Stormwater Utilities

Stormwater utilities in each community provide revenue to pay for operation and maintenance of stormwater infrastructure and permit compliance for stormwater discharge.

Most utilities nationwide assess fees to properties based on proportional benefit. Stormwater runoff is related to the amount of impervious surface that prevents water infiltration. A billing unit called an Equivalent Residential Unit (ERU) represents the average impervious surface on urban residential units. Generally 1 residential lot is assessed 1 ERU. Other land uses (commercial, industrial, agricultural) are assessed based on the ERU. The size of 1 ERU (square feet of impervious surface) and method of distributing ERUs to other land use types varies by municipality.

Yakima County


Yakima County adopted Ordinance 11-2007 (PDF) forming a stormwater utility and establishing rates in December of 2007. One ERU is set at 3600 square feet. All residential parcels are assigned 1 ERU. Commercial parcels are assigned ERUs by dividing the actual impervious surface by 3600. ERUs for agricultural parcels in the urban area are assigned by parcel size. The utility service area (PDF) is shown on a map.

City of Selah


The City of Selah has not yet established a stormwater utility.

City of Sunnyside


The City of Sunnyside adopted a stormwater utility ordinance in January of 2008. Ordinance 2207 changed the structure of the billing system and was passed on December 8, 2008. Ordinance 2018-12 (PDF) amending the utility fee rate was passed on November 13, 2018.

City of Union Gap


The City of Union Gap has not yet established a stormwater utility.