Snohomish River Basin Ecological Analysis for Salmonid Conservation Snohomish Basin Salmonid Recovery Technical Committee May 2004, Updated June 2005 0405WRIAtechComReportCover.ai Snohomish River Basin Ecological Analysis for Salmonid Conservation Snohomish Basin Salmonid Recovery Technical Committee in cooperation with NOAA Fisheries May 2004, Updated June 2005 Snohomish River Basin Ecological Analysis for Salmonid Conservation Snohomish River Basin Ecological Analysis for Salmonid Conservation Contributors Andy Haas, Snohomish County Surface Water Management Division (SWM), Chair of EASC Work Group of the Snohomish Basin Salmonid Recovery Technical Committee Krista Bartz, National Marine Fisheries Service, Northwest Fisheries Science Center (NWFSC) Greg Blair, Mobrand Biometrics Suzanne Brunzell, Snohomish County SWM Mike Chamblin, Washington Department of Fish and Wildlife (WDFW) Jon Houghton, Pentec Environmental, Inc. (representing City and Port of Everett) Stephanie Kaknes, Snohomish County SWM Sandy Kilroy, King County Department of Natural Resources and Parks (DNRP) Denise Krownbell, Seattle City Light Kerry Lagueux, National Marine Fisheries Service, NWFSC Gino Lucchetti, King County DNRP Martha Neuman, Snohomish County SWM L. Ted Parker, Snohomish County SWM Scott Powell, Seattle City Light Kit Rawson, Tulalip Tribes Mindy Rowse, National Marine Fisheries Service, NWFSC Mary Ruckelshaus, National Marine Fisheries Service, NWFSC Michael Rustay, Snohomish County SWM Beth Sanderson, National Marine Fisheries Service, NWFSC Mark Scheurell, National Marine Fisheries Service, NWFSC James Schroeder, King County DNRP Fran Solomon, King County DNRP Jim Starkes, Pentec Environmental, Inc. Tom Ventur, King County DNRP - i - Snohomish River Basin Ecological Analysis for Salmonid Conservation Contributors, continued Snohomish Basin Salmonid Recovery Technical Committee Members Andy Haas, Snohomish County SWM (Co-Chair) James Schroeder, King County DNRP (Co-Chair) Bob Aldrich, Snohomish County SWM Jamie Bails, Snohomish Conservation District Keith Binkley, Snohomish County Public Utility District Mike Chamblin, WDFW Barry Gall, U.S. Forest Service Jon Houghton, Pentec Environmental, Inc. (representing City and Port of Everett) Sandy Kilroy, King County DNRP Curt Kraemer, WDFW Denise Krownbell, Seattle City Light Kurt Nelson, Tulalip Tribes Martha Neuman, Snohomish County SWM Scott Powell, Seattle City Light Kit Rawson, Tulalip Tribes Mindy Rowse, National Marine Fisheries Service, NWFSC Anne Savery, Tulalip Tribes James Schroeder, King County DNRP Fran Solomon, King County DNRP Dave Steiner, Stillaguamish-Snohomish Fisheries Enhancement Task Force Ralph Svrjcek, Washington Department of Ecology Obtaining Copies Snohomish County Surface Water Management Division 2731 Wetmore Avenue, Suite 300 Everett, WA 98201-3581 Phone: 425-388-3464 Phone: 800-562-4367 Fax: 425-388-6455 - ii - Snohomish River Basin Ecological Analysis for Salmonid Conservation TABLE OF CONTENTS INTRODUCTION.........................................................................................................................................1 Overview of Document.............................................................................................................................1 Overview of Steps 1–8..............................................................................................................................3 STEP 1. RELATIVE CURRENT SALMONID USE ANALYSIS .............................................................5 Description................................................................................................................................................5 Methods.....................................................................................................................................................5 Chinook Salmon: Current Relative Use................................................................................................5 Bull Trout: Current Relative Use..........................................................................................................6 Coho Salmon: Current Relative Use.....................................................................................................8 STEP 2. CURRENT STREAM HABITAT CONDITIONS ......................................................................22 Description..............................................................................................................................................22 Methods...................................................................................................................................................22 Condition ............................................................................................................................................22 Level of Certainty ...............................................................................................................................23 STEP 3. WATERSHED PROCESS ANALYSIS ......................................................................................27 Description..............................................................................................................................................27 Methods...................................................................................................................................................27 Peak Flow Hydrology .........................................................................................................................27 Riparian Function ...............................................................................................................................29 Sediment Supply.................................................................................................................................31 Future Analyses.......................................................................................................................................32 STEP 4. CHANGE BETWEEN HISTORICAL AND CURRENT POTENTIAL TO SUPPORT CHINOOK SALMON .....................................................................................................................46 Introduction.............................................................................................................................................46 EDT Model .............................................................................................................................................46 Description..........................................................................................................................................46 Methods ..............................................................................................................................................46 Adult Spawning Potential Capacity Model.............................................................................................48 Description..........................................................................................................................................48 Methods...................................................................................................................................................49 The Spawning Habitat Index Model...................................................................................................49 Accessibility........................................................................................................................................51 Results.................................................................................................................................................51 Caveats....................................................................................................................................................51 STEP 5. SALMONID USE AND POTENTIAL SYNTHESIS .................................................................58 Description..............................................................................................................................................58 Methods...................................................................................................................................................58 - iii - Snohomish River Basin Ecological Analysis for Salmonid Conservation Relative Current Use...........................................................................................................................58 Potential – Gain with Restoration and Losses with Degradation........................................................58 Results.....................................................................................................................................................59 Caveats....................................................................................................................................................59 STEP 6. HYPOTHESES, STRATEGY GROUPS, AND ACTIONS........................................................66 Description..............................................................................................................................................66 Caveats....................................................................................................................................................67 Basin Scale Hypotheses ..........................................................................................................................67 Chinook Population Structure.............................................................................................................67