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Whatcom County, WA Environmental Rules: Flood Elevation Requirements (2026)

Some Restrictions
Compiled from the official code textEditor Martyn O'NeillLast verified September 2026

Key Facts

Freeboard rule
base flood elevation + 1 foot
Permit required
floodplain development permit, § 17.12.010
Residential rule
lowest floor, incl. basement, to FPE
Nonresidential option
dry floodproof to FPE, § 17.16.090
Data source
FEMA Flood Insurance Study, Jan. 18, 2019
Default freeboard
2 ft above grade if no FEMA data

Summary

In Whatcom County's mapped special flood hazard areas, the flood protection elevation is base flood elevation plus one foot, and new or substantially improved residential structures must have their lowest floor, including basement, built to or above that line under WCC § 17.10.020(D) and § 17.16.080(A).

City-specific rules exist: Bellingham has its own flood elevation requirements rules that differ from Whatcom County's county-level regulations. If you live in Bellingham, check the city-specific page instead.

D. The flood protection elevation shall be the base flood elevation plus one foot. ... A. New construction and substantial improvement of any residential structure shall have the lowest floor, including basement, elevated to or above the flood protection elevation, as determined in accordance with WCC § 17.10.020(D).

View official code

Full Breakdown

010). 020(A), (D)). 020(F)). 010). 080(B)). 090). 16 provisions on coastal high hazard areas). Applicants who cannot meet these standards may seek a variance, but any variance grant comes with written notice that flood insurance costs will rise because of the reduced elevation.

Violations & Fines

No structure or land may be constructed, extended, converted or altered in an SFHA without full compliance with Title 17 and a floodplain development permit (WCC § 17.04.080, § 17.12.010). Building below the required flood protection elevation without an approved variance exposes the owner to higher federal flood insurance premiums and can make a structure ineligible for standard-rate NFIP coverage. An administrator's interpretation of SFHA boundaries or a permit decision may be appealed to the Whatcom County hearing examiner (WCC § 17.10.010(B), § 17.12.060).

Frequently Asked Questions

How high above base flood elevation must I build in Whatcom County's floodplain?
One foot. WCC § 17.10.020(D) sets the flood protection elevation at the base flood elevation plus one foot, and WCC § 17.16.080(A) requires new or substantially improved residential structures to have their lowest floor, including any basement, built to or above that flood protection elevation.
Do I need a permit before building in a Whatcom County flood hazard area?
Yes. A floodplain development permit must be obtained from the county before construction or development begins within any mapped special flood hazard area, per WCC § 17.12.010. It can be issued as conditions within another required county permit if one applies to the same project.
Can a commercial building floodproof instead of elevating in Whatcom County?
Yes. WCC § 17.16.090 lets new or substantially improved nonresidential structures either elevate the lowest floor to the flood protection elevation or be dry floodproofed watertight to that elevation, with the design certified by a registered professional engineer.
What if FEMA hasn't mapped a base flood elevation for my Whatcom County property?
The administrator must obtain and use the best available federal, state or local elevation data (WCC § 17.10.020(F)). If none exists, the flood protection elevation defaults to two feet above the highest adjacent grade, and failure to reach that height can raise flood insurance rates.

Sources & Official References

Other rules in Whatcom County

Fence Regulations: Height LimitsSome RestrictionsStormwater ManagementSignificant RestrictionsErosion ControlSome RestrictionsBoat Dock PermitsSignificant RestrictionsCoastal DevelopmentHeavy RestrictionsFlood ZonesHeavy RestrictionsNoise Ordinances: Decibel LimitsSome RestrictionsNoise Ordinances: Barking DogsSome RestrictionsParking Rules: Loading ZonesSome RestrictionsParking Rules: Driveway RulesSome RestrictionsParking Rules: EV ChargingLight Restrictions

All Whatcom County rules

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Flood Elevation Requirements in Cities Across Whatcom County

Bellingham, WA