Upper Green Valley Creek Streamflow Improvement Plan Prepared by: The Russian River Coho Water Resources Partnership With Support from: December 2019 Upper Green Valley Creek Streamflow Improvement Plan Acknowledgements This project was funded by the National Fish and Wildlife Foundation. We would like to thank Sonoma Water, the California Department of Fish and Wildlife, the Natural Resources Conservation Service, the National Oceanic and Atmospheric Administration’s National Marine Fisheries Service and Restoration Center, the North Coast Regional Water Quality Control Board, the State Water Resources Control Board, the University of California, Berkeley, the U.S. Fish and Wildlife Service, the U.S. Army Corps of Engineers, and our reviewers. This work would be impossible without the support of the landowners, and many other partners in the Green Valley Creek watershed, and we are grateful for their time, feedback, access, participation, and stewardship. Authors Brock Dolman, Occidental Arts and Ecology Center’s WATER Institute John Green, Gold Ridge Resource Conservation District Mary Ann King, Mia van Docto, Gabriella Woodard, and Caitlin Boise, Trout Unlimited Mariska Obedzinski and Sarah Nossaman Pierce, California Sea Grant Katie Robbins, Russian River Coho Partnership & Sonoma Resource Conservation District Upper Green Valley Creek Streamflow Improvement Plan Table of Contents Table of Contents ................................................................................................................................... 3 Figures .................................................................................................................................................... 4 Tables ..................................................................................................................................................... 7 Acronyms ............................................................................................................................................... 8 Streamflow Improvement Plan overview .............................................................................................. 9 Executive summary .............................................................................................................................. 10 1 Introduction ................................................................................................................................. 12 2 Watershed conditions .................................................................................................................. 15 3 Human water use ......................................................................................................................... 35 4 Salmonids and flow-related habitat impacts ............................................................................... 45 5 Recommendations: Flow improvement strategies...................................................................... 61 6 Permitting and long-term considerations .................................................................................... 83 7 Conclusion .................................................................................................................................... 97 References ......................................................................................................................................... 100 Appendix A. Recovery Plan actions implemented by the Coho Partnership ..................................... 105 Page 3 Upper Green Valley Creek Streamflow Improvement Plan Figures Figure 1. Coho Partnership and SIP focus area within the Green Valley Creek watershed. ....................... 14 Figure 2. Upper Green Valley Creek watershed land use. .......................................................................... 16 Figure 3. Average monthly high and low temperatures (2000 – 2018) recorded in Graton, CA (NCDC Station USC00043578). ............................................................................................................................... 17 Figure 4. Average monthly rainfall recorded at Healdsburg, CA (NCDC Station #3875). ........................... 18 Figure 5. Annual rainfall recorded at Healdsburg, CA, 1941-2018 (NCDC Station #3875). ........................ 19 Figure 6. Annual rainfall recorded at Healdsburg, CA, during the study period 2010-2018 (NCDC Station #3875). ........................................................................................................................................................ 20 Figure 7. Streamflow gage locations in the Upper Green Valley Creek watershed. ................................... 22 Figure 8. Streamflow recorded in Upper Green Valley Creek at Bones Rd (GV01), WY2011. .................... 23 Figure 9. Monthly discharge as a percentage of annual discharge in Upper Green Valley Creek, 2011 and 2012 (WY2011 data from GV01, WY2012 data from GV02 [GV01 malfunctioned for part of WY2012]). 24 Figure 10. Upper Green Valley summer streamflow from WY2013 and WY2014, showing how summer rainfall events impact streamflow conditions. ........................................................................................... 24 Figure 11. Streamflow in Green Valley Creek, water year 2010, showing summer baseflow to illustrate the magnitude of the dry season flow recession. ....................................................................................... 25 Figure 12. Summer streamflow conditions in Upper Green Valley Creek, water year 2017, at all gage sites. ............................................................................................................................................................ 26 Figure 13. Summer streamflow conditions in Purrington Creek recorded at GV02, water year 2010, showing the impact of direct diversions on streamflow. ........................................................................... 27 Figure 14. Days when Green Valley Creek between project gages GV04 and GV01 was a gaining vs losing reach. Losing reach days were assumed when the difference in mean daily flow value between reaches was below 0.00 ft3/s. .................................................................................................................................. 27 Figure 15. Summer streamflow conditions in Upper Green Valley at gage site GV01, water years 2010 and 2011, showing streamflow conditions before the 2012-2016 drought. .............................................. 28 Figure 16. Summer streamflow conditions in Upper Green Valley at gage site GV01, water years 2010 thru 2016, showing streamflow conditions before (in blue) and during (in red) the 2012-2016 drought. 29 Figure 17. Summer streamflow conditions in Upper Green Valley at gage site GV01, water years 2010 thru 2018, showing streamflow conditions before (in blue), during (in red) and after (in green) the 2012- 2016 drought. ............................................................................................................................................. 30 Figure 18. Total summer discharge at gage site GV01, in water years 2010 thru 2018. ............................ 31 Figure 19. Total monthly discharge at GV01 in water years 2010 thru 2018. ............................................ 31 Figure 20. Upper Green Valley groundwater monitoring well and surface water gage locations. ............ 33 Figure 21. Total and summer water use by category in the Upper Green Valley Creek watershed. ......... 39 Page 4 Russian River Coho Partnership Upper Green Valley Creek Streamflow Improvement Plan Figure 22. Comparison of average annual rainfall, streamflow, and human water need in the Upper Green Valley Creek watershed; from TU streamflow monitoring, PRISM data, and land use digitization. 40 Figure 23. Comparison of total summer discharge in Upper Green Valley Creek watershed and human water use. ................................................................................................................................................... 40 Figure 24. Comparison of total monthly discharge in Upper Green Valley Creek watershed and monthly human water use (in black)......................................................................................................................... 41 Figure 25. Locations and types of water rights in the Upper Green Valley Creek watershed in eWRIMS as of July 2019. ................................................................................................................................................ 43 Figure 26. CSG’s stationary fish monitoring sites and current survey reaches in the Green Valley Creek watershed. Includes year-round PIT tag antenna arrays and the downstream migrant smolt trap operated each spring. Survey reaches, shown in green, receive routine biological and environmental sampling. ..................................................................................................................................................... 49 Figure 27. Estimates of adult coho returning to Green Valley Creek each winter. Numbers from 2008/09 and 2010/11 are based on spawner survey observations and the following years are derived from PIT tag antenna data. No adult fish or redds were observed during the 2009/2010 spawner surveys, but a minimum count of two adults was included to account for wild coho young-of-the-year observed in the summer of 2010. ........................................................................................................................................