Southfield, MI Environmental Rules: Flood Elevation Requirements (2026)

Southfield's freeboard standard sits inside the Floodplain Fringe District rules of § 5.49(6)(b), the zone where ordinary development is allowed but only under added flood-resistance conditions. Paragraph 1 sets the core elevation rule: the lowest floor designed or intended for human habitation or employment, including a basement, must be at least three feet above the elevation of the floodplain. That elevation requirement pairs with several companion standards in the same subsection. Any filling of the floodplain fringe needs erosion controls approved by the city engineer so soil does not wash into the regulatory floodplain or channel, and dumping or backfilling is otherwise prohibited unless compensating excavation keeps the fringe's flood-carrying capacity intact.

Substantial improvements must be designed and anchored against flotation, collapse, or lateral movement, built with flood-damage-resistant materials, and constructed using methods that minimize flood damage; water supply and sanitary sewage systems serving the property must be designed to minimize infiltration by floodwater and to avoid discharging into it. Paragraph 9 puts a recordkeeping duty on the city itself: the city engineer must obtain and record the actual elevation, relative to mean sea level, of the lowest habitable floor, including basements and cellars, of every new or substantially improved structure in the fringe.

Certain especially vulnerable uses, hospitals, senior citizen housing, nursing homes, schools, and toxic material storage, are barred from the Floodplain Fringe District outright under paragraph 10 because of how hard they are to evacuate during flooding.