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Great Lakes water diversions

Great Lakes St Lawrence Basin
Environment, Great Lakes, and Energy

Great Lakes water diversions

The Great Lakes and the St. Lawrence River Basin make up the world’s largest source of surface fresh water. It contains more than 20% of the world's supply of surface fresh water and about 84% of North America's surface fresh water.  

In 2008, the eight Great Lakes states (Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania, and Wisconsin) and the two Canadian provinces (Ontario and Quebec) signed the Great Lakes Compact protecting these waters.

The Great Lakes Compact is a federal agreement and prohibits new or increased diversions of water to areas outside the Great Lakes - St. Lawrence River Basin, with three exceptions:

  1. Communities that straddle the basin divide
  2. Intra-basin transfers
  3. Communities in counties that straddle the basin divide

These exceptions require communities to meet strict criteria to obtain approval. These criteria include conservation efforts, allotted water volume, and a 100% return flow requirement. Any community completely outside of the Great Lakes Basin is prohibited from withdrawals. To date, only a single diversion application has been approved - the City of Waukesha, Wisconsin. 

Waukesha, Wisconsin

The City of Waukesha's diversion application

Waukesha lies within a county that straddles the Great Lakes basin, allowing it to apply for Lake Michigan water if it meets Great Lakes Compact standards.

In January 2016, the City of Waukesha requested Lake Michigan water to address high levels of naturally-occurring radium present in its groundwater supply of drinking water. Radium is a carcinogen known to cause bone cancer and other health problems.

At the time of the application, the city was pumping about 1.6 million gallons of water per day (or more than a half billion gallons per year) from a deep well in an overstressed aquifer that drew from the Great Lakes Basin under an existing diversion. The city was using it for their municipal water supply, which was then treated and discharged into the Mississippi River Basin. This represented about 30% of the annual water pumped from the Great Lakes Basin at the time.

Waukesha was the first U.S. community in a straddling county to ask for a withdrawal of water out of the Great Lakes Basin under terms of the Compact. Their request was approved by the Compact Council on June 21, 2016.

Michigan’s involvement in the review process

Michigan worked in conjunction with the other Great Lakes states and provinces to develop essential conditions to safeguard the Great Lakes and protect the health of Great Lakes citizens. Michigan’s review of the plan involved evaluation by a collaborative team of subject experts organized by the Michigan Office of the Great Lakes, a thorough public engagement and comment process, and consultation with Michigan’s 12 federally-recognized Native American tribes. 

Those conditions included:

  • Reducing the service area size by 47%.
  • Lowering the amount of the withdrawal from 10.1 million gallons per day, as originally requested, to 8.2 million gallons per day.
  • Wisconsin must avoid adverse impacts to surface waters and wetlands in both the Lake Michigan and Mississippi River watersheds.
  • Cease extracting and dispersing radium-containing sludges into the environment.
  • Implement a recycling program for pharmaceuticals and personal care products.
  • Cease diverting water from Lake Michigan without return flow.
  • The Wisconsin Department of Natural Resources must regularly report on and enforce implementation of the conditions.

The Great Lakes Compact Council and its member states retain full ability to review and ensure adherence to implementation of conditions according to Compact law. 

On May 18, 2016, the Regional Body voted to advise the Council of its conditioned approval of the withdrawal. On June 21, 2016, the Compact Council voted to approve Waukesha's request with strict conditions.

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