St. Louis Region
MSD is a separate stormwater and sewer layer
St. Louis County utility questions often include a layer that is not the county government or the city hall. MSD Project Clear says MSD provides wastewater collection and treatment and also operates and maintains separate storm sewer systems serving much of the St. Louis County area.
For a homeowner, that means a sewer or stormwater issue may point to MSD even when the address is in a municipality. It also means stormwater is not just a private drainage complaint. MSD says stormwater can carry pollutants into lakes, creeks, and rivers, and the district helps regulate and improve that system regionally.
The practical move is to check MSD when a problem involves sewer service, storm drains, or runoff, then check the municipality for street or code issues.
References
More from St. Louis County: browse every local note for the county.
Last checked against the sources above: July 16, 2026.