Snohomish County, WA Swimming Pools & Spas: Fencing & Safety Requirements (2026)

22 SCC, so the use is permitted outright countywide subject to these standards. The section explicitly carves hot tubs and spas out of its scope: only in-ground and above-ground swimming and wading pools intended for the sole use of the occupants and their guests are covered. Two structural rules apply. First, no part of the pool structure may project more than one foot above the adjoining ground level when it sits within a required yard setback, limiting how much an above-ground pool can protrude into that setback space.

Second, the pool must be enclosed with a fence not less than four feet high, built with sufficient design and strength to keep out children; the code does not prescribe a specific material, gate hardware, or self-latching mechanism, leaving those details to the adopted state building code applied at permit review. 110(23), the special-setbacks section supplementing the base zone setback, requires that the pool itself be at least five feet from any property line, a distance measured the same way as the county's other special-use setbacks in that section.

A residential building permit is typically required before installing an in-ground pool or a large above-ground pool because the work involves excavation, electrical, and barrier construction reviewed by the Snohomish County Department of Planning and Development Services. Homeowners planning a pool should confirm both the fence height and the five-foot setback with the department before pouring concrete or ordering fencing, since correcting a pool sited too close to a property line after installation is far costlier than adjusting plans beforehand.