How is the stormwater fee calculated?
First, an Equivalent Residential Unit (ERU) is calculated. In Yakima County, the City of Yakima and City of Union Gap, this was done by statistically sampling residential properties and averaging the amount of impervious surface using aerial photography and the County Geographical Information System (GIS). Based on this analysis, one ERU is 3,600 square feet.

Next, the property or land area of all developed parcels in the County are classified into one of the following general classes based on zoning land use categories: Urban Residential; Urban Commercial/Industrial (including government, military, schools, churches, etc); Urban Agricultural; and Exempt.

Assignment of ERU to residential parcels varies between the regional municipalities. For urban commercial, industrial, institutional, and governmental parcels, the number of urban ERUs is determined by dividing the amount of impervious surface (in feet squared) on the parcel by 3,600 square feet. ERUs for urban agricultural parcels are based on parcel size, a complete listing of agricultural parcels is available online.

Show All Answers

1. What is the National Pollutant Discharge Elimination System (NPDES) Stormwater Program?
2. What is a Municipal Separate Storm Sewer System (MS4)?
3. Which Municipal Separate Storm Sewer Systems are regulated by the Eastern Washington Phase II Municipal Stormwater Permit?
4. How are the regional stormwater utility service areas determined?
5. What is stormwater and why is it a problem?
6. What is an impervious surface?
7. How will the stormwater management program benefit taxpayers, homeowners, etc.?
8. What kinds of pollutants are found in the storm drain system?
9. Are sewers and storm drains the same thing?
10. What can residents do to help improve stormwater quality?
11. What can you put down the storm drain?
12. What happens if the Regional Stormwater group does not comply with its NPDES stormwater discharge permit?
13. What is meant by a "larger common plan of development or sale?"
14. What kinds of stormwater discharges are required to have NPDES stormwater permit coverage?
15. What is the stormwater fee used for?
16. How is the stormwater fee calculated?
17. Is the utility fee just another tax?
18. Why a stormwater utility now?
19. No water runs off my property. Why am I being charged a stormwater fee?