Tacoma, WA Environmental Rules: Flood Elevation Requirements (2026)
Key Facts
- Governing section
- TMC § 13.11.620.D
- Minimum freeboard
- 3 feet above base flood elevation
- Alternative standard
- 500-year flood height, if higher
- Applies to
- New critical facilities only
- State framework
- Growth Management Act flood-hazard mandate
Summary
Tacoma requires new critical facilities built in the mapped 100-year floodplain to elevate their lowest floor at least three feet above base flood elevation, or to the 500-year flood height, whichever is higher.
Critical facilities. Construction of new critical facilities shall be, to the extent possible, located outside the limits of the special flood hazard area (SFHA) (100-year floodplain). Construction of new critical facilities shall be permissible within the SFHA if no feasible alternative site is available. Critical facilities constructed within the SFHA shall have the lowest floor elevated three feet or more above the level of the base flood elevation (100-year) at the site or to the height of the 500-year flood, whichever is higher. Access to and from the critical facility should also be protected to the height utilized above. Floodproofing and sealing measures must be taken to ensure that toxic substances will not be displaced by or released into floodwaters. Access routes elevated to or above the level of the base flood elevation shall be provided to all critical facilities to the extent possible. (Ord. 27294 § 2, 2004-11-16; Ord. 27431 § 48, 2005-11-15; Ord. 28070 Ex. B, 2012-05-08; Ord. 28906 Ex. D, 2023-08-15; Ord. 29114, 2026-07-14; Ord. 29114, 2026-07-14)
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: rev 4946110; v22 updated 2026-07-28).
Full Breakdown
TMC § 13.11.620.D, in the Critical Areas Preservation chapter Tacoma adopted to satisfy the state Growth Management Act's flood-hazard mandate, sets the City's freeboard standard for critical facilities: schools, hospitals, emergency-response buildings. New ones must avoid the special flood hazard area where feasible; if built inside it, the lowest floor must sit three feet or more above the 100-year base flood elevation, or at the 500-year flood height if higher, with access routes protected to the same level. This specific figure applies to critical facilities; ordinary homes and businesses fall under the separate general development standards in § 13.11.620 and § 13.11.640.
Violations & Fines
Building a critical facility's lowest floor below the required elevation, or failing to protect access routes to that height, is a Critical Areas Preservation violation enforced under TMC Chapter 1.82.
Frequently Asked Questions
Does Tacoma's 3-foot freeboard rule apply to houses?
What if there's no feasible site outside the flood hazard area?
Sources & Official References
Other rules in Tacoma
Compare Tacoma to another location·View the Washington environmental rules overview
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Flood Elevation Requirements in Nearby Cities
How other cities in this county handle flood elevation requirements.