APPENDIX L NATURAL RESOURCES TECHNICAL REPORT MAY 2020 and NATURAL RESOURCES TECHNICAL REPORT TABLE OF CONTENTS 1 INTRODUCTION ..........................................................................................................................1 1.1 Overview ....................................................................................................................................... 1 1.2 Study Corridors ............................................................................................................................. 1 1.3 Study Purpose and Need ............................................................................................................... 3 1.4 Alternatives Evaluated .................................................................................................................. 4 2 EXISTING CONDITIONS AND ENVIRONMENTAL EFFECTS ...............................................................9 2.1 Topography, Geology, and Soils .................................................................................................... 9 2.1.1 Regulatory Context and Methods ......................................................................................... 9 2.1.2 Existing Conditions .............................................................................................................. 10 2.1.3 Environmental Effects ......................................................................................................... 13 2.1.4 Avoidance, Minimization, and Mitigation ........................................................................... 14 2.2 Air Quality ................................................................................................................................... 15 2.2.1 Regulatory Context and Methods ....................................................................................... 15 2.2.2 Existing Conditions .............................................................................................................. 16 2.2.3 Environmental Effects ......................................................................................................... 16 2.2.4 Avoidance, Minimization, and Mitigation ........................................................................... 16 2.3 Waters of the US and Waters of the State, Including Wetlands................................................. 17 2.3.1 Regulatory Context and Methods ....................................................................................... 17 2.3.2 Existing Conditions .............................................................................................................. 21 2.3.3 Environmental Effects ......................................................................................................... 22 2.3.4 Avoidance, Minimization, and Mitigation ........................................................................... 32 2.4 Watersheds and Surface Water Quality ..................................................................................... 39 2.4.1 Regulatory Context and Methods ....................................................................................... 39 2.4.2 Existing Conditions .............................................................................................................. 45 2.4.3 Environmental Effects ......................................................................................................... 78 2.4.4 Avoidance, Minimization and Mitigation ............................................................................ 82 2.5 Groundwater and Hydrology ...................................................................................................... 84 2.5.1 Regulatory Context and Methods ....................................................................................... 84 2.5.2 Existing Conditions .............................................................................................................. 84 2.5.3 Environmental Effects ......................................................................................................... 91 2.5.4 Avoidance, Minimization and Mitigation ............................................................................ 91 May 2020 i NATURAL RESOURCES TECHNICAL REPORT 2.6 Floodplains .................................................................................................................................. 91 2.6.1 Regulatory Context and Methods ....................................................................................... 91 2.6.2 Existing Conditions .............................................................................................................. 92 2.6.3 Environmental Effects ......................................................................................................... 94 2.6.4 Avoidance, Minimization, and Mitigation ........................................................................... 94 2.7 Vegetation and Terrestrial Habitat ............................................................................................. 95 2.7.1 Regulatory Context and Methods ....................................................................................... 95 2.7.2 Existing Conditions .............................................................................................................. 96 2.7.3 Environmental Effects ....................................................................................................... 104 2.7.4 Avoidance, Minimization, and Mitigation ......................................................................... 106 2.8 Terrestrial Wildlife .................................................................................................................... 107 2.8.1 Regulatory Context and Methods ..................................................................................... 107 2.8.2 Existing Conditions ............................................................................................................ 109 2.8.3 Environmental Effects ....................................................................................................... 111 2.8.4 Avoidance, Minimization, and Mitigation ......................................................................... 112 2.9 Aquatic Biota ............................................................................................................................. 112 2.9.1 Regulatory Context and Methods ..................................................................................... 112 2.9.2 Existing Conditions ............................................................................................................ 118 2.9.3 Environmental Effects ....................................................................................................... 146 2.9.4 Avoidance, Minimization, and Mitigation ......................................................................... 151 2.10 Rare, Threatened, and Endangered Species ............................................................................. 152 2.10.1 Regulatory Context and Methods ..................................................................................... 152 2.10.2 Existing Conditions ............................................................................................................ 153 2.10.3 Environmental Effects ....................................................................................................... 161 2.10.4 Avoidance, Minimization, and Mitigation ......................................................................... 162 2.11 Unique and Sensitive Areas ...................................................................................................... 163 2.11.1 Regulatory Context and Methods ..................................................................................... 163 2.11.2 Existing Conditions ............................................................................................................ 164 2.11.3 Environmental Effects ....................................................................................................... 165 2.11.4 Avoidance, Minimization, and Mitigation ......................................................................... 165 REFERENCES .................................................................................................................................. 166 LIST OF ACRONYMS ........................................................................................................................ 181 GLOSSARY ..................................................................................................................................... 187 May 2020 ii NATURAL RESOURCES TECHNICAL REPORT LIST OF TABLES Table 2.1-1: Soils Hydrologic Group Descriptions ....................................................................................... 11 Table 2.1-2 Impact to Soils by Type in Acres .............................................................................................. 13 Table 2.1-3 Impacts to Steep Slopes and Highly Erodible Soils in Acres ..................................................... 14 Table 2.3-1: Total Delineated Features ....................................................................................................... 21 Table 2.3-2: Summary of Impacts to Wetlands and Waterways by Classification ..................................... 23 Table 2.3-3: Summary of Impacts to Wetland Buffers by Classification ....................................................