MMSD Storm Update: April 2026

The Milwaukee Metropolitan Sewerage District (MMSD) reported the following information to the Wisconsin Department of Natural Resources (WDNR) regarding overflows that occurred following record-breaking rainfall from April 14-18, 2026.

Post-Storm Report to WDNR April 14 – 19, 2026

How MMSD is Planning For Future Extreme Storms

The recent storms are part of a larger pattern of increasingly intense rainfall events in our region. MMSD is using data from these storms to analyze system performance, review infrastructure design standards, and adjust flood management strategies. Through the Executive Director’s Vision Forward 2035. MMSD is accelerating our flood management projects to better protect neighborhoods, rivers, and Lake Michigan from increasingly severe storms. 

Key Projects Being Accelerated

• West Basin Stormwater Management: Designed to hold 31 million gallons and reduce flooding up to a 100-year storm, this project will now start construction in 2027, two years ahead of the 2029 schedule in the most recent budget.  

• Jackson Park & Kinnickinnic River Project: Will increase the park’s storage from 30 million gallons to 80 million gallons, helping keep stormwater away from nearby homes. Construction is now scheduled to begin in 2027, four years earlier than planned in the most recent budget.  

• Wilson Park Flood Storage: Following the August floods, MMSD met with County Parks leadership, and both agreed this needed to be a priority. In December 2025, an agreement was reached with the respective governing bodies to move the project forward. Following discussions with County Parks, construction is now prioritized to start in 2031, four years earlier than the original 2035 schedule. The project will hold approximately 70 million gallons and provide critical protection for nearby neighborhoods.  

• Wilson Park Creek Reach 3: Significant progress has already been made, with about one-third of the work remaining to complete the basin, connect the river, and rebuild the 5th & 6th Street bridges. Final construction is planned for 2031–2032. 

These four project areas will add 220 million gallons of flood storage along our rivers. MMSD’s goal is to have zero homes or businesses in the 1%-probability floodplain, which carries a higher risk of flooding damage. Since 1995, MMSD flood management projects have resulted in 2,548 structures no longer remaining in the floodplain. As of 2026, 1,405 structures remain in flood-prone areas. Over the past 30 years, MMSD has invested $631 million in flood management projects. To complete the remaining work in the region, an estimated $907 million is needed.