Kirkland, WA Environmental Rules: Flood Elevation Requirements (2026)
Key Facts
- Residential freeboard
- 1 ft above BFE minimum
- Critical facility freeboard
- 3 ft above BFE
- Unnumbered A zone floor
- 2 ft above adjacent grade
- Permit needed
- Development permit, KMC 21.56.055
- Violation
- Misdemeanor, each day separate offense
- Enforcing office
- Building official
Summary
Kirkland requires new and substantially improved residential structures in special flood hazard areas to elevate the lowest floor, including any basement, at least one foot above the base flood elevation, with mechanical equipment and utilities waterproofed or raised to the same height. Critical facilities need three feet of clearance, and a development permit comes first.
In all areas of special flood hazards where base flood elevation data has been provided as set forth in Section 21.56.030 or 21.56.070(2), the following provisions are required: (1) Residential Construction. (A) New construction and substantial improvement of any residential structure shall have the lowest floor, including basement, elevated one foot or more above base flood elevation. Mechanical equipment and utilities shall be waterproof or elevated at least one foot above the base flood elevation.
Official source re-checked September 8, 2026: no newer edition of the code had been published (publisher’s edition: current through Ordinance 4945, passed July 21, 2026).
Full Breakdown
56, sets the elevation floor for anything built or substantially improved inside a mapped special flood hazard area. 090(1)(A), new construction and substantial improvement of a residential structure must have the lowest floor, including any basement, elevated one foot or more above base flood elevation (BFE), and mechanical equipment and utilities must be waterproofed or raised to that same one-foot freeboard. 090(1)(B)). Attached garages with a slab below BFE need the same automatic-entry venting design. 090(2)). 090(3)). Where no BFE has been published (an unnumbered A zone), the fallback is two feet above the highest adjacent grade. 055, and an elevation certificate documenting the as-built lowest floor must reach the building official before vertical construction continues past the foundation. 075.
Violations & Fines
Building or filling without complying with KMC 21.56 is a misdemeanor under 21.56.035, and each day the violation continues counts as a separate offense, so an unpermitted fill job or an under-elevated foundation can rack up daily charges. The city can also pursue any other lawful remedy, including stop-work orders and abatement, and flood insurance rates are set higher for any structure built below the required freeboard.
Frequently Asked Questions
How far above base flood elevation must a new Kirkland home be built?
Do I need a permit before building in a Kirkland flood hazard area?
What happens if I build below the required flood elevation in Kirkland?
Sources & Official References
Other rules in Kirkland
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Flood Elevation Requirements in Nearby Cities
How other cities in King County handle flood elevation requirements.