Hawthorne, CA Environmental Rules: Flood Zones (2026)

48, the city adopted FEMA's Flood Insurance Study for Los Angeles County and Incorporated Areas, dated December 2, 1980, along with its Flood Insurance Rate Maps and Flood Boundary and Floodway Maps, as the baseline for identifying flood-prone areas within city limits. That mapping data is kept on file at the building and safety department, 4455 126th Street. 100 requires a development permit for all proposed construction or other development in the community, including the placement of manufactured homes, so the city can determine whether the work falls inside a flood-prone area before it proceeds.

110 names the director of building and safety as the floodplain administrator, who grants or denies these permits. 120 include reviewing every application to confirm the permit requirements of the chapter are satisfied, that any other required state or federal permits have been obtained, and that the site is reasonably safe from flooding; the administrator must also notify adjacent communities and the California Department of Water Resources before any watercourse is altered or relocated, and must notify FEMA in writing of any annexation that changes the corporate boundary shown on flood maps.

130 requires new construction and substantial improvements, including manufactured homes, to be anchored against flotation, collapse, or lateral movement from hydrodynamic and hydrostatic loads, built with flood-damage-resistant materials, and designed so electrical, heating, plumbing, and HVAC equipment is placed to prevent water intrusion during flooding. 140 extends the same flood-minimization review to subdivision proposals and manufactured home parks, including utility placement and drainage adequacy.