Watershed health June 2020 Redwood River Watershed Monitoring and Assessment Report Authors Dan Fettig Jordan Donatell Joel Chirhart Kelli Nerem Mark Gernes David Duffey Bruce Monson Kim Laing Lee Engel Pam Anderson Contributors/acknowledgements Redwood Cottonwood River Control Area Project dollars provided by the Clean Water Fund (from the Clean Water, Land and Legacy Amendment). 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-ws3-07020006 Contents Contents ......................................................................................................................................................... i Tables ............................................................................................................................................................ ii Figures .......................................................................................................................................................... iii List of acronyms ............................................................................................................................................ v Executive summary ....................................................................................................................................... 1 Introduction .................................................................................................................................................. 2 The watershed monitoring approach ....................................................................................................... 3 Assessment methodology ........................................................................................................................ 7 Watershed overview .............................................................................................................................. 12 Watershed-wide data collection methodology ...................................................................................... 25 Individual aggregated 12-HUC subwatershed results ................................................................................. 29 Aggregated 12-HUC subwatersheds ....................................................................................................... 29 Upper Redwood River Aggregated 12-HUC HUC 0702000601-01 ........................................................ 30 Judicial Ditch 12 Aggregated 12-HUC HUC 0702000601-02 ................................................................. 35 Coon Creek Aggregated 12-HUC HUC 0702000602-01......................................................................... 40 Middle Redwood River Aggregated 12-HUC HUC 0702000603-01....................................................... 45 Threemile Creek Aggregated 12-HUC HUC 0702000604-01 ................................................................. 50 Clear Creek Aggregated 12-HUC HUC 0702000605-01 ........................................................................ 55 Ramsey Creek Aggregated 12-HUC HUC 0702000606-01 .................................................................... 59 Lower Redwood River Aggregated 12-HUC HUC 0702000607-01 ....................................................... 63 Watershed-wide results and discussion ..................................................................................................... 68 Stream water quality .............................................................................................................................. 68 Lake water quality .................................................................................................................................. 70 Fish contaminant results ........................................................................................................................ 71 Pollutant load monitoring....................................................................................................................... 74 Groundwater monitoring ....................................................................................................................... 78 Stream flow ............................................................................................................................................ 81 Wetland condition .................................................................................................................................. 84 Transparency trends for the Redwood River Watershed ....................................................................... 91 Priority Waters for Protection and Restoration in the Redwood River Watershed ............................... 92 Summaries and recommendations ............................................................................................................. 93 Literature cited............................................................................................................................................ 96 Appendix 1 – Water chemistry definitions ............................................................................................. 98 Appendix 2.1 – Intensive watershed monitoring water chemistry stations in the Redwood River Watershed ............................................................................................................................................ 100 Appendix 2.2 – Intensive watershed monitoring biological monitoring stations in the Redwood River Watershed ............................................................................................................................................ 101 Appendix 3.1 – Minnesota statewide IBI thresholds and confidence limits ........................................ 104 Appendix 3.2 – Biological monitoring results – fish IBI (assessable reaches) ...................................... 105 Appendix 3.3 – Biological monitoring results-macroinvertebrate IBI (assessable reaches) ................ 107 Appendix 4.1 – Fish species found during biological monitoring surveys ............................................ 109 Appendix 4.2 – Macroinvertebrate species found during biological monitoring surveys ................... 111 Appendix 5 – Minnesota Stream Habitat Assessment results.............................................................. 117 Appendix 6 – Lake protection and prioritization results ...................................................................... 119 Appendix 7 – Stream protection and prioritization results .................................................................. 120 i Tables Table 1. Tiered aquatic life use standards. ................................................................................................... 9 Table 2. Aquatic life and recreation assessments on stream reaches: Upper Redwood River Aggregated 12-HUC. Reaches are organized upstream to downstream in the table. ................................................... 31 Table 3. Lake assessments: Upper Redwood River Aggregated 12-HUC. ................................................... 32 Table 4. Aquatic life and recreation assessments on stream reaches: Judicial Ditch 12 Aggregated 12- HUC. Reaches are organized upstream to downstream in the table. ........................................................ 36 Table 5. Lake water aquatic recreation assessments: Judicial Ditch 12 Aggregated 12-HUC. ................... 37 Table 6. Aquatic life and recreation assessments on stream reaches: Coon Creek Aggregated 12-HUC. Reaches are organized upstream to downstream in the table. ................................................................. 41 Table 7. Lake assessments: Coon Creek Aggregated 12-HUC. .................................................................... 42 Table 8. Aquatic life and recreation assessments on stream reaches: Middle Redwood River Aggregated 12-HUC. Reaches are organized upstream to downstream in the table. ................................................... 46 Table 9. Lake assessments: Middle Redwood River Aggregated 12-HUC. ................................................. 47 Table 10. Aquatic life and recreation assessments on stream reaches: Threemile Creek Aggregated 12- HUC. Reaches are organized upstream to downstream in the table. ........................................................ 51 Table 11. Lake assessments: Threemile Creek Aggregated 12-HUC. .......................................................... 52 Table 12. Aquatic life and recreation assessments on stream reaches: Clear Creek Aggregated 12-HUC. Reaches are organized upstream to downstream in the table. ................................................................. 56 Table 13. Aquatic life and recreation assessments on stream reaches: Ramsey Creek Aggregated 12-HUC. Reaches are organized upstream to downstream in the table. ................................................................. 60 Table 14. Aquatic life and recreation assessments on stream reaches: Lower Redwood River Aggregated 12-HUC. Reaches are organized upstream to downstream in the table. ................................................... 64 Table 15. Lake assessments: Lower Redwood River Aggregated 12-HUC. ................................................. 65 Table 16. Assessment summary for stream water quality in the Redwood River Watershed. .................