UPPER GALL ATIN RIVER WATERSHED

Transcription

1 218 UPPER GALL ATIN RIVER WATERSHED MONITORING REPORT Kristin Gardner, PhD Executive Director, Gallatin River Task Force Jack Murray Big Sky Watershed Corps, Gallatin River Task Force January 216 The Gallatin River Task Force Community Water Quality Monitoring Program is supported by the Big Sky Resort Area Tax District, the Montana Department of Environmental Quality, Task Force donors, and volunteers. Thank you for investing in the health of the Upper Gallatin River Watershed.

2 TABLE OF CONTENTS Executive Summary...3 Introduction...4 Monitoring Program...5 Maps...6 Figure 1. Upper Gallatin River Monitoring Sites...6 Figure 2. West Fork Watershed Monitoring Sites...7 Routine Monitoring Results...8 Water Chemistry...8 Seasonal Trends...9 Aquatic Insects...1 Streamflow...1 References...1 Figure 3. Gallatin Nitrate Concentratinos...11 Figure 4. West Fork Nitrate Concentrations...11 Figure 5. Gallatin Chloride Concentration...12 Figure 6. West Fork Chloride Concentration...12 Figure 7. Gallatin Turbidity...13 Figure 8. West Fork Turbidity...13 Figure 9. Gallatin E. coli Concentration...14 Figure 1. West Fork E. coli Concentration...14 Figure 11. Sodium Concentration...15 Figure 12. Total Dissolved Solids Concentration...15 Figure 13. Magnesium Concentration...16 Figure 14. USGS 6435 Gallatin River near Gallatin Gateway, MT...16 Figure 15. Upper West Fork Streamflow...17 Figure 16. South Fork Streamflow...17 Figure 17. North Fork Streamflow...18 Figure 18. West Fork Streamflow...18 Invest in a Healthy Gallatin River

3 EXECUTIVE SUMMARY The Gallatin River Task Force began collecting routine water quality data in the Upper Gallatin River Watershed in 2. This data is used to assess and track the long-term health of rivers and streams, plan for restoration projects, and identify and monitor unforeseen events. Over 217, the Gallatin River Task Force and its volunteers collected over 2, data points. Indicators of river health, including temperature, ph, and dissolved oxygen, suggest cold and clean water in the Upper Gallatin River Watershed. Several monitoring sites within the West Fork Watershed exhibited elevated levels of nitrate and chloride. Nitrate concentrations were highest in the winter when nutrient uptake by plants and algae is low. High nitrate levels can increase algal growth and adversely impact fish and stream insect populations. Potential human sources of nitrate include fertilizer, land application of treated wastewater effluent on the Big Sky Golf Course and Big Sky Community Park, effluent from privately owned septic systems, and stormwater runoff. Chloride concentrations were well below the level toxic to aquatic life and generally were highest during the winter throughout the watershed. Wastewater and road salt likely contribute to elevated chloride levels. E. coli levels were generally below levels of concern. The highest levels occurred in the warm months when temperatures are conducive to bacteria growth. E. coli sources include wastewater and animal waste. Turbidity was low throughout the year, except for spring runoff, when water carries sediment (small pieces of sand, silt, and mud) downstream. Fine sediment on the streambed was elevated on the Middle Fork of the West Fork, which was likely due to a recent breach of a beaver dam. Analysis of stream insect populations at several river access sites in the Upper Gallatin suggested slightly degraded water quality and habitat. Streamflow calculations in the Gallatin and West Fork tributaries indicated an earlier than normal start to runoff beginning in early March

4 JeNelle Johnson, Stephanie Lynn, and Andrea Saari enjoying a sunny ski to monitor baseline conditions at the Big Horn site in Yellowstone National Park. INTRODUCTION The Gallatin River Task Force (Task Force) is a non-profit organization based in Big Sky, Montana working to protect the health of the headwaters of the Gallatin River, now and for future generations. Our mission is to partner with our community to inspire stewardship of the Gallatin River Watershed. The Task Force tackles this mission by monitoring watershed health; planning and implementing projects to improve the ecological health of the watershed; and providing water resource education to the residents and visitors of the Big Sky community. Over the past 17 years, the Task Force has collected routine watershed and aquatic insect data on the Upper Gallatin River and its tributaries. The Upper Gallatin River flows from the headwaters in Yellowstone National Park to the Spanish Creek confluence, just before the river exits Gallatin Canyon. We appreciate the many intrepid volunteers who have braved cold, high water, and blazing sun to build this invaluable record of watershed health. The Task Force and partners use this monitoring data to evaluate the health of the Upper Gallatin River Watershed, identify spatial and historical trends, and assess the impacts of unforeseen events. In addition, this dataset guides planning to improve water quality as well as fish and macroinvertebrate (aquatic insect) habitat, and allows us to evaluate the successes of these projects

5 MONITORING PROGRAM The Task Force monitors sixteen sites in the Upper Gallatin River Watershed. Seven sites are located on the mainstem Gallatin River (Figure 1), one site on the Taylor Fork, and eight sites on streams within the West Fork Watershed (Figure 2). These sites capture the potential impacts of changing geology and land use. All sixteen sites are monitored four times annually to track changes in water quality across hydrological regimes, such as high flow versus low flow, and biological regimes, such as the growing season versus the dormant season. At each quarterly monitoring event, the Task Force measures and records the following water quality parameters: ph, temperature, dissolved oxygen, turbidity, chloride, nitrate, E. coli, conductivity, and total coliform. For the summer baseflow (low flow) monitoring event, data collection also includes: total nitrogen, total phosphorus, fine sediment, macroinvertebrates (aquatic insects), and algae photo documentation. New in 217, sodium, magnesium, and total dissolved solids were collected to assess potential impacts on water quality from road salts. The Montana Department of Environmental Quality funded sampling events in September/ May 217 and January/March 218. This report will present the data collected in 217; however, a complete analysis of potential impacts of road salts on water quality will be available in the 218 Upper Gallatin Watershed Monitoring report. The Task Force maintains four streamflow stations in the West Fork Watershed that continuously measure stream stage (water level), temperature, and conductivity (Figure 2). Streamflows are calculated from rating curves developed from continuously recorded stream level and field streamflow measurements. The data from streamflow stations is available in real-time on the Task Force website. More details on our sampling and lab analyses methods can be found in the 217 Gallatin River Task Force Community Water Quality Monitoring Program Sampling Analysis Plan [Gardner et al., 217a] and Standard Operating Procedures [Gardner et al., 217b]. MORE INFORMATION: Glossary for technical terms: gallatinrivertaskforce.org/resources Real-time water data: gallatinrivertaskforce.org/stream-data To download long-term data set: gallatinrivertaskforce.org/stream-data - 5 -

6 N DOWN 2 DOWN 1 UP BUCK S TAYLOR FORK TF UPPER GALLATIN RIVER WATERSHED PARK LEGEND Gallatin Sites Flow Monitoring Sites Lone Mountain Trail HWY 191 Upper Gallatin River Gallatin River Tributaries Big Sky Meadow Village BIGHORN Figure 1: The Gallatin River Task Force monitors seven sites on the mainstem Upper Gallatin River and one site on the Taylor Fork (yellow circles) four times a year. Our sites are located on the Upper Gallatin River from the headwaters in Yellowstone National Park to immediately downstream of the West Fork confluence. -6-

7 Figure 2: The Gallatin River Task Force monitors eight sites for water quality (yellow circles) four times a year and maintains four continuous monitoring stations (black x s) in the West Fork Watershed

8 ROUTINE MONITORING RESULTS Water Chemistry Spatial Trends Indicators of river health, including temperature, ph, and dissolved oxygen, were at levels that support healthy fisheries and aquatic insects. Elevated levels of nitrate (>.1 mg/l in growing season) were measured at two monitoring sites on the West Fork, downstream of Little Coyote Bridge ( Community Park and WF above SF ) (Figures 3 & 4). Nitrate is a form of nitrogen readily available for consumption by plants and animals. Elevated nitrate stimulates algae growth, which in excess, can deplete dissolved oxygen vital to aquatic life. Potential human sources of nitrate to the West Fork include fertilizer, land application of treated wastewater effluent on the Big Sky Golf Course and Big Sky Community Park, effluent leaking from privately owned septic systems, and stormwater runoff. Chloride concentrations at all sites were well below the concentration that is toxic to aquatic life (>23 mg/l). Chloride levels were generally higher at sites in the West Fork Watershed compared to sites along the mainstem Gallatin (Figures 5 & 6). Chloride is an ion (charged molecule), that combines with other ions to form salt compounds. Salts dissolve easily in water. Potential human sources of chloride include wastewater, hot tubs, and road traction sand. Turbidity was highest at all South Fork sites during spring runoff (Figures 7 & 8). The South Fork Watershed is a geologically active landscape where landslides are common and likely the cause of increased turbidity during snowmelt. Turbidity is a measure of water clarity. Clear water has low turbidity and cloudy or murky water has a high turbidity level. Many factors can contribute to turbidity including an increase in streamflow, runoff, erosion, decay of organic material, and a lack of native streamside vegetation. E.coli levels at all sites except TF, on the Taylor Fork, were below the Montana Department of Environmental Quality summer and winter standards (Figures 9 & 1). The E.coli measured at TF in September was 633 (colony forming unit (cfu) per 1 ml), which greatly exceeds the 126 cfu/ 1 ml summer standard. Since E.Coli has been found to be highly variable throughout the watershed due to potential spikes from wildlife, additional data will be needed to fully evaluate the cause of the high E.coli levels at TF. E. coli is a bacterium commonly found in the lower intestines of warm-blooded animals. Rick Donaldson with a probe in each hand during a wintery water quality monitoring event. During spring runoff, sodium concentrations were highest at TF with no other distinguishable patterns; while, during summer baseflow, sodium concentrations were highest at TF and sites in the West Fork Watershed (Figure 11). Total dissolved solids (TDS) and magnesium were generally higher at the mainstem Gallatin sites, South Fork sites, and TF than at sites in the West Fork Watershed (Figures 12 & 13). Sodium and magnesium are ions typically associated with road salts. They also naturally occur in certain - 8 -

9 geology. TDS is a measure of anything dissolved in water. After the Task Force completes a full year of data collection, we will be able to better analyze sodium, TDS, and magnesium results for trends and sources. Fine sediment assessed through pebble counts indicated that the Middle Fork just before it joins the North Fork ( Lower Middle ) had more streambed sediment than is healthy for fish and aquatic insects. Fine sediment can smother trout eggs laid in gravel beds and fill in aquatic insect habitat. Excess fine sediment can originate from natural and human aggravated land disturbances, erosion from construction areas and unpaved roads, and road traction sand. Elevated fine sediment at the Lower Middle site may be a result of a recent large beaver dam failure that caused fine sediments built up behind the dam to release into the downstream reach (see adjacent photo). Breach in large beaver dam on the Middle Fork just upstream of the Lower Middle site. Seasonal Trends Nitrate concentrations at all monitoring sites varied significantly across seasons. Similar to historical data, nitrate concentrations at most sites were highest during the winter [Lynn and Gardner, 216]. During the winter, algae and aquatic plants use less nitrate for growth because of reduced sunlight and cold temperatures. During spring runoff, most nitrate concentrations were low from dilution when snow melts and streamflow increases. Nitrate concentrations were unusually high at runoff at TF and Bighorn (Figure 3). Additional data will discern whether or not these high values are a trend. Nitrate levels remain low during the summer because plants utilize nitrate to grow. The seasonal nitrate cycle is similar in the mainstem Gallatin and the streams in the West Fork Watershed, however, the magnitude of the winter nitrate peak is consistently much higher in the West Fork than in other streams (Figures 3 & 4). Chloride concentrations were highest during the winter at all sites except for those on the South Fork, where concentrations were highest in the summer. In the West Fork Watershed, concentrations were highest during pre-runoff in April (Figures 5 & 6). High chloride levels documented in the winter and pre-runoff monitoring events, suggest chloride originated from salt applied to winter roads for maintenance. Salt accumulates throughout the winter and is carried by snowmelt to rivers and streams in the spring. Turbidity was highest during spring runoff when snow melts and carries sediment (small pieces of sand, silt, and mud) downstream (Figure 7 & 8). Turbidity was extremely low the rest of the year throughout the Upper Gallatin River Watershed, indicating clear water. E. coli levels were highest during the spring and summer months when warmer temperatures provide more favorable conditions for bacteria survival (Figures 9 & 1). Sodium, TDS, and magnesium concentrations were higher in the summer than during spring runoff (Figures 11, 12 & 13)

10 Aquatic Insects In 217, aquatic insects were collected at the following four sites along the Gallatin mainstem: Moose Creek Flat Recreational area, Baetis Alley, Deer Creek, and Doe Creek access sites. These sites were chosen to acquire baseline data at sites the Task Force is planning and/or implementing restoration projects. Baseline data will allow for assessment of project impacts on aquatic insect populations. Mayflies, stoneflies, and caddisflies are extremely sensitive to pollution, which makes them powerful indicator species. The number of Mayflies at all sites were less than expected for a mountainous stream suggesting water quality impairment. The caddisfly populations at all sites were less diverse than expected suggesting that fine sediment on the streambed could be limiting habitat. The number of stoneflies were lower than expected at Moose Creek, Deer Creek, and Baetis alley suggesting that streambanks and riparian function may be disturbed. [Rhithron, 218] Streamflow Streamflow peaked at 5,2 cubic feet per second (cfs) on the Upper Gallatin at the USGS Gallatin Gateway gauge on June 5th, 217 (Figure 14) (USGS data). A sustained early increase in streamflow began in early March through the beginning of May when flows began to increase substantially. In the West Fork Watershed, streamflow peaked at 446 cfs in the Upper West Fork on May 13th (Figure 15). On June 5, the South Fork peaked at 127 cfs (Figure 16) and the North Fork peaked at 195 cfs (Figure 17). At the Lower West Fork streamflow station, a peak streamflow field measurement was not obtained so streamflow calculations during high flows is highly uncertain (Figure 18). References Gardner, K., S. Lynn and A. DeGroot. 217a. Gallatin River Task Force Community Water Quality Monitoring Program Sampling and Analysis Plan. Prepared for the Montana Department of Environmental Quality. Plan available at gallatinrivertaskforce.org. Gardner, K., S. Lynn and A. DeGroot. 217b. Standard Operating Procedures Gallatin River Task Force Community Water Quality Monitoring Program. Report available at gallatinrivertaskforce.org. Kerans, B. and W. Bollman Biological Assessment of Sites on the Gallatin River, Gallatin County, Montana: Macroinvertebrate Assemblages. Final Report. Lynn, S. and K. Gardner Upper Gallatin River Watershed Water Quality Monitoring Report. Report available at gallatinrivertaskforce.org

11 FIGURE 3) 217 GALLATIN NITRATE CONCENTRATIONS Big Horn Park TF Taylor Bucks Upstream Down 1 Down 2 Pre-runoff Spring Runoff Summer Baseflow Winter Baseflow FIGURE 4) 217 WEST FORK NITRATE CONCENTRATIONS North Fork Below Lake Lower Middle Ousel South Fork Community Park WF above SF West Pre-runoff Spring Runoff Summer Baseflow Winter Baseflow Figure 3 & 4) Nitrate concentrations at monitoring sites in the mainstem Upper Gallatin River (3) and the West Fork Watershed (4) measured during pre-runoff (light grey), spring runoff (light blue), summer baseflow (dark grey), and winter baseflow (dark blue). If nitrate exceeds the.1 mg/l critical value (red line), during the growing season (July 15th to September 3th), elevated nitrate may cause excess algae growth, which depletes dissolved oxygen that is vital to aquatic life. See Figures 1 & 2 for site locations

12 FIGURE 5) 217 GALLATIN CHLORIDE CONCENTRATIONS CHLORIDE (mg/l) 12 6 Big Horn Park TF Taylor Bucks Upstream Down 1 Down 2 Pre-runoff Spring Runoff Summer Baseflow Winter Baseflow FIGURE 6) 217 WEST FORK CHLORIDE CONCENTRATIONS CHLORIDE (mg/l) 12 6 North Fork Below Lake Lower Middle Ousel South Fork Community Park WF above SF West Pre-runoff Spring Runoff Summer Baseflow Winter Baseflow Figure 5 & 6) Chloride concentrations at monitoring sites in the mainstem Upper Gallatin River (5) and the West Fork Watershed (6) measured during pre-runoff (light grey), spring runoff (light blue), summer baseflow (dark grey), and winter baseflow (dark blue). Chloride can be toxic to aquatic life when the concentration exceeds 23 mg/l. All measurements taken in 217 were well below the critical value. See Figures 1 & 2 for site locations

13 FIGURE 7) 217 GALLATIN TURBIDITY 6 TURBIDITY (NTU) 4 2 Big Horn Park TF Taylor Bucks Upstream Down 1 Down 2 Pre-runoff Spring Runoff Summer Baseflow Winter Baseflow FIGURE 8) 217 WEST FORK TURBIDITY 6 TURBIDITY (NTU) 4 2 North Fork Below Lake Lower Middle Ousel South Fork Community Park WF above SF West Pre-runoff Spring Runoff Summer Baseflow Winter Baseflow Figure 7 & 8) Turbidity in the mainstem Upper Gallatin River (7) and the West Fork Watershed (8) measured during pre-runoff (light grey), spring runoff (light blue), summer baseflow (dark grey), and winter baseflow (dark blue). Turbidity is a measure of water clarity, and naturally varies throughout the year with the highest values occurring at all sites during runoff. See Figures 1 & 2 for site locations

14 FIGURE 9) 217 GALLATIN E.COLI CONCENTRATIONS 12 value of E. COLI (cfu/ 1mL) 8 4 Big Horn Park TF Taylor Bucks Upstream Down 1 Down 2 Pre-runoff Spring Runoff Summer Baseflow Winter Baseflow FIGURE 1) 217 WEST FORK E.COLI CONCENTRATIONS 12 E. COLI (cfu/ 1mL) 8 4 North Fork Below Lake Lower Middle Ousel South Fork Community Park WF above SF West Pre-runoff Spring Runoff Summer Baseflow Winter Baseflow Figure 9 & 1) E. coli in the mainstem Upper Gallatin River (9) and the West Fork Watershed (1) measured during pre-runoff (light grey), spring runoff (light blue), summer baseflow (dark grey), and winter baseflow (dark blue). The Montana Department of Environmental Quality set the E. coli primary standard as 126 cfu/ 1 ml (colony forming unit per 1 milliliters of water) during the warm months from April 1st through October 31st and 63 cfu/ 1 ml for the rest of the year. See Figures 1 & 2 for site locations

15 FIGURE 11) 217 SODIUM CONCENTRATIONS SODIUM (MG/L) 2 North Fork Below Lake Lower Middle Ousel South Fork Community SF West Fork 1 Big Horn Park Taylor Bucks Up Down 1 Down 2 TF Spring Runoff Summer Baseflow Figures 11) Sodium concentrations in the mainstem Upper Gallatin River and the West Fork Watershed during spring runoff (light blue) and summer baseflow (dark grey). Winter baseflow and pre-runoff will be measured in 218. See Figures 1 & 2 for site locations. FIGURE 12) 217 TOTAL DISSOLVED SOLIDS CONCENTRATIONS TDS (MG/L) 5 North Fork Below Lake Lower Middle Ousel South Fork Community SF West Fork Big Horn Park Taylor Bucks Up Down 1 Down 2 TF Spring Runoff Summer Baseflow Figures 12) TDS concentrations in the mainstem Upper Gallatin River and the West Fork Watershed during spring runoff (light blue) and summer baseflow (dark grey). Winter baseflow and pre-runoff will be measured in 218. See Figures 1 & 2 for site locations

16 FIGURE 13) 217 MAGNESIUM CONCENTRATIONS MAGNESIUM (MG/L) 5 North Fork Below Lake Lower Middle Ousel South Fork Community SF West Fork Big Horn Park Taylor Up Down 1 Down 2 TF Spring Runoff Summer Baseflow Figure 13) Magnesium concentrations in the mainstem Upper Gallatin River and the West Fork Watershed during spring runoff (light blue) and summer baseflow (dark grey). Winter baseflow and pre-runoff will be measured in 218. See Figures 1 & 2 for site locations. FIGURE 14) 217 USGS 6435 GALLATIN RIVER NEAR GALLATIN GATEWAY, MT DISCHARGE, CUBIC FEET PER SECOND Mar Apr May Jun Jul Aug Sep Oct Provisional Data Subject to Revision Graph courtesy of the U.S. Geological Survey Figure 14) 217 streamflow calculated on the West Gallatin River at the US Geological Survey Gallatin Gateway station

17 FIGURE 15) 217 UPPER WEST FORK STREAMFLOW DISCHARGE, CUBIC FEET PER SECOND /1/217 4/15/217 4/29/217 5/13/217 5/27/217 6/1/217 6/24/217 7/8/217 7/22/217 8/5/217 8/19/217 9/2/217 9/16/217 9/3/217 1/14/217 1/28/217 Figure 15) Streamflow calculated from water level data recorded continuously at the Gallatin River Task Force streamflow station on the Upper West Fork. See Figure 2 for location. FIGURE 16) 217 SOUTH FORK STREAMFLOW DISCHARGE, CUBIC FEET PER SECOND /1/217 4/15/217 4/29/217 5/13/217 5/27/217 6/1/217 6/24/217 7/8/217 7/22/217 8/5/217 8/19/217 9/2/217 9/16/217 9/3/217 1/14/217 1/28/217 Figures 16) Streamflow calculated from water level data recorded continuously at the Gallatin River Task Force streamflow station on the South Fork. See Figure 2 for location

18 FIGURE 17) 217 NORTH FORK STREAMFLOW DISCHARGE, CUBIC FEET PER SECOND 4 2 4/1/217 4/15/217 4/29/217 5/13/217 5/27/217 6/1/217 6/24/217 7/8/217 7/22/217 8/5/217 8/19/217 9/2/217 9/16/217 9/3/217 1/14/217 1/28/217 Figures 17) Streamflow calculated from water level data recorded continuously at the Gallatin River Task Force streamflow station on the North Fork. See Figure 2 for location. FIGURE 18) 217 WEST FORK STREAMFLOW DISCHARGE, CUBIC FEET PER SECOND /1/217 4/15/217 4/29/217 5/13/217 5/27/217 6/1/217 6/24/217 7/8/217 7/22/217 8/5/217 8/19/217 9/2/217 9/16/217 9/3/217 1/14/217 1/28/217 Figures 18) Streamflow calculated from water level data recorded continuously at the Gallatin River Task Force streamflow station on the West Fork. Peak streamflow was not measured at the lower West Fork site so streamflow calculations during high flows is highly uncertain. See Figure 2 for location

19 INVEST IN A HEALTHY GALLATIN RIVER FOR FUTURE GENERATIONS TOGETHER, WE CAN MAKE A DIFFERENCE! Learn More At the Task Force, we believe an educated community is the foundation for a healthy watershed. We work hard to bring engaging and relevant water resource information to the residents and visitors of the Big Sky community. Attend an educational event or workshop hosted by the Task Force and learn about stormwater management, septic system care and maintenance, trout friendly landscaping, and so much more. Apply for a Rebate Did you know that Big Sky has one of only two municipal water conservation programs in Montana? Through the Big Sky Water Conservation Program, you can help ensure adequate streamflows in the Gallatin by reducing your water use. Visit our website and apply to receive rebates for installing water efficient showerheads, toilets, and clothes washers inside your home. Our outdoor rebate program provides rebates for weather-based smart controllers, rain sensors, sprinkler heads and nozzles, and to perform spring outdoor audits/ system checkups. Become a Volunteer Do you want to get your feet wet with citizen science, engage your community in the conservation conversation, or get your hands dirty protecting the Gallatin River? Volunteers are assets, who partner with the Task Force at all levels. Visit our website to join the Volunteer Task Force today! Make an Investment We envision a future of cold, clean, and abundant water for the Gallatin River, now and for future generations. Together, we can collect credible data, engage in sound water resource planning, and educate the next generation of conservation leaders. We invite you to invest in the Gallatin River today

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