FEMA flood map notices

Flood map changes in Alameda County, California

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

Notices for Alameda County

Jul 9, 2026Map revisionChanges in Flood Hazard DeterminationsAlso covers 29 other counties
May 18, 2026Map revisionChanges in Flood Hazard DeterminationsAlso covers 29 other counties
Jan 29, 2026FinalFinal Flood Hazard DeterminationsAlso covers 3 other counties
Jan 16, 2025Map revisionChanges in Flood Hazard DeterminationsAlso covers 20 other counties
Jan 8, 2025ProposedProposed Flood Hazard DeterminationsAlso covers 1 other county · Appeal period closed Apr 8, 2025
Dec 6, 2024Map revisionChanges in Flood Hazard DeterminationsAlso covers 14 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