Lynnwood, WA Landscaping Rules: Rainwater Harvesting (2026)

0940 and is normally a hard line: structures must sit at or behind the minimum setback shown for their zoning district. Subsection D carves out limited encroachments, features allowed to project no more than two feet into a street or interior setback without triggering a variance. " A rain barrel over 50 gallons, or a larger cistern, does not qualify for the exemption and must be sited entirely outside the setback like any other accessory feature. 0420(G) excludes floor area devoted to rainwater collection, along with gray water collection and storage, from the floor area ratio calculation used to size a building, so a developer who builds indoor space to hold or route captured rainwater does not lose buildable square footage for it.

Washington does not preempt local stormwater or landscaping rules, and Lynnwood's own comprehensive plan and Unified Development Code, not the expired Title 21 zoning code, govern here. There is no separate rainwater harvesting permit or rebate program described in the Unified Development Code; the rule operates purely as a setback and floor-area accommodation for property owners who already choose to collect rainwater on site.