Seattle enforces comprehensive stormwater management under SMC Title 22 Subtitle VIII, requiring drainage control plans for all development and redevelopment to protect Puget Sound water quality.
The Seattle Department of Construction and Inspections (SDCI) administers the Stormwater Code, which requires drainage control review for all projects that add or replace impervious surfaces or disturb land. Projects exceeding 750 square feet of new or replaced impervious surface must implement flow control and water quality treatment best management practices (BMPs). Seattle Public Utilities manages the stormwater utility and charges drainage fees based on impervious surface area. The city requires on-site stormwater management using green stormwater infrastructure such as rain gardens, permeable pavement, and cisterns. The Stormwater Manual provides detailed technical requirements for design and installation of stormwater facilities. A major code update is scheduled for 2026 to strengthen protections.
Violations can result in stop-work orders, fines up to $5,000 per day per violation, permit denial or revocation, and required restoration of disturbed areas. Illicit discharges to the stormwater system carry additional penalties under state and federal Clean Water Act authority.
Seattle, WA
Seattle's Land Use Code allows residential lawn ornaments, statuary, and yard art without permits provided structures do not exceed accessory-structure heigh...
Seattle, WA
Seattle does not regulate residential inflatable holiday decorations by size or type. Standard Noise Ordinance (SMC 25.08) limits apply to blower-motor noise...
Seattle, WA
Seattle has no ordinance restricting when residents may put up or take down holiday lights. The general Noise Ordinance SMC 25.08 applies to any amplified ou...
Seattle, WA
Built-in outdoor kitchens in Seattle require building permits from SDCI when they include new electrical, plumbing, gas piping, or a structural roof under Se...
Seattle, WA
Backyard wood and pellet smokers in Seattle are allowed at single-family homes but are subject to Puget Sound Clean Air Agency (PSCAA) Regulation I, Section ...
Seattle, WA
Seattle Fire Code Section 308.1.4 prohibits open-flame cooking devices and LP-gas containers larger than 1 lb on combustible balconies of multi-family buildi...
Side-by-side rule comparisons with other cities in King County.
See how other cities in King County handle stormwater management.
See how Seattle's stormwater management rules stack up against other locations.
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