Sammamish, WA Environmental Rules: Flood Zones (2026)
FEMA flood zone rules in Sammamish, WA, also called floodplain regulations or special flood hazard area (SFHA) rules, determine flood insurance requirements and elevation standards for new construction.
Key Facts
- Permit required
- development permit, SMC 15.10.110
- Coverage
- all mapped special flood hazard areas citywide
- Map basis
- FIS/FIRM for King County, dated 8/19/2020
- Administrator
- City manager (floodplain administrator)
- Max penalty
- $1,000 fine and/or 90 days jail per violation
Summary
Sammamish requires a development permit before any construction, fill, grading or other development begins in a mapped area of special flood hazard, under Municipal Code 15.10.110. The chapter applies to all such areas within City jurisdiction and is enforced with misdemeanor penalties of up to $1,000 and 90 days in jail per violation.
15.10.110 Establishment of development permit. (1) Development Permit Required. A development permit shall be obtained before construction or development begins within any area of special flood hazard established in SMC 15.10.060. The permit shall be for all structures including manufactured homes, as set forth in SMC 15.10.040, Definitions, and for all development including fill and other activities, also as set forth in SMC 15.10.040, Definitions.
Official source re-checked September 8, 2026: no newer edition of the code had been published (publisher’s edition: current through Ordinance O2026-598, and legislation passed through August 18, 2026).
Full Breakdown
Chapter 15.10, Flood Damage Prevention, applies citywide to 'all areas of special flood hazards within the jurisdiction of the City of Sammamish' (SMC 15.10.050). Those areas are defined by the Federal Insurance Administrator's Flood Insurance Study for King County and the accompanying Flood Insurance Rate Maps, dated August 19, 2020 and any later revisions, which SMC 15.10.060 adopts by reference and keeps on file at City Hall. Before any construction, land alteration, or manufactured home placement can occur in one of those mapped areas, SMC 15.10.110 requires the applicant to obtain a development permit, with an application that must show, among other things, the elevation of the lowest floor and any floodproofing relative to mean sea level.
SMC 15.10.065 makes clear that 'all development within special flood hazard areas is subject to the terms of this chapter and other applicable regulations,' and SMC 15.10.080 provides that where this chapter conflicts with another ordinance, easement, or restriction, whichever standard is more stringent controls. The City manager is designated as floodplain administrator under SMC 15.10.120, with duties spelled out in SMC 15.10.130, including using the best available flood data when the FIRM has not yet been updated. Property owners in a special flood hazard area, per SMC 15.10.020(7), must also be notified at the time of a real estate transaction that their property sits in the mapped zone.
Violations & Fines
SMC 15.10.070 makes it a misdemeanor to construct, locate, extend, convert or alter any structure or land in violation of the chapter's requirements, punishable on conviction by a fine of up to $1,000, imprisonment of up to 90 days, or both, for each violation, plus all costs and expenses of the case; the City may also pursue any other lawful remedy to stop or correct the violation.
Frequently Asked Questions
Do I need a permit to build in a Sammamish flood hazard area?
How does Sammamish decide which areas count as flood hazard zones?
What happens if I build in a flood zone without a permit?
Sources & Official References
Other rules in Sammamish
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Flood Zones in Nearby Cities
How other cities in King County handle flood zones.