Idaho Nonpoint Source Management Plan 2020–2025 State of Idaho Department of Environmental Quality December 2020 www.deq.idaho.gov Acknowledgments Special thanks to contributors from state and federal agencies involved in nonpoint source management: • Idaho Department of Fish and Game • Idaho Department of Lands • Idaho Department of Water Resources • Idaho Soil and Water Conservation Commission • Idaho State Department of Agriculture • Idaho Transportation Department • Idaho Health Districts • US Army Corps of Engineers • Bureau of Land Management • Bureau of Reclamation • US Environmental Protection Agency • US Forest Service (Regions 1 and 4) • Natural Resources Conservation Service • US Geological Survey Prepared by Idaho Department of Environmental Quality Water Quality Division 1410 N. Hilton St. Boise, ID 83706 Printed on recycled paper, DEQ, December 2020, PID 319M, CA code 82808. Costs associated with this publication are available from the State of Idaho Department of Environmental Quality in accordance with Section 60-202, Idaho Code. iii Nonpoint Source Management Plan Table of Contents Abbreviations, Acronyms, and Symbols ....................................................................................... vi 1 Introduction .................................................................................................................................. 1 Purpose and Scope ...................................................................................................................... 1 2 Idaho Background ........................................................................................................................ 2 2.1 Water Resources .................................................................................................................... 2 2.2 Landownership ...................................................................................................................... 3 3 Idaho’s Nonpoint Source Management Program ......................................................................... 4 3.1 § 319 Project Subgrants ......................................................................................................... 4 3.2 Project Application and Review ............................................................................................ 4 3.3 Water Quality and Best Management Practice Effectiveness Monitoring ............................ 5 3.4 Project Evaluations and Reporting ........................................................................................ 6 3.5 Program Reporting and Financial Management .................................................................... 6 4 Nonpoint Source Pollution and Roles of the Public and Partner Agencies ................................. 6 4.1 Sources of Best Management Practices ................................................................................ 7 4.2 Nonpoint Source Pollution and Native American Tribes ...................................................... 7 4.3 Categories of Nonpoint Source Pollution .............................................................................. 8 4.3.1 Agricultural Practices ..................................................................................................... 9 4.3.2 Natural Resource Extraction ......................................................................................... 14 4.3.3 Timber/Silviculture Management ................................................................................. 15 4.3.4 Urban and Suburban Development ............................................................................... 17 4.3.5 Transportation ............................................................................................................... 19 4.4 Agency Coordination to Reduce NPS Pollution ................................................................. 20 4.4.1 Agreements with Partner Agencies .............................................................................. 21 4.4.2 Coordination with Federal Partners .............................................................................. 22 4.4.3 EPA Liaison .................................................................................................................. 22 4.5 Funding Implementation Activities ..................................................................................... 22 4.6 Protocol for Funding Nonpoint Source Projects with the State Revolving Fund ............... 24 4.6.1 NPS Project Sponsors ................................................................................................... 24 4.6.2 Point Source SRF Project Sponsors .............................................................................. 25 4.6.3 DEQ Staff Coordination after NPS Project Funding .................................................... 26 5 Nonpoint Source Pollution Framework at DEQ ........................................................................ 27 5.1 Prioritization of Watershed Protection Actions .................................................................. 27 5.2 Ground Water Program ....................................................................................................... 28 5.2.1 Beneficial Uses ............................................................................................................. 28 5.2.2 Ground Water Protection Process ................................................................................. 28 5.3 Source Water Assessment and Protection Program ............................................................ 33 iii Nonpoint Source Management Plan 5.4 Surface Water Bureau ......................................................................................................... 33 5.4.1 Beneficial Uses ............................................................................................................. 33 5.4.2 Surface Water Protection Process ................................................................................. 34 5.5 Drinking Water Bureau ....................................................................................................... 42 5.6 Idaho Pollutant Discharge Elimination System .................................................................. 43 5.7 § 404 Permitting .................................................................................................................. 43 5.8 Basin, Watershed, and Technical Advisory Groups ........................................................... 43 5.9 Continuing Planning Process .............................................................................................. 46 6 Addressing Waters Impaired by Nonpoint Source Pollution ..................................................... 46 6.1 Water Quality Reports ......................................................................................................... 47 6.1.1 Water Quality Status Reports ....................................................................................... 47 6.1.2 Water Body Studies and Plans ...................................................................................... 47 6.2 Addressing NPS Pollutants through Project Implementation ............................................. 47 6.3 Using Funds Efficiently ...................................................................................................... 48 6.4 Assessing the Effectiveness of BMPs ................................................................................. 48 6.5 Assessing Success in Reducing NPS Pollution ................................................................... 49 References ..................................................................................................................................... 51 Appendix A. Nonpoint Source Goals Appendix B. Idaho Department of Environmental Quality Planning Documents Appendix C. 2020 Memorandum of Understanding between the Idaho Department of Water Resources and the USDA, Forest Service Intermountain and Northern Regions Appendix D. Unfunded NPS Programs List of Tables Table 1. Summary of Idaho water resources. ................................................................................. 3 Table 2. Idaho landownership. ........................................................................................................ 3 Table 3. NPS categories and involved agencies. ............................................................................ 8 Table 4. Possible NPS project funding sources. ........................................................................... 23 Table 5. Example of funding using the SRF. ................................................................................ 24 Table 6. When should a § 319 funding applicant pursue SRF sponsorship? ................................ 25 Table 7. NPA trends. ..................................................................................................................... 31 Table 8. 2002–2014 NPA trends. .................................................................................................. 32 Table 9. Data tier comparison. ...................................................................................................... 36 Table A1. General program goals. .................................................................................................. 1 Table A2. Agricultural practices. .................................................................................................... 5 Table A3. Natural resource