SWM Utility Charges

SWM Budget Chart

Your Dollars at Work

Surface Water Management (SWM) is a utility that provides essential services in unincorporated Snohomish County. These services are funded by annual SWM utility charges paid by property owners in unincorporated Snohomish County. SWM partners with the community to reduce flood damage and to protect and enhance our water resources for future generations by providing customers with services in four core areas:

  • drainage and road flooding, 
  • water quality, 
  • salmon and marine habitat, and 
  • river flooding. 

Property owners help pay for solutions because each property contributes runoff to local ditches, streams, or groundwater, and SWM is responsible for managing many of the downstream surface water systems. The utility charges are based on the contribution of each property to downstream runoff, not the potential benefit to the property.

Who pays SWM utility charges?

Homeowners and owners of property in the SWM Utility District with houses, businesses, parking lots or other impervious additions pay the utility charge.  Owners of single-family residences pay a flat utility charge, whereas owners of apartments, businesses, and commercial structures are charged a rate based on the amount of impervious surface* on their properties.

* Impervious surface includes hard surfaced areas that prevent or delay the entry of water into the soil, or cause water to run off faster than under natural conditions. Common impervious surfaces include rooftops, sidewalks, pavement, patios, driveways, parking lots, gravel, and other surfaces that impede the natural infiltration or runoff of surface water.

How much are SWM utility charges?

Rate categories determine the charge amount. Rate categories include: single-family residences, condominiums, farms, commercial and non-residential properties. For a complete list of rate categories and charges, see Snohomish County Code 25.20.020

* 2022 Rates:

Annual Service Charge for Residential and Farm

Rate Category Impervious Surface Coverage Annual Service Charge
Single Family Residential  N/A $128.93
per dwelling unit
Condominium   N/A $116.03
per dwelling unit
Farm  N/A $128.93
per parcel

Annual Service Charge for Commercial,
Non-residential and Other Uses
Rate Category              Impervious Surface Coverage Annual Service Charge 
Exempt Less than 1%  $0.00
Very Light 1% to 19% $38.66
per quarter acre
Light 20% to 39% $128.93
per quarter acre
Moderate 40% to 59% $214.81
per quarter acre 
Heavy 60% to 79% $292.19
per quarter acre 
Very Heavy 80% to 100% $386.74
per quarter acre 

* 2022 rates reflect a 2.8% increase from 2021 in accordance with Ordinance 19-074.

Surcharges may apply to parcels near lakes. 

Exemptions and reductions may be available.

SWM utility billing

SWM utility charges appear as a line item in a customer's annual property tax bill -- listed as "Surface Water Utility Charge" under Special Assessments. See example* below: 

PropertyTaxStatement_SWM_Utility Charge
* The above example is for a single-family residential property in unincorporated Snohomish County for year 2020. If you reside in a city, your charges will differ.

Contact us to learn more

Billing questions? Email Lisa.Souza@snoco.org or call (425) 388-6498. 

Refunds and appeals require an appeal form be submitted by April 30. Documentation** or a site inspection of the property may be required. To appeal billing charges, complete this form Appeal Surface Water Management billing and mail to: 

Snohomish County Surface Water Management 
Attn: Utility Billing Assistant - Appeal 
3000 Rockefeller Ave M/S 303 
Everett, WA 98201 

**If not providing As-Built documentation, the completed form can be sent via email to: Lisa.Souza@snoco.org

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