Kirkland, WA Environmental Rules: Flood Zones (2026)

Kirkland regulates building in flood-prone land through Chapter 21.56 KMC, Flood Damage Prevention, which applies to all areas of special flood hazard in the city under KMC 21.56.025. Those areas are defined by the Federal Insurance Administration's Flood Insurance Study for King County and the accompanying flood insurance rate maps (FIRM), adopted by reference under KMC 21.56.030 and kept on file at City Hall, 123 Fifth Avenue.

KMC 21.56.055 requires a development permit before any construction or development begins within a special flood hazard area, covering all structures, including manufactured homes, and all development activity, including fill. An applicant developing within the special flood hazard area must also submit a habitat assessment following FEMA's Floodplain Habitat Assessment and Mitigation Regional Guidance Manual, either funded by the applicant and prepared by the city's consultant, or prepared by a qualified professional the city approves and then reviewed by the city's consultant. The permit application itself, under KMC 21.56.060, has to show the lowest floor elevation relative to mean sea level, any floodproofing elevation, engineer or architect certification of floodproofing for nonresidential structures, how a watercourse would be altered, and, for floodway development, an engineering analysis showing no rise in the base flood elevation.

The building official administers the chapter as floodplain administrator under KMC 21.56.065. Noncompliance carries real teeth: KMC 21.56.035 makes it unlawful to construct, locate, extend, convert or alter any structure or land without full compliance, classifies a violation as a misdemeanor, and treats each day of violation as a separate offense, on top of whatever other lawful action the city takes to prevent or remedy the violation.