South Superior Stormwater Project

During July 1999, severe storms caused significant damage in ten northern Wisconsin Counties. During this period, approximately 4 inches of rain fell on South Superior in a span of two hours causing extensive flooding. The damage to city property was over $174,000, while homeowner property damages exceeded $400,000.

The South Superior sewer district is a combination of sanitary, storm sewers and combined sewers. In the past, severe storms have overwhelmed this combined sewer system causing sewer backups, sewer overflows and other flooding issues.

To reduce the potential for future flooding, to protect the health, safety, and welfare of the citizens of South Superior, and to protect the waters surrounding the City, a storm sewer interceptor and a detention basin began construction in 2004.

The goals of the interceptor project are to reduce the North 56th Street Combined Sewer Trunk stormwater burden and to increase capacity to handle projected flows from future development and separation projects. The Interceptor Project, completed in Summer 2005, terminates at the new water quality basin that provides treatment and attenuates peak flows.

The completed storm sewer interceptor now captures stormwater that used to run into the combined sewer line. This stormwater is redirected into a water quality basin before eventually being discharged into the Nemadji River, which runs through South Superior on its way to Lake Superior.

Shown below are aerial pictures of the completed project.