Shoreline, WA Environmental Rules: Stormwater Management (2026)

SMC § 13.10.200(A) adopts by reference the Stormwater Management Manual for Western Washington published by the Washington Department of Ecology, and requires that all new development, redevelopment, and other activities with the potential to affect surface water comply with the current version of that manual, the Western Washington Phase II Municipal Stormwater Permit, and the City of Shoreline Engineering Development Manual. Subsection (B) directs applicants to employ low impact development techniques, such as bioretention, rain gardens, and permeable pavement, wherever feasible. The surface water utility created under SMC § 13.10.110 is administered by the public works director, who runs inspection programs to check compliance and, under SMC § 13.10.235, can require construction to stay exposed for inspection at the applicant's expense.

Separately, SMC § 13.10.320 bans illicit discharges into the municipal storm sewer system or waters of the state, listing over two dozen prohibited materials from sewage and pesticides to petroleum products and pool backwash, while carving out limited exceptions such as uncontaminated groundwater and properly dechlorinated pool discharges. SMC § 13.10.330 requires property owners to implement best management practices for any activity that could produce a prohibited discharge, and SMC § 13.10.340 gives the director inspection and sampling authority, including the right to require monitoring equipment at the property owner's expense.

Any violation of Chapter 13.10 SMC is declared a public nuisance under SMC § 13.10.400 and is enforced through the code-enforcement and abatement procedures in SMC §§ 20.30.720 through 20.30.790, with abatement costs assessed against the responsible party.