Des Moines River Watershed Characterization Report MINNESOTA DEPARTMENT OF NATURAL RESOURCES DIVISION OF ECOLOGICAL AND WATER RESOURCES 2016 Contents Table of Figures ............................................................................................................................................. 3 Table of Tables .............................................................................................................................................. 6 List of Acronyms ............................................................................................................................................ 7 Executive Summary ....................................................................................................................................... 9 Introduction ................................................................................................................................................ 10 Watershed Characterization ................................................................................................................... 10 Geology ............................................................................................................................................... 11 High Value Resources .......................................................................................................................... 16 Rare Natural Features ......................................................................................................................... 17 Native Plant Communities .................................................................................................................. 18 Study Background ................................................................................................................................... 21 Hydrology ................................................................................................................................................ 22 Connectivity ............................................................................................................................................ 23 Geomorphology ...................................................................................................................................... 24 Methods ...................................................................................................................................................... 27 Hydrology ................................................................................................................................................ 27 Discharge Analysis ............................................................................................................................... 27 Precipitation ........................................................................................................................................ 27 Double Mass Curve ............................................................................................................................. 27 Web-based Hydrograph Analysis Tool ................................................................................................ 27 Ground Water Usage .......................................................................................................................... 28 Connectivity ............................................................................................................................................ 28 Longitudinal Connectivity ................................................................................................................... 28 Lateral Connectivity ............................................................................................................................ 28 Geomorphology ...................................................................................................................................... 29 Field Methods ..................................................................................................................................... 29 Office Methods ................................................................................................................................... 30 Results ......................................................................................................................................................... 32 Hydrology ................................................................................................................................................ 32 Discharge Analysis ............................................................................................................................... 32 Precipitation ........................................................................................................................................ 37 Double Mass Curve ............................................................................................................................. 38 1 Web-based Hydrograph Analysis Tool ................................................................................................ 40 Ground Water Usage .......................................................................................................................... 41 Anticipated Trend in Appropriation .................................................................................................... 42 Connectivity ............................................................................................................................................ 45 Longitudinal Connectivity ................................................................................................................... 45 Lateral Connectivity ............................................................................................................................ 51 Geomorphology ...................................................................................................................................... 51 Des Moines River Headwaters Watershed ......................................................................................... 52 Upper Des Moines River Watershed ................................................................................................... 72 East Fork Des Moines River Watershed .............................................................................................. 75 Restoration and Protection Strategies ........................................................................................................ 89 Correlated Planning Efforts ..................................................................................................................... 91 Minnesota Prairie Conservation Plan ................................................................................................. 91 Minnesota State Wildlife Action Plan ................................................................................................. 93 2 Table of Figures Figure 1. Light Detection and Ranging (LiDAR) imagery depicting the north-to-south slope of the watershed’s landscape with the major and minor tributaries of the watersheds. .................................... 10 Figure 2. Geomorphic association of the three Des Moines River watersheds within southern Minnesota (from Minnesota Geological Survey). The Des Moines Lobe association comprises much of the landscape and very little exposed bedrock exists within the watersheds. ................................................ 11 Figure 3. Sedimentary association of the Des Moines River watershed within Minnesota (SSURGO). .... 12 Figure 4. Soil Survey Geographic database (SSURGO) map of soil organic matter within the Des Moines River watersheds of Minnesota. ................................................................................................................. 13 Figure 5. Marschner pre-settlement vegetation map of the Des Moines River watersheds within Minnesota. .................................................................................................................................................. 13 Figure 6. Soil Survey Geographic database (SSURGO) depiction of soil drainage capacity within the Des Moines River watersheds of Minnesota. .................................................................................................... 14 Figure 7. Index represents the proportion of the watershed that has been drained and converted out of wetland coverage (WHAF). ......................................................................................................................... 14 Figure 8. 2014 land use data for the Des Moines River watersheds (CropScape). .................................... 15 Figure 9. The relative proportion of total watershed acres harvested annually has risen over time. ...... 16 Figure 10. The total number of acres harvested for each crop type farmed within the Des Moines River watersheds. Over time, an increase in corn and soybeans has occurred while small grains have decreased. ................................................................................................................................................... 16 Figure 11. Rare features, native plant communities, and protected lands in the Des Moines River watersheds. ................................................................................................................................................. 19 Figure 12. Five components of a healthy watershed. All components are interrelated;