September 2015 Link Light Rail Operations and Maintenance Satellite Facility Final Environmental Impact Statement ECOSYSTEMS TECHNICAL REPORT Appendix E3 Central Puget Sound Regional Transit Authority LINK LIGHT RAIL OPERATIONS AND MAINTENANCE SATELLITE FACILITY ECOSYSTEMS TECHNICAL REPORT P REPARED FOR: Sound Transit Union Station 401 South Jackson Street Seattle, Washington 98104 Contact: Kent Hale, Senior Environmental Planner (206) 398-5103 P REPARED BY: ICF International 710 Second Avenue, Suite 550 Seattle, WA 98104 Contact: Torrey Luiting (206) 801-2824 September 2015 ICF International. 2015. Link Light Rail Operations and Maintenance Satellite Facility Ecosystems Technical Report. September. (ICF 00329.12) Seattle, WA. Prepared for Sound Transit. Seattle, WA. Contents List of Tables ......................................................................................................................................... iv List of Figures ......................................................................................................................................... v List of Acronyms and Abbreviations ..................................................................................................... vi Page Chapter 1 Introduction ...................................................................................................................... 1-1 1.1 Project Description .......................................................................................................... 1-1 1.1.1 Preferred Alternative ...................................................................................................... 1-2 1.1.2 SR 520 Alternative ........................................................................................................... 1-3 1.1.3 Lynnwood Alternative ..................................................................................................... 1-3 1.2 Data Gathered ................................................................................................................. 1-3 1.2.1 Agency and Organization Contacts .................................................................................. 1-4 1.2.2 Maps and Existing Documentation .................................................................................. 1-4 1.3 Related Laws and Regulations ......................................................................................... 1-6 1.3.1 Federal ............................................................................................................................. 1-6 1.3.2 State ................................................................................................................................ 1-6 1.3.3 Local ................................................................................................................................ 1-6 1.4 Study Areas ...................................................................................................................... 1-6 1.4.1 Aquatic Resources ........................................................................................................... 1-6 1.4.2 Vegetation and Wildlife Resources ................................................................................. 1-7 1.4.3 Wetland Resources .......................................................................................................... 1-7 1.5 Assumptions .................................................................................................................... 1-7 1.5.1 Impact Assessment .......................................................................................................... 1-7 1.5.2 Site Restoration ............................................................................................................. 1-10 1.5.3 Avoiding and Minimizing Impacts on Sensitive Ecosystem Resources .......................... 1-11 Chapter 2 Study Objectives and Methods .......................................................................................... 2-1 2.1 Aquatic Resources ........................................................................................................... 2-1 2.1.1 Aquatic Resources Study Objectives ............................................................................... 2-1 2.1.2 Aquatic Resources Methods ............................................................................................ 2-1 2.2 Vegetation and Wildlife Resources ................................................................................. 2-8 2.2.1 Vegetation and Wildlife Resources Study Objectives ...................................................... 2-8 2.2.2 Vegetation and Wildlife Resources Methods .................................................................. 2-8 2.3 Wetland Resources ........................................................................................................ 2-13 2.3.1 Wetland Resources Study Objectives ............................................................................ 2-13 Ecosystems Technical Report September 2015 Link Light Rail Operations and Maintenance Satellite Facility i Final Environmental Impact Statement Contents 2.3.2 Wetland Resources Methods ........................................................................................ 2-14 2.4 Waters of the United States .......................................................................................... 2-21 Chapter 3 Affected Environment ....................................................................................................... 3-1 3.1 Regulatory Context .......................................................................................................... 3-1 3.1.1 Aquatic Resources ........................................................................................................... 3-1 3.1.2 Vegetation and Wildlife ................................................................................................... 3-2 3.1.3 Wetlands ......................................................................................................................... 3-3 3.2 Aquatic Resources ........................................................................................................... 3-3 3.2.1 Study Area Watershed .................................................................................................... 3-4 3.2.2 Aquatic Species and Habitat ............................................................................................ 3-9 3.3 Vegetation and Wildlife Resources ............................................................................... 3-21 3.3.1 Vegetation Cover Types ................................................................................................ 3-22 3.3.2 Federal and State Threatened, Endangered, and Candidate Species and Federal Species of Concern ........................................................................................................ 3-25 3.3.3 Migratory Bird Treaty Act Species ................................................................................. 3-29 3.3.4 State Priority Habitats and Species ............................................................................... 3-29 3.3.5 Wildlife Habitat and Species by Alternative .................................................................. 3-35 3.4 Wetland Resources ........................................................................................................ 3-45 3.4.1 Wetland Determination ................................................................................................ 3-53 3.4.2 Wetland Descriptions .................................................................................................... 3-54 3.4.3 Wetland Ratings and Function Assessment .................................................................. 3-72 3.5 Jurisdictional Ditches ..................................................................................................... 3-76 3.5.1 Jurisdictional Ditches in the Preferred Alternative Site ................................................. 3-77 3.5.2 Jurisdictional Ditches in the SR 520 Alternative Site ..................................................... 3-77 Chapter 4 Environmental Consequences ........................................................................................... 4-1 4.1 Aquatic Resources ........................................................................................................... 4-1 4.1.1 Temporary Construction-Related Impacts ...................................................................... 4-3 4.1.2 Permanent Operational Impacts ................................................................................... 4-11 4.2 Vegetation and Wildlife ................................................................................................. 4-17 4.2.1 Temporary Construction-Related Impacts .................................................................... 4-17 4.2.2 Permanent Operational Impacts ................................................................................... 4-20 4.3 Wetland and Jurisdictional Ditch Resources ................................................................. 4-30 4.3.1 Temporary Construction Impacts .................................................................................. 4-30 4.3.2 Permanent Operational Impacts ................................................................................... 4-35 Chapter 5 Potential Mitigation Measures .........................................................................................