June 22, 2022

Media Contacts:

Ashleigh Chatel / C: 734-626-4252/

Molly Young /


  • Amount and intensity of rain created a natural disaster that no sewer system could handle.
  • Heavy and historic rainfall caused basement and surface flooding, not a defect in the regional collection system.


DETROIT –The Independent Investigative Team reviewing the rain events of June/July 2021 presented its final report today to the Great Lakes Water Authority (GLWA) Board of Directors. The report concluded that heavy and historic rainfalls exceeded the design capacity of the wastewater system, making surface flooding and basement backups inevitable.

For the June 25/26 rain event, the report also stated that even if every piece of piping and equipment in the regional system worked in an ideal manner, basement backups and surface flooding would still have occurred in GLWA’s system, or any other collection system designed to today’s standard. This standard reflects a collection system designed to handle 1.7 inches of rain in one hour (with no rain before/no rain after) or 3.31 inches in 24 hours. On June 25, more than six inches was experienced in only half that time, which is double the maximum design standard for 24 hours.

“The unprecedented rain events of last summer are a real-life example of the devastating impacts that climate change can have on our communities,” said Suzanne R. Coffey, Interim Chief Executive Officer, GLWA. “It is likely that we will continue to see more intense storms at a greater frequency. While it is not possible to eliminate the chance of flooding given these circumstances, we are taking actions that can help mitigate the extent of the flooding.”

Over the last year, GLWA took the following actions to improve climate resiliency in the regional system in the short-term:

  • Installed three new transformers at the Freud Pump Station and successfully converted the external power supply feeding the transformers to DTE Energy power via three independent power feeds;
  • Converted external power such that all wastewater facilities operated by GLWA in the collection system are serviced by DTE Energy;
  • Installed Power Quality Monitoring Systems (PQMs) on the Conners Creek, Freud and Blue Hill Pump Stations and all wet weather treatment facilities, which provide advance notice regarding power outages and help in diagnostics of power quality-related issues;
  • Developed additional operational strategies to improve system response for larger rain events;
  • Reviewed and recalibrated instrumentation throughout the system;
  • Reinspected approximately more than 20 miles of the regional system, which is about 13 percent of the total GLWA regional sewer system;
  • Increased frequency of notification of extreme wet weather events to the public through digital channels and the media;
  • Expanded coordination with member partner communities on both the eastside and westside of the regional system, including establishing lines of communication with public works directors to optimize flow through the regional system;
  • Ongoing government outreach to discuss resources available for flood mitigation, including more than two dozen meetings with state and federal legislators. Initial outcomes of this outreach include a $27 million in appropriations from state and federal budgets for wastewater collection system improvements.

GLWA has also begun working with its legislators to identify funding at the federal level for a Flood Risk Mitigation Study for southeast Michigan. The comprehensive feasibility study, which will be conducted in partnership with the Army Corps of Engineers, would evaluate the implementation of concepts such as wastewater storage at grade or deep tunnel levels, using pumping stations for discharge, constructing large diameter relief sewers, and strategic sewer separation to address the long-term impacts of climate change.

Contained within the Independent Investigative Team’s report was a series of short-, medium-, and long-term operational and programmatic recommendations. GLWA will immediately begin reviewing these recommendations to see if there are items: 1) that have already been accomplished, 2) can help inform adjustments/improvements to currently underway projects, 3) offer new approaches to ongoing concerns, or 4) are not entirely feasible within the operation of the regional system.

With the independent investigation complete and the report presented to the GLWA Board, the Authority expects to make a decision on claims within the next several weeks.


About the Great Lakes Water Authority (GLWA)

The Great Lakes Water Authority (GLWA) is the provider-of-choice for drinking water services to nearly 40 percent, and efficient and effective wastewater services to nearly 30 percent, of Michigan’s population. With the Great Lakes as source water, GLWA is uniquely positioned to provide those it serves with water of unquestionable quality. GLWA also has the capacity to extend its services beyond its 88 member partner communities. As part of its commitment to water affordability, the Authority offers a Water Residential Assistance Program to assist low-income households in participating member communities throughout the system. GLWA’s board includes one representative each from Oakland, Macomb and Wayne counties, two representatives from the city of Detroit, and one appointed by the Michigan governor to represent member partner communities outside of the tri-county area.