Redding, CA Environmental Rules: Flood Elevation Requirements (2026)

080 sets the construction standards that apply throughout the floodway and flood fringe. Residential structures and their accessories in zones A, AE, AO, or A1-30 must have their lowest floor, including the basement and any utility equipment servicing the building, elevated at least one foot above the base flood elevation as shown on the FIRM maps or the city's Master Storm Drain Study, whichever number is higher. Nonresidential buildings can meet the same elevation or instead be floodproofed watertight below that height, with structural components certified to resist hydrostatic and hydrodynamic forces.

Any new construction with an enclosed area below the lowest floor used only for parking, access, or storage needs at least two flood-vent openings on different walls, sized to at least one square inch of net opening per square foot of enclosed area, with the bottom of each opening no higher than one foot above grade. An elevation certificate on FEMA Form FF-206-FY-22-152 is required before a building permit is issued, again after the foundation is poured, and a final certificate before occupancy; skipping that paperwork is grounds for a stop-work order.

Levees get their own freeboard standard: three feet above the base flood water surface, with an extra foot required within a hundred feet of any bridge or other flow-constricting structure, tapering to no less than the three-foot minimum by the downstream end. Manufactured homes placed in the mapped floodplain must sit on a permanent foundation with the lowest floor at least one foot above the base floodplain elevation and be anchored against flotation and lateral movement.