Drakes Estero Road Crossing Improvements Environmental
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ENVIRONMENTAL ASSESSMENT COASTAL WATERSHED RESTORATION – DRAKES ESTERO ROAD CROSSING IMPROVEMENTS Point Reyes National Seashore National Park Service October 13, 2004 Environmental Assessment Point Reyes National Seashore Coastal Watershed Restoration Drakes Estero Road Crossing Improvements Environmental Assessment October 13, 2004 Table of Contents 1.0 Purpose and Need............................................................................................................................................1 1.1 Introduction .............................................................................................................................................................1 1.2 Project Need ...........................................................................................................................................................1 1.3 Project Purpose ......................................................................................................................................................3 1.4 Projects Considered in Cumulative Impacts Analysis .............................................................................................5 1.5 Issues Raised during Project Scoping.....................................................................................................................6 1.6 Impact Topics Addressed in the EA ........................................................................................................................7 1.7 Impact Topics Dismissed from Further Assessment ............................................................................................. 10 1.8 Environmental Compliance Requirements............................................................................................................ 11 2.0 Description of the Project Alternatives ....................................................................................................... 15 2.1 Existing Facility Conditions ................................................................................................................................... 15 2.2 Alternative Formulation Process ........................................................................................................................... 17 2.3 Alternative A: No Action ........................................................................................................................................ 20 2.4 Elements Common to Both Action Alternatives..................................................................................................... 21 2.5 Alternative B: Restore Fish Passage and Minimize Future Maintenance Needs ..................................................24 2.6 Alternative C: Restore Fish Passage and Maximize Long-Term Management Flexibility (Preferred Alternative).................................................................................................................... 25 2.7 Alternatives Considered but Dismissed.................................................................................................................. 27 2.8 Preferred Alternative (Alternative C) ...................................................................................................................... 28 2.9 Identification of Environmentally Preferred Alternative........................................................................................... 29 3.0 Project Setting and Affected Environment ................................................................................................. 41 3.1 Project Setting....................................................................................................................................................... 41 3.2 Affected Environment for Impact Analysis............................................................................................................. 43 4.0 Environmental Consequences...................................................................................................................... 65 4.1 Methods of Analysis.............................................................................................................................................. 65 4.2 Impact Analysis by Topic ...................................................................................................................................... 67 5.0 Impacts Analysis ......................................................................................................................................... 83 5.1 Geology, Geohazards, and Soils .......................................................................................................................... 83 5.2 Air Quality ............................................................................................................................................................. 88 5.3 Soundscapes ........................................................................................................................................................ 90 5.4 Hydrologic and Geomorphic Processes, including Water Quality ......................................................................... 93 5.5 Impacts to floodplains, wetlands, and riparian zones.......................................................................................... 100 5.6 Wildlife ............................................................................................................................................................... 109 5.7 Special Status Species, Critical Habitat, and Essential Fish Habitat................................................................... 110 5.8 Impacts to Cultural Resources ............................................................................................................................ 117 5.9 Impacts to Recreational resources, visitor experience, and aesthetic resources ................................................ 120 5.10 Impacts to public safety and transportation....................................................................................................... 124 6.0 Cumulative Impacts................................................................................................................................... 129 6.1 Current and Ongoing Actions.............................................................................................................................. 129 6.2 Past Restoration and Monitoring Activities.......................................................................................................... 129 6.3 Cumulative Impacts............................................................................................................................................. 129 6.4 Short-term uses versus long-term productivity.................................................................................................... 130 7.0 Consultation and Coordination ................................................................................................................ 131 7.1 Consultation Requirements................................................................................................................................. 131 7.2 Persons Consulted.............................................................................................................................................. 132 7.3 Report Preparers ................................................................................................................................................ 132 7.4 Public and Agency Scoping and Summary of Issues Raised.............................................................................. 132 8.0 References ................................................................................................................................................. 133 Appendix A: Special Status Species Table Appendix B: Best Management Practices Project Summary Point Reyes National Seashore proposes replacement or improvements to culverted road crossings at 6 locations within the Drakes Estero Watershed. The need for the project is to repair or replace existing road-crossing facilities (crossings) in a manner that is sustainable ecologically and hydrologically, with infrastructure that will require less maintenance for long-term park operations. Prior to acquisition of the land by the NPS, a network of roads and other infrastructure were constructed to support existing agricultural operations and planned residential development. Culverts comprise many of the park road crossings. Since the Seashore was established, the NPS has continued to manage the existing roads, drainage facilities, and other infrastructure. Many of these facilities are beyond their design life, and are either not compatible with current land use designations (e.g., Wilderness areas) or are in imminent danger of catastrophic failure. This project focuses on 6 separate crossings of drainages and streams in the Drakes Estero Watershed. These 6 project areas fall within 3 coastal subwatersheds, which eventually drain to Drakes Estero and Drakes Bay. The Mt. Vision Road and Estero Road project areas are located on East Schooner Creek, which parallels Sir Francis Drake. The Upper Home Ranch project area is located on North Home Ranch Creek at its junction with Estero Road. The Lower Home Ranch project area is located on Home Ranch Creek at the Home Ranch facility. The remaining 2 project areas (Upper and Lower Laguna) are located on Laguna Creek, where access