Walla Walla County, WA Fire Regulations: Wildfire Zones (2026)

Walla Walla County adopted the Mill Creek Wildfire Protection Area rules by Ordinance No. 384 in 2010, codified at Article X of Chapter 15.04 of the county code. The area covers the county's portion of the wildland-urban interface identified in the 2006 Mill Creek Community Wildfire Protection Plan, adopted by County Resolution 06-069. Anyone pulling a building permit for a new structure inside that boundary must build the entire structure to Section 15.04.520's five-part standard: non-combustible, fire-resistant or fire-retardant roofing and siding; screened chimney and vent outlets; a thirty-foot fire break; a fifteen-foot vegetation setback from chimney outlets; and screened, cleared permanent outdoor fireplaces.

Owners who only re-roof or re-side an existing house need not meet the whole list, but Section 15.04.520 still holds them to the material requirement in part A: the new roof or siding itself has to be non-combustible, fire-resistant, or fire-retardant treated, with fire-retardant coatings maintained per the manufacturer's instructions under Section 15.04.510(C). The Walla Walla County Community Development Department's building official reviews compliance through the permit process and can grant relief from the fire-break and vegetation clearances but not from the material standard itself.

Because the boundary tracks the 2006 wildfire plan rather than a zoning district, a parcel's status depends on where it falls inside that mapped study area, not on how it is zoned.