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 one residential lot is assessed one ERU. Other land uses (commercial, industrial, agricultural) are assessed based on the ERU. The size of one ERU (square feet of impervious surface) and method of distributing ERUs to other land use types varies by municipality.
Yakima County adopted Ordinance 11-2007 (PDF, 2 MB) forming a stormwater utility and establishing rates in December of 2007. One ERU is set at 3600 square feet. All residential parcels are assigned one 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 is shown on this map.
City of Yakima
A stormwater utility established by ordinance in 2004 by the City of Yakima sets one ERU at 3,600 square feet. Residential parcels are assigned ½, 1, or 2 ERUs if impervious area on the parcel is less than 1800 square feet, between 1800 and 5400 square feet, or greater than 5400 square feet, respectively. Rates per ERU were adopted by Ordinance 2007-55. Yakima Municipal Code chapter 7.80 describes the utility.
City of Sunnyside
The City of Sunnyside adopted a stormwater utility ordinance in January of 2008. Ordinance 2207 changing the structure of the billing system was passed on December 8, 2008. Ordinance 2010 - 05 setting the utility fee rate was passed on March 8, 2010.
City of Union Gap
The City of Union Gap has not yet established a stormwater utility.