Volume II - Appendices Nebraska Highway 12 Niobrara East And West Supplemental Draft Environmental Impact Statement January 3, 2020 Cooperating Agencies National Park Service U.S. Fish and Wildlife Service U.S. Environmental Protection Agency Federal Highway Administration Knox County ———————————————————————— Volume II - Appendices Appendix A - Preliminary Section 7(a) Wild and Scenic Rivers Evaluation Appendix B - Resources Not Affected or Minimally Affected by the Project Appendix C - Fish and Wildlife Technical Memorandum Appendix D - Protected Species Technical Memorandum and Biological Assessment Appendix E - Wetlands and Waters of the US Appendix F - Flood Storage Technical Memorandum Appendix G - Supporting Information for Section 404(b)(1) Analysis Appendix H - Visual Analysis Technical Memorandum Appendix I - Agency Coordination Appendix J - Tribal Coordination Appendix K - Public Involvement APPENDIX A Preliminary Section 7(a) Wild and Scenic Rivers Evaluation January 2020 Preliminary Section 7(a) Wild and Scenic Rivers Act Evaluation Supporting Information N-12 Niobrara East & West Project Supporting Information for the N-12 Project’s Effects on the Outstandingly Remarkable Values of the Missouri National Recreational River Table of Contents CONTENTS SECTION 1.0 INTRODUCTION .............................................................................................. 1 1.1 Purpose of this Document ........................................................................................................................ 1 1.2 Location and Description of the Missouri National Recreational River ..................................................... 1 SECTION 2.0 LEGISLATIVE PURPOSE FOR ESTABLISHING THE MISSOURI NATIONAL RECREATIONAL RIVER .................................................................................... 3 2.1 Management of the Missouri National Recreational River ........................................................................ 3 2.1.1 General Management Plan ........................................................................................................ 4 2.1.2 Nondegradation and Enhancement Policy ................................................................................. 4 2.1.3 National Park Service Organic Act ............................................................................................. 4 2.2 Outstandingly Remarkable Values ........................................................................................................... 5 SECTION 3.0 DETAILED DESCRIPTION OF THE PROPOSED WATER RESOURCES PROJECT ............................................................................................................................... 6 3.1 Project and Its Sponsors........................................................................................................................... 6 3.2 Purpose of and Need For the Project ....................................................................................................... 6 3.3 Location of the Project .............................................................................................................................. 7 3.4 Detailed Project Description ..................................................................................................................... 7 3.4.1 No-Action Alternative .................................................................................................................. 7 3.4.2 Alternative S-1, Elevation Raise No Offset with Temporary Road Offset South ......................... 9 3.4.3 Alternative S-2, Elevation Raise and Temporary Road Offset South ....................................... 13 3.4.4 Alternative S-3, Elevation Raise and Temporary Road Offset North ........................................ 13 3.4.5 NDOT’s Applied-for Project ...................................................................................................... 14 3.5 Duration of the Project ............................................................................................................................ 14 3.6 Relationship to Past and Future Management Activities ........................................................................ 14 3.7 Proposed Mitigation ................................................................................................................................ 17 SECTION 4.0 THE FREE-FLOWING CONDITION OF THE MISSOURI NATIONAL RECREATIONAL RIVER ...................................................................................................... 18 4.1 Hydrology of the Missouri River in the Study Area ................................................................................. 18 4.2 Temporary Impact on the Free-Flowing Character of the Missouri National Recreational River ............ 19 4.3 Permanent Impact on the Free-Flowing Character of the Missouri National Recreational River ............ 19 4.4 Conclusion .............................................................................................................................................. 20 SECTION 5.0 WATER QUALITY OF THE MISSOURI NATIONAL RECREATIONAL RIVER21 5.1 Existing Water Quality ............................................................................................................................ 21 5.2 Temporary Impacts on Water Quality ..................................................................................................... 22 5.2.1 Temporary Within-River Impacts .............................................................................................. 22 5.2.2 Temporary Impacts from Construction of the Roadway ........................................................... 23 5.3 Permanent Impacts on Water Quality ..................................................................................................... 23 5.3.1 Sedimentation .......................................................................................................................... 23 5.3.2 Materials from the Roadway and Storm Runoff Control System .............................................. 23 5.3.3 Road Maintenance Materials .................................................................................................... 24 5.4 Conclusion .............................................................................................................................................. 24 SECTION 6.0 CULTURAL VALUES OF THE MISSOURI NATIONAL RECREATIONAL RIVER ................................................................................................................................... 25 6.1 Outstandingly Remarkable Cultural Values ............................................................................................ 25 N-12 Niobrara East and West SDEIS i January 2020 Preliminary Section 7(a) Evaluation Supporting Information Table of Contents 6.2 Existing Historic and Cultural Resources ................................................................................................ 25 6.3 Impact on Cultural Resources ................................................................................................................ 26 6.4 Inadvertent Late Discoveries .................................................................................................................. 26 6.5 Conclusion .............................................................................................................................................. 27 SECTION 7.0 ECOLOGICAL VALUES OF THE MISSOURI NATIONAL RECREATIONAL RIVER ................................................................................................................................... 28 7.1 Outstandingly Remarkable Ecological Values ........................................................................................ 28 7.2 Natural Environment ............................................................................................................................... 28 7.2.1 Impact on Riparian or Floodplain Conditions ............................................................................ 28 7.2.2 Impact on Upland Conditions ................................................................................................... 29 7.3 Conclusion .............................................................................................................................................. 29 SECTION 8.0 FISH AND WILDLIFE VALUES OF THE MISSOURI NATIONAL RECREATIONAL RIVER ...................................................................................................... 31 8.1 Outstandingly Remarkable Fish and Wildlife Values .............................................................................. 31 8.2 Fish and Wildlife ..................................................................................................................................... 31 8.2.1 Fisheries ................................................................................................................................... 31 8.2.2 Wildlife ...................................................................................................................................... 32 8.2.3 Threatened and Endangered Species ...................................................................................... 32 8.2.4 Impact on Existing Hydrologic or Biologic Processes ............................................................... 32 8.2.5 Impact on Fish and Wildlife Habitat .........................................................................................