San Francisco Floodplain Administration

As the designated Floodplain Administrator, the City Administrator’s Office:

• communicates with the Federal Emergency Management Agency (FEMA) about the National Flood Insurance Program (NFIP) and the Flood Insurance Rate Map (FIRM)
• coordinates the City's implementation of the Floodplain Management Ordinance
• notifies FEMA and the state NFIP Coordinator of physical changes that can affect flooding conditions

and other responsibilities.

The City and County of San Francisco is a participant in the National Flood Insurance Program (NFIP), which is managed by the Federal Emergency Management Agency (FEMA).  Under this program, homeowners, renters, and businesses in San Francisco are eligible to purchase federally subsidized flood insurance to protect their properties.

Under Federal laws, flood insurance is required only for structures in San Francisco meeting both of these conditions:

1. Located in Special Flood Hazard Areas (SFHAs) as designated in the Flood Insurance Rate Map (FIRM). Learn more
2. Have mortgages from federally backed or federally regulated lenders

Learn how to buy flood insurance and how much it costs

Otherwise, flood insurance purchase is voluntary. Homeowners, tenants, and business owners in areas of the City that are at risk of flooding are encouraged to purchase flood insurance because general hazard insurance does not cover flood damage.

Find out if your property is at risk of flooding in a major rainstorm

To support the NFIP, FEMA publishes Flood Insurance Rate Maps (FIRMs) that are used for flood insurance and floodplain management purposes in participating communities. FIRMs show Special Flood Hazard Areas (SFHAs) that are defined as areas subject to inundation during a flood having a 1-percent chance of occurrence in any given year (also referred to as the Base Flood or 100-year flood).

In San Francisco, the FIRM has been “effective” (that is, formally published and required for use for flood insurance and floodplain management purposes) since March 23, 2021.

The final FIRM designates coastal flood hazard zones for portions of the waterfront piers, Mission Bay, Islais Creek, Bayview Hunters Point, Hunters Point Shipyard, Candlestick Point, Treasure Island, San Francisco International Airport, and Ocean Beach.

Learn what is required if your property is in a Special Flood Hazard Area

As a condition of participating in the NFIP, the City adopted and enforces a Floodplain Management Ordinance (No. 226-20) to reduce the risk of damage from flooding.

To develop the Floodplain Management Ordinance, the City Administrator led a Citywide Floodplain Management Working Group that included the Airport, Department of Building Inspection, Office of Community Investment and Infrastructure, Planning Department, Department of Public Works, Port of San Francisco, San Francisco Public Utilities Commission, and the City Attorney’s Office.

The ordinance requires that, in federally designated flood hazard areas, new construction of and substantial improvements to buildings must be protected against flood damage. It also prohibits uses that would increase flood risks. The ordinance provides for variances for exceptional circumstances, including historic preservation, maritime uses, and extraordinary hardship. In general, the Floodplain Management Ordinance:

• Requires the first floor of a new or substantially improved residential structure in a SFHA to be constructed above the Base Flood Elevation.
• Requires the first floor of a new or substantially improved non-residential structure in a SFHA to be constructed above the Base Flood Elevation, or to be floodproofed.
• Ties the construction standards required by the more stringent floodplain management requirements to the San Francisco Building Code, which incorporates flood design standards published in American Society of Civil Engineers (ASCE) 24.
• Provides for variances in exceptional circumstances, including historic preservation, maritime uses, and extraordinary hardship.
• Applies to areas outside of the City where the City owns property and/or facilities and must enforce floodplain management requirements based on the SFHAs shown on the FIRMs for the counties in which those properties/facilities are located.

The City Administrator’s Office is working with other City agencies and departments to ensure that floodplain management requirements are being incorporated into ongoing planning for projects in flood-prone areas.

Comply with floodplain management requirements