Stormwater Utility

The City of Woodinville owns and operates a surface water utility that collects, carries, and treats surface water (primarily rain/snow runoff from streets) before being discharged into waterways. This utility manages surface water flows and protects water quality and public health. To cover the expenses for the operation, maintenance, and capital utility service needs, the City has an established Surface Water Management fee that is charged to all property owners. This fee can be found included in your property tax statement.

Are there any discounts available?

The City provides an exemption to low-income seniors and there is a discount for any new or remodeled commercial building that utilizes a permissive rainwater harvesting system.

For assistance with discount eligibility, call the King County Assessor's Office at 206-296-3920 or visit the King County Department of Natural Resources & Parks Surface Water Management Fee webpage.

How is my rate calculated?

Residential parcels and parcels with 10% or less impervious surface coverage are charged a flat rate. Fees for other non-residential parcels are calculated based on the percentage of impervious area of a parcel and the total parcel acreage. The annual fee is due in two installments on April 30th and October 31st with your King County property tax statements.


Rate Category Percent Impervious Surface 2022 Annual Service Charge
1) Residential: Single-Family Home N/A $206.00/parcel
2) Very Light ≤ 10% $206.00/parcel
3) Light More than 10%, ≤ 20% $480.69/acre
4) Moderate More than 20%, ≤ 45% $995.72/acre
5) Moderate Heavy More than 45%, ≤ 65% $1,922.76/acre
6) Heavy More than 65%, ≤ 85% $2,437.75/acre
7) Very Heavy More than 85%, ≤ 100% $3,193.15/acre