Technical Report BIOLOGICAL RESOURCES ASSESSMENT Mokelumne Watershed Routine Maintenance Project April 2021 Prepared for: Michelle Workman East Bay Municipal Utility District 1 Winemasters Way, Unit K Lodi, California 95240 Prepared by: Horizon Water and Environment, LLC P.O. Box 2727 Oakland, CA 94612 Eric Christensen This page intentionally left blank. Table of Contents Executive Summary ..........................................................................................................................................1 1 Introduction ..............................................................................................................................................5 1.1 Location and Study Area ...................................................................................................................................... 5 1.1.1 Biological Resources Study Area ..................................................................................................... 5 1.2 Project Overview ..................................................................................................................................................... 6 1.2.1 Description of the Watershed and Infrastructure ................................................................... 6 1.2.2 Existing Regulatory Approval ........................................................................................................... 6 1.2.3 Project Activities ...................................................................................................................................... 7 1.3 Personnel .................................................................................................................................................................... 8 2 Regulatory Setting ................................................................................................................................ 13 2.1 Federal Laws, Regulations, and Standards .............................................................................................. 13 2.1.1 Endangered Species Act of 1973................................................................................................... 13 2.1.2 Magnuson-Stevens Fishery Conservation and Management Act (Sustainable Fisheries Act) .............................................................................................................. 14 2.1.3 Migratory Bird Treaty Act ................................................................................................................ 14 2.1.4 Bald and Golden Eagle Protection Act ........................................................................................ 15 2.1.5 Clean Water Act (Sections 401 & 404)....................................................................................... 15 2.2 State Agencies, Laws, and Programs ........................................................................................................... 15 2.2.1 California Fish and Game Code ...................................................................................................... 15 2.2.2 Porter-Cologne Water Quality Control Act .............................................................................. 17 2.2.3 California Environmental Quality Act ........................................................................................ 17 2.3 Local and Regional Laws and Plans ............................................................................................................. 18 3 Study Area Description ....................................................................................................................... 19 3.1 Environmental Setting ....................................................................................................................................... 19 3.1.1 Location .................................................................................................................................................... 19 3.1.2 Topography and Elevation .............................................................................................................. 19 3.1.3 Climate and Hydrology ...................................................................................................................... 19 3.1.4 Soils ............................................................................................................................................................. 20 3.1.5 Land Use ................................................................................................................................................... 20 4 Existing Biological Resources ........................................................................................................... 23 4.1 Inventory Methods .............................................................................................................................................. 23 4.1.1 Literature Reviewed ........................................................................................................................... 23 4.1.2 Field Survey ............................................................................................................................................ 24 4.2 Land Cover Types ................................................................................................................................................. 35 4.2.1 Wetlands ................................................................................................................................................... 35 4.2.2 Aquatic (Reservoirs, Streams, Ponds, Sloughs) ..................................................................... 36 4.2.3 Woodland ................................................................................................................................................. 37 4.2.4 Chaparral .................................................................................................................................................. 38 4.2.5 California Annual Grassland ........................................................................................................... 39 4.2.6 Ruderal ...................................................................................................................................................... 40 4.2.7 Developed (includes landscaped areas).................................................................................... 40 4.3 Potential Jurisdictional Features .................................................................................................................. 40 4.3.1 Wetlands and other Waters of the U.S./Waters of the State ........................................... 40 Biological Resources Assessment April 2021 Mokelumne Watershed Routine Maintenance Project i 4.3.2 Streams and Riparian Habitat Regulated under California Fish and Game Code ............................................................................................................................................................ 41 4.3.3 Sensitive Natural Communities and other California Department of Fish and Wildlife-Designated Sensitive Habitat .............................................................................. 41 4.4 Special-Status Species ........................................................................................................................................ 41 4.4.1 Plants .......................................................................................................................................................... 41 4.4.2 Wildlife ...................................................................................................................................................... 43 4.4.3 Fish .............................................................................................................................................................. 50 4.5 Critical Habitat ....................................................................................................................................................... 51 4.6 Essential Fish Habitat ......................................................................................................................................... 51 5 Summary and Conclusions ................................................................................................................. 53 5.1 Special-Status Species ........................................................................................................................................ 53 5.2 Federal and State Waters and Wetlands ................................................................................................... 53 Appendices Appendix A Special-status Plant Species Appendix B Special-status Wildlife Species Appendix C Special-status Fish Species Appendix D USFWS, CNDDB, & CNPS Species Lists Figures Figure 1 Project Vicinity and Study Area ........................................................................................................... 9-11 Figure 2 Soils Map of the Mokelumne Watershed ............................................................................................ 21 Figure 3 CNDDB Records and Observation Locations of Special-status Plant Species within Five Miles of Mokelumne Watershed ............................................................................ 25-27 Figure 4 CNDDB Records and Observation Locations of Special-status Wildlife Species within Five Miles of Mokelumne