LaPorte County, IN Environmental Rules: Flood Elevation Requirements (2026)

The county's floodplain ordinance defines the flood protection grade (FPG) as the regulatory flood elevation plus two feet of freeboard. 41, a new residential structure or manufactured home, or one undergoing substantial improvement, must have its lowest floor, including a basement, at or above the FPG. Commercial, industrial and other non-residential structures must either be elevated to the FPG or floodproofed to that level, with a registered professional engineer or architect certifying to the Floodplain Administrator that the design is watertight and can resist flood forces including velocity, duration, hydrostatic pressure and debris or ice impact.

The building-protection requirement is triggered by any new structure over 400 square feet, an addition or improvement costing 50% or more of the structure's value, repairs after damage costing 50% or more of market value, installing a travel trailer or RV on a site for more than 180 days, placing a manufactured home on a new site, or work on a repetitive-loss structure. Elevated structures with enclosed areas below the FPG must include flood-vent openings totaling at least one square inch per square foot of enclosed area, sited in at least two exterior walls, with owners required to record a flood-openings affidavit with the LaPorte County Recorder.

A floodplain development permit is required before any development activity begins in a special flood hazard area, and the Floodplain Administrator conducts periodic inspections to confirm the vents are maintained.