An Integral Partner in Flood Control

The Federal Emergency Management Agency (FEMA), created in 1979, is an agency of the US Department of Homeland Security. Its purpose is to “prepare for, protect against, respond to and recover from” disasters that are large enough to strain local and state agencies, such as earthquakes, fires, floods, and other natural and man-made hazards.

The District works closely with FEMA to safeguard Alameda County citizens from potential flooding. For example, the District is currently working with FEMA to evaluate all levees in western Alameda County to ensure they meet new FEMA requirements. The District is also working toward complying with FEMA’s new, more stringent flood control standards.

Flood Insurance Rate Maps (FIRMs)

FEMA maintains Flood Insurance Rate Maps (FIRMs) that indicate flood zones and floodplain boundaries across the United States. FEMA updated its FIRMs in 2011 with stricter criteria for flood control boundaries.

As one of the Cooperating Technical Partners, the District has assisted FEMA in the development of FIRMs in western Alameda County. District staff has, in some instances, reanalyzed FEMA’s studies to more accurately depict hydrologic conditions.

Property owners in high-risk flood zones, such as Special Flood Hazard Areas, are encouraged to carry flood insurance. In fact, FEMA requires property owners with federally secured mortgages within the new flood boundaries to carry flood insurance (effective August 1, 2009).

The District develops flood control projects to help lower the risk of potential flooding to a 100-year flood level (meaning the potential for flooding is 1 percent in any given 100-year period). When these projects are complete, FEMA changes its FIRMs accordingly so that properties that were once in high-risk areas are reassigned to lower-risk categories.

National Flood Insurance Program (NFIP)

FEMA manages the National Flood Insurance Program (NFIP). The program lets property owners in participating communities, such as Alameda County, buy insurance to protect against losses from flooding.

Alameda County can participate in the program because the District has committed to taking additional steps to enforce a floodplain management ordinance that reduces flood risk to new construction in Special Flood Hazard Areas.

Special Flood Hazard Areas are indicated on FIRMs. Property located in a Special Flood Hazard Area has a 26 percent chance of flooding over a 30-year period, the length of most mortgages.

Owners of property located in a Special Flood Hazard Area within unincorporated Alameda County may be eligible for a 15 percent reduction in the cost of flood insurance because of the District’s participation in FEMA’s Community Rating System program.


Is Your Property Affected by FEMA Flood Map Revisions?

Advisory: FEMA Revises Preferred Risk Policy for Property Owners
Eligible property owners of buildings that have been newly mapped into high-risk flood zones due to a map revision on or after October 1, 2008, and before January 1, 2011, are eligible to receive a Preferred Risk Policy (PRP) for two policy years effective between January 1, 2011, and December 31, 2012. Learn more.

District Letter to Concerned Parties

Properties Newly Designated Within High-Risk Flood Zones
Should you have flood insurance? Click on the lists below to see if your property address appears on the 2009 FEMA Flood Insurance Rate Map of Unincorporated Alameda County:

  • List 1—Properties in Castro Valley
  • List 2Properties in Castro Valley, Hayward, and San Lorenzo