City of Waukesha Diversion
- The DNR approved the city of Waukesha’s diversion application to divert up to 8.2 million gallons per day.
- The city purchases drinking water from the city of Milwaukee, whose water source is Lake Michigan.
- The city of Waukesha discharges its treated wastewater to the Root River, a tributary of Lake Michigan and the Fox River. Treated wastewater, up to the volume of annual average diversion, is then discharged to the Root River. Wastewater in excess of the diversion volume is discharged to the Fox River. The source of additional wastewater is inflow and infiltration into the city’s sewer system.
- Waukesha applied to the DNR for a diversion of Lake Michigan water under the Great Lakes Compact and Agreement as a “community in a straddling county” in a revised application in 2013.
- The DNR forwarded its application review to the Great Lakes Regional Body and Compact Council in 2016, which include representatives from all 10 Great Lakes states and provinces. The Compact Council approved Waukesha's diversion application with conditions including:
- A reduced diversion volume of 8.2 million gallons per day;
- A smaller diversion area of only the area currently served by the Waukesha water utility;
- Monitoring wastewater impacts to the Root River; and
- Annual reporting to the Great Lakes states and provinces on the diversion.
- The DNR’s approval came in 2021 after all permits and approval needed to implement the diversion were in place.
- The city applied for a switch to a Lake Michigan water source because its previous source, groundwater from the deep aquifer, was contaminated by high radium concentrations that required costly treatment. As a result, the city was under an amended court order to comply with state and federal radium standards by September 2023.
- The city worked with the DNR to test its new water source and ensure that changing to Lake Michigan water would not cause unexpected water quality problems.
- The city is required to monitor water quality in the distribution system following standard Safe Drinking Water Act requirements.
Find more information on the city of Waukesha’s transition to a Lake Michigan water supply on the Great Water Alliance website.
State of Wisconsin Diversion Approval
The DNR approved the City of Waukesha’s diversion and the water supply service area plan in June 2021. The City of Waukesha has obtained all necessary federal, state and local permits to implement the diversion.
Compact Council Approval
Other Permits and Correspondence
The DNR has completed a final environmental impact statement (EIS) for the proposed project and has issued a determination of compliance with the Wisconsin Environmental Policy Act. For more information, see Waukesha Water Diversion EIS.
The City of Waukesha has obtained permits and approvals to discharge wastewater to the Root River, for wastewater facilities, for pipeline stream and wetland crossings, for the water supply pipeline, construction stormwater management from the Department of Transportation and construction authorization from the Wisconsin Public Service Commission.
The City of Waukesha submitted a revised application for a Lake Michigan diversion in October 2013.
The DNR submitted the City of Waukesha application to the Regional Body and Compact Council in January 2016. Compact Council decision documents are available from the Compact Council.
Prior to submitting the City of Waukesha Application for Regional Review, the DNR reviewed the City of Waukesha diversion application between 2010 and 2015. The DNR did additional review for permit and approval applications to implement the diversion after the Compact Council approval of the diversion.
The DNR also used the EIS process to analyze environmental effects and alternatives of the proposed Waukesha diversion under the Wisconsin Environmental Policy Act (WEPA) and Chapter NR 150, Wis. Adm. Code. As a result of this process, the department issued a final EIS in 2019.
In addition to the Regional Review public participation process, the DNR held public comment periods in 2010, 2013 and 2015.