FEMA flood map notices

Flood map changes in Contra Costa County, California

FEMA has published 6 flood hazard notices covering Contra Costa County, California since November 2023. The most recent, map revision flood hazard determinations, was published Jul 9, 2026.

Notices for Contra Costa County

Jul 9, 2026Map revisionChanges in Flood Hazard DeterminationsAlso covers 29 other counties
Jun 11, 2026Map revisionChanges in Flood Hazard DeterminationsAlso covers 29 other counties
May 18, 2026Map revisionChanges in Flood Hazard DeterminationsAlso covers 29 other counties
Aug 23, 2024Map revisionChanges in Flood Hazard DeterminationsAlso covers 13 other counties
Apr 22, 2024Map revisionChanges in Flood Hazard DeterminationsAlso covers 18 other counties
Jan 5, 2024Map revisionChanges in Flood Hazard DeterminationsAlso covers 47 other counties

Also covered by these notices

FEMA often studies whole watersheds, so one notice can span several counties.

What these notices mean

Proposed: FEMA has new draft flood maps. This starts a 90-day window when owners can appeal with technical data. It's the best time to act.
Final: Appeals are resolved. The new maps usually take effect about six months later, when lenders start applying the new zones.
Map revision: A Letter of Map Revision changes one stretch of the map, often after a levee, channel project or new survey.

Notices are organized by county and community, so a notice for your county doesn't mean your property is changing zones. What flood zones mean