Total Maximum Daily Loads for Total Phosphorus and Total Suspended Solids Upper Fox and Wolf Basins Final U.S. EPA approved Report Including Forest, Langlade, Menominee, Shawano, Outagamie, Waupaca, 02/27/2020 Winnebago, Waushara, Calumet, Fond Du Lac, Green Lake, Marquette, Columbia, Adams, Dodge, and Portage Counties, Wisconsin Prepared For: WI Department of U.S. Environmental Natural Resources Protection Agency 101 S. Webster St Region 5 PO Box 7921 77W.JacksonBlvd. Madison, WI 53707-7921 Chicago, IL 60604 Prepared By: The Cadmus Group LLC Finalized by the WI Department of Natural Resources Page intentionally left blank 2 TABLE OF CONTENTS TABLE OF CONTENTS ................................................................................................................................ i Appendices ......................................................................................................................................................... iii LIST OF FIGURES ......................................................................................................................................... iv LIST OF TABLES ............................................................................................................................................ v List of Acronyms .............................................................................................................................................. vi INTRODUCTION ................................................................................................................................... 1 1.1 Background ..................................................................................................................................... 1 1.2 Problem Statement ........................................................................................................................ 1 1.3 Watershed Framework ................................................................................................................... 3 1.4 Report Organization ..................................................................................................................... 14 APPLICABLE WATER QUALITY STANDARDS AND NUMERIC TARGETS .................. 15 2.1 Narrative Water Quality Criteria .................................................................................................. 15 2.2 Numeric Water Quality Criteria .................................................................................................... 15 2.3 Designated Uses ........................................................................................................................... 16 2.4 Evaluation of Potential Site-Specific Criteria ................................................................................ 17 2.5 Numeric Water Quality Targets .................................................................................................... 20 2.6 Replacement of Existing TMDLs for Parson’s Creek ..................................................................... 22 WATERSHED CHARACTERIZATION .......................................................................................... 25 3.1 Watershed Setting ........................................................................................................................ 25 3.2 Hydrology and Water Resources .................................................................................................. 28 3.3 Ecological Landscapes .................................................................................................................. 32 3.4 Water Quality ............................................................................................................................... 36 SOURCE ASSESSMENT ...................................................................................................................... 46 4.1 Review of Phosphorus and Sediment Sources ............................................................................. 46 4.2 Analysis of Baseline Phosphorus and Sediment Loading ............................................................. 50 4.3 Summary of Baseline Phosphorus and Sediment Loading ........................................................... 67 DETERMINATION OF LOAD CAPACITY .................................................................................. 72 5.1 Phosphorus Loading Capacity ....................................................................................................... 72 5.2 Sediment Loading Capacity .......................................................................................................... 80 5.3 Critical Conditions......................................................................................................................... 82 POLLUTANT LOAD ALLOCATIONS ........................................................................................... 83 i 6.1 TMDL Equation ............................................................................................................................. 83 6.2 Allocation Approach ..................................................................................................................... 83 6.3 Load Allocations ........................................................................................................................... 85 6.4 Wasteload Allocations .................................................................................................................. 86 6.5 Tribal Lands ................................................................................................................................... 89 6.6 Margin of Safety ........................................................................................................................... 89 6.7 Reserve Capacity .......................................................................................................................... 91 6.8 Seasonal Variation ........................................................................................................................ 93 IMPLEMENTATION............................................................................................................................ 95 7.1 Implementation Planning ............................................................................................................. 95 7.2 Reasonable Assurance for Point Sources ..................................................................................... 95 7.3 Reasonable Assurance for Nonpoint Sources .............................................................................. 96 7.4 Follow-up Monitoring ................................................................................................................. 103 PUBLIC PARTICIPATION .............................................................................................................. 105 8.1 Technical Meetings ..................................................................................................................... 105 8.2 Draft Data Review ....................................................................................................................... 105 8.3 Draft TMDL Allocations and Draft TMDL Report Review ........................................................... 105 8.4 Public Informational Meeting and Comment Period ................................................................. 106 REFERENCES ..................................................................................................................................... 108 ii Appendices APPENDIX A. TMDL Subbasin Land Use APPENDIX B. Impairments Requiring Additional Evaluation APPENDIX C. SWAT Model Setup, Calibration, and Validation for the Upper Fox-Wolf Basins TMDL APPENDIX D. WiLMS Lake Model Setup and Results for the Upper Fox-Wolf Basins TMDL APPENDIX E. Water-Quality Response to Changes in P Loading of the Winnebago Pool Lakes, Wisconsin, with Special Emphasis on the Effects of Internal Loading in a Chain of Shallow Lakes APPENDIX F. Report of Lake Winnebago Paleoecological Study APPENDIX G. Baseline Load Tables APPENDIX H. Total Phosphorus Allocation Tables APPENDIX I. Sediment Allocation Tables APPENDIX J. Agricultural Phosphorus and Sediment Targets APPENDIX K. Trading and Adaptive Management Information APPENDIX L. Response to Comments APPENDIX M. Public Informational Hearing Comments APPENDIX N. Response to Public Informational Hearing Comments APPENDIX O. Copy of Agricultural Surveys iii LIST OF FIGURES Figure 1. Location of waters impaired by phosphorus and sediment in the Upper Fox-Wolf Basins. ......... 9 Figure 2. Map of TMDL subbasins. .............................................................................................................. 13 Figure 3. Regression curves for total phosphorus (TP) and chlorophyll-a (CHL) for the Lake Winnebago south (station ID 713244; top-left), middle (station ID 713243; top-right), and north (station ID 713245; bottom) monitoring stations.. .................................................................................................................... 19 Figure 4. Summary of land use in the Upper Fox and Wolf Basins. Based on the land cover dataset derived for watershed modeling described in Appendix C. ..................................................................................... 26 Figure 5. Land use in the Upper Fox and Wolf River Basins. Source data is the land cover dataset derived for watershed modeling described in Appendix C. ....................................................................................