Franklin County, WA Environmental Rules: Defensible Space (2026)
Key Facts
- Trigger
- No hydrant/suppression system within 500 ft
- On-site water storage required
- 20,000 gallons minimum
- Front/rear setback
- 25 feet each
- Side setback
- 20 feet (min 10 ft even if reduced)
- Between-structures setback
- 15 feet without fire wall
- Governing section
- Franklin County Code § 8.40.080
Summary
Where a proposed home in unincorporated Franklin County sits more than 500 feet from a working fire hydrant or approved suppression system, Franklin County Code § 8.40.080 requires 25-foot front and rear setbacks, a 20-foot side setback, and 15 feet between structures, or 20,000 gallons of on-site water storage instead.
A.Standardized On-Site Water Storage.1.Where year round, on-site water storage is required (as determined by building occupancy classifications) in accordance with this code, a minimum of twenty thousand (20,000) gallons shall be provided. ... 2.If no fire suppression system, as described in Section 8.40.080(A)(1), or no approved, working fire hydrant is located within five hundred (500) feet of a structure, then the following setbacks for primary and accessory structures shall apply: Front: Twenty-five (25) feet. Rear: Twenty-five (25) feet. Side: Twenty (20) feet. Between structures: Fifteen (15) feet (without an approved one-hour intervening fire wall)
Full Breakdown
080 sets 'land development fire suppression standards' for parcels where adequate, reliable water for firefighting is not otherwise available. Under subsection A, if no fire suppression system or approved, working fire hydrant sits within 500 feet of a structure, the county requires either year-round on-site water storage of at least 20,000 gallons (stored above ground, below ground, or by another method the fire code official or fire district chief approves), or increased structure setbacks: 25 feet in front, 25 feet in the rear, 20 feet on the side, and 15 feet between structures unless an approved one-hour fire wall separates them.
On parcels of two acres or less, the 20-foot side setback can be reduced if a one-hour fire wall is used, but no side setback may ever drop below 10 feet from the property line. Subsection B extends the same standard into the land division process: dividing land into four or fewer lots without an approved on-site suppression system triggers the increased setback, while dividing into five or more lots (a long plat or subdivision) requires the 20,000-gallon on-site water storage for proposed lots of two acres or less; larger proposed lots may use the increased setbacks instead.
These standards, retitled from 'Rural area land development standards' by Ordinance No. 03-2021, apply countywide to unincorporated Franklin County parcels reviewed under the permit and subdivision process.
Violations & Fines
Land development fire suppression standards are enforced through the permit and subdivision review process: the Franklin County fire code official or fire district chief must approve the chosen water storage method before development proceeds. Once adopted, noncompliance with § 8.40.080 as part of the Franklin County Fire Code is enforceable as a misdemeanor under § 8.40.100, punishable by a fine up to $1,000, up to 90 days in jail, or both, with each day of continuing violation a separate offense.
Frequently Asked Questions
What triggers the increased fire setbacks in Franklin County?
Can I avoid the setbacks by installing a water tank instead?
Do these standards apply when I subdivide my land?
Sources & Official References
Other rules in Franklin County
Compare Franklin County to another location·View the Washington environmental rules overview
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