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

Section 15.08.170 sets the construction standard that applies once a project needs the development permit required by Section 15.08.130. Residential new construction or substantial improvement must have its lowest floor, including any basement, elevated to or above the base flood elevation in an A zone or in any zone other than AO. In an AO Zone, shown on the Flood Insurance Rate Map with a shallow-flooding depth number, the floor must clear the highest adjacent grade by that depth or by at least two feet if the map lists no depth number.

Nonresidential construction may instead be floodproofed below the required elevation so the structure is watertight, with walls substantially impermeable to water and structural components able to resist hydrostatic and hydrodynamic loads; a registered professional engineer must certify that the floodproofing standard is met. Whichever path is used, a registered professional engineer or surveyor must certify the as-built lowest-floor elevation, and the community building inspector verifies the structure was properly elevated before that certification goes to the Floodplain Administrator. Enclosed areas below the lowest floor used only for parking, building access, or storage must be designed to let floodwater automatically enter and exit, either through engineer certification or a minimum of two openings totaling at least one square inch of net area per square foot of enclosed space, with opening bottoms no higher than one foot above grade.

Manufactured homes carry a separate elevation standard under Section 15.08.200, and floodway encroachments under Section 15.08.220 cannot raise the base flood water surface elevation by more than one foot at any point. The chapter sets these as minimum requirements under Section 15.08.100 and does not guarantee properties outside a mapped zone will stay dry.