Thurston County Storm and Surface Water Utility

Storm and Surface Water Utility Base Rate

The Thurston County Storm and Surface Water utility rate has two components: a base rate (described on this page) and a capital rate. The rates appear as a single stormwater charge on annual property tax statements.

Click here to see how 2011 stormwater rates are calculated for your particular parcel.

Base Rate for 2011

The base rate pays for all utility services except those related to construction projects.  The rate reflects how much a property contributes to stormwater runoff.

All single-family residential properties are charged a fixed rate per parcel.  The rate is based on the footage of impervious surface found on an average residential property. Impervious surfaces are hard surfaces, such as roofs or driveways, that don't allow water to percolate into the ground.  

Duplexes, triplex and fourplex parcels; residential parcels; multi-family (more than fourplex) units; and mobile-home parks also pay a fixed rate based on the average counterpart property.

Commercial and public property rates are site-specific; these are calculated according to each individual property's actual area of impervious surface.

Agricultural and vacant properties are charged a flat $1 per acre.

Base rates per year
Class of property	Rate per parcel	How the rate is calculated
Parcels containing single-family residences, including mobile homes	$53.60 per parcel plus $1 per acre in excess of 1/2 acre	Average of 3,600 sq. ft. of impervious surface times $14.89 per 1,000 sq. ft. of impervious surface.
Parcels containing duplex, triplex or fourplex residential units	$38.71 per dwelling unit plus $1 per acre in excess of 1/2 acre per unit	Average of 2,600 sq. ft. of impervious surface times $14.89 per 1,000 sq. ft. of impervious surface
Parcels containing multifamily units (more than fourplex), residential condominiums or mobile-home parks	$16.08 per dwelling unit plus $1 per acre in excess of 1/2 acre	Average of 1,080 sq. ft. of impervious surface times $14.89 per 1,000 sq. ft. of impervious surface
Commercial, industrial, schools, churches or government services	$14.89 per 1,000 sq. ft. of impervious surface plus $1 per acre for vacant area	Actual impervious surface area per parcel
Public/private roads	$4.47 per 1,000 sq. ft. of impervious surface	Estimated impervious surface area per ownership
Other parcels, including vacant and agricultural property	$1 per acre	Acreage per parcel

Return to main rates page.

Contact Us

 Staff contact: Jim Bachmeier: (360) 754-4275. E-mail: bachmej@co.thurston.wa.us.