Caldwell, ID Environmental Rules: Flood Elevation Requirements (2026)

Caldwell's flood damage prevention ordinance defines Base Flood Elevation (BFE) at Caldwell City Code § 12-15-03 as the water-surface elevation of the flood having a one percent chance of being equaled or exceeded in any given year, determined by FEMA or FEMA-approved engineering studies. " Combined, BFE plus freeboard sets the Flood Protection Elevation (FPE) that governs construction. Under the specific standards at Caldwell City Code § 12-15-09(2)A, new construction, substantial improvements and development of any residential structure, including manufactured homes, located in a special flood hazard area where BFE data has been provided must have its lowest floor, including any basement, elevated no lower than the flood protection elevation.

Non-residential structures face the identical elevation floor under subsection (2)B, though they may floodproof to that elevation instead of physically raising the building, certified by a registered professional engineer or architect. Manufactured homes under subsection (2)C must have their lowest floor at or above the FPE and be anchored to resist flotation and lateral movement. Where no FEMA base flood elevation data exists for a Zone A area, subsection (3)D requires the lowest floor to be elevated or floodproofed to at least two feet above the highest adjacent grade.

Compliance is verified through an elevation certificate submitted to the Floodplain Administrator, who administers the article under Caldwell City Code § 12-15-07, including issuing floodplain development permits before construction begins. The article was adopted by Ordinance 3207 on March 4, 2019.