DOI-BLM-NV-S010-2009-1020-EA Overton Power District No. 5 Power Transmission Expansion Project Environmental Assessment Clark County, Nevada March 2014 U.S. Department of the Interior Bureau of Land Management Las Vegas Field Office 4701 North Torrey Pines Las Vegas, NV 89130 Phone: 702-515-5000 Table of Contents 1.0 INTRODUCTION ............................................................................................................ 1 1.1 Background .................................................................................................................... 1 1.2 Purpose of and Need for the Proposed Action ............................................................... 8 1.3 Relationship to Statutes, Regulations, Plans or Other Environmental Analyses ............ 8 1.3.1 Conformance With Land Use Plan ........................................................................... 8 1.3.2 Local Land Use Plans ..................................................................................................... 8 1.3.3 Authorizing Actions ................................................................................................... 8 1.4 Scoping, Public Involvement, and Issues ....................................................................... 8 2.0 PROPOSED ACTION AND ALTERNATIVES .............................................................. 10 2.1 Alternative I – No Action Alternative ............................................................................. 10 2.2 Alternative II – Proposed Action ................................................................................... 10 2.2.1 Design and Construction, 230-kV Structures ......................................................... 20 2.2.2 Design and Construction, 69-kV Structures ........................................................... 23 2.2.3 Design and Construction, 138-kV Structures ......................................................... 23 2.2.4 Substations ............................................................................................................. 23 2.2.6 Operation and Maintenance ................................................................................... 27 2.2.7 Reclamation, Stabilization, and Abandonment ....................................................... 27 2.2.8 Workforce ............................................................................................................... 27 2.2.9 Hazardous Materials .............................................................................................. 28 2.2.10 Applicant-committed Practices ............................................................................... 28 2.3 Alternatives Considered but not Analyzed in Detail ...................................................... 29 3.0 AFFECTED ENVIRONMENT ....................................................................................... 31 3.1 Introduction ................................................................................................................... 31 3.2 Climate and Air Quality ................................................................................................. 31 3.2.1 Climate ................................................................................................................... 31 3.2.2 Air Quality ............................................................................................................... 33 3.3 Areas of Critical Environmental Concern ...................................................................... 35 3.4 Wild and Scenic Rivers ................................................................................................. 37 3.5 Cultural Resources ....................................................................................................... 38 3.6 Paleontological Resources ........................................................................................... 40 3.7 Soils .............................................................................................................................. 40 3.8 Vegetation .................................................................................................................... 44 3.9 Invasive, Non-Native Species ....................................................................................... 46 3.10 Special Status Species ................................................................................................. 48 3.10.1 Special Status Wildlife and Fish Species ............................................................... 48 3.10.2 Special Status Plants ............................................................................................. 55 3.11 Wildlife and Fisheries ................................................................................................... 59 3.12 Wetlands and Riparian Zones ...................................................................................... 61 3.13 Floodplains ................................................................................................................... 64 3.13.1 Muddy River ........................................................................................................... 64 3.13.2 Virgin River ............................................................................................................. 64 Bureau of Land Management | DOI-BLM-NV-S010-2009-1020-EA Page i 3.14 Water Quality, Surface and Ground ............................................................................. 65 3.15 Wastes, Hazardous or Solid ......................................................................................... 70 3.16 Environmental Justice .................................................................................................. 71 3.17 Transportation and Access ........................................................................................... 71 3.18 Rangeland Management .............................................................................................. 72 3.19 Fuels and Fire Management ......................................................................................... 74 3.20 Noise ............................................................................................................................ 74 3.21 Health and Safety ......................................................................................................... 74 3.22 Recreation .................................................................................................................... 74 3.23 Visual Resources .......................................................................................................... 75 3.24 Geology ........................................................................................................................ 83 3.25 Socioeconomics ........................................................................................................... 84 4.0 ENVIRONMENTAL EFFECTS ..................................................................................... 86 4.1 Direct and Indirect Effects ............................................................................................ 87 4.1.1 Climate and Air Quality ........................................................................................... 87 4.1.2 Areas of Critical Environmental Concern ............................................................... 87 4.1.3 Wild and Scenic Rivers .......................................................................................... 87 4.1.4 Cultural Resources ................................................................................................. 88 4.1.5 Paleontology ........................................................................................................... 88 4.1.6 Soils ........................................................................................................................ 89 4.1.7 Vegetation .............................................................................................................. 89 4.1.8 Non-Native, Invasive Species and Noxious Weeds ............................................... 90 4.1.9 Special Status Species ........................................................................................... 90 4.1.9.1 Special Status Wildlife Species .............................................................................. 91 4.1.9.2 Special Status Plant Species ................................................................................. 95 4.1.10 Wildlife and Fisheries ............................................................................................. 97 4.1.11 Wetlands and Riparian Zones ................................................................................ 99 4.1.12 Floodplains ............................................................................................................. 99 4.1.13 Water Quality, Surface and Ground ....................................................................... 99 4.1.14 Wastes, Hazardous or Solid ................................................................................. 101 4.1.15 Environmental Justice .......................................................................................... 101 4.1.16 Transportation and Access ................................................................................... 101 4.1.17 Rangeland Management ...................................................................................... 102 4.1.18 Fuels and Fire Management