Federal Way, WA Environmental Rules: Flood Zones (2026)
FEMA flood zone rules in Federal Way, 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
- Before any development in flood hazard area
- Floodway housing rule
- New/rebuilt residential structures prohibited
- Repair exception
- Under 50% of structure's market value
- Manufactured home elevation
- 1 foot above base flood elevation
- Flood maps used
- King County FIRM dated Aug. 19, 2020
- Exempt work
- Routine landscaping, reroofing, street maintenance
Summary
Federal Way requires a floodplain development permit under FWRC 19.142.060 before any construction, fill, or development begins in a mapped area of special flood hazard, and the floodway subset of that hazard area bars new or reconstructed residential structures outright except for narrow repair exceptions. The city administers the rule against FEMA's Flood Insurance Study and rate maps for King County.
(1) Floodplain development permit required. A floodplain development permit shall be obtained before construction or development begins within any area of special flood hazard established in FWRC 19.142.050(1). The permit shall be for all structures including manufactured homes, as set forth in FWRC 19.142.040, and for all development including fill and other activities, also as set forth in FWRC 19.142.040. ... Construction or reconstruction of residential structures is prohibited within designated floodways, except for (a) repairs, reconstruction, or improvements to a structure which do not increase the ground floor area; and (b) repairs, reconstruction or improvements to a structure, the cost of which does not exceed 50 percent of the market value of the structure either (i) before the repair, or reconstruction is started, or (ii) if the structure has been damaged, and is being restored, before the damage occurred.
Official source re-checked September 8, 2026: no newer edition of the code had been published (publisher’s edition: current through Ordinance 26-1049, passed August 11, 2026).
Full Breakdown
050(1), covering all structures, including manufactured homes, and all development including fill. 050(1). 060(2), but any other change to the land, including grading or new fill, needs the permit under subsection (3). 160(1) bars any encroachment, fill, or new construction unless a registered engineer certifies it will not raise flood levels, and subsection (2) goes further for housing, prohibiting construction or reconstruction of residential structures within designated floodways except for repairs that do not enlarge the ground floor or that cost less than 50 percent of the structure's market value.
140. A 'violation' under this chapter is defined broadly: a structure lacking the required elevation certificate or other compliance documentation is presumed noncompliant until the owner produces it.
Violations & Fines
Developing without a floodplain permit, or building within a floodway in violation of FWRC 19.142.160, is a violation of this chapter; a structure missing its elevation certificate or other required documentation is presumed noncompliant under FWRC 19.142.040. Where a violation creates an immediate threat to health, safety, or the environment, the director may summarily abate it and bill the property owner for the abatement costs.
Frequently Asked Questions
Do I need a permit to build in a Federal Way flood zone?
Can I rebuild a house that sits in a designated floodway?
What documentation does Federal Way require for a floodplain permit?
Sources & Official References
Other rules in Federal Way
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Flood Zones in Nearby Cities
How other cities in King County handle flood zones.