PROGRAMMATIC ENVIRONMENTAL ASSESSMENT Dam Maintenance Activities Bureau of Indian Affairs and Confederated Salish and Kootenai Tribes Flathead Indian Reservation, Montana February 2021 Assembled by: 1055 Mount Avenue Missoula, MT 59801 This Environmental Assessment becomes a federal document when evaluated, signed and dated by the responsible Bureau of Indian Affairs (BIA) Official. Responsible BIA Official Date TABLE OF CONTENTS CHAPTER 1 PROPOSAL PURPOSE AND NEED ...................................................................... 1 1.0 INTRODUCTION .............................................................................................................1 1.1 BACKGROUND AND EXISTING FACILITIES ................................................................. 2 1.2 PURPOSE OF THE PROPOSED ACTION ................................................................... 14 1.3 NEED FOR THE PROPOSED ACTION ........................................................................ 14 CHAPTER 2 ALTERNATIVES .................................................................................................. 15 2.0 INTRODUCTION ........................................................................................................... 15 2.1 NO ACTION ALTERNATIVE ......................................................................................... 15 2.2 THE PREFERRED ALTERNATIVE/PROPOSED ACTION ............................................ 15 2.3 SELECTION OF THE PROPOSED ACTION ................................................................. 17 CHAPTER 3 AFFECTED ENVIRONMENT ............................................................................... 18 3.0 INTRODUCTION ........................................................................................................... 18 3.1 LAND RESOURCES ..................................................................................................... 18 3.1.1 Topography ........................................................................................................ 18 3.1.2 Soils ................................................................................................................... 18 3.1.3 Geology, Mineral and Paleontological Resources .............................................. 18 3.2 WATER RESOURCES .................................................................................................. 18 3.2.1 Floodplains ........................................................................................................ 18 3.2.2 Wetlands ............................................................................................................ 19 3.2.3 Water Quality ..................................................................................................... 19 3.2.4 Water Quantity ................................................................................................... 20 3.2.5 Water Use .......................................................................................................... 21 3.2.6 Water Rights ...................................................................................................... 21 3.2.7 Irrigation ............................................................................................................. 21 3.3 AIR QUALITY ................................................................................................................ 21 3.4 LIVING RESOURCES ................................................................................................... 22 3.4.1 Wildlife ............................................................................................................... 22 3.4.2 Vegetation.......................................................................................................... 26 3.4.3 Ecosystems and Biological Communities ........................................................... 30 3.4.4 Agriculture.......................................................................................................... 31 3.5 CULTURAL RESOURCES ............................................................................................ 31 3.5.1 Historic and Archeological Resources ................................................................ 31 3.5.2 Cultural, Sacred and Traditional Cultural Properties ........................................... 32 3.6 SOCIOECONOMIC CONDITIONS ................................................................................ 32 3.6.1 Employment and Income ................................................................................... 32 3.6.2 Demographic Trends ......................................................................................... 32 3.6.3 Lifestyle and Cultural Values .............................................................................. 32 3.6.4 Community Infrastructure ................................................................................... 33 3.6.5 Environmental Justice ........................................................................................ 33 i 3.7 RESOURCE USE PATTERNS ...................................................................................... 33 3.7.1 Hunting, Fishing, Gathering ............................................................................... 33 3.7.2 Timber Harvesting .............................................................................................. 34 3.7.3 Agriculture.......................................................................................................... 34 3.7.4 Mineral Extraction .............................................................................................. 34 3.7.5 Recreation ......................................................................................................... 34 3.7.6 Transportation Networks .................................................................................... 34 3.7.7 Land Use Plans ................................................................................................. 34 3.7.8 Energy ............................................................................................................... 35 3.8 OTHER VALUES ........................................................................................................... 35 3.8.1 Wilderness Areas ............................................................................................... 35 3.8.2 Wild and Scenic Rivers ...................................................................................... 35 3.8.3 Noise and Light .................................................................................................. 35 3.8.4 Visual ................................................................................................................. 35 3.8.5 Public Health and Safety .................................................................................... 35 3.8.6 Climate Change ................................................................................................. 36 3.8.7 Indian Trust Assets ............................................................................................ 36 3.8.8 Hazardous Materials .......................................................................................... 36 CHAPTER 4 ENVIRONMENTAL CONSEQUENCES/ENVIRONMENTAL IMPACTS ............... 37 4.0 INTRODUCTION ........................................................................................................... 37 4.1 LAND RESOURCES ..................................................................................................... 37 4.1.1 Topography and Soils ........................................................................................ 37 4.1.2 Geology, Mineral and Paleontological Resources .............................................. 38 4.1.3 Conclusion ......................................................................................................... 38 4.2 WATER RESOURCES .................................................................................................. 38 4.2.1 Conclusion ......................................................................................................... 39 4.3 AIR QUALITY ................................................................................................................ 39 4.3.1 Conclusion ......................................................................................................... 39 4.4 LIVING RESOURCES ................................................................................................... 39 4.4.1 Wildlife ............................................................................................................... 39 4.4.2 Conclusion ......................................................................................................... 43 4.4.3 Vegetation.......................................................................................................... 44 4.4.4 Conclusion ......................................................................................................... 45 4.5 ECOSYSTEMS AND BIOLOGICAL COMMUNITIES ..................................................... 45 4.6 AGRICULTURE ............................................................................................................. 45 4.7 CULTURAL RESOURCES ............................................................................................ 45 4.8 SOCIOECONOMIC CONDITIONS ................................................................................ 46 4.9 RESOURCE USE PATTERNS .....................................................................................