Great Lakes

Located along the border of the Midwestern United States and Canada, the five Great Lakes are a vital environmental, economic and social resource. They cover over 95,000 square miles, account for 84% of North America’s surface fresh water, and represent 21% of the volume of global fresh surface water.[1][2]

Wisconsin has over 1,000 miles of shoreline on the Great Lakes (namely, Lakes Superior to the north and Lake Michigan to the east), and over 1.6 million Wisconsinites depend on them for drinking water.[3]

Unfortunately, the Great Lakes face many threats from pollution running off farm fields and city streets, sewage overflows, algae blooms, toxic chemicals, invasive species, climate change and more.

Key Points

  • The Great Lakes contain one-fifth of the world’s fresh surface water and drinking water for over 40 million people.[1] 
  • The Great Lakes provide habitat for over 350 species of fish.
  • Wisconsin has more than 1,000 miles of Great Lakes shoreline.[3]
  • Over half of Wisconsin’s population live within the Great Lakes basin.[3]
Clean Wisconsin's Work

Clean Wisconsin works to protect and restore the Lakes to ensure they remain as magnificent for future generations as they are today. Our Great Lakes work reflects the wide range of threats that the lakes face: toxic pollution, excess nutrients from runoff, algae blooms, invasive species and climate change are just a few.

Clean Wisconsin was instrumental in the passage of the Great Lakes Compact in Wisconsin. We help lead a coalition of environmental conservation organizations committed to the proper implementation of the Great Lakes Compact in the state. In that capacity, we monitor applications to divert Great Lakes water outside of the basin, ensure the DNR is meeting its requirements as a state program under the Compact to track and properly regulate all Great Lakes water users, and ensure that planning and sound water management guide the use of Great Lakes water in this state.

Since 2008, we have worked with partners from Wisconsin and around the Great Lakes Basin to urge federal leadership in investing in the restoration of the amazing but vulnerable Great Lakes ecosystem. Thanks to those national efforts, since 2009 the federal government has annually appropriated several hundred million dollars to the Great Lakes Restoration Initiative.

Clean Wisconsin’s polluted runoff work covers both of Wisconsin’s large-scale watersheds, the Great Lakes Basin and the Mississippi River Basin. Wisconsin’s Fox-Wolf River system is one of the Great Lakes’ largest contributors of nutrient pollution. Clean Wisconsin is working with partners in the Green Bay area to find innovative solutions to reducing the pollution flowing into Lake Michigan through the Fox and Wolf Rivers. See more details on these efforts on our phosphorus pollution page.

Related Topic Pages

Great Lakes Compact
The Great Lakes Compact, signed into law in October 2008, is an agreement between eight participating Great Lakes state, including Wisconsin, and two Canadian provinces. The purpose of the Compact is to set rules for diversions of Great Lakes water and to establish a framework for regional cooperative management for protection of this freshwater resource.

Waukesha Water Diversion
As part of a county that straddles the Great Lakes basin, the city of Waukesha is eligible, under the rules of the Great Lakes Compact, to apply for a diversion of water from the Great Lakes.  As Waukesha has struggled with water quality and quantity problems for many years, it has chosen to apply for a 10.1 million gallon/day diversion. Wisconsin’s Department of Natural Resources and the other eight Great Lakes states must apply the standards in the Great Lakes Compact to Waukesha’s proposal and approve or deny it.


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Please cite this resource as: Clean Wisconsin, Inc. “Great Lakes.” Clean Wisconsin Enviropedia. Retrieved from