Lake County, CA Environmental Rules: Flood Elevation Requirements (2026)

Chapter 25 of the Lake County Ordinance Code applies to all areas of special flood hazard mapped on FEMA's Flood Insurance Rate Maps and Flood Boundary and Floodway Maps for the county, based on the Flood Insurance Study dated September 30, 1992 (Sec. 2). Under Sec. 1(c)(1), new or substantially improved residential construction must have its lowest floor, including any basement, elevated at least one foot above the base flood elevation in an A zone (as determined by the Floodplain Administrator) and in all other zones; in an AO zone the floor must clear the FIRM depth number by at least one foot above the highest adjacent grade or nearest downstream road.

Sec. 1(b)(3) additionally requires electrical, heating, ventilation, plumbing and air-conditioning equipment to be elevated at least one foot above base flood elevation, and Sec. 1(c)(1)(iv) requires flood-resistant materials and methods in any enclosed area below base flood elevation plus one foot. Once built, the lowest-floor elevation must be certified by a registered professional civil engineer or licensed land surveyor on FEMA's current Elevation Certificate form, submitted to both the Chief Building Official and the Floodplain Administrator (Sec. 1(c)(1)). Nonresidential structures may instead be floodproofed watertight below that elevation, with structural components able to resist hydrostatic and hydrodynamic loads, certified by a registered civil engineer or licensed architect (Sec.

1(c)(2)). No development permit in a Special Flood Hazard Area may issue without review by the Floodplain Administrator, a role assigned to the Director of the Lake County Flood Control and Water Conservation District (Sec. 2). A property owner seeking relief from these standards must apply for a variance, which under Sec. 1(b) carries a $350 fee payable to the Flood Control and Water Conservation District; appeals of Floodplain Administrator decisions cost $300 (Sec. 1(a)).