Watershed health May 2019 Otter Tail River Monitoring and Assessment Report The MPCA is reducing printing and mailing costs Authors by using the Internet to distribute reports and Dave Dollinger information to wider audience. Visit our Megan Handt website for more information. Cadie Olson Sophia Vaughan MPCA reports are printed on 100% post- Mark Gernes consumer recycled content paper Andrew Butzer manufactured without chlorine or chlorine Shawn Nelson derivatives. Bruce Monson Contributors/acknowledgements Becker County SWCD Bemidji State University Buffalo Red River Watershed District Citizen Lake Monitoring Program Volunteers Citizen Stream Monitoring Program Volunteers Clearwater County Clearwater County SWCD Headwaters Science Center Interstate Engineering Minnesota Department of Agriculture Minnesota Department of Health Minnesota Department of Natural Resources Otter Tail County Coalition of Lake Associations Pelican River Watershed District Red Lake Watershed District Project dollars provided by the Clean Water Fund Tamarac Interpretive Association (from the Clean Water, Land and Legacy Amendment). Tamarac National Wildlife Refuge White Earth Nation 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-ws3-09020103b Contents List of acronyms ................................................................................................................................ vi Executive summary ............................................................................................................................1 Introduction ......................................................................................................................................3 The watershed monitoring approach .......................................................................................................... 4 Assessment methodology .......................................................................................................................... 9 Watershed overview ................................................................................................................................ 13 Watershed-wide data collection methodology ......................................................................................... 36 Individual aggregated HUC-12 subwatershed results ......................................................................... 40 Aggregated HUC-12 subwatersheds ......................................................................................................... 40 Headwaters Otter Tail River Aggregated HUC-12 HUC 0902010301-01 ......................................... 41 Upper Otter Tail River Aggregated HUC-12 HUC 0902010302-01 .......................................... 47 Toad River Aggregated HUC-12 HUC 0902010303-01 .......................................... 53 Otter Tail Lake-Otter Tail River Aggregated HUC-12 HUC 0902010306-01 ......................................... 58 Dead River Aggregated HUC-12 HUC 0902010304-01.......................................... 64 West Battle Lake Aggregated HUC-12 HUC 0902010305-01.......................................... 68 Middle Otter Tail River Aggregated HUC-12 HUC 0902010309-01 ......................................... 73 Upper Pelican River Aggregated HUC-12 HUC 0902010307-02 ......................................... 80 Middle Pelican River Aggregated HUC-12 HUC 0902010307-01 ......................................... 87 Lower Pelican River Aggregated HUC-12 HUC 0902010308-01 ......................................... 92 Judicial Ditch No. 2 Aggregated HUC-12 HUC 0902010310-02 ......................................... 97 Lower Otter Tail River Aggregated HUC-12 HUC 0902010310-01 ....................................... 101 Watershed-wide results and discussion .......................................................................................... 105 Stream water quality .............................................................................................................................. 105 Lake water quality .................................................................................................................................. 106 Fish contaminant results ........................................................................................................................ 107 Pollutant load monitoring ...................................................................................................................... 121 Stream flow ........................................................................................................................................... 124 Wetland condition ................................................................................................................................. 125 Transparency trends for the Otter Tail River Watershed ......................................................................... 133 Remote sensing for lakes in the Otter Tail River Watershed .................................................................... 133 Priority Waters for Protection and Restoration in the Otter Tail River Watershed ................................... 135 Summaries and recommendations ................................................................................................. 136 Groundwater Summary and Recommendations ..................................................................................... 139 Literature cited .............................................................................................................................. 140 Appendix 1 – Water chemistry definitions .............................................................................................. 143 i Appendix 2.1 – Intensive watershed monitoring water chemistry stations in the Otter Tail River Watershed .............................................................................................................................................................. 144 Appendix 2.2 – Intensive watershed monitoring biological monitoring stations in the Otter Tail River Watershed ............................................................................................................................................. 145 Appendix 3.1 – Minnesota statewide IBI thresholds and confidence limits .............................................. 146 Appendix 3.2 – Biological monitoring results – fish IBI (assessable reaches) ............................................ 147 Appendix 3.3 – Biological monitoring results-macroinvertebrate IBI (assessable reaches) ....................... 149 Appendix 4.1 – Fish species found during biological monitoring surveys ................................................. 151 Appendix 4.2 – Macroinvertebrate species found during biological monitoring surveys .......................... 153 Appendix 5 – Minnesota Stream Habitat Assessment results .................................................................. 160 Appendix 6 – Lake protection and prioritization results .......................................................................... 162 Appendix 7 – Stream protection and prioritization results ...................................................................... 169 ii Figures Figure 1. The Intensive watershed monitoring design in the Otter Tail River Watershed. .......................... 5 Figure 2. Intensive watershed monitoring sites for streams in the Otter Tail River Watershed. ................. 6 Figure 3. Monitoring locations of local groups, citizens and the MPCA lake monitoring staff in the Otter Tail River Watershed. .................................................................................................................................... 8 Figure 4. Flowchart of aquatic life use assessment process. ...................................................................... 12 Figure 5. The Otter Tail River Watershed within the Lake Agassiz Plain, Northern Lakes and Forest, and North Central Hardwoods ecoregions of western Minnesota. ................................................................... 14 Figure 6. Land use in the Otter Tail River Watershed. ................................................................................ 16 Figure 7. Map of percent altered streams by major watershed (HUC-8). .................................................. 19 Figure 8. Comparison of natural to altered streams in the Otter Tail River Watershed ............................ 20 Figure 9. Statewide precipitation total (left) and precipitation departure (right) during 2016 ................. 20 Figure 10. Precipitation trends in northwest Minnesota from 1997-2016 (top) and 1917-2016 (bottom) (Source: WRCC 2018). ................................................................................................................................. 21 Figure 11. Precipitation trends in west central Minnesota from 1997-2016 (top) and 1917-2016 (bottom) (Source: WRCC 2018). ................................................................................................................................. 22 Figure 12. Groundwater provinces within the Otter Tail River Watershed (GIS Source: DNR 2001). ........ 24 Figure 13. Pollution sensitivity of near surface materials for the Otter Tail River Watershed ..................