Bois de Sioux River Watershed Total Maximum Daily Load Study A quantification of the total amount of phosphorus, total suspended solids, and bacteria that can be received by the lakes and streams in the Bois de Sioux River Watershed, and maintain their ability to support swimming, fishing, and healthy biological communities. April 2020 wq-iw5-12e Authors and contributors: Emmons & Olivier Resources, Inc.: Meghan Funke, PhD Jason Ulrich Paula Kalinosky Jason Naber Sean Marczewski Etoile Jensen Minnesota Pollution Control Agency: Cary Hernandez Kevin Stroom Holly Christiansen Josh Stock Marco Graziani Tim James Jamie Beyer (Bois de Sioux Watershed District) Bois de Sioux River Watershed TMDL • 2020 Minnesota Pollution Control Agency Contents Acronyms .............................................................................................................................................. i Executive Summary ............................................................................................................................ iii 1 Project Overview .......................................................................................................................... 1 Purpose ................................................................................................................................................ 1 Identification of Waterbodies .............................................................................................................. 3 Priority Ranking .................................................................................................................................... 5 Description of the Impairments and Stressors..................................................................................... 5 Lake Eutrophication .............................................................................................................. 5 Stream E. coli ......................................................................................................................... 6 Stream Turbidity ................................................................................................................... 6 Stream Fish and Macroinvertebrate Bioassessments ........................................................... 7 Stream Dissolved Oxygen ...................................................................................................... 8 2 Applicable Water Quality Standards and Numeric Water Quality Targets ..................................... 9 Lakes ..................................................................................................................................................... 9 Lake Eutrophication .............................................................................................................. 9 Streams .............................................................................................................................................. 10 Bacteria ............................................................................................................................... 10 Turbidity .............................................................................................................................. 11 Stream Eutrophication ........................................................................................................ 12 Dissolved Oxygen ................................................................................................................ 12 3 Watershed and Water body Characterization ............................................................................. 13 Lakes ................................................................................................................................................... 13 Ash Lake .............................................................................................................................. 14 Upper Lightning Lake .......................................................................................................... 18 Mud Lake ............................................................................................................................. 21 Lake Traverse ...................................................................................................................... 23 Streams .............................................................................................................................................. 26 Subwatersheds ................................................................................................................................... 27 Land Use ............................................................................................................................................. 28 Current/Historical Water Quality ....................................................................................................... 30 Lake Eutrophication (Total Phosphorus) ............................................................................. 30 Shallow Lakes .................................................................................................................. 30 Stream Monitoring Stations ................................................................................................ 32 River Eutrophication (Total Phosphorus) ............................................................................ 34 Bois de Sioux River Watershed TMDL • 2020 Minnesota Pollution Control Agency Bois de Sioux River (09020101-501) ............................................................................... 34 Rabbit River (09020101-502) .......................................................................................... 36 Stream Dissolved Oxygen .................................................................................................... 39 Bois de Sioux River (09020101-501) ............................................................................... 39 Rabbit River (09020101-502) .......................................................................................... 41 Stream E. coli ....................................................................................................................... 44 Rabbit River (09020101-502) .......................................................................................... 44 Unnamed Creek – Doran Slough (09020101-510) .......................................................... 47 Stream Total Suspended Solids ........................................................................................... 49 Bois de Sioux River (09020101-501) ............................................................................... 49 Rabbit River (09020101-502) .......................................................................................... 51 Pollutant Source Summary ................................................................................................................. 53 Lake Phosphorus ................................................................................................................. 53 Permitted Sources ........................................................................................................... 53 Non-permitted Sources ................................................................................................... 53 Stream Total Phosphorus and Total Suspended Solids ....................................................... 60 Permitted ........................................................................................................................ 60 Non-permitted ................................................................................................................ 60 Stream E. coli ....................................................................................................................... 69 Permitted ........................................................................................................................ 70 Non-permitted sources ................................................................................................... 71 Strengths and Limitations ............................................................................................... 75 Summary ......................................................................................................................... 76 4 TMDL Development .................................................................................................................... 78 Phosphorus ........................................................................................................................................ 78 Loading Capacity ................................................................................................................. 78 Lake Response Model ..................................................................................................... 78 Stream Load Duration Curves ......................................................................................... 81 Load Allocation Methodology ............................................................................................. 81 Wasteload Allocation Methodology ................................................................................... 82 MS4 Regulated Stormwater ............................................................................................ 82 Regulated Construction Stormwater .............................................................................. 82 Regulated Industrial Stormwater