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Flood Hazard Maps Start
Flood Risks
Do you live or work in a floodplain? Flood hazard maps
help determine the flood risk to your home or business.
More about flood risks
The Department of Ecology highly recommends contacting
the community Floodplain Administrator, Community Development Director, or Public
Works Department for specific flood risks and regulations.
Flood Insurance Rate Maps (FIRMs):
FIRMs outline flood hazards in a community. A FIRM may include flood insurance risk
zones, 1% and 0.2% annual chance floodplains, floodways, base flood elevations or
depths, roads, streams, and more. They are developed by FEMA.
Data comes in two forms:
- DFIRM database product: Digital
FIRM. These are gradually being updated by county.
- Digital Q3 flood data product:
The current FIRM if there is no DFIRM for a county.
MAP TERMS
Floodway:
Stream channel, plus floodplain areas, that must be kept free from building so the
1% annual chance of flood can occur without increasing flood heights.
1% annual chance flood:
1% annual chance of flooding may be equaled or exceeded in any given year (100 year flood).
Velocity zone:
These areas are subject to high velocity wave action (a 3-foot breaking wave) from the 1% annual chance coastal flood.
High-risk zones are areas that have a 1% chance of flooding each year.
If you live in a Special Flood Hazard Area or high-risk
area and have a Federally-backed mortgage, your mortgage lender requires you to
have flood insurance.
More about flood insurance