Yuba City, CA Environmental Rules: Flood Elevation Requirements (2026)

401. In an A zone where FEMA has not determined base flood elevations, the floor must sit at least one foot above the base flood elevation as the Floodplain Administrator determines using FEMA's approximate Zone A methodology; in every other zone, the same one-foot freeboard above base flood elevation applies. In an AO zone, the standard instead ties to the depth number printed on the Flood Insurance Rate Map, requiring elevation above the highest adjacent grade that exceeds that depth number by at least one foot, or at least three feet above the highest adjacent grade if no depth number is shown.

A registered professional engineer or surveyor must certify the lowest floor elevation at the first form inspection, with that certification provided to the Floodplain Administrator, the Public Works Director. Nonresidential buildings may instead be floodproofed watertight below that same elevation if a registered engineer or architect certifies the structure meets the floodproofing standard. 504: homes placed or substantially improved on sites in zones A1-30, AH, and AE on Sutter County's Flood Insurance Rate Map, whether outside a park, in a new or expanded park, or replacing a home with substantial flood damage, must sit on a permanent foundation with the lowest floor at least one foot above base flood elevation and be securely anchored against flotation, collapse, and lateral movement. In an existing manufactured home park, the alternative is a chassis on reinforced piers at least 36 inches above grade, also securely anchored.