Auburn, WA Environmental Rules: Erosion Control (2026)

225(D), new development and redevelopment in Auburn must obtain city permits and comply with minimum requirements tied to the city's municipal stormwater NPDES permit and the Surface Water Management Manual (SWMM). Subsection (D)(2) specifically requires preparation of a Construction Storm Water Pollution Prevention Plan for Erosion and Sediment Control, designed to satisfy the SWMM and any applicable sections of ACC Titles 15, 16, 17 and 18. The plan must mark clearing limits, establish construction access routes and controls, control flow rates, install sediment controls, stabilize soils, protect slopes, protect storm drain inlets, stabilize channels and outlets, control pollutants, control dewatering, maintain BMPs, manage the project, and protect low impact development (LID) BMPs.

Existing single-family and duplex lots can be exempt from the separate storm water site plan requirement (not the erosion-control SWPPP) if the lot was approved under regulations in effect between January 1, 1987 and December 31, 2016, and can connect to an existing centralized storm water system. 10 ACC, and an off-site analysis extending at least one-quarter mile downstream for impacts including stream bank and channel erosion. 240 is required for land-disturbing activity, addition of hard surfaces, or work affecting a storm drainage facility, and it is unlawful to construct, connect to, or alter public or private storm drainage facilities without one.

226, but the city engineer must find the deviation equally protective of public health and water quality, and any deviation request triggers published public notice at the requester's cost.