skip to main content

Flooding services

King County, Washington

To offer a suggestion or report an error on the King County flooding services and information website, please contact Fred Bentler, webmaster.

Flooding services and information in King County, WA

Preliminary Flood Insurance Rate Maps and Flood Insurance Study
King County, Washington

MapThe Federal Emergency Management Agency has produced Preliminary Flood Insurance Rate Maps (FIRMs) and Flood Insurance Study (FIS) for the incorporated and unincorporated areas of King County.

The four volumes (PDF) of the February 1, 2013 Flood Insurance Study (FIS) includes revisions to these areas: The Sammamish River and tributaries (Bear Creek, Evans Creek, North Creek, Swamp Creek), Coastal areas (Vashon Island and mainland), White River (from ¼ mile downstream of Hwy 410 near Enumclaw to the Outlet Works at Mud Mountain Dam).
Volume 1
Volume 2
Volume 3
Volume 4

The four volumes (PDF) of the November 6, 2010 Flood Insurance Study (FIS) includes all floodplain areas in King County.
Volume 1
Volume 2
Volume 3
Volume 4

Part of the national Map Modernization Program, the new digital maps can be used with geographic information systems. The mapped information is widely used by lending institutions and insurance agents in determining who must purchase flood insurance and the cost of that insurance should it be necessary. In addition, the maps will be used by the county and local communities for floodplain management and permitting purposes.

The most recent Preliminary FIRMs are dated February 1, 2013 and reflect areas where mapping studies that have occurred over the past few years. All other areas in King County are included the Preliminary FIRMs dated November 6, 2010.

If you have questions about the Map Modernization Program, please contact Ted Perkins, FEMA Regional Engineer, 425-487-4684.

If you would like information about King County’s floodplain mapping program please contact: