Elk River Sediment Remediation and Habitat Rehabilitation Pilot Implementation Project California Environmental Quality Act (CEQA) Draft Initial Study and Mitigated Negative Declaration State Clearinghouse #2019-xx-xxx Prepared for: North Coast Regional Water Quality Control Board 5550 Skylane Boulevard, Suite A Santa Rosa, CA 95403-1072 Project Applicant/Prepared by: April 2019 Funding for this project has been provided through an agreement with the State Water Resources Control Board Elk River Sediment Remediation and Habitat Rehabilitation Pilot Implementation Project North Coast RWQCB Draft Initial Study/Mitigated Negative Declaration (IS/MND) 2019 California Trout. Elk River Sediment Removal Implementation Pilot Project—Initial Study/Mitigated Negative Declaration. April 2019. Unincorporated Humboldt County, CA 2 Elk River Sediment Remediation and Habitat Rehabilitation Pilot Implementation Project North Coast RWQCB Draft Initial Study/Mitigated Negative Declaration (IS/MND) 2019 TABLE OF CONTENTS List of Figures ................................................................................................................................................. 4 List of Tables .................................................................................................................................................. 6 List of Appendices .......................................................................................................................................... 7 Chapter 1 ..................................................................................................................................................... 8 INTRODUCTION.......................................................................................................................................... 8 1.1 Introduction ................................................................................................................................... 8 Watershed Setting .................................................................................................................................................. 8 Watershed Condition and Impairment .................................................................................................................. 9 Regulatory Setting ................................................................................................................................................. 10 The Elk River Recovery Assessment ...................................................................................................................... 13 The Elk River Watershed Stewardship Program ................................................................................................... 13 1.2 Project Goals and Objective ..................................................................................................... 14 1.3 Project Location ........................................................................................................................... 15 1.4 Landowner Coordination and Agency Partnerships ............................................................ 21 1.5 Intent and Scope of this Document ........................................................................................ 21 1.6 Public Involvement Process ..................................................................................................... 22 1.7 Organization of this Document ............................................................................................... 22 1.8 Impact Terminology ................................................................................................................... 23 Chapter 2 .................................................................................................................................................. 25 PROJECT DESCRIPTION .......................................................................................................................... 25 2.1 Background and Regulatory Setting ............................................................................................ 25 2.1 Proposed Project .............................................................................................................................. 30 2.2.1 Wrigley Orchard Project Reach .................................................................................................. 33 2.2.2 Elk River Flood Curve Project Reach ........................................................................................ 38 2.3 Project Action Elements ................................................................................................................. 49 2.5 Project Implementation/Construction Methods ....................................................................... 58 Timing of Work ...................................................................................................................................................... 58 Environmental Commitments............................................................................................................................... 58 Construction Access .............................................................................................................................................. 58 Staging and Stockpiling ........................................................................................................................................ 60 Fish Removal and Relocation and Channel Dewatering and Rewatering .......................................................... 60 Riparian Understory Clearing and Vegetation and Tree Removal ....................................................................... 61 Channel and Floodplain Excavation ...................................................................................................................... 62 Sediment Disposal/Reuse ...................................................................................................................................... 62 3 Elk River Sediment Remediation and Habitat Rehabilitation Pilot Implementation Project North Coast RWQCB Draft Initial Study/Mitigated Negative Declaration (IS/MND) 2019 Channel and Floodplain Recontouring ..................................................................................................................63 In-Channel Habitat Enhancement..........................................................................................................................63 Pool Enhancement ............................................................................................................................................ 64 Large Wood Habitat Structures ....................................................................................................................... 64 Riffle Reconstruction and Enhancement with Gravel Augmentation ............................................................ 66 Site Revegetation ................................................................................................................................................... 67 Erosion Control ....................................................................................................................................................... 71 2.6 Post-Project Monitoring and Reporting ..................................................................................... 72 2.7 Maintenance ...................................................................................................................................... 76 2.8 Required Permits and Approvals .................................................................................................. 77 2.9 Impacts and Environmental Commitments ........................................................................... 79 Chapter 3 .................................................................................................................................................. 94 ENVIRONMENTAL CHECKLIST .............................................................................................................. 94 3.1 Aesthetics......................................................................................................................................... 98 3.2 Agriculture Resources ...................................................................................................................... 101 3.3 Air Quality ........................................................................................................................................107 3.4 Biological Resources ........................................................................................................................ 113 3.6 Cultural Resources ...........................................................................................................................145 3.7 Geology and Soils............................................................................................................................. 152 3.8 Greenhouse Gas Emissions .............................................................................................................. 164 3.9 Hazards and Hazardous Materials ................................................................................................... 169 3.9 Hydrology and Water Quality ........................................................................................................... 175 3.10 Land Use and Planning ...................................................................................................................