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

501(c) sets the elevation and floodproofing standards that apply throughout the City's special flood hazard areas. For residential construction, all new construction or substantial improvements must have the lowest floor, including any basement, elevated to or above the base flood elevation in Zones AE, AH and A1-30. 402(c). Once construction is complete, a registered civil engineer or licensed land surveyor must certify the elevation of the lowest floor, and the City's Building Official verifies that the structure was properly elevated before that certification and verification go to the Floodplain Administrator.

Nonresidential structures have an alternative: instead of elevating to the same height, they can be floodproofed so the structure is watertight, with walls substantially impermeable to water and structural components able to resist hydrostatic and hydrodynamic loads, certified by a registered civil engineer or architect. Enclosed areas below the lowest floor that are used only for parking, building access or storage must have flood vents, at least two openings on different walls providing one square inch of net area per square foot of enclosed area, with the bottom of each opening no higher than one foot above grade, so hydrostatic pressure equalizes automatically during flooding.