Grant May 2020 Pipestone, Split Rock, and Mound Creeks Section 319 Small Watershed Focus Nine Element Plan Authors Kyle Krier, Pipestone SWCD Nicole Schwebach, Pipestone SWCD Doug Bos, Rock County SWCD Minnesota Pollution Control Agency Greg Johnson Cindy Penny Abel Green Minnesota Pollution Control Agency 520 Lafayette Road North | Saint Paul, MN 55155-4194 | 651-296-6300 | 800-657-3864 | Or use your preferred relay service. | [email protected] This report is available in alternative formats upon request, and online at www.pca.state.mn.us. Document number: wq-cwp2-12 Contents Contents ............................................................................................................................................ i List of figures .................................................................................................................................... iii List of tables ..................................................................................................................................... iv Executive summary ............................................................................................................................1 1. Introduction ...................................................................................................................................2 1.1 Document overview ............................................................................................................................. 2 1.2 Planning purpose and process ............................................................................................................. 3 1.3 Planning foundations ........................................................................................................................... 3 2. Watershed prioritization ................................................................................................................4 3. Watershed description ...................................................................................................................4 3.1 Geology and soils ........................................................................................................................................ 8 3.2 Wetlands .................................................................................................................................................... 9 3.3 Groundwater ............................................................................................................................................ 12 3.4 Land use ................................................................................................................................................... 13 3.5 Climate/precipitation ............................................................................................................................... 18 4. Water quality and quantity ........................................................................................................... 19 4.1 Water quality standards and beneficial uses ........................................................................................... 19 4.2 Impairments ....................................................................................................................................... 22 4.3 Water quality summary ..................................................................................................................... 23 4.4 Stressor Identification .............................................................................................................................. 31 5. Pollutant source assessments ....................................................................................................... 33 5.1 Pollutant source types .............................................................................................................................. 33 5.2 Pollutant-specific source summaries by land use and watershed ........................................................... 34 5.3 Pipestone Creek Watershed pollutant sources ........................................................................................ 35 5.4 Split Rock Creek Watershed ..................................................................................................................... 37 5.5 Mound Creek Watershed ......................................................................................................................... 38 5.6 TMDLs ....................................................................................................................................................... 39 6. Watershed goals .......................................................................................................................... 46 6.1 Priorities and critical areas ....................................................................................................................... 47 7. Management strategies and activities ........................................................................................... 52 7.1 Implementation strategies ....................................................................................................................... 52 7.2 Results achieved following implementation ............................................................................................ 80 i 8. Information and education activities ............................................................................................ 85 9. Monitoring ................................................................................................................................... 85 10. Costs to implement this plan ...................................................................................................... 89 Literature Cited ................................................................................................................................ 91 Appendix A. STEPL output and assumptions ..................................................................................... 92 Pipestone Creek Watershed ........................................................................................................................... 94 Split Rock Creek Watershed ........................................................................................................................... 95 Mound Creek Watershed ............................................................................................................................... 96 Estimated reduction summary for all watersheds for streambank restoration and SSTS ............................. 97 Appendix B. Success Story Skunk Creek ............................................................................................ 99 ii List of figures Figure 1. Pipestone Creek, Split Rock Creek, and Mound Creek Watersheds .............................................. 5 Figure 2. Elevation map of Pipestone Creek Watershed .............................................................................. 6 Figure 3. Elevation in the Split Rock Creek Watershed ................................................................................. 7 Figure 4. Elevation in the Mound Creek Watershed ..................................................................................... 8 Figure 5. Restorable wetlands in Pipestone Creek Watershed .................................................................. 10 Figure 6. Restorable wetlands identified in Split Rock Creek Watershed .................................................. 11 Figure 7. Restorable Wetlands in Mound Creek Watershed ...................................................................... 12 Figure 8. Land use in Pipestone Creek Watershed ..................................................................................... 15 Figure 9. Land use in Split Rock Creek Watershed ...................................................................................... 17 Figure 10. Land use in Mound Creek Watershed ........................................................................................ 18 Figure 11 Figure 12. E. coli monthly geometric means in impaired reaches in planning area (data from Wenck Associates 2018) ............................................................................................................................. 25 Figure 13. Total phosphorus average monthly concentrations in Split Rock Creek (10170203-512), 2008– 2018 ............................................................................................................................................................ 26 Figure 14. 2007 dissolved oxygen concentrations in Split Rock Creek from Split Rock Lake to Pipestone Creek (10170203-507) ................................................................................................................................ 27 Figure 15. Fish class 2 IBI metric value scores in the Pipestone Creek watershed *Average score of multiple sites ............................................................................................................................................... 28 Figure 16. Fish class 3 IBI metric value scores for Unnamed Creek in the Pipestone Creek Watershed.... 28 Figure 17. Macroinvertebrate class 5 IBI metric value scores in the Pipestone Creek watershed ............. 29 Figure 18. Macroinvertebrate class 7 IBI metric value scores in the Pipestone Creek Watershed ............ 29 Figure 19. Fish class 1 metric value scores at site 11MS013 along Split Rock Creek (10170203-512)