Groundwater Report Rum River Watershed November 2016 The MPCA is reducing printing and mailing costs Authors by using the Internet to distribute reports and Sophia Vaughan information to wider audience. Visit our website for more information. Editing MPCA reports are printed on 100% post- David Duffey consumer recycled content paper Andrew Streitz manufactured without chlorine or chlorine derivatives. Support 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-ws1-11 Contents I. Introduction ..................................................................................................................................... 1 The watershed monitoring approach ............................................................................................................... 2 Watershed overview ........................................................................................................................................ 2 Land use ........................................................................................................................................................... 4 Ecoregion and soils ........................................................................................................................................... 5 II. Climate and precipitation ................................................................................................................. 8 III. Surface water hydrology ............................................................................................................. 11 Streamflow ..................................................................................................................................................... 12 Lake levels ...................................................................................................................................................... 14 IV. Hydrogeology ............................................................................................................................. 20 Surficial and bedrock geology ........................................................................................................................ 20 Groundwater Provinces.................................................................................................................................. 23 Aquifers .......................................................................................................................................................... 24 Groundwater pollution sensitivity ................................................................................................................. 25 Groundwater potential recharge ................................................................................................................... 26 V. Groundwater quality ...................................................................................................................... 29 Ambient groundwater network ..................................................................................................................... 29 Regional groundwater quality ........................................................................................................................ 32 VI. Groundwater quality .................................................................................................................. 37 Groundwater and surface water withdrawals ............................................................................................... 37 Minnesota Department of Natural Resources Observation Wells ................................................................. 40 VII. Evapotranspiration ..................................................................................................................... 44 Evapotranspiration Definition ........................................................................................................................ 44 Evapotranspiration Variation across Minnesota ............................................................................................ 44 VIII. Conclusion: Statement of groundwater condition ........................................................................ 46 Surface water quality ..................................................................................................................................... 46 Groundwater protection ................................................................................................................................ 47 Recommendations ......................................................................................................................................... 50 IX. References ................................................................................................................................. 51 Figures Figure 1: Simplified hydrologic cycle demonstrating the changing states of water above and below the earth’s surface .................................................................................................................................................................. 1 Figure 2: The location of the Rum River Watershed ............................................................................................. 3 Figure 3: Rum River 8-HUC watershed relief (GIS Source: MNDNR) .................................................................... 4 Figure 4: Land cover in the Rum River Watershed (GIS Source: NLCD, 2011) ...................................................... 5 Figure 5: Three levels of Ecological Classification System for the Rum River Watershed .................................... 6 Figure 6: Soil classification for the Rum River Watershed (GIS Source: USDA NRCS, 2006) ................................. 7 Figure 7: Precipitation within the hydrologic cycle .............................................................................................. 8 Figure 8: Statewide precipitation levels during 2014 (Source: MNDNR State Climatology Office, 2015) ............ 9 Figure 9: Precipitation trends in East Central Minnesota (1955-2014) with five-year running average ............ 10 Figure 10: Precipitation trends in East Central Minnesota (1915-2014) with 10-year running average ............ 10 Figure 11: Surface water within the hydrologic cycle ......................................................................................... 11 Figure 12: Lakes, wetlands and waterbodies in the Rum River Watershed ....................................................... 12 Figure 13: Annual mean discharge for Rum River near St. Francis, Minnesota (1955-2014) ............................. 13 Figure 14: Mean monthly discharge for Rum River near St. Francis, Minnesota (1955-2014) ........................... 13 Figure 15: Shakopee Lake within Rum River Watershed .................................................................................... 14 Figure 16: Shakopee Lake water level elevations (1993-2015) .......................................................................... 15 Figure 17: Green Lake within the Rum River Watershed ................................................................................... 16 Figure 18: Green Lake water level elevations (1966-2015) ................................................................................ 17 Figure 19: Round Lake within Rum River Watershed ......................................................................................... 18 Figure 20: Round Lake water level elevations (1996-2015)................................................................................ 19 Figure 21: Groundwater within the hydrologic cycle ......................................................................................... 20 Figure 22: Geologic county atlases, Part A surficial geology for available Rum River Watershed counties ....... 21 Figure 23: Quaternary geology, glacial sediments within the Rum River Watershed (GIS Source: MGS, 2010) 22 Figure 24: Bedrock geology of the Rum River Watershed: Paleozoic and Precambrian (GIS Source: MGS, 2011) ............................................................................................................................................................................ 23 Figure 25: Metro, Central and Arrowhead Province generalized cross section (Source MNDNR, 2001) ........... 24 Figure 26: Minnesota’s three basic types of aquifers (MPCA, 2005) .................................................................. 25 Figure 27: Groundwater contamination susceptibility for the Rum River Watershed (GIS Source: MPCA, 1989) ............................................................................................................................................................................ 26 Figure 28: Average annual potential recharge rate to surficial materials in Rum River Watershed (1996-2010) ............................................................................................................................................................................ 27 Figure 29: Average annual potential recharge rate percent of grid cells in the Rum River Watershed (1996- 2010) ..................................................................................................................................................................