Water Availability Certificate

CAM 1201

SPU regulates new water services and changes to existing water services. Our water service areas include:

  • Seattle
  • Shoreline
  • Burien
  • Renton
  • Lake Forest Park
  • Parts of unincorporated King County

SPU prepares a water availability certificate (WAC) that confirms SPU water infrastructure exists to supply the parcel(s). The document identifies requirements, system improvements, and conditions necessary to provide water service to the parcel. A WAC is required for most development projects in Seattle and in other jurisdictions within SPU's direct service area. A WAC expires 18 months from the issuance date and a new WAC application is required once a WAC has expired. WACs are issued based on the code requirements in effect upon application.

Apply for a water availability certificate

  1. If your project is within the City of Seattle, and you require a building permit or a master use permit for a platting action from Seattle Department of Construction and Inspections (SDCI), SDCI will request a water availability certificate for you as part of their process.
  2. If your project is in an SPU direct water service area outside of the City of Seattle, or within Seattle, but does not require the above-mentioned permit(s) from SDCI, you may apply directly for a WAC through the Seattle Services Portal.

Water availability certificate issuance

Water availability certificates are typically issued within 45 days, depending on the volume of requests. There is no charge for this service.

What is a water availability certificate?

SPU issues a water availability certificate to confirm that there is adequate domestic water flow, and water pressure to accommodate or supply new development. The water availability certificate is a basic report that we prepare for parcel owners who need new water service, like for new construction or renovating a facility to use for a new purpose.

The water availability certificate may show fire flow information for a nearby tested or modeled hydrant, but doesn’t determine whether the fire flow is adequate. Fire flow requirements are determined by your local fire department.

A water availability certificate is required for most development projects in Seattle or SPU-direct water service areas. Information about on-site or privately owned water mains or hydrants isn’t included.

What is the purpose of a water availability certificate?

Washington state building code RCW 19.27.097 requires that building permit applicants provide proof of adequate water supply for the intended use of the parcel. For Seattle, the document used to provide adequate proof is the water availability certificate. In addition, SPU wants to ensure that:

  • Property owners are notified early in the permitting process that their project may require system improvements, such as a water main extension, hydrants, or additional water main line valves.
  • An adequate water supply to service each new development project exists.
  • New development projects will utilize their water service in a manner consistent with approved water usage regulations.
  • A new water service meets current SPU regulations.

Does my project require a water availability certificate?

Property owners who are constructing a new building or renovating an existing building to use for a new purpose typically need a water availability certificate. The following project types require a water availability certificate:

  • Any project requiring a change in water service.
  • Any project requiring a building permit for new construction or additions greater than 2,500 square feet of habitable space.
  • Any project requiring a master use permit for the division or re-division of land (i.e. subdivision, short plat, unit lot subdivision, or lot boundary adjustment).

Not all projects require a water availability certificate. SPU and the Seattle Department of Construction & Inspections (SDCI) will determine whether a water availability certificate is required based upon project parameters.

Reduce delays

  • Check with your local fire department to ensure the water service requested is sufficient to meet all fire department standards for the property.
  • For example, fire sprinkler systems require a separate or larger water service.
  • Contact the Development Services Office if a hydrant flow test is required by your local fire department.
  • Changes to a project after a water availability certificate is issued, particularly changes in parcel configuration, or water needs (such as fire sprinklers or landscape irrigation), require a new water availability review. This may result in delays or additional costs to your project.
  • Water availability certificates expire 18 months from the date of issue. Make sure your water availability certificate is valid when applying for a water service.

How are water services regulated?

Seattle Municipal Code (SMC) outlines water rates and regulations in SMC Chapter 21.04. The State of Washington defines basic regulatory requirements to protect the health of consumers using public drinking water in WAC Chapter 246-290.