Milwaukee Metropolitan Sewerage District

Weathering the Storm Where Rain Falls

In Milwaukee, one inch of rainfall amounts to 7.1 billion gallons of water. To control this influx of stormwater, the local utility, Milwaukee Metropolitan Sewerage District (MMSD), receives flows from two sewer systems – a combined system constructed over 130 years ago and a separate system built following World War II. Faced with sewer overflows and basement backups, MMSD made significant updates to these systems in 1993 by installing a network of over 19 miles of tunnels 300 feet below ground. Despite these massive investments and time-intensive infrastructure upgrades, the Milwaukee community continued to voice concerns about sewer overflows.

Responding ongoing concerns, MMSD decided to prioritize ratepayer involvement in a solution. MMSD recognized that because localized infrastructure can be installed right on a home or business owner’s property, it is more likely to gain public support since it is easily visible and accessible to the community. In 2002, MMSD began deploying localized strategies including bioswales, permeable pavement, stormwater trees, rain gardens, and more to help capture stormwater where it falls, reduce the strain on centralized infrastructure, minimize pollution caused by overflows, and improve water quality.