Skagit County, WA Environmental Rules: Stormwater Management (2026)

010 sets the policy for Skagit County's Stormwater Management chapter: the chapter exists to protect adjacent landowners and others from downstream flooding, erosion, and pollution in compliance with the county's NPDES permit, and it governs both temporary and long-term stormwater management, describing the county's authority, regulatory requirements, submittal requirements, and procedures for stormwater drainage design, review, approval, construction, maintenance, and management across unincorporated Skagit County. The chapter is written to track the county's NPDES permit itself, and where the two conflict, the code states the permit controls.

010(2) lists the chapter's goals: managing stormwater through a land development strategy that conserves on-site natural features and mimics predevelopment hydrologic conditions, encouraging creative and coordinated site planning, reducing hard and impervious surfaces, preserving or restoring native vegetation, protecting water quality, and making low-impact development the preferred, commonly used approach to site development. 020 puts teeth on those goals: no site development activity requiring review under the chapter, meaning land disturbance, structural development, or the creation of hard surfaces, may begin until the county has reviewed the proposal and issued any required project permit.

17, from redevelopment, which applies to a site already carrying 35 percent or more existing hard-surface coverage. 130 requires erosion and sediment control during construction.