El Dorado County, CA Environmental Rules: Flood Zones (2026)

El Dorado County participates in the National Flood Insurance Program (NFIP) and administers a floodplain management ordinance consistent with 44 CFR Part 60 minimum requirements. The County's Planning and Building Division maintains the FEMA Flood Insurance Rate Maps (FIRMs) for the unincorporated area and administers floodplain development permits. Most of El Dorado County is steep mountain or foothill terrain in the State Responsibility Area, so the mapped Special Flood Hazard Area (SFHA) is generally limited to the floodplains and floodways of larger waterways and their tributaries - including the South Fork American River, the Cosumnes River, Weber Creek, Webber Creek, Hangtown Creek, and various Lake Tahoe tributaries on the east side. Flood Zone designations follow FEMA standards: Zone A (1% annual chance flood, BFE not determined), Zone AE (1% annual chance flood, BFE determined), Zone AO (sheet flow, depth in feet specified), Zone X shaded (0.2% annual chance, the 500-year), and Zone X unshaded (minimal flood hazard). Within Zone A, AE, and AO (the SFHA), federal NFIP rules and the County's floodplain ordinance apply: any new construction, substantial improvement (50% or more of structure value), or substantial repair of damage requires a floodplain development permit. The lowest floor of a residential structure in the SFHA, including basement, must be elevated at or above the BFE (44 CFR Section 60.3). Non-residential structures may be elevated or dry-floodproofed. An Elevation Certificate prepared by a licensed surveyor or engineer is required at permit application and as-built. Manufactured homes have specific anchoring and elevation requirements. Federal regulations and the California Cobey-Alquist Floodplain Management Act (California Water Code Section 8400 et seq.) also restrict encroachment in the regulatory floodway. Federally backed mortgages on structures in the SFHA require flood insurance under the Flood Disaster Protection Act. Within the Lake Tahoe Basin, TRPA Code of Ordinances adds stream environment zone (SEZ) protections that further limit development near waterways.