St. Louis Region
Franklin County floodplain work starts with map and permit checks
A dry-looking lot near a creek can still carry floodplain paperwork. In unincorporated Franklin County, floodplain administration and flood plain development permit requests run through Planning and Zoning, while FEMA maps are the outside reference for the mapped flood risk.
Use both pieces before buying, building, or filling land near water. A FEMA flood-map lookup covers the mapped-risk side for an address or parcel. Franklin County Planning and Zoning handles the local development steps outside city limits.
The risk is not only whether the ground looks wet. A regulated floodplain can affect permits, lender questions, insurance, and the shape of a project. Getting the map and local permit path in the same conversation makes the next step clearer.
References
More from Franklin County: browse every local note for the county.
Last checked against the sources above: July 16, 2026.