Climate variability and change and its Impacts on Michigan water resources

Upcoming webinar series will discuss Michigan’s abundant water resources and the impacts future climate variability and change may have on these resources.

Michigan is well known as a water-rich state due in large part to its geographical location within the Upper Great Lakes Region. No matter where you are in the state, you are no farther than 85 miles from a Great Lake, and 40 of Michigan’s 83 counties actually touch at least one of the Great Lakes or their connecting channels. There are approximately 3,288 miles of Great Lakes shoreline, more shoreline than any other U.S. state except Alaska. Inland waters are also abundant, with more than 11,000 inland lakes greater than five acres in size and about 35,000 of at least one acre. Michigan’s river and stream network, including perennial and intermittent waters and connecting channels, have been estimated to stretch over 76,000 miles. Michigan also has a vast groundwater supply. Nearly 44% of Michigan residents get their drinking water from groundwater, and within the entire basin, groundwater provides drinking water for about 8.2 million people.

With this great abundance of water, what effect is climate variability and change likely to have on the availability of water resources, and of its use and water quality in the state? A 2008 paper from the National Conference of State Legislatures indicates that recent climate models predict warmer temperatures and lower water levels for much of Michigan. While precipitation is estimated to increase by 20% to 40% in the Midwest, it will be more than offset by the increased evaporation caused by higher temperatures in both summer and winter. However, more extreme events such as severe storms, flooding or drought may occur. These occurrences may be more frequent and damaging. Changes in ice cover, evaporation and transpiration, and water currents may all translate into problems that will need to be addressed across the state.

While not all changes are predicted to have negative outcomes, studies have indicated that fluctuating lake levels, while already occurring, may increase due to climate change and have an impact on shorelines and shoreline erosion. Coastal wetland habitats and species may be most severely affected by climate change because of their sensitivity to water level changes. Changes in lake stratification, a normal process where lakes are prevented from mixing due to temperature and density differences, may also occur. Some climate change scenarios have predicted that by the end of the century, lakes will remain stratified for several months longer than normal, leading to increased oxygen depletion in bottom waters and causing additional stress on fish and other animals (NOAA Climate Ready Great Lakes).

As reported by the Intergovernmental Panel on Climate Change in 2008, water quality problems associated with sediment, nutrients, dissolved organic carbon, and pathogens are all predicted to worsen with climate change because of the projected increases in temperature, precipitation, and runoff. Water quality impacts may also be prevalent as storm events intensify, causing increased runoff of pollution, and in some cases combined sewer overflows. Unintentional wastewater discharge or contaminated runoff may result in economic damage and health-related issues, such as beach closings and waterborne disease outbreaks caused by fecal contamination and pathogens in contaminated drinking or recreational waters. Studies have shown many of the past waterborne disease outbreaks were associated with extreme weather events.

These topics and other issues related to water and climate variability and change will be addressed as part of a series of five webinars on “Climate, Water, and Agriculture.” These free webinars run from 1 p.m to 2 p.m. on the following Fridays: March 9, 16, 23, 30 and April 13. Water -- Michigan’s Abundant Resource will be held March 16. Registration is requested at

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