Storm and Surface Water Management (SSWM) Utility

A Storm and Surface Water Management (SSWM) Utility was created and established by Ordinance No. 86-27, passed on July 16, 1986. The utility purpose is to minimize property damage, promote and protect the public health, safety, and welfare, minimize water quality degradation by preventing siltation, contamination and erosion of the city’s waterways, protect aquifers, ensure the safety of city roads and rights-of-way, assure compliance with federal and state regulations, surface water management, and water quality regulations and legislation, promote educational and recreational opportunities, encourage the preservation of natural drainage systems, and foster other beneficial public uses.

The Utility is funded by SSWM fees assessed to each developed property on Bainbridge Island pursuant to RCW 35.67.020 for the furnishing of service to those served or receiving benefits, or to be served or to receive benefits from, any drainage facility or contribute surface water runoff within the city. The fee provides revenue to water resources programs to address impacts from stormwater runoff such as flooding, erosion, pollution, habitat degradation, and low stream flows; activities include, but are not limited to:

  • Providing operations and maintenance of public stormwater systems
  • Compliance with National Pollutant Discharge Elimination System (NPDES) Permits
  • Use low impact development standards wherein infiltration of stormwater is preferred over surface discharge to downstream systems.
  • Design and construct stormwater systems that provide for removal of pollutants and sediment through bio-filtration or other means.
  • Minimize disruption and/or degradation of natural drainage systems, minimize impervious areas by restricting site coverage, and encourage site permeability by retaining natural vegetation and buffers.
  • Manage surface water in a manner which prevents pollutants from industrial, commercial, and agricultural land uses from entering ground or surface waters.

How SSWM fees are calculated

(13.24.110 utility service charge calculation)

Impervious surface unit (ISU) is estimated at 3,000 square feet of impervious ground cover and is the unit of measurement used by the utility in assessing service charges. 

  1. Single family residential property will be charged one ISU
    • Single family residential parcels that contain an additional structure that is equal to or exceeds 3000 square feet of impervious ground cover will be assessed an additional service charge for each such structure.
  2. Other developed property parcels within mixed use condominium properties that include both residential and nonresidential properties will be deemed to contain one equivalent ISU per condominium unit.

  3. Multifamily and other developed property parcels
    • Actual impervious ground cover/3,000 square feet x single family service charge.
    • Fractions shall be rounded to the nearest whole number but not less than one ISU per developed property.

How fees is collected

Kitsap County collects SSWM fees on behalf of the City and the fee is included on each annual property tax statement. The fee is not a tax, it is a fee for use and benefit, like other fees for services such as from local fire or library districts, for example. 


How to request a fee rate reduction

  1. Review code chapter 13.24.131 - rate reductions to learn if you and/or your property are eligible.
  2. If you meet eligibility criteria, fill out this form: COBI Application - Service Charge Adjustment Form

Contacts for questions

  • For specific billing questions (delinquencies, missed payments, incorrect billing amount) contact Utility Billing at 206-780-8603.
  • For questions on parcel changes, storm water mitigation credits, and impervious surface area calculations, contact Water Resources at  Please include your parcel number and a short description of your issue in your email so we can respond as quickly as possible.