Bear-Evans Watershed Temperature, Dissolved Oxygen and Fecal Coliform Bacteria Total Maximum Daily Load Water Quality Implementation Plan March 2011 Publication No.11-10-024 Publication and Contact Information This report is available on the Department of Ecology’s website at www.ecy.wa.gov/biblio/1110024.html For more information contact: Washington State Department of Ecology Water Quality Program Northwest Regional Office Bellevue, WA 98008 Phone: 425-649-7105 Washington State Department of Ecology - www.ecy.wa.gov/ o Headquarters, Olympia 360-407-6000 o Northwest Regional Office, Bellevue 425-649-7000 o Southwest Regional Office, Olympia 360-407-6300 o Central Regional Office, Yakima 509-575-2490 o Eastern Regional Office, Spokane 509-329-3400 Cover photo: Bear Creek above Avondale Road. If you need this document in a format for the visually impaired, call the Water Quality Program at 360- 407-6404. Persons with hearing loss can call 711 for Washington Relay Service. Persons with a speech disability can call 877-833-6341. Bear-Evans Watershed Temperature, Dissolved Oxygen and Fecal Coliform Bacteria Total Maximum Daily Load Water Quality Implementation Plan By Chris Coffin, Sinang Lee, and Dave Garland Water Quality Program Northwest Regional Office Washington State Department of Ecology Bellevue, Washington 98008 This page is purposely left blank Table of Contents Page List of Figures and Tables....................................................................................................v Acknowledgements ............................................................................................................ vi Executive Summary .......................................................................................................... vii What is a Total Maximum Daily Load (TMDL) .................................................................1 Federal Clean Water Act requirements ..........................................................................1 TMDL process overview ...............................................................................................1 Elements required in a TMDL .......................................................................................2 What part of the process are we in? ...............................................................................2 Bear-Evans Watershed .........................................................................................................3 Watershed description ....................................................................................................3 Climate ...........................................................................................................................4 Resources .......................................................................................................................4 Water quality monitoring ...............................................................................................6 Water quality problems ..................................................................................................8 Fecal coliform bacteria ..........................................................................................8 Temperature and Dissolved Oxygen ...................................................................10 Establishing the TMDLs ..............................................................................................12 Bacteria loadings under different flow conditions ..............................................12 Riparian areas that lack effective shade ..............................................................15 What Will Be Done ............................................................................................................19 Overview ......................................................................................................................19 Implementation strategy...............................................................................................20 Organizational roles, actions, and schedules ...............................................................23 Potential municipal stormwater permit requirements ..................................................33 Adaptive management .................................................................................................33 Measuring Progress toward Goals .....................................................................................35 Performance measures and targets ...............................................................................35 Water quality monitoring .............................................................................................35 Effectiveness monitoring .............................................................................................36 Funding Opportunities .......................................................................................................37 Implementation projects and tools .....................................................................................39 On-going nonpoint source control ...............................................................................39 Increasing awareness through educational efforts .......................................................41 Technical assistance and voluntary efforts ..................................................................42 Water quality monitoring and special studies ..............................................................43 Legal authority .............................................................................................................43 Conclusions ........................................................................................................................49 Summary of Public Involvement Methods ........................................................................51 Bear-Evans Watershed Water Quality Implementation Plan Page iii References ..........................................................................................................................52 Appendices .........................................................................................................................55 Appendix A. Description of Implementation Partners ............................................57 Federal, tribal, and state entities ..........................................................................57 Local government resources ................................................................................60 Nonprofit and volunteer organizations ................................................................67 Appendix B. Tables of 303(d)-listings & TMDL Allocations ................................73 Appendix C. Glossary and Acronyms .....................................................................81 Glossary ...............................................................................................................81 Acronyms ............................................................................................................84 Bear-Evans Watershed Water Quality Implementation Plan Page iv List of Figures and Tables Page Figures Figure 1. Average monthly precipitation in Bear-Evans watershed. ..................................4 Figure 2 Bear-Evans watershed including cities of Woodinville, Redmond, and Sammamish ..........................................................................................................5 Figure 3. Sub-basins and monitoring stations in Bear-Evans watershed. ........................7 Figure 4. Stream segments in Bear-Evans watershed impaired for fecal coliform bacteria and listed on the 2004 303(d)-list.. ........................................................9 Figure 5. Stream segments in Bear-Evans watershed impaired for temperature and DO and listed on the 2004 303(d)-list.. .............................................................11 Figure 6. Relative levels of concern for bacteria pollution at stream segments under different flow conditions based on percent reductions needed to meet the bacteria 90th percentile target. .......................................................................14 Figure 7. Effective shade deficits in Bear-Evans stream system based on difference between current and system potential mature riparian vegetation (Ecology, 2008b). ............................................................................................................16 Figure 8. Feedback loop for determining need for adaptive management. ......................34 Tables Table 1. Monitoring stations in Bear-Evans watershed. .....................................................6 Table 2. Potential sources of fecal coliform bacteria in the Bear-Evans watershed. ..........8 Table 3. Daily load and wasteload allocations set at Bear Creek near the mouth (Site O484). .........................................................................................................15 Table 4. Effective shade and solar load allocations on July 24 to improve temperature and DO conditions in Bear Creek. ...............................................18 Table 5. TMDL targets and goals for meeting water quality standards in Bear- Evans watershed. .................................................................................................19 Table 6. Priority streams in Bear-Evans watershed for WRIA 8 Salmon Recovery (WRIA 8, 2005). .................................................................................19 Table 7. Summary of implementation