BONNEVILLEPOWERADMINISTRATION In cooperation with the U.S. Army Corps of Engineers Columbia Estuary Ecosystem Restoration Program Final Environmental Assessment July 2016 DOE/EA-2006 BONNEVILLE POWER ADMINISTRATION DOE/BP-2006 • July 2016 Table of Contents Chapter 1 Purpose of and Need for Action ................................................................................................ 1 1.1 Introduction ................................................................................................................................................... 1 1.2 Need .................................................................................................................................................................. 3 1.3 Purposes.......................................................................................................................................................... 3 1.4 Background .................................................................................................................................................... 4 1.4.1 Federal Columbia River Power System ................................................................................... 4 1.4.2 Status of the Columbia River Estuary ...................................................................................... 4 1.4.3 Federal Columbia River Power System Biological Opinion ............................................ 5 1.4.4 Columbia Estuary Ecosystem Restoration Program .......................................................... 7 1.4.5 ERTG and SBUs.................................................................................................................................. 8 1.4.6 Columbia Estuary Ecosystem Restoration Program Management Actions .............. 9 1.4.7 The Council’s Fish and Wildlife Program ............................................................................... 9 1.5 Lead and Cooperating Agencies ......................................................................................................... 10 1.5.1 Bonneville Power Administration (Lead Agency) ........................................................... 10 1.5.2 U.S. Army Corps of Engineers (Cooperating Agency) ..................................................... 10 1.6 Public Involvement .................................................................................................................................. 12 1.6.1 Scoping .............................................................................................................................................. 12 1.6.2 Responses to Scoping .................................................................................................................. 12 1.6.3 Public Comments on the Draft Environmental Assessment ........................................ 13 1.6.4 Changes to the Environmental Assessment ....................................................................... 13 Chapter 2 Proposed Action and Alternatives ........................................................................................ 15 2.1 Proposed Action ........................................................................................................................................ 15 2.1.1 Tiering under NEPA ..................................................................................................................... 15 2.1.2 Tiering Future Projects to this NEPA Document .............................................................. 16 2.2 No Action Alternative (status quo) ................................................................................................... 17 2.3 Estuary Management Actions and Activities Common in Both Alternatives ................... 17 2.4 Mitigation Measures ................................................................................................................................ 21 2.5 Summary of Environmental Effects .................................................................................................. 25 2.6 Comparison of Proposed Action and the No Action Alternative ........................................... 27 Chapter 3 Affected Environment and Environmental Consequences ......................................... 29 3.1 Common Effects of Restoration Planning and Construction Activities .............................. 29 3.1.1 Resource Inventory and Surveying ........................................................................................ 30 Columbia Estuary Ecosystem Restoration Program i 3.1.2 Site Preparation and Construction ......................................................................................... 31 3.1.3 Post-Construction Activities and Restoration Benefits ................................................. 32 3.2 Fish ................................................................................................................................................................. 33 3.2.1 Affected Environment ................................................................................................................. 33 3.2.2 Types of Impacts from Restoration Activities ................................................................... 37 3.2.3 Effects of Restoration Activities .............................................................................................. 37 3.2.4 Conclusion for effects to fish from the Restoration Activities..................................... 42 3.3 Hydrology and Hydraulics .................................................................................................................... 43 3.3.1 Affected Environment ................................................................................................................. 43 3.3.2 Types of Effects from Restoration Activities ...................................................................... 45 3.3.3 Effects of Restoration Activities .............................................................................................. 45 3.4 Water Quality ............................................................................................................................................. 48 3.4.1 Affected Environment ................................................................................................................. 48 3.4.2 Types of Impacts from Restoration Activities ................................................................... 51 3.4.3 Effects of Restoration Activities .............................................................................................. 52 3.5 Geomorphology, Soils, and Topography ......................................................................................... 54 3.5.1 Affected Environment ................................................................................................................. 54 3.5.2 Types of Impacts from Restoration Activities ................................................................... 56 3.5.3 Effects of Restoration Activities .............................................................................................. 56 3.6 Sediment Quality ...................................................................................................................................... 58 3.6.1 Affected Environment ................................................................................................................. 58 3.6.2 Types of Impacts from Restoration Activities ................................................................... 60 3.6.3 Effects of Restoration Activities .............................................................................................. 61 3.7 Air Quality ................................................................................................................................................... 63 3.7.1 Affected Environment ................................................................................................................. 63 3.7.2 Types of Impacts from Restoration Activities ................................................................... 64 3.7.3 Effects of the Restoration Activities ...................................................................................... 65 3.8 Wildlife ......................................................................................................................................................... 65 3.8.1 Affected Environment ................................................................................................................. 65 3.8.2 Types of Impacts from Restoration Activities ................................................................... 68 3.8.3 Effects of Restoration Activities .............................................................................................. 69 3.9 Wetlands, Floodplains, and Vegetation ........................................................................................... 70 3.9.1 Affected Environment ................................................................................................................. 70 Columbia Estuary Ecosystem Restoration Program ii 3.9.2 Types of Impacts from Restoration Activities ................................................................... 76 3.9.3 Effects of Restoration Activities .............................................................................................. 76 3.10 Land Use and Recreation ......................................................................................................................