Elk Grove, CA Environmental Rules: Flood Elevation Requirements (2026)

EGMC Section 16.50.060(C) sets the elevation standards that apply once a project sits inside a FEMA-mapped special flood hazard area and needs a floodplain development permit under Section 16.50.050. For all new subdivisions, manufactured home parks, and other new development, subsection (C)(1)(d) requires the lowest finished floor to sit at least two feet above the base flood elevation (BFE), the surface elevation of the flood having a one-percent annual chance of occurrence. Building pads for slab-on-grade construction must reach at least one and one-half feet above the BFE before that two-foot finished-floor freeboard is even measured. Critical infrastructure, the code names nursing homes and hospitals as examples, has to clear three feet above the BFE or the elevation of the 500-year floodplain, whichever produces the higher elevation.

In areas without FEMA-mapped BFEs, subsection (C)(1)(e) still requires two feet of freeboard above a BFE the Floodplain Administrator establishes under Section 16.50.030(B)(4), and slab-on-grade pads in those unmapped areas must also clear two feet above that administratively determined BFE. Where a developer proposes to raise a site above the BFE using fill, subsection (C)(1)(f) requires filing a conditional letter of map revision based on fill (CLOMR-F) with FEMA before the City treats the site as elevated. Elevation of new floor area on remodels to existing structures is handled separately under Section 16.50.060(A)(3)(a): two feet of freeboard in Zone AE or AH, the FIRM depth number or two feet in Zone AO, and BFE compliance in unmapped A Zones. All new floor elevations must be certified by a registered civil engineer or licensed land surveyor and the certification filed with the Floodplain Administrator.