FEMA Floodplain Management Program

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The Contra Costa County Floodplain Management Program is for unincorporated County areas only. Engineering Services Division coordinates the program and provides floodplain information for existing structures and proposed projects within the Special Flood Hazard Area (SFHA).

In July 1987, the Federal Emergency Management Agency (FEMA) produced a Flood Insurance Study (FIS) and printed Flood Insurance Rate Maps (FIRMs). These watersheds are re-studied and re-mapped periodically, showing areas with a one percent chance of flooding each year. These areas are commonly referred to as "100-year floodplains," and are shown as SFHAs on the FIRMs. Flood insurance is mandatory for residential, commercial, and industrial developments within SFHAs, and for federally-backed mortgages. Flood insurance may also be required by lenders.

In compliance with the National Flood Insurance Program (NFIP), the County adopted a Floodplain Management Ordinance. This Ordinance requires that the lowest floor, including basement, for all new structures or substantial improvements to existing structures within a SFHA, shall be elevated one to two feet above the 100-year Base Flood Elevation (BFE) for that area. Lower insurance rates are available when the lowest floor is above the BFE.

Visit the FEMA website and the FloodSmart website for information on the NFIP. These websites offer information on floodplains, flood insurance coverage for residential and commercial structures, and flood preparation and recovery. 

Visit the FEMA website to determine if your property is within the SFHA.

Public Works staff can determine your flood zone designation using available Assessor's Parcel Map, County base maps, FEMA information, and other documents or maps. The fee for this written determination is $100 per parcel. If a site visit is warranted, there will be an additional $400 plus time and material fee.

For the Flood Zone Determination (PDF), please have the address and/or parcel number, as well as the phone number, for the property in question available. The information provided in response to your request includes the FIRM designation, community number, panel number and effective date, base flood elevation (if available on the FIRM), and average depth of inundation.