Resilience in Water Resources

Different regions of Minnesota will experience unique flooding challenges due to their unique landscapes; yet, many regions in Minnesota are already seeing significant increases in flood magnitudes ^2,3. More intense rainfall events can overwhelm existing stormwater infrastructure, especially in urban areas with extensive paved surfaces. Flooding can lead to injury and death, and introduce waterborne diseases to humans in surrounding areas.⁴ As springtime precipitation increases, runoff is expected to increase, which can lead to increased soil erosion⁵, nutrient runoff⁶, and reductions in water quality⁷.  At the same time, decreases in summertime precipitation and increases in wintertime precipitation in the state could result in fluctuating surface water levels and necessitating adaptable water storage solutions to meet demand. Changes in flood generating processes may result from new climate regimes and cause unexpected floods that current emergency response is not accustomed to managing: for example, severe summer rainfall-induced flooding in a location where snowmelt has caused most historically observed flooding events^8,9, or a possibility for more frozen ground because of less insulation from snow.¹⁰ 

Hotter, drier summers with longer dry spells are expected to increase evaporation and decrease water availability¹¹ while increasing demand (e.g., proliferation of crop irrigation to adapt to increasing drought frequency.¹² In addition, higher air temperatures intensify potential evapotranspiration¹³, increasing the risk of rapid-onset “flash” droughts, the speed of which lead to a reduced ability to implement mitigation measures.¹⁴ Additionally, low water on rivers can limit navigation and shipping on these key arteries for commerce, such as the Lower Minnesota and Mississippi Rivers, driving up shipping costs and squeezing supply chains.¹⁵

Warmer waters and reduced ice cover affect fish populations and water quality. Statewide, as temperatures warm, some lakes will become too warm for certain species of fish. Many lakes in the region where iconic coolwater species such as Walleye are currently supported are expected to shift in the future towards more warmwater species such as Largemouth Bass, with possible future widespread loss of Walleye recruitment where it is currently supported.¹⁶ Declining fish populations can disrupt ecosystems and fishing industries. Notably, Lake Superior is rapidly warming,^17,18 with temperatures rising about 1°F per decade 1979-2021, with annual average ice coverage decreasing 18% per decade in that same time period. These trends in Lake Superior alter fisheries and habitat, and favor species that are more tolerant to the warmer water.¹⁹ Warmer waters also have water quality impacts, including increasing the risk of harmful algal blooms²⁰, exposure to which can lead to a range of health issues in humans and animals, making water activities unsafe. Additionally, when large algal blooms die and decompose, the process consumes significant amounts of dissolved oxygen in the water, leading to hypoxic conditions or "dead zones", which are unsuitable for aquatic life to thrive.²¹

As temperatures warm, more wintertime precipitation is expected to fall as rain, leading to less snowpack and a shorter snow season.⁴ Additionally, popular winter recreation activities like skiing, ice fishing, snowmobiling and dogsledding will likely be impacted. Typical soil freeze-thaw cycles may be disrupted; while cold temperatures are required for soil to freeze, snow actually insulates the soil from freezing as hard; thus, there may be a tug-of-war between increased winter temperatures but also decreased insulating snowpack with unclear results on timing, length, and depth of soil frost.¹⁰ 

1. Liess, S. et al. MN CliMAT. Fine-scale Climate Projections over Minnesota for the 21st Century. https://app.climate.umn.edu/?output_type=numDif&scenario=ssp370_2060-2079&model=ensemble&variable=tmax-degF&time_frame=yearly&aoi=p%7EMN_outline%7E0#intro_pane (2025). 

2. Mallakpour, I. & Villarini, G. The changing nature of flooding across the central United States. Nat. Clim. Change 5, 250–254 (2015). 

3. Levin, S. B. Nonstationary Flood Frequency Analysis Using Regression in the North-Central United States. 

4. Payton, E. A. et al. Water. Fifth National Climate Assessment https://nca2023.globalchange.gov/chapter/4/ (2023). 

5. Srivastava, A., Grotjahn, R. & Ullrich, P. A. Evaluation of historical CMIP6 model simulations of extreme precipitation over contiguous US regions. Weather Clim. Extrem. 29, 100268 (2020). 

6. Baule, W. J., Andresen, J. A. & Winkler, J. A. Trends in Quality Controlled Precipitation Indicators in the United States Midwest and Great Lakes Region. Front. Water 4, (2022). 

7. Johnson, T. et al. A review of climate change effects on practices for mitigating water quality impacts. J. Water Clim. Change 13, 1684–1705 (2022). 

8. Demaria, E. M. C., Roundy, J. K., Wi, S. & Palmer, R. N. The Effects of Climate Change on Seasonal Snowpack and the Hydrology of the Northeastern and Upper Midwest United States. https://doi.org/10.1175/JCLI-D-15-0632.1 (2016) doi:10.1175/JCLI-D-15-0632.1. 

9. Byun, K., Chiu, C.-M. & Hamlet, A. F. Effects of 21st century climate change on seasonal flow regimes and hydrologic extremes over the Midwest and Great Lakes region of the US. Sci. Total Environ. 650, 1261–1277 (2019). 

10. Friesen, H. C., Slesak, R. A., Karwan, D. L. & Kolka, R. K. Effects of snow and climate on soil temperature and frost development in forested peatlands in minnesota, USA. Geoderma 394, 115015 (2021). 

11. Anurag, H. & Ng, G.-H. C. Assessing future climate change impacts on groundwater recharge in Minnesota. J. Hydrol. 612, 128112 (2022). 

12. Lu, J., Carbone, G. J., Huang, X., Lackstrom, K. & Gao, P. Mapping the sensitivity of agriculture to drought and estimating the effect of irrigation in the United States, 1950–2016. Agric. For. Meteorol. 292–293, 108124 (2020). 

13. Allen, R., Pereira, L., Raes, D. & Smith, M. Crop Evapotranspiration - Guidelines for Computing Crop Water Requirements - FAO Irrigation and Drainage Paper 56. https://www.fao.org/4/x0490e/x0490e00.htm (1998). 

14. Global distribution, trends, and drivers of flash drought occurrence | Nature Communications. https://www.nature.com/articles/s41467-021-26692-z. 

15. Chen, Z., Li, Z. & Cheng, J. The nonlinear impact of climate change on inland waterway transportation in the Upper Mississippi—Illinois River Region. Environ. Res. Infrastruct. Sustain. 4, 031001 (2024). 

16. Hansen, G. J. A., Read, J. S., Hansen, J. F. & Winslow, L. A. Projected shifts in fish species dominance in Wisconsin lakes under climate change. Glob. Change Biol. 23, 1463–1476 (2017). 

17. Cannon, D. et al. Investigating Multidecadal Trends in Ice Cover and Subsurface Temperatures in the Laurentian Great Lakes Using a Coupled Hydrodynamic–Ice Model. https://doi.org/10.1175/JCLI-D-23-0092.1 (2024) doi:10.1175/JCLI-D-23-0092.1. 

18. Austin, J. A. & Colman, S. M. Lake Superior summer water temperatures are increasing more rapidly than regional air temperatures: A positive ice-albedo feedback. Geophys. Res. Lett. 34, (2007). 

19. Cline, T. J., Bennington, V. & Kitchell, J. F. Climate Change Expands the Spatial Extent and Duration of Preferred Thermal Habitat for Lake Superior Fishes. PLOS ONE 8, e62279 (2013). 

20. Blooms Like It Hot | Science. https://www.science.org/doi/10.1126/science.1155398. 

21. US EPA, O. Climate Change Connections: Minnesota (Lakes). https://www.epa.gov/climateimpacts/climate-change-connections-minnesota-lakes (2024).