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Whatcom County, WA Environmental Rules: Flood Zones (2026)

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

FEMA flood zone rules in Whatcom County, WA, also called floodplain regulations or special flood hazard area (SFHA) rules, determine flood insurance requirements and elevation standards for new construction.

Key Facts

Program
National Flood Insurance Program
County Rule
WCC 16.16 frequently flooded areas
State Law
Flood Control Zone Act, RCW 86.16
Requirement
Lowest floor above BFE
Floodway
No new residential structures

Summary

Whatcom County enforces floodplain rules along the flood-prone Nooksack River. In FEMA Special Flood Hazard Areas, new homes must sit above base flood elevation, building in the floodway is barred, and a floodplain development permit is required.

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

Every county and incorporated city and town shall submit to the department of ecology any new floodplain management ordinance or amendment to any existing floodplain management ordinance.

Source: Revised Code of WashingtonView official code

Full Breakdown

Whatcom County participates in the National Flood Insurance Program, and its frequently flooded areas are regulated under the Critical Areas Ordinance, WCC 16.16. The Nooksack River floods recurrently, most severely in the November 2021 event that inundated Everson, Nooksack, and Sumas, so floodplain rules are enforced closely. Properties in FEMA-mapped Special Flood Hazard Areas must meet minimum construction standards: new and substantially improved structures need their lowest floor elevated above base flood elevation, and a floodplain development permit is required for building, fill, or grading. Washington's Flood Control Zone Act, RCW 86.16, has Ecology review local floodplain ordinances. New residential construction in the mapped floodway is prohibited, and flood insurance is required for federally backed mortgages.

Violations & Fines

Building below base flood elevation, or placing fill or structures in the floodway without a floodplain development permit, violates county rules and NFIP standards, forcing corrective elevation, removal, and loss of insurance eligibility.

Frequently Asked Questions

Is my Whatcom County property in a flood zone?
Check the FEMA Flood Map Service Center or the county Planning Division. Much of the lower Nooksack River valley sits in mapped Special Flood Hazard Areas.
Can I build in the Nooksack floodway?
New residential construction in the designated floodway is prohibited. Only limited repairs that do not increase floor area or exceed half the structure's value are generally allowed.

Sources & Official References

Other rules in Whatcom County

All Whatcom County rules

Compare Whatcom County to another location·View the Washington environmental rules overview

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