MMSD Storm Update: April 2026

On April 14, 2026, the Greater Milwaukee area experienced intense rain combined with fully saturated ground conditions. This heavy rain throughout the day led to an initial round of combined and separate sewer overflows that night. Rainfall continued into April 15th, with a second storm system depositing an additional 3.63 inches of rain into the combined sewer area. With storage capacity reduced and additional precipitation forecasted, the decision was made to close the combined sewer gates to preserve remaining capacity for sanitary sewage and prevent basement backups. Continued rain and storms are forecasted for Greater Milwaukee through April 18, 2026.

MMSD Rain gauges show the volume of rain throughout MMSD's service area.

One inch of rain in MMSD's service area equals 7.1 billion gallons of water.

View a map of the impacted waters from the sewer overflow in the Greater Milwaukee area.