Flood Zone Determination Website - Information

The Los Angeles County Flood Zone Determination Website allows you to see the Federal Emergency Management Agency (FEMA) flood zones on your property, and whether your property is within a Los Angeles County Capital Flood floodplain.

FEMA Flood Zones

FEMA publishes Flood Insurance Rate Maps (FIRMs) depicting areas subject to different types and levels of flooding hazards. The FIRMs are used to determine if there is a federal mandate to have flood insurance for structures receiving federally backed loans or funding. The FIRMs are also used to regulate development of properties (including but not limited to activities requiring building and grading permits) to ensure they are appropriately resilient for the flooding events that are the most likely to occur on the properties, and do not increase flood hazards to others.

Click here for FEMA Flood Zone Definitions.

The latest Flood Insurance Study (FIS) report for Los Angeles County was issued by FEMA on June 2, 2021. The FIS report is a collection and presentation of flood hazard data for specific watercourses, lakes and coastal areas in the communities within Los Angeles County participating in the National Flood Insurance Program. The FIS report contains useful information, including detailed flood elevation profiles and data tables upon which the FIRMs in Los Angeles County are based, and discussion of the engineering methods used in preparing the FIRMs, flood profiles and data tables.

The FIS report consists of nine volumes: Vol. 1, Vol. 2, Vol. 3, Vol. 4, Vol. 5, Vol. 6, Vol. 7, Vol. 8, Vol. 9

To learn more about the County’s participation in FEMA’s National Flood Insurance Program, go to website: pw.lacounty.gov/WMD/NFIP.

County Capital Flood Severe Flood Hazard Areas

In addition to the FEMA FIRMs, Los Angeles County has adopted County Floodway Maps to identify additional potential severe flood hazard areas associated with the County’s Capital Flood. The County Floodway Maps are not used to determine federal flood insurance mandates. The maps are used to regulate development (including not limited to activities requiring building and grading permits) within the Capital Flood floodplain.