Skagit Wildlife Area Island Unit Draft Alternatives Analysis
Total Page:16
File Type:pdf, Size:1020Kb
NOVEMBER 16, 2020 SKAGIT WILDLIFE AREA ISLAND UNIT DRAFT ALTERNATIVES ANALYSIS Analysis by: Washington Department of Fish and Wildlife Region 4 Staff Preferred alternative to be selected by: WDFW Table of Contents Acronyms and Abbreviations ........................................................................................................................................ 3 1. Executive Summary ................................................................................................................................................... 4 2. Project Introduction .................................................................................................................................................. 4 2.1 Site Description ................................................................................................................................................... 4 2.2 Background ........................................................................................................................................................ 6 2.3 Decision-Making Process ................................................................................................................................... 7 2.4 Stakeholder and Public Engagement .................................................................................................................. 7 3. Conceptual Design Alternatives ................................................................................................................................ 8 3.1 Alternative 1: No Restoration ........................................................................................................................... 12 3.2 Alternative 2: Partial Restoration—East Island ................................................................................................ 13 3.3 Alternative 3: Partial Restoration—Levee Setback ........................................................................................... 15 3.4 Alternative 4: Full Restoration .......................................................................................................................... 17 4. Criteria .................................................................................................................................................................... 18 4.1 Management, Regulatory & Policy Considerations .......................................................................................... 19 4.1.1 WDFW Policies ........................................................................................................................................... 19 4.1.2 Obligations and Agreements ..................................................................................................................... 20 4.1.3 Future Cost and Funding ............................................................................................................................ 22 4.2 Fish and Wildlife Needs .................................................................................................................................... 23 4.2.1 ESA-Listed Chinook and Southern Resident Killer Whale Recovery .......................................................... 23 4.2.2 Food fish and Game fish ............................................................................................................................ 24 4.2.3 Shorebird and Waterfowl Conservation .................................................................................................... 25 4.3 Community Interests ....................................................................................................................................... 25 4.3.1 Agriculture ................................................................................................................................................. 25 4.3.2 Passive Recreation ..................................................................................................................................... 26 4.3.3 Recreational Fishing ................................................................................................................................... 26 4.3.4 Waterfowl Hunting .................................................................................................................................... 26 4.4 Climate Change Resilience ............................................................................................................................... 27 5. Analysis of Conceptual Design Alternatives ............................................................................................................ 28 5.1 Management, Regulatory & Policy Considerations .......................................................................................... 30 5.1.1 WDFW Policies ........................................................................................................................................... 30 5.1.2 Obligations and agreements ...................................................................................................................... 31 5.1.3 Future Costs and Funding .......................................................................................................................... 32 5.2 Fish and Wildlife Needs .................................................................................................................................... 35 5.2.2 ESA-listed Chinook and Southern Resident Killer Whale Recovery ........................................................... 35 5.2.1 Food fish and Game fish ............................................................................................................................ 36 5.2.3 Shorebird and waterfowl conservation ..................................................................................................... 36 5.3 Community values ............................................................................................................................................ 38 5.3.1 Agriculture ................................................................................................................................................. 38 5.3.2 Passive recreation ...................................................................................................................................... 38 5.3.3 Recreational fishing ................................................................................................................................... 38 5.3.4 Waterfowl hunting ..................................................................................................................................... 39 5.4 Climate change resilience ................................................................................................................................. 40 Appendix A: Barn Field and Seattle Pond Tidegates and Water Control Structures ..................................................42 Appendix B: Advisory Group and Public Comment Summary .....................................................................................51 Appendix C: Tidal Channel and Chinook Salmon Technical Memorandum.................................................................56 Appendix D: Geomorphic Assessment Technical Memorandum ................................................................................87 Appendix E: Waterfowl and Shorebird Technical Memorandum ..............................................................................113 Appendix F: Opinion of Probable Construction Costs ...............................................................................................135 Appendix G: Cost Estimates for Annual O&M at Island Unit .....................................................................................139 Appendix H: Changes in WDFW-Managed Land and Habitat Types Since 2000 ........................................................41 Figures and Tables Figure 1. Project site location. ...................................................................................................................................... 5 Figure 2. Current site layout. ........................................................................................................................................ 5 Figure 3. LiDAR elevation data on the site. ................................................................................................................. 10 Figure 4. Approximate acreages of actively managed fields.. .................................................................................... 11 Figure 5. Alternative 1: no restoration. ...................................................................................................................... 12 Figure 6. Alternative 2: partial restoration—east island ............................................................................................ 13 Figure 7. Channel locations and outlets for Alternative 2. ......................................................................................... 13 Figure 8. Alternative 3: partial restoration – levee setback ....................................................................................... 15 Figure 9. Channel locations and outlets for Alternative 3. ......................................................................................... 16 Figure 10. Alternative 4: full restoration. ..................................................................................................................