Pasco, WA Environmental Rules: Stormwater Management (2026)

PMC 13.80.020 creates the storm water management utility under Chapter 35.67 RCW and RCW 35A.80.010 as part of the water/sewer utility, administered by the Director of Public Works. PMC 13.80.070 sets monthly rates by rate category, published in the fee schedule at Chapter 3.35 PMC: single-family residential parcels pay $6.85 per month, multifamily and apartment units pay $3.42 per unit, vacant buildings pay $6.85, and undeveloped parcels pay nothing. Industrial and commercial parcels are billed by parking capacity, from $6.85 for zero to five vehicles up to $34.25 for sixteen or more vehicles, plus an additional charge of $135.11 per acre (minimum $1.39) for private property runoff draining to the City system and $32.78 per acre for state highway right-of-way runoff.

A property owner who thinks a charge was miscomputed can petition the Director of Public Works in writing for review under PMC 13.80.080, and the Director's decision is final. New development must retain and dispose of storm runoff on site, with none permitted to enter the public right-of-way, and all storm water and drainage improvements must follow the Washington Department of Ecology's Stormwater Management Manual for Eastern Washington and be designed by a Washington-licensed professional engineer under PMC 13.80.090. Projects triggering certain SWMMEW Core Elements must obtain a storm water construction permit under PMC 13.80.100, which costs $25.00 per PMC 3.35.190.

PMC 13.80.110 bans illicit discharges into any storm drain system outright, while PMC 13.80.120 conditionally allows specific discharges, such as dechlorinated pool water (0.1 ppm chlorine or less, pH 6.0 to 9.0) and controlled construction site water, subject to volumetric and pollution controls.