728 ’01, ‘05 ’99, ’00, ’01, ’04, ’05, ’07, 08 14 48.65541 ’78, ’94, ’96, ’05, ’78,’94, 96, 112.74588 ’99,’00, ’01, ’04, ’05, ’07, 08 Lower Willow 122A 48.51479 ‘08 ‘08 113.06632 122B 48.51704 ‘08 ‘08 113.06439

59 48.55129 ’05, ’07, ‘08 ’01, ’07, ‘08 ’04, ’05, ‘07 112.99881 58 48.55401 ’05, ’07, ‘08 ’00, ’05, ’07, ‘08 ’00, ’01, ’04, ’05, 112.98740 ’07, ‘08

54 48.57227 ’99,’00, ’01, ’04, 112.98986 ’05, ’07, ‘08 Flatiron Creek Flatiron Creek

Several criteria were considered in selecting new sites. These general criteria were applied for both water morphology sites and water quality assessment sites. In the case of water quality sites, locations were chosen in areas where water quality data was not readily available, or where major inputs to the stream could potentially alter stream conditions. In the case of Depot Creek, for example, two BEO water quality sites existed downstream of sewage treatment ponds. Watershed Consulting sampled for biology and chemistry both above (D-02) and below (D-01) older treatment ponds and additional potential inputs, and added two water quality monitoring stations on Willow Creek below the Depot confluence. Stream morphology and habitat conditions on Depot Creek were measured to provide a more complete picture of conditions above and below the treatment ponds. The main criteria for site selection were as follows:  Proximity to existing Blackfeet monitoring sites  Major inputs (confluences, treatment ponds, concentration of return flows)  Access from landowners  Aerial photo interpretation results for potential pollutant sources

4.2.1 Sediment

The term sediment is used in this document to refer collectively to several closely-related pollutant categories, including suspended sediment, stream channel geometry that can affect sediment delivery and transport, and sediment deposition on the stream bottom. Excess sediment often has detrimental effects on streams and the aquatic communities living in them. High suspended sediment levels reduce light penetration, which may cause a decline in primary production. As a result, aquatic invertebrate communities may also decline, which may then cause a decline in fish populations. Excess sediment may also impair biological processes of individual aquatic organisms (Newcombe and MacDonald, 1991).

A combination of parameters was used to gauge the relative contribution of sediment by each land use and sample location. These data sets were instrumental in the source assessment of pollutants in the watershed and also in determining restoration recommendations.

Stream Condition Assessment Stream condition assessments were conducted on all 2008 sample sites using the USDA NRCS Riparian Assessment Form (RAF). Reaches at each site were assessed for geomorphic, vegetative, and functional considerations and assigned numeric values for their potential and actual condition. Reach lengths varied and were determined based on segments of the stream that represented well the conditions of the overall stream area, physical and access barriers, and proximity to other reaches. Habitat assessments were conducted to help determine land use

influences on stream condition and water quality, and to ground-truth the initial GIS-based assessment.

The BEO also had conducted a habitat assessment of specific sites at three reaches, assigning each a score on a 100 point scale. Though methodologies differ between the two forms, qualitative results from all reaches are evaluated together to determine relative condition of each stream segment as compared to highest possible scoring.

The habitat assessment used by the BEO serves to provide a quantitative assessment of the overall stability and/or impacts on a stream channel. The assessment differs from the USDA NRCS RAF form in several aspects. The BEO form, with a maximum score of 180 points, asks observers to score 12 questions, whereas the RAF form asks 10 questions in which observers mark both actual scores and potential scores. As potential scores are not required of the BEO form, there is an assumption that all streams can attain a perfect score. In terms of content, the BEO form emphasizes in-stream fish habitat and benthic substrate more so than the RAF methodology. Four questions were essentially identical between the two forms. Both forms are similarly effective for evaluating stream morphological stability and vegetative cover.

Streambank Erosion During the 2008 surveys conducted by Watershed, estimations of the severity and causes of visible streambank erosion were determined. Where streambanks were bare and visibly contributing sediment to the stream, these locations were listed as either a “General” or “Discrete” source of sediment, depending on whether the sediment source occurred throughout the reach or was limited to a specific location. Estimations of vegetative cover, length, height and severity of erosion were made at all assessed eroding banks to provide a relative erosion severity. A comprehensive and more quantitative sediment load assessment (such as Rosgen BEHI analysis) was not deemed necessary or feasible for this stage of assessment of the watershed, as relative loading and bank instability can be estimated to help determine priority areas for restoration and the assessment budget did not cover an in-depth sediment loading analysis for the watershed.

4.2.2 Physical Stream Characteristics

TSS Suspended solids consist of organic and inorganic materials that are transported to surface waters by overland flow or introduced into a system from streambank erosion. TSS is often used as an indicator of the amount of fine sediment moving through the system. Suspended sediment monitoring provides a direct measure of sediment transport dynamics.

Insufficient data for turbidity and TSS exist to determine natural conditions, which fluctuate dramatically throughout the water year. Therefore, sediment targets will not be expressed in terms of TSS or turbidity. This approach is taken based on the assumption that addressing other indicators of sediment will reduce TSS inputs to levels expected with reasonable land, water, and soil conservation practices in place.

Streamflow Flow data were not evaluated during this project because the Blackfeet Environmental Office is currently addressing flow as part of Tribal negotiations over water rights. Though some data are available, analysis of flow at this time would be premature. 19

Dissolved Oxygen Dissolved oxygen is related to the support of aquatic life because low oxygen levels may harm or cause mortality of aquatic species. Dissolved oxygen solubility decreases with increasing water temperature, and is often considered a concern for streams with elevated temperatures or increased biological activity due to increased temperatures. Decomposition of plant material, waste, and debris may take up oxygen in the stream, further stressing the system (FISRWG, no date). Dissolved oxygen is often associated with nutrients because oxygen and nutrient levels both affect, and are affected by, algal growth. Dissolved oxygen fluctuates diurnally, especially in systems with excessive algal growth, with levels often decreasing at night as plants use more oxygen.

Stream Temperature Temperature data loggers were installed at 5 locations throughout the watershed for mid-August during a low-flow period. These stations were installed to complement the existing temperature monitoring stations established by the BEO. Temperature loggers were placed to capture representative conditions for the listed stream segments. Loggers were placed close to water quality sampling sites and were installed in deep water areas in discreet locations to maintain data quality and avoid vandalism. The loggers recorded stream temperature every 10 minutes during that time. Seasonal maximum and weekly average maximum temperature values were calculated for the two-week period.

Existing temperature data collected prior to 2008 include one-time measurements taken during water quality field measurements since 2000. No conclusive information can be drawn from these spot temperature measurements, but the data were used to reinforce observed trends in stream condition.

Channel Morphology Channel cross-section measurements were taken at eight of the assessment sites in order to better understand the current morphological condition of channels in the watershed and their sediment catchment function. A laser level was used to measure the active stream channel and adjacent near floodplain. Where the floodplain was visibly wider than 250 feet, a default of 250 was given as the floodprone width, which allows accurate stream typing for the size of channels surveyed.

Road Inventory Assessment An inventory of the dirt and gravel roads in the watershed was conducted to assess the contribution of culverts and road crossings to the overall sediment load of the waterways. Twenty-eight sites were documented and their relative sediment contributions calculated. This analysis allowed us to determine the priority sites for restoration of road-related sediment sources. Road conditions and crossings were documented with field forms and digital photos.

Total sediment to streams from road impacts was calculated by adding approximate contributions from road surfaces, fill slopes and cut slopes, measured at the sites of culverts and road crossings. Fill slope sediment contributions were calculated by multiplying the eroding bank width by the length. The eroding bank width was determined as the hypotenuse of the triangle formed by the height and width of eroding area determined from field measurements. Photographs, field notes and the percent delivery from road tread data were used to estimate the

percent cover and potential delivery to waterbodies or stormwater conveyance channels for fill slope components of the road prism.

These calculations use coefficients standard to analyses used in Washington and western Montana, and should only be considered relative yields, due to potential error in applying coefficients to a different landscape than that for which they were originally developed.

4.2.2 Nutrients

Water quality analysis was conducted by combining recent and pre-existing data sets for various nutrients. Median values in both high and low-flow conditions were calculated. For sites with fewer than four data points, a mean average value was used. These values were used to determine spatial trends across the watershed and to compare water quality results with existing Standards (See Section 2.0). For the purpose of this analysis we used July 15 as the beginning of the period of low stream flow, based on USGS daily streamflow data of neighboring hydrologic units. These historic and recent data from the Two Medicine and Cut Bank drainages show summer flows peaking in June and dropping from over 200cfs in early July to below 30cfs in late July (USGS 2007, 2008).

Summary statistics were calculated for each pollutant of concern and summarized by listed stream segments. Date ranges, sample sizes, and median values were summarized for high and low flow conditions. Calculations of the 25th percentile value for each pollutant are also provided to facilitate comparison to EPA reference reach values.

4.3 Community Outreach and Restoration Planning

As part of the outreach efforts of the BEO and in order to inform the residents of the watershed about the assessment being conducted, Watershed Consulting presented a preliminary report on the purpose and status of the Willow Creek Assessment Project at the Blackfeet Community College in Browning. The Watershed Symposium, sponsored by BEO, was attended by tribal water quality experts, landowners, concerned citizens and students. Local experts provided information as to historical land use patterns, stream conditions and locations.

Watershed Consulting has worked with the BEO during the analysis to review results and prioritize recommendations for restoration. Final results and recommendations will be presented in community outreach meetings in cooperation with the BEO.

5.0 RESULTS AND ANALYSIS

5.1 Aerial Photo Interpretation Results

Listed segments were assessed for the overall land-use characteristics of their respective watersheds. Aerial maps and photos, as well as BEO map layers were used to identify the probable proportional impact of each land use on listed segments. Table 3 earlier in this report summarized these characteristics. Major tributaries, roads, confluences and general stream characteristics of the watershed were also determined from aerial photos.

Table 7 below summarizes the potential pollutant sources identified in aerial photo interpretation.

Table 7. Potential pollution sources from aerial photo interpretation Potential Pollution Type Listed Segment Source Depot Cr. Lower Upper Flatiron Cr. Willow Willow Cr. Cr. Stream Crossings Dirt/Gravel 6 9 14 7 Paved 2 12 7 7 Trail 6 17 3 7 Unimproved 7 17 21 12 Railroad 1 2 1 1 Irrigation Returns 0 12 0 6 Check Dams 5 16 0 4

Results of this analysis were incorporated into GIS shape files, which have been used in maps to portray water quality and land use trends in the Willow Creek watershed. These maps are presented by pollutant and include layers from the aerial photo interpretation as needed to portray possible land use influences on pollutant levels. Stream crossings are shown in the map for Total Suspended Solids further in this report.

Aerial photo analysis was also useful in the watershed assessment planning process, providing indications as to where new field data stations and sample points ought to be located.

5.2 Field Results: Sediment

Sediment is a pervasive yet elusive pollutant to characterize. A combination of studies allowed for a rough estimate of sources of sediment contributions into the system, based on the dominant land uses characterized earlier.

5.2.1 Stream Condition Assessment Watershed Consulting evaluated overall stream conditions on all 2008 sampling sites. Data were collected using the NRCS Riparian Assessment Form (RAF), which evaluates geomorphic, vegetative and functional aspects of the stream. This assessment is important for ascertaining the

site-specific nature of disturbance to the stream, and correlates strongly to land uses. Habitat conditions near lagoons on Depot Creek, for example are providing adequate ecosystem functions, allowing us to discount grazing or other land-use influences as primary sources of pollution. Table 8 and Figure 1 below show RAF and BEO ratings in tabular and graphic form, respectively. Scores are determined by dividing actual scores by their potential and multiplying by 100. BEO habitat ratings are also a percentage of the potential score; however, the questions differ between the two forms and BEO ratings require higher scores for equivalent condition ratings. Stream condition was only assessed in limited areas because the project budget did not support an extensive condition survey throughout the watershed.

Table 8. RAF scores. Listed Reach Sampler(s) Condition RAF Scores BEO Habitat Segment (Upstream to Rating (BEO or (2008) Rating (2001) Downstream) RAF) 83A BEO Full support but 72.0 Threatened W-83 DS WsC At Risk 66.7 57 BEO Partial support, 69.0 mod. impaired W-12U WsC At Risk 59.0 W-12 BEO Full support but 80.0 Threatened W-12D WsC At Risk 64.2 W-131A WsC At Risk 65.5 Upper Willow Creek W-05 WsC Sustainable 80.0 W-06 WsC Sustainable 82.7 131SP WsC Sustainable 94.0 Median At Risk 66.7 72.0 W-04 WsC Sustainable 88.3 03W WsC At Risk 56.3

W-02 WsC Not Sustainable 44.2

Creek W-01 WsC Sustainable 86.5 W-01.5 WsC At Risk 55.8 Lower Willow

Median At Risk 56.3 D-02 WsC Sustainable 88.3

D-01 WsC Sustainable 87.1 Depot Creek Average Sustainable 87.7

The best habitat conditions sampled in 2008 were found at the Depot Creek Reaches, where riparian Willow growth is vigorous and streambanks are stable.

Figure 1. Stream Reach Assessment Scores The Reach with the highest habitat score was found in Browning 100 90 at the site of a replaced 80 70 sewer pipe (131SP). 60 Despite being traversed 50

Score 40 by bridges on either end 30 20 and having a road 10 alongside, the 0 5 6 4 2 1 2 1 57 12 1.5 83A 12U 83D 12D W- 03W

vegetation (except for 131A 131SP the area immediately Upper Willow Lower Willow Depot surrounding the Reach ID Creek replaced sewer pipe) is well established and diverse. Upstream of 131SP, sites 06 and 05 near the North American Indian Days Pow-Wow Grounds are areas whose riparian vegetation has been re-established in recent years due to BEO projects in the area. Frequent motorized vehicle crossings are visibly contributing sediment to the channel. Stream condition ratings throughout the watershed are presented in Map 3, in Appendix A.

5.2.1 Road Inventory Assessment

The road inventory documented road crossings and near-stream segments that could contribute sediment to streams. The inventory also documented which crossings are likely barriers to migration for fish and amphibians. Results of the inventory were used to prioritize culverts and crossings as restoration sites. Table 9 lists crossings that pose the largest risk of excess sediment contributions, as estimated following Washington roads analysis methods (WFPB 1997).

Table 9. Road-related Sediment Sources with Highest Sediment Contributions Site ID Source Description Estimated Yield (tons/yr) Affected Segment and nearest Reach ID 1 Fillslope, Tread 0.06 Upper Willow (tributary)/ W-05 2 Fillslope 0.01 Upper Willow/ W-05 4 Fillslope 0.01 Upper Willow 9 Tread 1.02 Upper Willow/ 83DS, 57 12 Fillslope 0.02 Depot Creek/ W-04 14 Tread 0.01 Depot Creek/ W-04 16 Fillslope, Tread 0.02 Depot Creek/ W-04 24 Fillslope, Tread 0.01 Lower Willow 25 Fillslope, Tread 0.01 Lower Willow 28 Fillslope, Tread 0.09 Lower Willow

Table 10 lists culverts that appear to pose a risk of failure (in bold), based on standard metrics used in culvert risk analysis in Washington and western Montana (WFPB 1997). Constriction ratio (the ratio of culvert width to stream bankfull width) is used to evaluate the potential of culverts to pass stream flows and debris. Culverts with widths less than the stream width are considered undersized. A constriction ratio of less than 0.7 is considered a risk of culvert failure. Culverts with >30% obstruction at the inlet are also considered at risk, as are culverts with a rust 24

line at greater than 30% the culvert diameter, as measured from the bottom of the culvert. These metrics are used for forest road analysis, and may not be completely applicable for the dynamics of a foothill to prairie system east of the Continental Divide, but they provide a means to prioritize the crossings posing the greatest risk of failure. Risk of failure does not consider flow conditions, as stream flow is outside the scope of this watershed assessment.

Culverts were assigned a relative risk of failure based on the magnitude of risk as related to rust line, undersized culverts, and inlet obstruction. These three factors combined gave an overall ranking for risk of failure, with a rating of 5 or greater posing a high risk of failure, and a rating of 4 indicating a moderate risk. Culverts potentially at risk of failure are included in Map 4, in Appendix A. Only one of the sites inventoried, site 4, appeared to be a hindrance to fish passage. Full road inventory results are included in data Appendix B.

Table 10. Culverts displaying at least one indicator of higher risk of failure. Relative Affected Segment Comments Culvert Risk of and nearest Reach Site Diam./Channel %Blocked Rustline % of Failure ID Number BFW at Inlet Diam. rating 1 25% 3 Upper Willow 0.3 (tributary)/ W-05 2 3 Upper Willow/ W- 0.4 05 4 35% 1 Upper Willow Two culverts; 0.02 probable fish barrier 6 0.4 3 Upper Willow 11 0.3 3 Depot Creek 12 0.2 NA 4 Depot Creek/ W-04 3 pipes 13 0.2 60% 8 Depot Creek/ W-04 14 0.4 75% 6 Depot Creek/ W-04 15 0.2 15% 5 Depot Creek/ W-04 2 pipes 16 9.1 35% 1 Depot Creek/ W-04 2 pipes 17 0.3 100% 7 Depot Creek/ W-04 PVC pipe 18 1.2 25% 35% 3 Depot Creek 21 2 Lower Willow 0.6 (tributary) 22 5% 15% 3 Lower Willow 0.4 (tributary) 24 0.5 65% 5 Lower Willow 3 culverts 25 0.2 50% 7 Lower Willow 3 pipes 26 1.0 35% 4 Lower Willow 27 1.5 40% 6 Lower Willow

5.2.2 Channel Morphology

Detailed channel characteristics were obtained at 8 sampling sites in 2008. Morphology assessments were conducted between July and August, 2008. Key metrics from channel morphological surveys are listed in Table 11.

Table 11. Stream Type and Morphology Listed Reach Width/Depth Entrenchment Sinuosity Slope Substrate Pct Fines Rosgen Segment Ratio Ratio Class <6mm Stream (Wolman) Type

W-12U 8 2.0 2.9 0.002 Silt/clay 94 E6

W-12D 8 3.8 2.8 0.002 Silt/clay 100 E6

Creek W- 16 16.6 1.6 0.007 Silt/clay 67 C6

Upper Willow 131A W-01.5 11 3.9 1.6 0.002 Silt/clay 100 E6

W-01 15 2.6 2.1 0.002* Silt/clay 100 C6

Creek W-02 5 4.9 2.3 2.540 Gravel 34 E4b

Lower Willow W-04 7 5.4 2.1 0.005 Silt/clay 56 E6

D-02 49 7.7 1.9 0.007 Silt/clay 79 C6

Depot Depot Creek

* estimated

The stream types characteristic of this ecoregion and found in the Willow Creek Watershed are naturally sediment-rich streams, as they are in the transitional area between mountains. Wolman pebble counts for sediments <6mm show that all streams surveyed have over 34% fines, which is expected in stream segments exhibiting prairie conditions or with heavy influence from beaver activity.

Channel morphology of the study reaches did not exhibit significant departure from expected channel dimensions for the stream type. Stream condition assessments (Section 5.2.1) were more revealing as to impacts to the stream channel. Morphological surveys did indicate possible overwidening in lower Willow Creek reaches W-01 and W-01.5, and some reduction in sinuosity in reach W-131A, which is influenced by urban land use.

5.2.3 Streambank Erosion Stream condition assessments included walking the entire length of station reaches and assigning values to visibly eroding streambanks to estimate the relative stability of the streams banks. Dimensions and relative severity were estimated at each eroding bank. Severity of erosion values between 0-2 generally were associated with erosion of natural origins, while severities of 4-5 generally correlated with direct human disturbance or general land uses in and around the riparian area. Best available bank stability conditions, which correlate strongly to the highest RAF scores, were found at sites W-04, W-06, 131SP, W-01, and Depot Creek D-01. Table 12 provides a summary of relative eroding area per reach, which was derived by normalizing the eroding area of streambank to 1000 ft, thus avoiding skew due to reach length. Bolded values show excessive erosion.

Table 12. Eroding area of streambank for each reach, normalized to rate/1000ft.

Eroding Eroding Area (ft2) % Eroding Area per 1000 Bank (discrete + linear ft. of Listed (discreet + general) stream (2000 Segment Reach ID Ft. Eroding Bank general) (ft) ft of bank) General Discrete Total W-12U 1680.0 0.0 1680 20 10080 1200.0 W-12 D 393.0 82.5 476 6 275 45.5 W-131A 105.6 35.0 141 11 264 141.6 W-05 153.0 145.5 299 6 1530 492.8 Upper W-06 0.0 108.0 108 1 108 63.3 Willow 131SP 0.0 42.0 42 1 42 45.2 W-01 62.0 0.0 62 2 156 50.0 W-02 3774.0 0.0 3774 75 3774 750.0 03W 5162.0 0.0 5162 65 1549 360.0 Lower W-01.5 3198.0 160.0 3358 40 7872 979.5 Willow W-04 0.0 40.0 40 1 40 20.4 D-02 1122.0 0.0 1122 22 1326 260.0 Depot D-01 373.0 420.0 793 8 965 168.2

Figure 2 provides a general picture of the magnitude of erosion on each assessed reach.

Figure 2. Eroding Bank Area Source Types and Total Contribution

6000.0

5000.0

4000.0 Gen eral 3000.0 Discrete Eroding Area/1000 ft. 2000.0

1000.0 Eroding Bank Area (ft) 0.0 5 6 1 2 4 2 1 1.5 3W 12U 12 D 12 131SP W-131A Upper Willow Lower Willow Depot Reach ID

Tables 55-68 in Appendix D list the sources and severity of streambank erosion at each assessed reach.

5.2.4 Total Suspended Solids Total Suspended Solids (TSS) data were available from 2006-2008. High TSS concentrations affect the feeding and health of aquatic organisms. Many of the stream reaches are naturally high in deposited sediment, but high TSS levels may indicate substrate instability or disturbance. Currently there are no numerical standards for TSS established by the BEO, allowing for only cursory observations to be drawn.

Strong correlations between turbidity and TSS often can be established in a given area. In the absence of numeric standards, turbidity levels could be compared to TSS to determine a relative standard (Packman, 2000). However, measurements would have to have been taken on the same day as studies have shown that particle size seems to affect the relationship between turbidity and TSS, indicating that the relationship is site-specific (Snyder et al., 2008). Turbidity and TSS data are both available for the Willow Creek watershed, but not for the same sampling event and thus can not be used to derive TSS standards for the study area.

Applying the BEO’s best available conditions narrative standard to the data set, 2.0 and 4.0 mg/L were designated as the “natural” condition low-flow and high-flow TSS levels. For the purposes of this report, 2.4 and 4.8 mg/L (120% of natural) are used as the TSS thresholds for low and high flow seasons, respectively. Values in bold in tables 13-16 exceed the TSS guideline values of 2.4 and 4.8 mg/L.

Table 13. Total Suspended Solids Summary Data. Listed Segment Date Range Sample Size Max Median 25th Percentile (mg/L) (mg/L) (mg/L) LF1 HF1 LF HF LF HF

Upper Willow 09/06-07/08 9 9 9.0 2.5 4.0 2.0 4.0 Lower Willow 07/08 1 1 (0) 13.0 13.0 ------Depot Creek 05/07- 08/08 2 2 32.0 15.0 11.0 13.5 9.5 1 LF = Low flow (after falling limb); HF = High flow, based on annual hydrograph

Table 14. Upper Willow Creek Total Suspended Solids Results by Reach. Reach Date Range Sample Size Average Values (mg/L) LF HF LF HF

83A 09/06-07/08 2 1 2.5 5.0 83B 07/08-08/08 1 1 2.0 3.0 130A 08/08 1 -- 2.0 -- 130B 07/08-08/08 1 1 2.0 4.0 W-12 07/08-08/08 1 1 4.0 4.0 W-12D 07/08-08/08 1 1 2.0 4.0 13 07/08-08/08 1 1 3.0 6.0 W-131A 07/08-08/08 1 1 4.0 9.0 131AB 07/08-08/08 1 1 1.0 6.0 131B 07/08-08/08 1 1 1.0 5.0

Table 15. Lower Willow Creek Total Suspended Solids by Reach Reach Date Range Sample Size Average Values (mg/L) LF HF LF HF

14 08/08 1 1 (0) 13.0 --

Table 16. Depot Creek Total Suspended Solids by Reach Reach Date Range Sample Size Average Values (mg/L) LF HF LF HF

58 10/07-8/08 2 1 15.0 32.0 59 05/07 -- 1 -- 8.0

Overall, TSS readings during high flow are consistently higher and often double those during low-flow. Data show that TSS readings in Depot Creek are four to five times higher than in Upper Willow. It should be noted that reaches lower in the watershed are more likely to have higher natural loads of sediment than the higher elevation reaches due to geologic differences. Map 5, Appendix A displays median values for TSS at all sampling sites.

5.2.5 Turbidity Turbidity measures the amount of light scattered by suspended particles in a water body. These readings are loosely correlated to TSS, as they both are measures of suspended sediments. Turbidity readings were analyzed dating back from 2000 until 2009 on 15 individual reaches, summarized in Table 17 and shown by listed segment in Tables 18-20. Summary box plots (Figures 3, 4, 5) show the 25th, 50th and 75th percentiles of data ranges for each station and the median values. As with TSS, readings from Depot Creek are significantly higher than in Upper Willow. Higher TSS readings in the Lower Willow segment may be attributable to the sediment coming from Depot Creek. The EPA’s standard for turbidity is 30 NTUs. The BEO currently has no numeric standard for turbidity. Median values across all listed segments fall below the standard, but maximum values at stations 13, 14, 58 and 59 are very high. Maximum values at sites 13, 58 and 59, all in close proximity to the lagoons, were recorded during high flows of 2008.

Table 17. Turbidity Summary Data

Listed Date Range Sample Size Max Median 25th Percentile Segment LF HF LF HF LF HF

Upper Willow 08/00- 08/08 110 108 278 3.48 4.93 2.68 3.15

Lower Willow 07/05-08/08 18 13 998 9.99 5.92 8.43 3.50

Depot 08/00- 08/08 27 37 344 10.06 9.52 5.97 6.58

Figure 3. Upper Willow Turbidity Range and Median value by Reach

12.0

10.0

) 8.0

6.0

4.0 Turbidity (NTU

2.0

0.0 57 12 13 83A 83B 130A 131A 130B 131B 131AB Reach ID

Table 18. Upper Willow Creek Turbidity by Reach Reach Date Sample Max Median Value Range Size (NTU) (NTU) LF HF LF HF

83A 06/01- 09/08 4 11 7.7 3.2 1.5 83B 04/01- 09/08 6 12 7.7 2.2 2.7 57 08/00- 08/08 11 12 10.0 4.3 7.1 130A 05/07- 5 6 7.2 3.8 3.1 09/08 130B 05/07- 3 6 4.2 3.2 3.3 09/08 04/00- 33 26 22.1 3.8 4.7 W-12 09/08 W-131A 05/07- 4 8 12.6 3.5 5.1 09/08 131AB 05/07- 3 8 11.1 2.2 6.1 09/08 131B 05/07- 3 4 9.6 2.5 5.1 08/08 04/00- 18 16 278.0 5.4 7.4 13 08/08

Figure 4. Depot Creek Turbidity Range by Reach

60.0

50.0

40.0

30.0

20.0

Turbidity (NTU) Turbidity

10.0

0.0 122A 122B 59 58 Reach ID

Table 19. Depot Creek Turbidity by Reach

Reach Date Sample Size Max Median Values Range (NTU) (NTU)

LF HF LF HF

122A 05/08- -- 5 12.8 -- 5.6 06/08 122B 05/08- -- 5 13.1 -- 7.2 06/08 59 11/04- 06/08 3 6 344.0 6.0 11.9

07/00- 24 21 264.0 14.1 12.7 58 09/08

Figure 5. Lower Willow Turbidity Range by Reach

Turbidity (NTU) Turbidity 6

0 14 Re ach ID

Table 20. Lower Willow Turbidity by Reach

Reach Date Sample Size Max Median Range (NTU) Values (NTU) LF HF LF HF

06/00- 14 06/08 18 13 998.0 10.0 5.9

5.4 Field Results: Nutrients Water quality measurements from BEO monitoring stations were analyzed along with 2008 data collected by Watershed Consulting. Results by pollutant category are summarized in the tables below and separated by listed segment. Reaches in each listed segment are provided in order from upstream to downstream to facilitate spatial analysis.

Per consultation with BEO, available data below the detectable limit (listed as non-detect in raw data) were not used in calculating median and percentile values. This approach provides flags the most critical conditions but does not show the true averages. With such a small dataset, the true averages probably do not reflect true average conditions. It may be desirable to update the analyses using all data once further monitoring following a consistent approach provides a more robust dataset. All data are tallied as part of total sample sizes. Average values are given for sites with fewer than four data points. Larger sample sizes are summarized by median values.

5.4.1 Nitrogen

Total Nitrogen Total Nitrogen is the sum of Total Kjeldahl Nitrogen (TKN) and Nitrites and Nitrates. High levels of nitrogen in streams are associated with algae growth and subsequent decreasing availability of oxygen for aquatic life. Total Nitrogen values were derived for each reach by adding the values for TKN with those for Nitrates and Nitrites, for samples taken during the same visit. Summary results are given below in Table 21. Where the guidance value of 0.61 mg/L was surpassed, values are shown in bold.

Map 6, Appendix A displays median values and exceedences for TN at all sampling sites.

Table 21. Total Nitrogen by Listed Segment. Listed Date Range Sample Size Max Median 25th Percentile Segment LF1 HF1 LF HF LF HF

Upper Willow 08/00- 08/08 11 7 0.38 0.46 0.37 0.45 0.32

Lower 07/05-08/08 2 6 1.89 1.35 1.43 1.89 1.22 Willow Depot 08/00- 08/08 5 3 12.03 11.05 0.93 10.82 0.90

1 LF = Low flow (after falling limb); HF = High flow, based on annual hydrograph

Tables 22-24 list Total Nitrogen results for each site in each listed segment.

Table 22. Upper Willow Creek Total Nitrogen by Site

Reach Date Range Sample Size Average Values (mg/L) LF HF LF HF

130A 07/08- 08/08 1 -- 0.44 -- 130B 07/08- 08/08 1 1 0.44 0.34 W-12 07/08- 08/08 1 1 0.45 0.27 W-12D 08/08 1 -- 0.46 -- W-131A 07/08- 08/08 1 1 0.50 0.40 131AB 07/08- 08/08 1 1 0.46 0.38 131B 07/08- 08/08 1 1 0.47 0.37 13 08/00- 08/08 4 2 0.51 0.26

Table 23. Lower Willow Creek Total Nitrogen by Site

Reach Date Range Sample Size Average Values (mg/L) LF HF LF HF

W-04 05/08-06/08 -- 1 -- 1.47 W-01 05/08-06/08 -- 2 -- 1.03 W-02 05/08-06/08 -- 2 -- 1.10 14 07/05-08/08 2 1 1.35 1.89

Table 24. Depot Creek Total Nitrogen by Site

Reach Date Range Sample Size Average Values (mg/L) LF HF LF HF

122B 07/08 -- 1 -- 0.87 D-01 05/08 -- 1 -- 0.93 58 08/00-08/08 5 1 11.05* 10.33 * Median value

Total Kjeldahl Nitrogen (TKN) Neither the BEO nor DEQ provide a numeric standard for TKN. The Total Nitrogen (TN) guideline value of 0.61 mg/L (see Section 2, Standards) was used as reference for TKN data. Since Total Nitrogen includes TKN, it can be reasonably deduced that any TKN levels above the overall Total Nitrogen standard would also be above any TKN standard, were it available. Values in bold in the following tables exceed the TN guideline value of 0.61 mg/L.

Summary data for TKN are listed in Table 25.

Table 25. TKN Summary Data by Listed Segment. Listed Date Range Sample Size Max Median 25th Percentile Segment LF1 HF1 LF HF LF HF

Upper Willow 08/00- 08/08 10 11 1.05 0.42 0.34 0.40 0.31

Lower 07/05-08/08 2 9 1.30 1.06 1.03 .94 .84 Willow Depot 08/00- 08/08 6 7 16.20 11.00 0.87 5.97 0.79

1 LF = Low flow (after falling limb); HF = High flow, based on annual hydrograph

Tables 69-71 in Appendix D list TKN results for each site in each listed segment.

Nitrites and Nitrates (NO2 + NO3) Data for Nitrates and Nitrites were available from 2000 to 2008. The total sample sizes were 22 for low-flow conditions and 24 for high-flow conditions; median and 25th percentile readings were determined form these values. Both the Lower Willow and Depot Creek listed segments show values in both high and low flow periods exceeding the values that would maintain the stream’s ability to provide for their designated beneficial uses. High flow values in Lower Willow Creek are more than an order of magnitude greater than the EPA guideline value of 0.060 mg/L. Values that exceed the EPA regional guideline value of 0.060 mg/L are indicated in bold in Table 29. Summary tables for listed segments are provided in Tables 72 to 74 in Appendix D. Heavy riparian grazing, the inflow from Depot Creek, the sewage lagoons, and sewer overflow in urban runoff are likely sources.

Table 26. NO2+NO3 Summary Data. Listed Segment Date Range Sample Size Max Median Value 25th Percentile LF1 HF1 LF HF LF HF

Upper Willow 07/04- 08/08 17 (12) 10 (4) 0.50 0.04 0.06 0.03 0.04 Lower Willow 07/05- 08/08 2 9 (7) 2.59 0.29 0.69 0.16 0.05 Depot Creek 08/00- 08/08 6 7 (5) 3.94 0.43 0.13 0.03 0.07 1 LF = Low flow (after falling limb); HF = High flow, based on annual hydrograph

Map 7, Appendix A displays median values and exceedences for total nitrates+nitrites at all sampling sites.

Total Ammonia (NH3 + NH4) BEO standards for ammonia are temperature and pH-dependent. Formulas for calculating the appropriate standard are available in Appendix C. Lacking similar standards for total ammonia (NH3+NH4), the BEO’s ammonia (NH3) standards were applied to total ammonia readings.

The existing data set was insufficient to allow detailed analysis of total ammonia. For most total ammonia readings, a temperature and/or pH reading were not available for the same day. Temperature ranges for each reach were derived from temperatures readings from the same station during the same year as the ammonia reading. Values in bold in Table 27 indicates values exceeding either chronic or acute guidance values. As no reach was sampled over 7 consecutive days, no conclusions can be drawn about the “chronic” or 7-day average ammonia values. Summary data by reach are provided in Tables 75-80, Appendix D.

Table 27. Total Ammonia Summary Data Date Range Sample Size Max Median Value (mg/L) 25th Percentile (mg/L) LF1 HF1 LF HF LF HF

Upper Willow 07/04-08/08 13 10(8) 0.52 0.46 0.35 0.40 0.31 Lower Willow 07/05-08/08 1 1 0.86 0.86 0.84 -- -- Depot Creek 07/08-08/08 4 4 16.40 10.22 0.87 8.44 0.83 1 LF = Low flow (after falling limb); HF = High flow, based on annual hydrograph

Ammonia (NH3) Numeric Ammonia standards are temperature and pH dependent. Summary statistics in Table 28 provide an overview per listed segment. Temperature and pH readings in the data set are not always available on the same date as ammonia readings, making complete analysis difficult. Summary data by reach are provided in Tables 81-86, Appendix D. Using the most conservative estimates for pH and temperature, ammonia readings were consistently below the acute target values. Although some readings exceed chronic standards on Depot creek (in bold), there is insufficient data to make conclusive statements about the ammonia levels at Depot Creek sites. Recommendations for continued concurrent monitoring of pH, temperature, and ammonia on Depot Creek are included in Section 6.3.

Table 28. Ammonia (NH3) Summary Data Reach Date Range Sample Size Max Median Value 25th Percentile (mg/L) LF1 HF1 LF HF LF HF

Upper Willow 08/00- 08/08 16(10) 11(9) 0.30 0.10 0.05 0.10 0.02 Lower Willow 07/05- 08/08 2 3 0.12 0.07 0.12 0.05 0.11 Depot 08/00- 08/08 6 9 (7) 11.90 6.67 0.22 1.86 0.22 1 LF = Low flow (after falling limb); HF = High flow, based on annual hydrograph

Map 8, Appendix A displays median values and exceedences for ammonia at all sampling sites.

5.4.2 Total Phosphorous

Phosphorous data were collected in 2008 and analyzed together with existing data. Lab results were returned with readings for Phosphorous as P and Total Low-Level Phosphorous. These readings differ only in their detection rates. Because readings were detected for all phosphorous data, all data points are summarized together. Summary of listed segment Phosphorous data are shown in Table 29.

Median values for phosphorous exceeded the guideline value of 0.041 mg/L in all three listed segments and are indicated in bold in Tables 87-89 in Appendix D. Phosphorous levels above the guideline value were recorded from 2000 to the present. Spatially, the highest phosphorous levels are concentrated in the area downstream of Upper Willow reach 13 and Depot Creek reach 58 near the sewage ponds. Data from Depot Creek from the previous two field seasons show high levels of phosphorous during both high and low flows. Values in bold exceed the guideline value of 0.041 mg/L.

Table 29. Phosphorous Summary Data. Date Range Sample Max Median Value 25th Percentile (mg/L) Size (mg/L) LF1 HF1 LF HF LF HF

Upper Willow 08/00-08/08 16 11 0.23 0.05 0.04 0.03 0.02 Lower Willow 07/05-08/08 2 9 0.18 0.04 0.08 0.03 0.05 Depot Creek 10/07-08/08 2 8 3.60 2.50 0.17 1.92 0.07 1 LF = Low flow (after falling limb); HF = High flow, based on annual hydrograph

Map 9, Appendix A displays median values and exceedences for TP at all sampling sites.

5.4.3 Dissolved Oxygen Dissolved oxygen is often associated with nutrients because oxygen and nutrient levels both affect, and are affected by, algal growth. Dissolved oxygen is related to the support of aquatic life because low oxygen levels may cause decreased vigor or even mortality of aquatic species. Dissolved Oxygen levels below the guideline values of 8.0 mg/L for salmonid streams were found consistently in the Upper Willow listed segment during low flows and during low and high flow periods of reach 59 on Depot Creek. A summary of listed segment DO readings are provided in Table 30. Based on trends revealed in the large data set and consistent sampling over eight years, measures should be taken to increase DO levels in Upper Willow Creek and Depot Creek (see section 6.0).

Table 30. Dissolved Oxygen Summary Data Date Sample Size Min Median Values 25th Percentile Range (mg/L) (mg/L) (mg/L) LF1 HF1 LF HF LF HF

Upper Willow 07/00- 102 98 3.0 7.60 8.80 6.41 8.11 09/08 Lower Willow 06/00- 18 13 0.2 5.75 8.60 1.05 6.60 06/08 Depot Creek 07/00- 26 35 0.1 5.20 7.50 1.00 6.91 09/08 1 LF = Low flow (after falling limb); HF = High flow, based on annual hydrograph

Box Plot diagrams are provided in Figures 6, 7 and 8 for Upper Willow, Lower Willow and Depot Creek listed segments, respectively , and summaries of Dissolved Oxygen data per listed segment are shown in Tables 31-33. Values for lower Willow creek, a non-salmonid stream, are related to a standard of 5.0 mg/L.

Figure 6. Upper Willow Creek Dissolved Oxygen Ranges by Reach

14.0

12.0

10.0

8.0

6.0 DO (mg/L) DO 4.0

2.0

0.0 13 57 12 83A 83B 130A 131A 131B 130B 131AB Reach ID

Table 31. Upper Willow Creek Dissolved Oxygen Summary data by Reach Date Range Sample Size Median Values (mg/L) LF HF LF HF

83A 06/01- 09/08 5 11 8.70 8.80 83B 04/01- 09/08 12 6 8.95 8.90 57 07/00- 08/08 15 10 6.20 9.10 130A 05/07- 09/08 5 6 6.80 8.59 130B 05/07- 09/08 3 6 6.41* 8.47 W-12 07/00- 09/08 32 25 8.57 9.00 W-131A 05/07- 09/08 4 8 9.01 8.10 131AB 05/07- 09/08 3 8 7.32* 8.00 131B 05/07- 08/08 4 3 7.41 8.80* 13 06/00- 09/08 19 15 7.80 9.10 * Average values

Figure 7. Lower Willow Creek Dissolved Oxygen Range by Reach

14.0 Table 32. Lower Willow Creek Dissolved Oxygen 12.0 Summary data by Reach

10.0 Date Range Sample Size Median Values 8.0 (mg/L) 6.0 DO (mg/L) LF HF LF HF 4.0 14 06/00- 18 13 5.75 8.60 2.0 06/08 0.0 14 Re ach ID

Figure 8. Depot Creek Dissolved Oxygen Range by Reach

14.0

12.0

10.0 Table 33. Depot Creek Dissolved Oxygen Summary 8.0 Data by Reach 6.0 DO (mg/L) Date Sample Size Median Values 4.0 Range (mg/L) 2.0 LF HF LF HF

0.0

59 58 122A 05/08- -- 5 -- 7.10 122B 122A Re ach ID 06/08 122B 05/08- -- 5 -- 7.60 06/08 59 11/04- 3 6 6.35 7.33 06/08 58 07/00- 23 19 3.97 9.10 09/08

5.5 Field Results: Temperature

Temperature loggers were installed by Watershed Consulting at 5 sites from August 13-25th to monitor daily in-stream temperature variations. In addition, 4 sites on Upper Willow Creek are regularly monitored by BEO. Sample sites on Depot and Upper Willow are in streams designated to support salmonid populations. The BEO maintains these uses through application of narrative standards that prevent the input of pollutants that would raise the water temperature above appropriate levels for cold-water fisheries. In addition, a 2005 BEO report cites 68°F (20°C) as the standard for salmonid streams and 77°F (25°C) as the standard for non-salmonid streams, in this case applicable to the Lower Willow segment.

Although some salmonids can survive at relatively high temperatures, most are placed in life- threatening conditions when temperatures exceed 73.4-77°F (23-25°C) (Bjornn and Reiser 1991). Optimum range for sustained swimming and growth is around 57-59°F (14-15°C). The lower limit of survivorship for salmonids occurs at around 1-2°C. Salmonids have spawned when water temperatures were as low as 33.8°F (1°C) and as high as 68°F (20°C), but usually the temperatures range from about 42.8-59°F (6-15°C) when they spawn (Bjornn 1991). A general literature review indicates 68°F (20°C) to be a reasonable and conservative threshold for a healthy salmonid population (McMahon et al., 2006).

Summary data from 2008 water monitoring sites indicate that 7-day average maximum water temperatures exceed those desirable to maintain the BEO’s aquatic beneficial uses. Willow Creek is given a classification of B-2 in the Montana State Surface Water Quality standards. Upper Willow Creek is considered to be capable of providing marginal cold water fish and aquatic life support, but lower Willow Creek is not considered a salmonid fishery. The seven-day average maximum values at one site on Depot Creek may exceed temperatures supporting beneficial uses for coldwater species (Map 10, Appendix A). Seven-day average maximum temperatures in Upper Willow Creek are consistently and considerably above standard values appropriate to maintain beneficial uses.

Summary data is provided in Table 34. Numbers in parenthesis after the logger number indicate the nearest downstream Reach ID. Values in bold exceed the guideline values of 68°F (20 °C) and 77°F (25°C).

Table 34. Temperature Summary Data Listed Segment Logger Number/ Date Range Maximum 7- Day Average (Reach ID) Value (°F/°C) Max (°F/°C) Upper Willow (W-12) 08/31/08—09/25/08 82.0/27.8 70.2/21.2 (131AB) 08/31/08—09/25/08 80.1/26.7 71.6/22.0 (131B) 08/31/08—09/25/08 73.2/22.9 68.7/20.4 (13) 08/31/08—09/25/08 73.4/23.0 68.9/20.5 Lower Willow 722 (W-02) 08/13/08- 08/25/08 72.8/22.7 69.6/20.9 721 (W-01) 08/13/08- 08/25/08 62.4/16.9 59.4/15.2 720 (14) 08/13/08- 08/25/08 72.9/22.7 70.0/21.1 Depot Creek 719 (D-01) 08/13/08- 08/25/08 61.3/16.3 58.8/14.9 723 (58) 08/13/08- 08/25/08 71.5/21.9 68.8/20.4

Instantaneous readings for temperature, those collected using a hand-held meter at the time of water quality sampling, provide some additional information, although the dataset is not robust enough on its own to draw solid conclusions about support of beneficial uses. Readings at or above 68 °F for salmonid streams and 77°F for non-salmonid streams from this dataset are listed in Table 35.

Table 35. Maximum Water Temperature Readings Listed Segment Reach Total Water Date Temperature Temp. Sample (°F) Size (2000-2008)

Upper Willow W-12 50 06/22/05 68.2 06/28/07 70.7 08/03/07 68.3 08/30/07 68.5 13 47 08/01/00 68.0 08/13/01 72.5 57 24 07/09/01 68.9 06/28/07 69.7 130A 11 06/28/07 69.7 131A 12 06/28/07 70.7 131AB 11 06/28/07 76.0 131B 7 06/28/07 71.8 Lower Willow 14 42 07/19/00 77.0 07/9/01 79.7 Depot 58 49 07/25/00 68.0 06/19/01 68.7 07/09/01 73.3 07/25/01 70.5 08/13/01 71.7 09/04/01 68.8 08/31/05 70.0

5.6 Field Results: Pathogens

5.6.1 Total Coliform

Lacking a numeric standard for total coliform, we are using the current DEQ standards for E. coli as guideline values, recognizing that E. coli only makes up a portion of total coliform. These values provide a rough guideline with which to compare the existing dataset; it is safe to assume that values below the E. coli standards are unlikely to represent a threat from total coliform, which should be in greater concentration than E. coli alone. Too few samples are available to use geometric means; median and 25th percentile values are used to represent a composite value for total coliform colony forming units (CFU). Results for Total Coliform are not mapped because the dataset is too small to indicate spatial trends.

The 2008 surface water quality standards for the State of Montana (ARM Chapter 30) state: “The water quality standard for Escherichia coli bacteria (E-coli) varies according to season, as follows: (i) from April 1 through October 31, the geometric mean number of E-coli may not

exceed 126 colony forming units per 100 milliliters and 10% of the total samples may not exceed 252 colony forming units per 100 milliliters during any 30-day period”

Summary of listed segments in Table 36, show one sample where the E. coli standard was exceeded. This is from a single sample and not a geometric mean.

Table 36. Total Coliform Summary Data Listed Segment Date Sample Size Max Median Value 25th Percentile Range (CFU/100ml) (CFU/100ml) LF1 HF1 LF HF LF HF

Lower Willow 05/08- -- 4 248 -- 58 -- 10.8 06/08 Depot Creek 05/08- -- 2 26 -- 11 -- 1.0 06/08 1 LF = Low flow (after falling limb); HF = High flow, based on annual hydrograph

Tables 37-38 below show individual sample values for Lower and Depot Creek, respectively.

Table 37. Lower Willow Creek Total Coliform Summary data by Reach Reach Date Range Sample Size Average Values (CFU/100ml) LF HF LF HF

W-04 05/08-06/08 -- 2 -- 18 W-03 05/08-06/08 -- 2 -- 16 W-02 05/08-06/08 -- 2 -- 99 W-01 05/08-06/08 -- 2 -- 125

Table 38. Depot Creek Total Coliform Summary Data by Reach Reach Date Range Sample Size Average Values (CFU/100ml) LF HF LF HF

D-01 05/08-06/08 -- 2 -- 9 D-02 05/08-06/08 -- 2 -- 14

5.7 Water Quality Data Analysis Summary

All results from field measurements and data sets were compared to the standards to which they are applied. In the cases where numerical standards were not available from the BEO, EPA or Montana DEQ standards were used to provide guideline values to indicate general water quality conditions. Of concern to this report are the stream segments in which summary data exceeded standards or guideline values. Tables 39-41 below list which sites exhibit some degradation or pollution within each listed segment based on comparison of assessment variables to standards or guideline values. Sites (left to right) are listed from upstream to downstream.

Table 39. Assessment Sites with Indicators of Degradation: Depot Creek Pollutant Depot Creek Reaches 122A 122B D-02 D-01 59 58

TKN Nitrogen X X X X X

Total Nitrogen X X X NO2+NO3 X X X

Total Ammonia (NH3+NH4) X

Ammonia (NH3) X

Phosphorous X X X X X

Total Coliform Fecal Coliform X X Habitat Condition Bank Erosion TSS X X

Turbidity X X Temperature X DO X X X X

Table 40. Assessment Sites with Indicators of Degradation: Lower Willow Creek

Indicator Lower Willow Reaches W-04 W-03 03W W-02 W-01 W-01.5 14 TKN Nitrogen X X X X X Total Nitrogen X X X X NO2+NO3 X X X NH3+NH4 Total Ammonia Ammonia (NO2) Phosphorous X X X X Total Coliform Fecal Coliform X Habitat X X X Condition Bank Erosion X X X TSS X Turbidity X Temperature X DO

Table 41. Assessment Sites With Indicators of Degradation: Upper Willow Creek Indicator Upper Willow Reaches 83A 83B W-83 D 57 130A 130B W-12U W-12 12D 131A W-131A W-05 131AB W-06 131 SP 131B 13

TKN Nitrogen NO2+NO3 X X NH3+NH4 Total Ammonia Phosphorous X X X X X X Total Coliform Fecal X Coliform Habitat X X X X Condition Bank X X Erosion TSS X X X X X X Turbidity X Temperature X X X X X X X DO X X X X X X

5.7.1 Pollutant Reduction Targets

In this section, median values for pollutants for each stream segment (compiled in previous section) are compared to the water quality standards or baseline condition to determine the reduction needed in pollutant levels for each listed segment to achieve water quality targets. The BEO has determined that pollutant standards should be the target values achieved for each pollutant in order to maintain the stream’s beneficial uses. The final column of each table in this section indicates the percent reduction required for each pollutant category by listed segment, referred to henceforth as “improvement targets.” These targets guide our Management Recommendations (Section 6.0). These targets should be considered interim and function to guide a prioritization of management objectives. More consistent sampling and data are needed to refine reduction goals and to establish robust indicators of the effectiveness of management actions.

Stream Condition Assessment

The RAF habitat assessment form asserts that a rating of 80% considers riparian condition to be “Sustainable” for maintaining ecological services over the long term. This value is used as the target against which both RAF and BEO Habitat Assessments were compared. Depot Creek shows sustainable habitat conditions and does not require habitat restoration. Though the invasive reed canarygrass (Phalaris arundinacea) is the dominant vegetation in the reaches surveyed, the vegetation is maintaining adequate riparian habitat and streambank stability. Lower Willow Creek, heavily impacted from grazing and stream crossings at some sites, requires a 30% habitat improvement, as shown in Table 42, below. Comparing values below to RAF and BEO habitat scores in Table 8, as well as streambank erosion calculations from Table 9, leads to a more specific determination of problem reaches and informs our management recommendations. Physical condition of the stream has a great influence on water quality, particularly for sediment, temperature, or phosphorus, which is closely tied to sediment loading. Stream condition links water quality and beneficial uses such as habitat for coldwater fisheries. Implementing BMPs to improve stream condition is part of achieving pollutant reductions, and has a direct positive influence on beneficial uses.

Table 42. Stream condition improvement targets Listed segment Standard (%) Lowest score Lowest Median Median score % Value Increase below (%) needed standard (%) Upper Willow Creek- 80.0 69.0 13.8 72.0 10.0 BEO Upper Willow Creek- 80.0 59.0 26.3 66.7 16.6 RAF Lower Willow Creek 80.0 44.2 44.8 56.3 29.6 Depot Creek 80.0 87.1 0.0 87.7 0.0

Dissolved Oxygen Both high and low flow median value readings for each listed segment were compared to DO standards below in Table 43. Depot Creek presents the biggest challenge in relation to DO, showing levels below standards during both low and high flows.

Table 43. Dissolved oxygen improvement targets Listed segment Standard Min. value Min value % Median Value % Improvement (mg/L) (mg/L) below std needed Low High Low High Flow Flow Flow Flow Upper Willow Creek 8.0 3.0 62.5 7.6 8.8 5.0 0.0 Lower Willow Creek 5.0 0.2 96.0 5.8 8.6 0.0 0.0 Depot Creek 8.0 0.1 98.8 5.2 7.5 35.0 6.3

Phosphorous Excessively high concentrations of total phosphorous low flow readings were recorded during two sample events in 2007 and 2008 at stream reach 58 in Depot creek. Though the data set is not robust enough to make definite conclusions about the site, values measured clearly indicate the need for further monitoring. Excessive phosphorous readings in the Upper Willow creek segment during low flows was determined from 16 sample events over 8 years, demonstrating a consistent exceedence of target levels. Table 44 below shows percent reductions needed to meet targets for total phosphorus.

Table 44. Phosphorous improvement targets Listed segment Standard Max. value Max value Median Value Median % Over (mg/L) (mg/L) % over std Standard Low High Low Flow High Flow Flow Flow Upper Willow Creek 0.04 0.23 460.98 0.05 0.04 21.95 0.00 Lower Willow Creek 0.04 0.18 339.02 0.04 0.08 0.00 95.12 Depot Creek 0.04 3.60 8680.49 2.50 0.17 5997.56 314.63

Total Suspended Solids Data sets for TSS are small for Lower Willow Creek (1 sample) and Depot Creek (3 samples), but show high levels of suspended sediments (Table 45 below).

Table 45. TSS improvement targets Listed Standard Max. value Max value Median Value Median % Over segment (mg/L) (mg/L) % over std Standard

Low High Low High Flow Flow Flow Flow

Upper Willow Creek 4.0 9.00 125.0 2.5 4.0 0.0 0.0 Lower Willow Creek 4.0 13.0 225.0 13.0 0.0 225.0 0.0 Depot Creek 4.0 32.0 700.0 15.0 11.0 275.0 175.0

Nitrogen The following three analyses of nitrogen-based pollutants all follow a similar trend, both spatially and proportionally. Upper Willow Creek generally shows nitrogen levels below standard values. As we move downstream toward the confluence with Depot Creek, we begin seeing high levels of these pollutants. Readings from both Lower Willow Creek (reach 14) going back to 2005 and Depot Creek (reach 58) going back to 2000 demonstrate consistently high levels of nitrogen in its varied forms. All stream segments for all three nitrogen-based pollutants exhibited maximum values significantly above standards. Though these values are single readings and should not be considered representative of the stream segment, they do recommend further monitoring to pinpoint causes of water quality issues in the area.

NO2+NO3 Nitrates and nitrites are at or below standards in the Upper Willow Creek segment. Levels of NO2 + NO3 are consistent with high nitrogen levels (TKN and Total Nitrogen) in the same segments. Table 46 shows improvement targets based on reductions needed to meet water quality standards.

Table 46. NO2+NO3 improvement targets Listed segment Standard Max. value Max Median Value Median % Over (mg/L) (mg/L) value % Standard over std Low High Low High Flow Flow Flow Flow Upper Willow Creek 0.06 0.50 733.33 0.04 0.06 0.0 0.0 Lower Willow Creek 0.06 2.59 4216.67 0.29 0.69 383.33 1050.00 Depot Creek 0.06 3.94 6466.67 0.43 0.13 616.67 116.67

TKN Table 47 shows improvement targets for TKN, based on reductions needed to meet water quality standards. Depot Creek exhibits the highest TKN concentrations, greatly exceeding water quality standards.

Table 47. TKN improvement targets Listed segment Standard Max. value Max value % Median Value Median % Over (mg/L) (mg/L) over std Standard Low High Low Flow High Flow Flow Flow Upper Willow Creek 0.61 1.05 72.13 0.42 0.34 0.00 0.00 Lower Willow Creek 0.61 1.30 113.12 1.06 1.03 73.77 68.85 Depot Creek 0.61 16.20 2555.74 10.30 0.79 1703.28 42.62

Total Nitrogen Table 48 shows improvement targets for TN, based on reductions needed to meet water quality standards. TN, which is calculated as the sum of TKN and NO2+NO3, mirrors trends for those nitrogen fractions. 46

Table 48. Total Nitrogen improvement targets Listed segment Standard Max. value Max value Median Value % Over Standard (mg/L) (mg/L) % over std Low Flow High Low Flow High Flow Flow Upper Willow Creek 0.61 0.38 0.00 0.46 0.37 0.00 0.00 Lower Willow Creek 0.61 1.89 209.84 1.35 1.43 121.31 134.43 Depot Creek 0.61 12.03 1872.13 10.30 0.79 1588.52 29.51

NH3* As stated previously, ammonia values are pH and temperature-dependent. Each ammonia reading, therefore, must be accompanied by a pH and temperature reading taken during the same sampling visit. Overall, complete data sets are lacking for this pollutant, as pH and temperature readings are typically not available when NH3 samples were taken. Table 49 below shows the one available data point that exceeded standards.

Table 49. NH3 stream reach target levels Listed segment and site Sample Date Standard Value % Over (mg/L)* Standard Depot Creek- 58 08/01/2000 5.72 10.4 81.8% *Acute standard

Total Ammonia Though slightly more robust, the data set for Total Ammonia echoes that of NH3 and is generally lacking in necessary information for in-depth analysis. Table 50, below, shows the four sampling events at site 58 for which data is available. Of note are the elevated ammonia levels in both high and low flow scenarios over the past two years.

Table 50. Total Ammonia stream reach target levels Listed Sample Date Standard Value % Over segment and (mg/L)* Standard site 07/07/2007 2.59 9.9 282.2% Depot Creek- 08/29/2007 13.3 16.4 23.3% 58 07/01/2008 6.77 10.3 52.1% 08/19/2008 6.77 12 77.3% * Acute standard

5.8 Temporal Analysis The existing water quality dataset is no rigorous enough to determine water quality trends over time. All available data between 2000 and 2008 were summarized in the previous sections and should be understood as a “snapshot” of current stream conditions. Available historic data is summarized in Table 90 in Appendix D. No conclusions can be drawn as to whether or not current readings are consistent with historical conditions. A lack of a closely monitored nearby

reference condition also complicates attempts to gauge the current situation as a departure from the probable desired outcome.

5.9 Data Gaps Data gaps limit the confidence level with which specific pollutant amounts can be attributable to their probable sources. This document, by highlighting the existing gaps in data, provides some direction for future BEO monitoring activities and the creation of a more robust data set. Additional resources for monitoring would greatly benefit the already increased capacity of the BEOs water quality team.

The weakness of the existing water quality dataset is largely due to changes in collection and analysis methods over time. The lack of comparable data means that the dataset is neither consistent nor complete enough to determine water quality trends over time. The scope of sampling also has been limited, especially in past decades. As a result of these factors there is no large dataset that spans more than a decade to allow analysis of water quality trends over time. The current sampling program at the BEO is likely to result in a more rigorous dataset that can be used to map temporal trends since 2000, if the monitoring effort is continued for several years.

Currently, there are insufficient data to make conclusive statements about the ammonia levels at Depot Creek sites, other than that some of the sample values are high relative to samples from other sites. We recommend continued concurrent monitoring of pH, temperature, and ammonia on Depot Creek, as well as continued monitoring for other nutrient fractions and pathogens on Depot Creek and on Willow Creek just below the confluence with Depot Creek. Section 6.3 includes more detailed monitoring recommendations.

The current sampling program appears to be sufficient to characterize water quality influences in a general manner, in areas close to Browning. Continued monitoring at additional sites would help to characterize the influences of land use better on lower Willow Creek and Depot Creek, and pinpoint additional pollutant inputs in areas influences by stormwater runoff in the urban areas.

6.0 DISCUSSION AND MANAGEMENT RECOMMENDATIONS

From spatial and temporal analysis of the combined data sets, several stream segments appear to be of importance for restoration and management priorities. These segments are described below, as well as a range of short, medium, and long-term management options that could be implemented to decrease pollutant loads to the affected streams.

6.1 Influences on Stream Segment Condition

The following discussion highlights the influences on the condition of listed stream segments and reaches within listed segments.

Lower Willow Creek The lower Willow Creek segment has much higher nutrient levels than either the upper Willow Creek segment or Depot Creek upstream of the highway crossing by Browning. The Lower Willow segment, particularly sites W-02 and W-01.5, are lacking sufficient riparian vegetation to stabilize streambanks against grazing pressure and scouring runoff flows. Seen together with nutrient levels, particularly nitrogen and phosphorous, which are consistently above the allowable standard, data from these stream segments suggest a need for targeted management actions. Morphological data also indicated possible over-widening in lower Willow Creek reaches W-01 and W-01.5, and some reduction in sinuosity in reach W131A, which is influenced by urban land use. Agriculture is the primary influence on the lower reach of Willow Creek, including irrigation, fertilizer inputs, cropping in floodplain areas, corrals within the floodplain, and intensive riparian grazing. Willow Creek near the confluence of Depot Creek appears to have been impacted by contamination from the sewage lagoons and other pollution in Depot Creek.

Upper Willow Creek Willow Creek above Browning is affected in areas by overgrazing, corrals, and other agricultural influences, but also has highly functioning areas that have been maintained by beaver activity. Urban influences on Willow Creek within Browning are related primarily to stream crossings and solid waste.

Depot Creek The major pollutant influences on Depot Creek can be attributed to the sewage lagoons. In addition, sewer overflow affects Depot Creek, and is being addressed by the City of Browning. Riparian condition is also a factor at the lower end of Depot Creek. Though vegetation is well established, in many cases it is dominated by reed canary grass (Phalaris arundinacea), which thrives in high nutrient environments and moist conditions. More diverse vegetation communities would be desirable for habitat and armoring streambanks. The headwaters of Depot Creek appear to be affected primarily by grazing and related range management.

Watershed-wide Influences Road crossings, although generally only providing minor sediment contributions, are numerous and widespread throughout the watershed. Efforts have been initiated to reduce the number of crossings in key areas in and around Browning, but many crossing remain a management issue. 49

Crossings contribute sediment and present risk of large future sediment inputs from culvert failure. Culverts with high risk of failure are mapped in Appendix A, Map 4. Solid waste, generally in the form of plastic refuse, is abundant in streams, particularly in the urban areas of the watershed. In addition to being unsightly, the large amount of solid waste may contribute a variety of pollutants, clog waterways, and cause harm to fish and wildlife. Dumping of solid waste in ephemeral stream channels and draws is an issue in the watershed, and has unknown effects on water quality.

The following table summarizes proportionate influence of land uses by listed segment, by areal extent. There is not enough information to determine the magnitude of the influence of land uses associated with the use by area. Implementing grazing, road, and stormwater BMPs over the land areas and proportions of stream length in Table 51 is expected to achieve needed reductions in most areas. Updating the wastewater treatment plant on Depot Creek will be necessary to achieve reductions in nutrients on lower Depot Creek and sites on Willow Creek downstream of the Depot creek confluence.

Table 51. Percent Land Use and Percent Pollution Source

Segment and Land Use Primary pollutants % of land % stream miles in affected use by area land use Depot Creek Grazing/Agriculture Nutrients, Temperature, 53 71 Sediment, Pathogens Urban Pathogens, Nutrients, <1 1.7 Temperature Sewage Treatment Lagoons Nutrients, Temperature <1 <1 Roads/Culverts Sediment <1 <1

Upper Willow Grazing/Agriculture Nutrients, Temperature, 54 54 Sediment, Pathogens Urban Pathogens, Nutrients, 1 2 Temperature Roads/Culverts Sediment <1 <1

Lower Willow Grazing/Agriculture Nutrients, Temperature, 34 84 Sediment, Pathogens Urban Pathogens, Nutrients, 0 0 Temperature Sewage Treatment Lagoons Nutrients, Temperature 0 0 Roads/Culverts Sediment <1 <1

Flatiron Creek Grazing/Agriculture Nutrients, Temperature, 39 40 Sediment, Pathogens Urban Pathogens, Nutrients, <1 4.1 Temperature Roads/Culverts Sediment <1 <1

6.2 Restoration Priorities and Recommendations

The following management measures are recommended for reducing pollutants to the Willow Creek Watershed over the next 5 years. These recommendations support the implementation of the recently adopted Blackfeet Solid Waste Ordinance #53. Measures are designed to reduce current point-sources of pollutants and to support current watershed management priorities to reduce non-point source pollution.

Restoration Priority Matrix Restoration activities have been prioritized based on several criteria related to project impact and feasibility:

Prioritization Criteria: . Human health risk . Magnitude of current pollutant contribution vs. expected cost . Magnitude of potential future impacts . Land ownership and landowner participation . Influence on listed species or fragile habitat . Relative number of individuals benefitted

Table 52 represents a matrix of priority restoration activities based on the criteria listed above. This matrix also includes estimated costs to meet cost estimate requirements of EPA’s Nine Elements of Watershed Plans. Projects listed in this matrix are based on analysis of culvert risk of failure, sediment and other pollutant inputs, and additional restoration priorities related to range management.

Improvement of the sewage lagoons is of highest importance but is not addressed in the restoration priorities matrix because the IHS and City of Browning are planning restoration for that source of pollution. The City is also fixing manholes to address sewer overflow that affects Depot Creek. The matrix also does not include recent and ongoing restoration at the North American Indian Days Pow-Wow grounds, which are already addressing pollutant sources. The Monitoring recommendations for these projects are addressed in the following section under Effectiveness Monitoring.

Table 52. Restoration Priorities Matrix Recommendation Quantity (Units/miles) Estimated Price Pollutants/Issues Range addressed Relocation of all corrals in 1 in progress; 8 other Corral Replacement- Nutrients, floodplain, including nutrient corrals in floodplain or $25,000 Revegetation Sediment, management and revegetation. potentially draining to and Nutrient Pathogens, streams Management- $10,000- Temperature, $20,000 Habitat quality Sod- $2,000 Planning -$2000 Replacement of high-risk culverts 9 moderate and high-risk Less than $10,000 per Sediment, Habitat and eroding Crossings. culverts (Table 24, Map site for simple culvert quality 4) replacement; $10,000- $50,000 for bridges Planning $2000 Engineering Design avg. $10,000.

Recommendation Quantity (Units/miles) Estimated Price Pollutants/Issues Range addressed Hardened crossings and off-site Opportunities throughout $10,000 - $20,000 per Nutrients, water for overgrazed areas; watershed, depending on project, including Sediment, temporary exclusion fencing per landowner involvement; planning Pathogens, Tribal Conservation Agreement priority in lower Willow Temperature, Creek below Flatiron Ck Habitat quality Confl., upper reaches of Willow and Depot Creeks Willow-sprigging and browse Opportunities throughout Less than $5000 in Nutrients, protection in areas lacking riparian watershed, depending on most cases; $1000 Sediment, vegetation, in conjunction with landowner involvement; planning Pathogens, improved grazing management; This priority in lower Willow Temperature, would encourage more widespread Creek below Flatiron Ck Habitat quality beaver activity, resulting in greater Confl., upper reaches of shrub cover, water supply, and Willow and Depot Creeks habitat quality Wetland restoration projects, Applicable to pothole $10,000- $30,000 Nutrients, including extraction of soil region in upper watershed, depending on size, Sediment, cores/seedbanks from reference sites springs in lower scope of restoration; Pathogens, to revegetate degraded sites. watershed includes planning Temperature, Habitat quality Restoration projects at Kipp Lake, 1 barrier, 2 shoreline $110,000 for all Nutrients, including repair of migration barrier, projects and generalized projects and planning Sediment, shoreline stabilization, and revegetation and traffic Temperature, revegetation management Habitat quality Fencing park and campground areas Approx 4,000 feet of $20,000 per footbridge, Nutrients, to reduce erosion form user-created fence, 2 footbridges $1.75 per foot of fence Sediment, stream crossings; Installation of $2500 project planning Temperature, footbridges to improve park access Habitat quality and reduce erosion at allowed crossings

Within the general restoration categories listed in Table 52, several priority restoration projects have been selected. These projects are listed in Table 53 and mapped in Maps 11 and 12, Appendix A.

Table 53. Detail of Priority Restoration Projects included on Maps 11 and 12, Appendix A. Project ID Management Class Project Decription Project Status Xing01 Recreation Design stable crossing /establish alternative access Recommended Chan 01 Urban Add in-stream habitat, riparian vegetation In progress Buffer 01 Urban Create treatment wetland/Swale Recommended COR130A Agriculture Move corral from floodplain In progress Xing02 Recreation Install 2 footbridges and fence Planned 132_Kipp#1 Fisheries Reinforce fish barrier Planned 135_Kipp#4 Agriculture Stabilize and reveg shoreline Planned 134_Kipp#3 Agriculture Stabilize and reveg shoreline Planned 133_Kipp#2 Roads Improve road crossing Planned COR_LW01 Agriculture Move corral from floodplain Recommended Buffer_02 Agriculture Create wetland swale and redirect drainage Recommended Buffer_03 Agriculture Create wetland swale and redirect drainage Recommended Range01 Agriculture Off-site water, harden crossings, temp fencing Recommended Buffer_04 Agriculture Increase buffer; improve crossing and channel Recommended Buffer_05 Agriculture Establish buffer; revise drainage Recommended 52

Project ID Management Class Project Decription Project Status Buffer_06 Urban Create treatment wetland/Swale Recommended Range02 Agriculture Off-site water, harden crossings, temp fencing Recommended

Outreach/Long-term Restoration Activities

Environmental Education: Public education efforts may show less short-term effectiveness or less obvious results than active restoration efforts, but they are essential to achieve long-term watershed restoration. We recommend funding public education activities for a variety of issues: . The benefits of clean streams and good water quality . What defines good or poor stream condition . Beneficial riparian grazing management . The function of beaver in maintaining late-season stream flow and good habitat . Lakeshore habitat considerations/benefits and lake ecology

Solid Waste: Trash and debris in waterways has negative impacts on stream quality, but also detract from the aesthetic appeal and pride of a community. A targeted public outreach campaign along with measures to decrease the amount of trash flowing into waterways would be of great benefit to the residents of Browning and the larger Blackfeet Reservation. Outreach activities may include school programs, public campaigns against hauling unsecured trash in open truck beds and dumping at undesignated sites, working with other local entities to increase accessibility to managed trash collection or disposal, and public workshops and trash cleanup days to raise awareness. This effort could be dovetailed with an effort to establish a local industry of producing re-usable bags, designed specifically for residents, with potential for outside markets as well. Establishing this industry and changing the paradigm of frequent use of plastic grocery bags will require cooperation and participation of local businesses and agencies; for this reason we recommend pursuing grant funds that will support a project coordinator as part of the program development. The coordinator should work closely with the Tribal government to identify and solicit applicable funding sources available for tribal entities.

Addressing illegal dumpsites is important to prevent impacts by industrial pollutants and solid waste. While those pollutants are not part of the scope of this study, the issue must be addressed to allow watershed recovery. Mapping and removing illegal dumpsites would be the first step in addressing the issue; however, education and outreach must be part of the restoration effort to help prevent future illegal dumping. The solution likely will need to include elements related to policy and infrastructure, and will need to be based on a thorough feasibility analysis that includes social and economic factors. Site clean-up could also be worked into local economy if funding were secured to hire local residents to clean up sites and reclaim scrap metal.

Stormwater: Sources of urban pollution could be reduced dramatically by working with City of Browning and other cooperators to develop plans to upgrade stormwater management structure in urban areas, prioritizing feasibility study and design of low-impact development techniques for alternative stormwater management, such as structures using native vegetation and infiltration galleries. The stormwater system is outdated and needs to be replaced. More housing and more building is expected to put additional strain on the system.

Outreach should also include meeting with other agency personnel and private residents to compile stakeholder priorities and identify all efforts and information needs. Priorities based on

53 current and planned efforts would first be outlined by the core technical stakeholder group, then presented to other community members as appropriate to incorporate community priorities that will aid individual participation in restoration planning and action.

Water quantity: Stream flow and irrigation management are not within the scope of this study, as these issues are being addressed separately by the BEO. Recommendations from this report should be dovetailed with the other water management recommendations as much as possible when both analyses are complete, as water quantity affects water quality and habitat to a great degree.

Technical and Financial Assistance The schedule for implementing these restoration recommendations will depend on funding available for planning, monitoring, and restoration, and other internal management considerations at BEO.

6.3 Monitoring Recommendations

Monitoring recommendations fall into three categories: Filling data gaps, effectiveness monitoring, and monitoring to support additional pollution assessment for pollutants not addressed within the scope of this project. A summary of monitoring recommendations and cost ranges is included at the end of this section in Table 54.

6.3.1 Filling data gaps

Consistent data over time are lacking. Recent monitoring efforts by the BEO are beginning to establish a strong dataset that will greatly aid future management. Monitoring should be continued, keeping variables and procedures as consistent as possible with current efforts. The water quality dataset is particularly sparse for the Lower Willow Creek segment near and below the confluence of Flatiron Creek, with the exception of a sampling site at the mouth of Willow Creek.

More consistent monitoring of coliform, ammonia and other nutrients should be carried out annually, including at sample sites established by WSC in 2008. New monitoring sites should be established in lower Willow Creek in order to help the BEO bracket pollution sources more effectively, including irrigation returns. Further monitoring is also needed to pinpoint sources of high nutrient loading into Depot Creek other than the sewage lagoons. It is also important to continue with the current monitoring program, including additional sites, to establish a dataset rigorous enough to analyze temporal trends in water quality in the future and track watershed condition over time.

The current dataset does not allow for comparison of ammonia levels with water quality standards. In order to monitor Ammonia levels effectively, technicians should always take pH and temperature readings at the same time the samples are taken. We recommend continued concurrent monitoring of pH, temperature, and ammonia on Depot Creek and Willow Creek above and below the Depot Creek confluence. We also recommend more monitoring at urban area lakes and stormwater returns to pinpoint sources of nutrients and to monitor for common pollutants from urban sources, including volatile organic compounds (VOCs) and other potential carcinogens. Also needed is water quality monitoring for industrial pollutants below dump and

landfill sites. This should include baseline monitoring below a planned landfill and regular runoff monitoring below the landfill.

Finally, more consistent stream temperature monitoring is needed in July through mid-September using continuously recording temperature loggers in order to determine spatial trends in temperature. Loggers should be placed by mid-July at all sites and left through the hot season to log temperature over the same timeframe at all sites.

6.3.2 Effectiveness Monitoring Effectiveness monitoring recommendations are described below by project type.

Sewage Lagoon Improvements Taking substantial and detailed nutrient and bacterial samples before and after improvements to the sewage lagoons is essential to make sure restoration improvements were successful in removing the pollution source.

Monitoring activities: Intensive pre-and post-restoration sampling for nutrients, chlorophyll-a, bacteria, and water temperature (using continuous recorders) above and below sewage lagoons and above all sewer outlets and potential overflows; this should also be initiated to help address data gaps

Effectiveness criteria: Pollutant levels below sewage lagoons do not exceed levels found at sites above all sewer influence

Corral Relocation Projects Corrals in floodplains are widely recognized as sources of nutrient and sediment pollution to streams. Depending on use and design, these also may be a source of pathogens. BEO has initiated efforts to relocate corrals currently in floodplains, with one project underway. The following monitoring recommendations will help track the benefits of these projects to the stream and floodplain.

Monitoring activities: Pre-and post-restoration sampling for nutrients, chlorophyll-a, bacteria, sediment, and water temperature (using continuous recorders) above and below sites Habitat condition assessments before restoration and in 1, 3, and 6 years after restoration

Effectiveness criteria/Milestones: Pollutant levels below sites do not exceed levels found above original corral sites Habitat assessments reflect an upward trend in condition and reflect sustainable conditions by year 6.

Culvert Replacement Projects Priority culverts for replacement or removal were identified based on risk of failure and effect on fish passage. Most of these culverts are undersized and are at least partially blocked or buried.

Monitoring activities: Complete crossing inventory at culvert replacement sites after restoration to document improvement in culvert stability/lowered risk of failure; use same methods as used for pre- replacement monitoring Document road crossing sediment inputs using road inventory methods in years 1, 3, and 6 after culvert restoration projects Conduct monitoring of surface fines using wire grid in glides and pool tail-outs at sites with naturally gravel-dominated substrate

Effectiveness criteria/Milestones: All at-risk culverts replaced will be properly sized and will have low risk of failure after culvert replacement, as documented by road crossing inventory in year 1 All road crossings will contribute only minimal or no sediment to streams by year 3 and will remain stable, as documented in year 6. Where applicable, wire grid surface sediment assessment will not show higher sediment downstream of road crossings compared to upstream, by year 3 after construction.

Current and Planned Stream Crossing Closures and Restoration Projects Some stream crossings have been closed and are being restored at the Pow-wow grounds. Perimeter fencing and installation of a footbridge have been planned for All Chiefs’ Park. The monitoring recommendations below apply to these planned projects and others for managing user-created crossings in and near urban areas.

Monitoring activities: Riparian condition assessment before and after project completion, including plant community composition and cover assessment; includes monitoring in years 1, 3, and 6 after restoration Streambank erosion inventory to document eroding area due to user-created stream crossings Qualitative monitoring and photopoints to document effectiveness of crossing closures and improvements

Effectiveness criteria/Milestones: Riparian condition and streambank erosion inventory indicate good quality habitat and stable banks at crossing areas by year 6 Photopoints and field observations indicate stable crossings; no new user-created crossings established

Planned Shoreline Restoration Restoration projects at Kipp Lake are in the planning phase. Pre-restoration monitoring was initiated in 2009. Monitoring should continue through 2015, or 5 years after restoration, whichever is more inclusive.

Monitoring activities: Shoreline vegetative community composition and cover assessment, before and after restoration Survey of bare ground and active erosion due to hoof shear and other human causes to document percent of shoreline actively eroding in restoration areas before restoration and in years 1, 3, and 5 after restoration

Fisheries monitoring above and below the planned fish barrier reinforcement, before and after project completion, to make sure fish from Kipp lake are not able to move into upper reaches of Willow Creek

Effectiveness criteria/Milestones: Vegetative cover increases to at least 70% above high water mark/active wave action (bare ground less than 30%) by year 3; Cover increases to at least 85% by year 5. Shrub cover increases to natural conditions, based on adjacent areas in best available condition; obvious regeneration by year 3, significant increase in cover by year 5. Hoof shear and other human-caused erosion is not evident in restored areas by year 5. No recruitment of non-native fish to Willow Creek above the fish barrier

Solid Waste Clean-up Efforts Illicit solid waste dumping is a widespread problem in the watershed, and, because much of the dumping occurs in or near low-relief areas that are at least seasonal conveyances for runoff, the potential for pollution to water resources is great. Solid waste dumping is a non-point source pollution issues because of the widespread nature of dumping, and the many potentially toxic pollutant sources in the material dumped. Regular high winds also spread garbage throughout the landscape, making a point-source approach less effective. This pollution issue is strongly tied to socioeconomic and policy issues; therefore an outreach component is critical for restoration success, as is a cooperative approach that involves other local agencies and educational outlets.

Monitoring activities: Map illegal dump sites to determine monitoring locations Water quality sampling (for sites near water) for industrial pollutants, sediment, and pathogens above and below solid waste clean-up sites; water quality monitoring for industrial pollutants below dump and landfill sites to start baseline monitoring for sites below planned landfill and regular runoff monitoring for landfill Site monitoring (photopoints, observation, or repeated garbage collection and quantification) to ensure that sites are no longer used

Effectiveness criteria/Milestones: Dumping no longer occurs at sites and receiving waters directly downstream do not show signs of related pollutants at outlet points Sites remain free of dumped solid waste for at least 5 years to indicate long-term change in behavior.

Monitoring related to community outreach efforts may consist of the following strategies: Use survey/bag counts at businesses Photopoints Weigh garbage from specified plot every couple years with community clean-up day General public behavior and attitude – surveys or observation of trends

Weed Mapping and Control Invasive weed species were present in varying densities throughout the project area. If left untreated, some species can out-compete native riparian communities, eventually leading to a loss of biodiversity, degraded riparian habitats and water quality, which could impact a given stream’s beneficial uses. Early detection and eradication of invasive weed species in critical

habitat is the most cost-effective approach and is essential to maintaining stream health. As invasive weeds are generally related to disturbances such as stream crossings (roads, culverts, ATV’s), inventory and control projects can be done alongside other restoration activities and are an effective channel for community involvement in the watershed.

Monitoring Activities: Survey/Rapid Assessment of invasive weeds in critical riparian habitats (observation, photography and digital mapping) before and after treatment Identify priority weed-free areas (headwaters, high-visibility/traffic areas) and establish regular monitoring for early detection

Effectiveness criteria/Milestones: Invasive weed species eliminated from target treatment areas, or populations drastically reduced by year 5 and decreasing over time Regular reporting from functional weed groups Increase in educational materials/workshops related to invasive species identification and eradication

Proposed Rangeland Management and Restoration Projects Additional assessment reaches could be established in lower and upper Willow Creek to collect more information about habitat quality and stream corridor condition in potential areas for rangeland management projects, such as establishing hardened crossings and off-site water.

Monitoring activities: Stream condition/geomorphic assessments prior to restoration activities, and in years 3 and 6 after restoration Water quality sampling for TSS, nutrients, chlorophyll-a, and macroinvertebrates before restoration and at least 5 years after restoration; monitoring above and below project area Interviews with landowners or lessees to track livestock health and growth rates before and after management changes and suitability of range management improvements

Effectiveness criteria/Milestones: Improved water quality at four or more priority sites by year 3; samples below project site have same concentrations/metrics as upstream samples by year 5 Stream condition shows significant improvement by year 3; project area in sustainable condition by year 6

Rangeland managers satisfied with water tank and crossing for improved calf growth rate and livestock health

6.3.3 Monitoring to support additional efforts

Monitoring for additional planned restoration activities may include:

Water quality monitoring and Stormwater Pollution Prevention Plan for future Blackfeet Community College (BCC) egg production facility and other barns/buildings in Depot Coulee riparian area and higher floodplain near the college; could be conducted as class projects Monitoring at any potential Brownfields cleanup sites discovered during illegal dump mapping

Increase the number of condition assessment sites in the watershed to improve available data set and better identify pollutant sources.

Groundwater monitoring in Lower Willow Creek to help map agricultural returns.

Collecting and propagating native seedbed (in soil) from high-quality wetlands for different recorded wetland types within the Reservation to support native wetland revegetation; record species and viability at varying depths below surface in a variety of communities and settings; this could be a project for students at BCC with technical guidance form a contractor as needed.

6.3.4 Budget for Proposed Monitoring Approach

Table 54 lists monitoring priorities and budget estimates for categories of monitoring required to support project priorities and data needs.

Table 54. Summary of Monitoring Recommendations and Estimated Budget Monitoring Recommendation Frequency/Cost basis Estimated Price Applicable Projects Range or Monitoring goals Establish additional water quality 3 new sites monitored at $30,000 to $40,000, New agricultural stations on Depot Creek least twice per year (high including sampling, development on flow and low flow) for at analysis, and Depot Creek; Track least 5 years; additional reporting sewer overflows and sampling above and below other urban inputs sewage lagoon Establish 5 additional temperature Stream temperature $8,000, including 5 Determine spatial monitoring sites; implement monitored continuously new loggers, and temporal trends standardized temperature from mid-July to mid- installation and in stream sampling using data loggers in September for 5 years at downloading, and temperature; monitor consistent timeframe at 12 or established sites data mgt and improvement in more sites reporting stream temperature at restoration sites Conduct stream condition At least 10 project sites for Average cost per Effectiveness assessments and shoreline rangeland, stream, or assessment: $1,000, monitoring for vegetation / stability assessments shoreline restoration, plus $500 if stream crossing at restoration projects and range monitored once prior to geomorphology restoration, range management improvements restoration and twice after included: includes management restoration data collection, improvements, and management, shoreline analysis, and stabilization reporting Road crossing inventory and At 9 priority culvert sites Cost per restoration Road crossing sediment source assessment and potentially 5 other site approx. $3000 for improvements and crossing sites; monitored 2- all visits; includes culvert replacements 3 times after restoration analysis and reporting Fine sediment monitoring at corral Potentially at 15-18 sites, Est. $1000 per site Effectiveness and crossing restoration sites three times including analysis and monitoring for reporting culvert replacements, corral relocation, and stream crossing improvements Weed inventory and mapping 2-3 weeks full time Est. $15,000 for first Effectiveness mapping noxious weeds year, $8000 per year monitoring for throughout watershed, thereafter noxious weed every 2 years management

Monitoring Recommendation Frequency/Cost basis Estimated Price Applicable Projects Range or Monitoring goals Monitor solid waste dump sites Photo monitoring and Estimated ballpark Prevent illicit trash included in restoration efforts qualitative documentation $20,000-40,000 over dumping in drainage of site use; water quality time, depending on ways sampling at sites near water number of sites in close proximity to water Additional water quality Before and after restoration, Approximately Effectiveness monitoring at new corral at least two times per year, $10,000 per site over monitoring for corral relocation sites at least four years; 5 years, assuming 4 relocation projects potentially at 8 sites, above sample years with and below project macroinvertebrate analysis and all reporting and travel included

Additional monitoring priorities will develop as additional restoration priorities come to light during stakeholder outreach efforts.

6.4 Adaptive Management

The monitoring recommendations included in this report are designed to update BEO’s understanding of conditions and sources of pollution in the watershed, and to determine the effectiveness of restoration activities undertaken to improve water quality. A watershed restoration plan should be considered a “living document” that will change as needed to fit the framework of current conditions and management needs in the watershed. Effectiveness monitoring allows managers to determine whether or not the restoration activities they implemented are meeting restoration goals, and if other strategies need to be followed. The effectiveness criteria specified for the monitoring recommendations provide the ruler by which to measure the effectiveness of restoration activities.

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Sheffield, R.E., S. Mostaghimi, D.H. Vaughan, E.R. Collins, Jr., and V.G. Alien, 1997. Off- Stream Water Sources for Grazing Cattle as a Stream Bank Stabilization and Water Quality BMP. Trans. ASAE 40(3):595-604.

Snyder, A., K.M. Ostrowski, J. Boll, E.E. Brooks. 2008. Particle Size Influence on the Relationship Between Turbidity and Total Suspended Solids. Am. Geophys. Union Fall Meeting.

USGS (US Geological Survey). 2007. Water-data report 2006: Cut Bank Creek at Cut Bank, MT. Available online at http://wdr.water.usgs.gov/wy2006/pdfs/06099000.2006.pdf. USGS, Washington, D.C.

USGS. 2008. National Water Information System. Available online at: http://waterdata.usgs.gov/mt/nwis/. USGS, Washington, D.C.

Washington Forest Practices Board. 1997. Board Manual: Standard Methodology for Conducting Watershed Analysis. Version 4.0.

Appendix A: Maps

(Map 1 and 1a in body of document)

Map 13. Temperature and Monitoring Sites Map2a. Land Use Map Map 14. Stream Condition Ratings Map 15. Culverts at risk Map 16. TSS Results Map 17. TN Results Map 18. Nitrates and Nitrites Results Map 19. Ammonia Results Map 20. Total Phosphorous Results Map 21. Temperature Influences Map 22. Priority Restoration Sites: West Half Map 23. Priority Restoration Sites: East Half

Appendix B

1. List of criteria for aerial survey

2. Road inventory data

Appendix C

1. Narrative Standards- Coliform

2. Ammonia Calculations

APPENDIX D: DATA SUMMARIES BY SEGMENT

Sediment Source Data by Listed Segment Numbers in parentheses listed with causes indicate relative percentages of sediment attributable to each cause. A cause is assigned 100 percent of sediment contribution if no other percentage is specified. Values in bold indicate excessive erosion.

Table 55. Upper Willow Reach W-83 DS Sediment Source Detail Sed. Source Bank % Bank Eroding Area Veg. Cover Severity Type Feet Eroding (ft2) Percent 1-5 Cause General * 3 0 1 1 Natural scour (70); Hoof shear (30) * No coordinates taken—bear trap detected on site.

Table 56. Upper Willow Reach W-12U Sediment Source Detail Sed. Source Bank % Bank Eroding Area Veg. Cover Severity Type Feet Eroding (ft2) Percent 1-5 Cause General Livestock crossing/wading 8400 20 10,080 0 5 (100)

Table 57. Upper Willow Reach W-12D Sediment Source Detail Sed. Source Bank % Bank Eroding Area Veg. Cover Severity Type Feet Eroding (ft2) Percent (1-5) Cause Discrete 1 390 0 4.5 Grazing 0 45 25 1 Crossing 7860 0 38 20 1 Grazing General 5 275 0 0.5 Natural Scour

Table 58. Upper Willow Reach W-131A Sediment Source Detail Sed. Source Bank % Bank Eroding Area Veg. Cover Severity Type Feet Eroding (ft2) Percent 1-5 Cause Discrete 0 35 60 3 Old Crossing (80); Veg. Removal (20) 2112 General 5 264 85 1 Natural Scour (90); Veg. removal (10)

Table 59. Upper Willow Reach W-05 Sediment Source Detail Sed. Source Bank % Bank Veg. Cover Severity Type Feet Eroding Eroding Area (ft2) Percent 1-5 Cause Discrete 0.51 87.5 60 5 ATV crossing Discrete 0.12 22 55 3 ATV crossing 3400 Discrete 0.35 36 15 5 ATV crossing General 4.50 1530 60 2 ATV/people/horse crossing

Table 60. Upper Willow Reach W-06 Sediment Source Detail Sed. Source Bank % Bank Veg. Cover Severity Type Feet Eroding Eroding Area (ft2) Percent 1-5 Cause Discrete 1706 1.06 108 0.5 3 ATV/people/horse crossing (80); Natural (20)

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Table 61. Upper Willow Reach 131SP Sediment Source Detail Sed. Source Bank % Bank Veg. Cover Severity Type Feet Eroding Eroding Area (ft2) Percent 1-5 Cause Discrete 1858 2 84 15 3 Sewer pipe removal

Table 62. Lower Willow Reach 03W Sediment Source Detail Sed. Source Bank % Bank Veg. Cover Severity Type Feet Eroding Eroding Area (ft2) Percent 1-5 Cause Horse Grazing (90); General 4302 30 387 70 4 Veg. Removal (10) 90 1162 50 5 Beaver activity

Table 63. Lower Willow Reach W-01 Sediment Source Detail Sed. Source Bank % Bank Veg. Cover Severity Type Feet Eroding Eroding Area (ft2) Percent 1-5 Cause Old Livestock Water General 3116 2 156 96 1 Source (90); Veg. Removal (10)

Table 64. Lower Willow Reach W-02 Sediment Source Detail Sed. Source Bank % Bank Veg. Cover Severity Type Feet Eroding Eroding Area (ft2) Percent 1-5 Cause General Livestock Activity (80); 5032 75 3774 NC 4 Lack of DBR* (20) * Deep binding rootmass; NC= not calculated

Table 65. Lower Willow Reach W-04 Sediment Source Detail Sed. Source Bank % Bank Veg. Cover Severity Type Feet Eroding Eroding Area (ft2) Percent 1-5 Cause Discrete 1960 0.8 40 20 1 Natural (70); Veg. Removal (30)

Table 66. Lower Willow Reach W-01.5 Sediment Source Detail Sed. Source Bank % Bank Veg. Cover Severity Type Feet Eroding Eroding Area (ft2) Percent 1-5 Cause Discrete 0.5 160 10 3 Hoof shear/Veg. removal, Grazing/Past General 8200 20 1640 5 0.5 Natural Scour 9 2952 10 3 Hoof shear 10 3280 15 1 Veg. Removal (50); Natural Scour (50)

Table 67. Depot Creek Reach D-01 Sediment Source Detail Sed. Source Bank % Bank Veg. Cover Severity Type Feet Eroding Eroding Area (ft2) Percent 1-5 Cause Discrete 5740 0.73 420 20 3 Old Road General 0.5 86 10 0.5 Wildlife crossing 5 287 20 0.5 Natural very low scour 1 172 25 1 Natural low scour

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Table 68. Depot Reach D-02 Sediment Source Detail Sed. Source Bank % Bank Eroding Area Veg. Cover Severity Type Feet Eroding (ft2) Percent 1-5 Cause General Natural scour (70); Veg. 2 306 30 1 removal (30) 5098 20 1020 40 1 Natural low scour

Total Kjedahl Nitrogen Data by Listed Segment

Table 69. Upper Willow Creek TKN Data by Site. Reach Date Range Sample Size Average Values (mg/L) LF HF LF HF

83A 07/08- 08/08 -- 1 -- 0.40 83B 07/08- 08/08 -- 1 -- 0.41 130A 07/08- 08/08 1 1 0.40 0.26 130B 07/08- 08/08 1 1 0.40 0.34 W-12 07/08- 08/08 1 1 0.41 0.27 W-12D 08/08 -- 1 -- 0.42 W-131A 07/08- 08/08 1 1 0.46 0.40 131AB 07/08- 08/08 1 1 0.43 0.38 131B 07/08- 08/08 1 1 0.43 0.36 13 08/00- 08/08 4 2 0.50* 0.34 * Median value

Table 70. Lower Willow Creek TKN Data by Site. Reach Date Range Sample Size Average Values (mg/L) LF HF LF HF

W-04 05/08-06/08 -- 2 -- 1.05 W-03 05/08-06/08 -- 2 -- 0.88 W-02 05/08-06/08 -- 2 -- 1.10 W-01 05/08-06/08 -- 2 -- 1.03 14 07/05-08/08 2 1 1.06 0.84

Table 71. Depot Creek TKN Summary Data by Site. Reach Date Range Sample Size Average Values (mg/L) LF HF LF HF

122A 07/08 -- 1 -- 0.69 122B 07/08 -- 1 -- 0.87 D-02 05/08-06/08 -- 2 -- 0.85 D-01 05/08-06/08 -- 2 -- 0.95 58 08/00-08/08 6 1 10.65* 10.10 * Median value

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Nitrates and Nitrites Data by Listed Segment

Table 72. Upper Willow Creek NO2+NO3 Summary Data by Site. Reach Date Range Sample Size Average Values (mg/L) LF HF LF HF

83A 07/04- 08/08 3 (2) 1 0.05 0.05 83B 07/08-08/08 2 1 0.04 0.07 130A 08/08 1 -- 0.04 -- 130B 07/08-08/08 1 1 (0) 0.04 -- W-12 08/08 2 (1) 1 (0) 0.04 -- W-12D 07/08-08/08 1 1(0) 0.04 -- W-131A 07/08- 08/08 1 1 (0) 0.04 -- 131AB 07/08- 08/08 1 1 (0) 0.03 -- 131B 07/08- 08/08 1 1 0.04 0.01 13 08/00- 08/08 4 (1) 2 (1) 0.03 0.18

A duplicate sample for NO2+NO3, taken by BEO at site 83B, had a concentration of 15.2 mg/L, compared to the original sample concentration of 0.06, indicating high variability in sample results.

Table 73. Lower Willow Creek NO2+NO3 Data by Site. Date Range Sample Size Average Values (mg/L) LF HF LF HF

W-04 5/08-6/08 -- 2 -- 0.33 W-03 5/08-6/08 -- 2 -- 0.01 W-01 05/08-06/08 -- 2 -- 1.34 W-02 05/08-06/08 -- 2 (0) -- -- 14 07/05-08/08 2 1 0.29 1.05

Table 74. Depot Creek NO2+NO3 Data by Site.

Date Range Sample Size Average Values (mg/L) LF HF LF HF

122B 07/08 -- 1 (0) -- -- 58 08/00- 08/08 6 2 0.43* 0.13 D-01 05/08- 06/08 -- 2 (1) -- 0.50 D-02 05/08- 06/08 -- 2 (1) -- 0. 01 * Median Value

Total Ammonia (NH3+NH4) Data by Listed Segment

Table 75. Upper Willow Creek Total Ammonia Summary Data by Reach Date Range Sample Size Average Values (mg/L) LF HF LF HF

83A 07/04-07/08 3 1(0) 0.23 -- 83B 07/04-07/08 2 1 (0) 0.34 -- 130A 07/08 -- 1 -- 0.26 130B 07/08-08/08 1 1 0.34 0.44 W-12 07/05- 08/08 2 1 0.43 0.27 D-4

W-12D 07/08-08/08 1 1 0.46 0.32 13 07/08-08/08 1 1 0.52 0.34 W-131A 07/08-08/08 1 1 0.40 0.50 131AB 07/08-08/08 1 1 0.46 0.38 131B 07/08-08/08 1 1 0.47 0.36

Table 76. Upper Willow Creek Total Ammonia Relative to pH and Temperature Reach Date pH Temp. Range Chronic Acute Target Value (mg/L) (°C) Target Values Values Range Range (mg/L) (mg/L) LF HF

83A 7/23/04 8.3 9.4- 16.0 1.52- 1.39 3.15 0.10 -- 83A 9/13/06 8.4 12.0- 16.0 1.29- 1.17 2.59 0.12 -- Non- 83A 7/2/08 8.4 7.9- 11.7 1.29 2.59 -- detect 83A 8/20/08 7.9 7.9- 11.7 2.80 6.77 0.47 -- 83B 7/23/04 8.1 9.2- 16.1 2.10- 1.91 4.64 0.20 -- Non- 83B 7/2/08 8.1 7.3- 12.2 2.10 4.64 -- detect 83B 8/20/08 8.2 7.3- 12.2 2.10 3.83 0.47 -- 130A 7/1/08 8.0 8.5- 15.1 2.43 5.62 -- 0.26 130B 7/2/08 7.9 8.4- 15.5 2.80-2.54 6.77 0.34 -- 130B 8/20/08 7.6 8.4- 15.5 4.73- 4.30 11.4 -- 0.44 W-12 7/25/05 7.4 9.2- 20.1 4.73- 3.32 15.4 0.40 -- W-12 7/2/08 8.3 9.4- 16.0 1.52- 1.39 3.15 -- 0.27 W-12 8/20/08 7.4 9.4- 16.0 4.73- 2.92 15.4 0.45 -- W-12D 7/2/08 8.3* 9.4- 16.0* 1.52- 0.64* 3.15 -- 0.32 W-12D 8/20/08 7.4* 9.4-16.0* 4.73- 2.92* 15.4 0.46 -- 13 7/1/08 8.1 9.5- 17.6 2.10- 1.68 4.64 -- 0.34 13 8/19/08 8.1 9.5- 17.6 2.10- 1.68 4.64 0.52 -- W-131A 7/2/08 8.2 10.3- 18.2 1.79- 1.43 3.83 -- 0.50 W-131A 8/20/08 8.2 10.3- 18.2 1.79- 1.43 3.83 0.40 -- 131AB 7/2/08 8.2 6.7- 19.0 1.79- 1.26 3.83 -- 0.38 131AB 8/20/08 8.3 6.7- 19.0 1.79- 1.26 3.15 0.46 -- 131B 7/2/08 8.3 12.3- 18.6 1.52- 1.22 3.15 -- 0.36 131B 8/20/08 8.4 12.3- 18.6 1.29- 1.03 2.59 0.47 -- * No pH readings available. Readings used are from nearest upstream source

Table 77. Lower Willow Creek Total Ammonia Data by Reach Reach Date Range Sample Size Average Values (mg/L) LF HF LF HF

14 07/08-08/08 1 1 0.86 0.84

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Table 78. Lower Willow Creek Total Ammonia Relative to pH and Temperature Reach Date pH Temp. Range Chronic Acute Value (mg/L) (°C) Target Target Values Values Range Range (mg/L) (mg/L) LF HF

14 7/01/08 8.3 7.7-17.0 1.52- 1.39 4.71 -- 0.86 14 8/19/08 8.3 7.7-17.0 1.52- 1.39 4.71 -- 0.84

Table 79. Depot Creek Total Ammonia Data by Reach Reach Date Range Sample Size Average Values (mg/L) LF HF LF HF

122A 07/08 -- 1 -- 0.69 122B 07/08 -- 1 -- 0.87 58 07/08- 08/08 4 2 10.2* 10.1 * Median value

Table 80. Depot Creek Total Ammonia Relative to pH and Temperature Reach Date pH Temp. Chronic Target Acute Value (mg/L) Range Values Target (°C) Range (mg/L) Values Range (mg/L) LF HF

122A 7/1/08 8.1 8.1-11.5 2.10 4.64 -- 0.69 122B 7/1/08 8.1 7.8- 2.10 4.64 -- 0.87 11.5 58 7/7/07 8.4 13.3- 1.29- 0.70 2.59 -- 9.90 17.3 58 8/29/07 7.5 13.3- 4.36- 3.97 13.30 16.40 -- 17.3 58 10/23/07 7.5 13.3- 4.36- 3.97 13.30 8.40 -- 17.3 58 7/1/08 7.9 9.7- 2.80- 1.96 6.77 -- 10.30 19.4 58 8/19/08 7.9 9.7- 2.80- 1.96 6.77 12.00 -- 19.4

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Ammonia (NH3) Data by Listed Segment

Table 81. Upper Willow Creek Ammonia (NH3) Data by Reach Reach Date Range Sample Size Average Values (mg/L) LF HF LF HF

83A 07/04- 08/08 3 (1) 1 0.12 0.02 83B 07/04- 08/08 2 (1) 1 0.11 0.10 130A 07/08-08/08 1 1 0.10 0.09 130B 07/08-08/08 1 1 0.10 0.04 W-12 07/05-08/08 2 1 0.04 0.05 13 08/00-08/08 4(2) 2(0) 0.02 -- W-131A 07/08-08/08 1 1 0.30 0.01 131AB 07/08-08/08 1 -- 0.30 -- 131B 07/08-08/08 1 1 0.12 0.01

Table 82. Upper Willow Creek Ammonia (NH3) Data Relative to pH and Temperature Reach Date pH Temp. Range Chronic Acute Target Value (mg/L) (°C) Target Values Values Range Range (mg/L) (mg/L) LF HF

Non- 83A 7/23/04 8.3 9.4- 16.0 1.52- 1.39 3.15 -- detect Non- 83A 9/13/06 8.4 12.0- 16.0 1.29- 1.17 2.59 -- detect 83A 7/2/08 8.4 7.9- 11.7 1.29 2.59 -- 0.02 83A 8/20/08 7.9 7.9- 11.7 2.80 6.77 0.12 -- Non- 83B 7/23/04 8.3 9.2- 16.1 1.52 - 1.39 3.15 -- detect 83B 7/2/08 8.1 7.3- 12.2 2.10 4.64 -- 0.10 83B 8/20/08 8.4 7.3- 12.2 1.29 2.59 0.11 -- 130A 7/2/08 8.0 8.5- 15.1 2.43 5.62 -- 0.09 130A 8/20/08 7.8 11.5-15.1 3.18-2.89 8.11 0.10 -- 130B 7/2/08 7.9 8.4- 15.5 2.80-2.54 6.77 -- 0.04 130B 8/20/08 7.6 8.4- 15.5 4.73- 4.30 11.40 0.10 -- W-12 7/25/05 7.4 9.2- 20.1 4.73- 3.32 15.40 0.01 -- W-12 7/2/08 8.3 9.4- 16.0 1.52- 1.39 3.15 -- 0.05 W-12 8/20/08 7.4 9.4- 16.0 4.73- 2.92 15.40 0.09 -- Non- -- 13 8/01/00 8.2 6.0- 20.0 1.79- 1.26 3.83 detect Non- -- 13 10/13/00 8.2 6.0- 20.0 1.79- 1.26 3.83 detect Non- 13 6/25/01 8.0 6.0- 18.5 2.43- 1.94 5.62 -- detect 13 7/27/05 7.9 0.02 -- Non- 13 7/1/08 8.1 9.5- 17.6 2.10- 1.68 4.64 -- detect

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Reach Date pH Temp. Range Chronic Acute Target Value (mg/L) (°C) Target Values Values Range Range (mg/L) (mg/L) 13 8/19/08 8.1 9.5- 17.6 2.10- 1.68 4.64 0.10 -- W-131A 7/2/08 8.2 10.3- 18.2 1.79- 1.43 3.83 -- 0.01 W-131A 8/20/08 8.2 10.3- 18.2 1.79- 1.43 3.83 0.30 -- Non- 131AB 7/2/08 8.2 6.7- 19.0 1.79- 1.26 3.83 -- detect 131AB 8/20/08 8.3 6.7- 19.0 1.79- 1.26 3.15 0.20 -- 131B 7/2/08 8.3 12.3- 18.6 1.52- 1.22 3.15 -- 0.01 131B 8/20/08 8.4 12.3- 18.6 1.29- 1.03 2.59 0.12 --

Table 83. Lower Willow Creek Ammonia (NH3) Data by Reach Reach Date Range Sample Size Average Values (mg/L) LF HF LF HF

W-01 06/08 -- 1 -- 0.12 W-02 06/08 -- 1 -- 0.11 W-04 06/08 -- 1 -- 0.21 W-03 06/08 -- 1 -- 0.12 14 07/05-08/08 2 1 0.07 0.03

Table 84. Lower Willow Creek Ammonia (NH3) Relative to pH and Temperature Reach Date pH Temp. Range Chronic Acute Value (mg/L) (°C) Target Target Values Values Range Range (mg/L) (mg/L) LF HF

W-01 6/18/08 8.3* 5.6-18.9 1.52- 1.22* 4.71 -- 0.12 W-02 6/18/08 8.3* 10.1- 22.5 1.52- 1.22* 4.71 -- 0.11 14 7/25/05 8.2 12.1- 17.8 1.79- 1.43 5.72 0.03 -- 14 7/01/08 8.3 7.7-17.0 1.52- 1.39 4.71 -- 0.03 14 8/19/08 8.3 7.7-17.0 1.52- 1.39 4.71 0.10 -- * No value due to equipment failure. Reach 14 values used to determine chronic values range

Table 85. Depot Creek Ammonia (NH3) Data by Reach Date Range Sample Size Average Values (mg/L) LF HF LF HF

122A 07/08 -- 1(0) -- -- 122B 07/08 -- 1(0) -- -- D-02 06/08 -- 1 -- 0.12 D-01 06/08 -- 1 -- 0.21 59 06/01- 07/07 -- 3 -- 0.23 58 08/00- 08/08 6 2 6.67* 2.55 * Median value

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Table 86. Depot Creek Ammonia Relative to pH and Temperature Reach Date pH Temp. Chronic Target Acute Value (mg/L) Range (°C) Values Target Range (mg/L) Values Range (mg/L) LF HF

122A 7/1/08 8.1 8.1-11.5 2.10 4.64 -- Non- detect 122B 7/1/08 8.1 7.8- 11.5 2.10 4.64 -- Non- detect D-01 6/19/08 8.1* 10.1- 13.3 2.10* 4.64* -- 0.21 D-02 6/19/08 8.8 6.2- 12.2 0.66 1.23 -- 0.12 59 6/25/01 --* --* --* --* 0.03 -- 59 7/07/07 9.0 13.3 0.48 1.32 0.23 -- 58 8/1/00 8.2 6.0- 20.0 1.79- 1.26 5.72 10.4 -- 58 7/27/05 7.9 13.9- 20.6 2.80- 1.96 10.10 5.95 -- 58 7/7/07 8.4 13.3 1.29 3.88 -- 0.26 58 7.5 17.3 3.97 19.90 -- 8/29/07 11.9 58 10/23/07 7.5 17.3 3.97 19.90 0.21 -- 58 10/23/07 7.5 17.3 3.97 19.90 0.50 -- 58 7/1/08 7.9 9.7- 19.4 2.80- 1.96 10.10 -- 4.84 58 8/19/08 7.9* 18.5 2.24* 10.10* 7.39 -- * No values or equipment failure. Nearest spatial and chronological upstream data point used to derive chronic target values range (none available for 2001 sample of station 59).

Phosphorous

Table 87. Upper Willow Creek Phosphorous Summary data by Reach Reach Date Range Sample Size Average Values (mg/L) LF HF LF HF

83A 07/04-08/08 3 1 0.04 0.02 83B 07/04-08/08 2 1 0.06 0.02 130A 07/08 -- 1 -- 0.05 130B 07/08-08/08 1 1 0.06 0.05 W-12 07/05-08/08 2 1 0.05 0.04 W-12D 07/08-08/08 1 1 0.04 0.04 131A 07/08-08/08 1 1 0.05 0.04 131AB 07/08-08/08 1 1 0.03 0.04 131B 07/08-08/08 1 1 0.03 0.04 13 08/00-08/08 4 2 0.05* 0.03 * Median value

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Table 88. Lower Willow Creek Phosphorous Data by Reach Reach Date Range Sample Size Average Values (mg/L) LF HF LF HF

W-04 05/08-06/08 -- 2 -- 0.22 W-03 05/08-06/08 -- 2 -- 0.30 W-02 05/08-06/08 -- 2 -- 0.08 W-01 05/08-06/08 -- 2 -- 0.05 14 07/05-08/08 2 1 0.04 0.02

Table 89. Depot Creek Phosphorous data by Reach Date Range Sample Size Average Values (mg/L) LF HF LF HF

122A 07/08 -- 1 -- 0.05 D-02 05/08-06/08 -- 2 -- 0.07 D-01 06/08 -- 1 -- 0.23 59 07/07-08/08 -- 3 -- 0.38 58 10/07-08/08 2 1 2.50 3.11

Table 90. Historic Data Summaries Listed Date Sample Size Max Median AVG Segment Range LF HF LF HF LF HF Water Temp Upper 05/78- 6 18 20.8 12.975 14.5 12.53 14.14 Willow 07/99 Lower 05/78- 4721.9 15.75 10 15.75 10 Willow 06/99 04/99- Flatiron 06/99 0 3 15 -- 10 -- 10

Listed Date Sample Size Max Median AVG Segment Range LF HF LF HF LF HF

Upper 05/78- 7 12 10 9.6 8.85 9.02 7.88 Willow 07/99 Lower 05/78- 4511.1 8.55 10.4 8.55 10.8 DO Willow 06/99 04/99- Flatiron 06/99 -- 3 10.5 -- 10.4 -- 9.9

Listed Date Sample Size Max Median Average Segment Range LF HF LF HF LF HF D-10

Upper 05/78- 5 14 55 17.1875 9.815 17.99 5.67 Willow 07/99 Lower 8/78- 2 4 13.7 3.8 5.6 3.8 7.3 Turbidity Willow 6/99 4/99- Flatiron 6/99 0 3 6.6 -- 4.6 -- 5.2

Listed Date Sample Size Max Median Average Segment Range LF HF LF HF LF HF

Upper 05/78- 6 14 8.66 8 8.585 7.97 8.04 Willow 07/99 Lower 08/78- 3 4 8.7 8.3 8.7 8.2 8.6 pH Willow 6/99 4/99- Flatiron 6/99 0 3 8.7 -- 8.7 -- 8.7

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