Lake Washington General Investigation (LW GI): Environmental Restoration Projects for Salmon and Wildlife

1. Lake Washington General InvestigationJulie Hall, Seattle Public Utilities

2. Study purpose History Accomplishments Status So what next? What I’d like to cover today…

3. LW GI Purpose Identify and implement environmental restoration projects for the Lake Washington system to: 1) improve habitat conditions for salmon and other wildlife; 2) use water efficiently at the Locks to benefit salmon.

4. History of the GI 1999: Chinook listed Feasibility Reconnaissance Split LW GI into 2 phases: 1997: LW GI began Seattle and King County local sponsors Phase 1 = King Co. Project formulation Feasibility analyses 2006: Discontinued Salmon Synthesis Report 1998: Reconnaissance report 905(b) Phase 2 = Seattle Further studies LW Chinook Habitat Use LW Predators Smolt Flume Efficiency Locks Passage Acoustic Tracking

5. History of the GI 1999: Chinook listed Feasibility Reconnaissance Split LW GI into 2 phases: 1997: LW GI Seattle and King County local sponsors Phase 1 = King Co. Project formulation Feasibility analyses 2006: Discontinued Salmon Synthesis Report 1998: Reconnaissance report 905(b) Phase 2 = Seattle Further studies LW Chinook Habitat Use LW Predators Smolt Flume Efficiency Locks Passage Acoustic Tracking

6. USFWS: Chinook smolt outmigration 2004-2008 P.Johnson: Filling Culvert entrainment 2000-2004 USFWS: Chinook smolt outmigration 2005-2006 R2: PIT Tagging and Locks Passage 1998-2008 WDFW: LW and Ship Canal predators 2000-2001, 2003 WDFW/R2: Smolt Flume Efficiency 2002, 2004 USFWS: Dock observations 2004-2006 Corps/MIT: Adult return timing/behavior 2000, 2005-2007 UW: Chinook habitat preferences 2004-2005 LW GI Studies USFWS: Juvenile Chinook habitat use 2000-2006

7. Lake Washington

8. Chinook fry need rearing habitat and “rest stops” for the 3-5 months they inhabit Lake Washington February-May • Preferred rearing habitat includes: • Shoreline areas with shallow depths (>1 m) and gentle slopes • Fine substrates • Overhanging vegetation/small woody debris • Small creeks: mouths and shallow, low gradient, upstream portions

9. Density of juvenile Chinook, relative to distance from the Cedar River March – June

10. Small creek mouths = highly used Comparison of Deltas and Lake Shore (South L.Washington and L. Sammamish) From "Nearshore Habitat Use by Juvenile Chinook Salmon in Lentic Systems of the Lake Washington Basin". Annual Report, 2002 by Roger Tabor, US Fish and Wildlife Service

11. To Avoid Predators, Juvenile Chinook: Avoid areas with little light, like under docks Avoid shorelines without shallow water areas due to bank armoring Bulk heading and rip rap provide a refuge for predators, reduce shallow water areas, and prevent bank sloughing (which supplies fine sediment) Over-water structures cause juveniles to detour to deeper water

12. Docks affect how fish move along the shoreline May-June Fish continue to move along the shoreline, close to shore After passing under or around the dock, the school moves closer to shore As the school approaches a dock, the fish move offshore into deeper water and pass under or around the dock Fish move in schools close to shore (within a few meters)

13. Effect of structures: • Increase distance traveled • Force migrating smolts into deeper water (increase predation risk?) Fish moved back to shallower water once beyond the last structure direction of travel Microacoustic Tracking at Tennis Club

14. Ship Canal and Lake Union

15. Tracking System 1. “Listening station” RECEIVER

16. Tracking System 2. Get a fish and a tag

17. Tracking System 3. Track your fish RECEIVER

18. Example Chinook smolt track from Portage Bay

19. Gas Works 2005

20. All Chinook combined into one density plot with each fish weighted equally. Gas Works 2005

21. Acoustic Results Behavior very different between Lake Washington and the Ship Canal/Lake Union In Ship Canal, fish are widely distributed and not just along shoreline Chinook smolts use south Lake Union! Fish appear to spend longer periods of time in Lake Union (several days) Fish appear to hold/delay in Union Bay Predators associated with overwater structures, steep sloping shorelines, and edge of aquatic vegetation

22. Ballard Locks

23. Juvenile Salmon at the Locks Numerous projects and studies have occurred at the Locks to increase the safety of juvenile fish passage Removing barnacles from the filling culverts Operation of strobe lights to deter smolts from entering the filling culverts Smolt slides Pit Tagging studies

24. Fish Passage and Water Flow Studying the amount of water needed to pass the maximum number of smolts through the flumes At flows > 80cfs, > 95% of juvenile salmon used the flumes to pass through the Locks

25. Declining Detection Rates & Surface Water Temperature at the Fremont Bridge

26. Research Wrap-Up • Synthesis report of research due end of 2008 • Microacoustic tracking report due in 2009

27. LW GI Status – Both Phases Discontinued • Seattle, similar to King County, discontinuing participation • Authority does not go away • Reasoning: • Heavy staff and money investment in bureaucratic process • Uncertain future return • Reduced priority federally • Other avenues more cost-effective

28. So what is next? • Other Corps partnership opportunities: • Section 206 • Section 1135 • Puget Sound and Adjacent Waters (PSAW) • Section 22 – Planning Assistance Salt water drain adult excluder Installed 6/08 • Biological Opinion: • Continuing and new • actions at the Locks