Draft Environmental Impact Report Upper York Creek Ecosystem Restoration Project Napa County, California (State Clearinghouse No. 2006092096) CEQA Lead Agency City of St. Helena 1480 Main Street St. Helena, CA 95474 Contact: Jonathon Goldman Director of Public Works/City Engineer 707-968-2658 A Joint Project of the City of St. Helena, Napa County, California U.S. Army Corps of Engineers, San Francisco District, South Pacific Division April 20, 2007 Upper York Creek Ecosystem Restoration Draft EIR City of St. Helena Upper York Creek Ecosystem Restoration Draft EIR TABLE OF CONTENTS Page EXECUTIVE SUMMARY ............................................................................................................................ ES-1 1 PROPOSED ACTION ................................................................................................................................ 1 1.1 Project Description and Objectives .......................................................................................... 1 1.2 Project Location .......................................................................................................................... 1 1.3 Characteristics of the Project Area ........................................................................................... 3 1.4 Project Background and History .............................................................................................. 3 1.5 Environmental Process and Timeline ...................................................................................... 5 1.5.1 Project Sponsors .............................................................................................................. 5 1.5.2 CEQA Lead Agency ....................................................................................................... 5 1.5.3 CEQA Responsible and Trustee Agencies .................................................................. 6 1.5.4 Public Participation and Timeline ................................................................................ 6 1.5.5 Timeline for Project Implementation ........................................................................... 7 1.6 Regulatory Background for the Project ................................................................................... 7 1.6.1 Ecological Permits .......................................................................................................... 7 1.6.2 Fish and Wildlife Coordination Act ............................................................................. 9 1.6.3 National Historic Preservation Act .............................................................................. 9 1.6.4 Migratory Bird Treaty Act ........................................................................................... 10 1.6.5 California Global Warming Solutions Act of 2006 .................................................. 10 2 ALTERNATIVES CONSIDERED FOR THE PROJECT ................................................................................ 11 2.1 All Alternatives Considered ................................................................................................... 11 2.2 Alternatives Analyzed in DEIR .............................................................................................. 12 2.2.1 No Project ...................................................................................................................... 12 2.2.2 Small Notch ................................................................................................................... 12 2.2.3 Full Dam Removal ........................................................................................................ 14 2.2.4 Fish Ladder .................................................................................................................... 14 2.2.5 Summary of Alternatives ............................................................................................ 15 2.3 Elements Included in All Action Alternatives ..................................................................... 16 2.3.1 Habitat Restoration ...................................................................................................... 16 2.3.2 Stabilization of Spring Mountain Road ..................................................................... 17 2.3.3 Species of Concern ........................................................................................................ 17 2.3.4 Dewatering .................................................................................................................... 17 2.3.5 Construction Access ..................................................................................................... 17 2.3.6 Sediment Reuse/Disposal ........................................................................................... 17 3 ENVIRONMENTAL SETTING AND CONSEQUENCES OF PROJECT ALTERNATIVES ............................. 23 3.1 Aesthetics ................................................................................................................................... 23 3.1.1 Setting ............................................................................................................................. 23 3.1.2 Standards ....................................................................................................................... 23 3.1.3 No Project Alternative: Impacts and Mitigation Measures .................................... 23 3.1.4 Preferred Alternative – Small Notch: Impacts and Mitigation Measures ............ 25 3.1.5 Full Dam Removal: Impacts and Mitigation Measures .......................................... 26 3.1.6 Fish Ladder: Impacts and Mitigation Measures ...................................................... 26 3.1.7 Section References ........................................................................................................ 26 City of St. Helena Page i Upper York Creek Ecosystem Restoration Draft EIR Page 3.2 Air Quality ................................................................................................................................. 27 3.2.1 Setting ............................................................................................................................. 27 3.2.2 Standards ....................................................................................................................... 30 3.2.3 No Project Alternative: Impacts and Mitigation Measures .................................... 31 3.2.4 Preferred Alternative – Small Notch: Impacts and Mitigation Measures, ........... 33 3.2.5 Full Dam Removal: Impacts and Mitigation Measures .......................................... 35 3.2.6 Fish Ladder: Impacts and Mitigation Measures ...................................................... 36 3.2.7 Section References ........................................................................................................ 36 3.3 Biological Resources ................................................................................................................ 38 3.3.1 Setting ............................................................................................................................. 38 3.3.2 Standards ....................................................................................................................... 77 3.3.3 No Project Alternative: Impacts and Mitigation Measures .................................... 78 3.3.4 Preferred Alternative - Small Notch: Impacts and Mitigation Measures ............. 86 3.3.5 Full Dam Removal: Impacts and Mitigation Measures .......................................... 91 3.3.6 Fish Ladder: Impacts and Mitigation Measures ...................................................... 92 3.3.7 Section References ........................................................................................................ 93 3.4 Cultural Resources ................................................................................................................... 97 3.4.1 Setting ............................................................................................................................. 97 3.4.2 Standards ....................................................................................................................... 98 3.4.3 No Project Alternative: Impacts and Mitigation Measures .................................... 98 3.4.4 Preferred Alternative – Small Notch: Impacts and Mitigation Measures ............ 98 3.4.5 Full Dam Removal: Impacts and Mitigation Measures .......................................... 99 3.4.6 Fish Ladder: Impacts and Mitigation Measures ...................................................... 99 3.4.7 Section References ........................................................................................................ 99 3.5 Geology, Soils, Landslides, and Seismic Activity .............................................................. 101 3.5.1 Setting ........................................................................................................................... 101 3.5.2 Standards ..................................................................................................................... 104 3.5.3 No Project Alternative: Impacts and Mitigation Measures .................................. 105 3.5.4 Preferred Alternative – Small Notch: Impacts and Mitigation Measures .......... 105 3.5.5 Full Dam Removal: Impacts and Mitigation Measures .......................................