Surface Water Management fee rates are set as part of the City’s budget. On November 18, 2024, the City Council approved the SWM fee rates for 2025. Rates are increased each year so the Utility has enough funding to do our work. Some increases are needed to keep pace with rising costs from inflation. Some increases are to better meet the community’s needs. For a single-family home, the 2026 rate is $33 per month.

The table below shows Shoreline’s current and projected SWM fees from 2025-2030 for single-family properties, including a 6% Utility tax. Rates are not official until adoption of the City’s rate schedules in November of the previous year. The SWM fees shown below for 2026-2030 are estimates and will be reviewed and finalized before adoption. For more information, visit the Surface Water Master Plan webpage.

Surface Water Management Rate: Single-Family Residence

*In 2027 the City will adopt a new SWM fee rate structure. This change will slightly reduce single-family residential fees relative to other property types. 

SWM fee rates vary by the type of property and the amount of "hard surface" they contain. Single-family homes and properties covered with less than 10% hard surfaces pay $397.68 per year ($33/month), plus a 6% Utility tax.  All other parcel types pay on a per acre basis using a sliding rate based on the amount of hard surface. If you own more than one property in Shoreline, you will pay SWM fees for each property. The table below shows how rates are calculated.

 

Rate Category	Percent Hard Surface	2026 Annual SWM Fee + 6% Utility Tax
1. Single-Family Home		$421.54/per parcel
2. Very Light	Less than or equal to 10%	$421.54/per parcel
3. Light	More than 10%, less than or equal to 20%	$979.05/per acre
4. Moderate	More than 20%, less than or equal to 45%	$2,022.60/per acre
5. Moderately Heavy	More than 45%, less than or equal to 65%	$3,922.79/per acre
6. Heavy	More than 65%, less than or equal to 85%	$4,969.80/per acre
7. Very heavy	More than 85%, less than or equal to 100%	$6,509.69/per acre
Minimum Rate		$421.54/per parcel

 

The 2026 Surface Water Management fee amounts billed to ratepayers (per Shoreline Municipal Code 3.01.400) include a Utility Tax of 6% calculated on the gross revenue of the Surface Water Utility. More information on the City’s Utility Tax can be found here.

View the full SWM Rate Table.

Surface Water Management (SWM) fees are paid for at the same time as property taxes. King County collects property taxes and SWM fees in two installments on April 30 and October 31. For more information about property taxes and to pay your taxes online, visit the King County Department of Assessments webpage. 

Below are Surface Water Management fee credits and rate adjustments and Surface Water Utility rebates:

Credits

Several special rate categories are automatically assigned to those who qualify. 

1. An exemption for any home owned and occupied by a low income senior citizen determined by the assessor to qualify under RCW 84.36.381. Customers living in Shoreline can learn more and apply for the discount here.
2. A public school district shall be eligible for a waiver of up to 100 percent of its standard rates based on providing curriculum which benefits surface water utility programs. The waiver shall be provided in accordance with the Surface Water Management Educational Fee Waiver procedure.
3. Alternative Mobile Home Park Charge. Mobile home park assessment can be the lower of the appropriate rate category or the number of mobile home spaces multiplied by the single-family residential rate.
4. New or remodeled commercial buildings utilizing a permissive rainwater harvesting system, properly sized to utilize the available roof surface of the building, are eligible for a 10 percent reduction in total surface water management fee, as per RCW 35.67.020(3). The city will consider rate reductions in excess of 10 percent dependent upon the amount of rainwater harvested.

Rate Adjustments

Any person receiving a bill may file a request for a rate adjustment within two years of the billing date. (Filing a request will not extend the payment period.)

Property owners should file a request for a change in the rate assessed if:

1. The property acreage is incorrect; 
2. The measured hard surface is incorrect;
3. The property is charged a sliding fee when the fee should be flat; 
4. The person or property qualifies for an exemption or discount; or
5. The property is wholly or in part outside the service area. 

Rebate

Developed properties shall be eligible for the rebate under SMC 13.10.120 for constructing approved rain gardens or native vegetation landscaping. The rate is $7.00 per square foot and not to exceed $5,600 for any single-family residential parcel and $20,000 for any non-single-family residential parcel.

Any person receiving a bill may file a request for a rate adjustment within two years of the billing date. (Filing a request will not extend the payment period). Property owners should file a request for a change in the rate assessed if:

1. The property acreage is incorrect;
2. The measured hard surface is incorrect;
3. The property is charged a sliding fee when the fee should be flat;
4. The property is wholly or in part outside of the service area.

Packed gravel prevents water from seeping into the soil. Scientific studies show that once gravel is compacted, for example, from cars or heavy equipment, the gravel acts like paved surfaces and surface water runs off it in greater quantities than if natural soil conditions existed.