Seattle Public Utilities Ray Hoffman, Director

Water Availability Certificate

Client Assistance Memo 1201

Property owners who are constructing a new home or building, or renovating an existing facility to use for a new purpose, will most likely need a water availability certificate. The City of Seattle must make sure adequate water flow and pressure is available for the new and existing properties in the area. The water availability certificate shows fireflow information for a nearby tested or modeled hydrant, if there is one, but does not determine whether the fireflow is adequate. That decision is up to the Seattle Fire Department.

A water availability certificate is required for most development projects in Seattle, Shoreline and unincorporated King County. A water availability certificate may be issued during the Master Use Permit process or during the Building Permit process.

Property owners may request a water availability certificate, before applying for a permit, to learn if there is adequate water service for a proposed project. A water availability certificate already on file may need to be reissued if the building plans change prior to the Certificate of Occupancy being issued or if the water availability certificate has expired due to elapsed time.

Projects Subject to a Water Review

  • Any project requiring a change in water service.
  • Any project that moves, removes or creates property lines.
  • Any project requiring a building or land use permit.
  • Water availability inquiries.

Not all projects require a water availability certificate. The Seattle Department of Construction & Inspections (SDCI) or SPU will determine whether a water availability certificate is required based upon project parameters. In some cases, SDCI will issue a water availability approval without requiring a water availability certificate from SPU.

Purpose of the Water Availability Certificate

SPU wants to ensure that:

  • An adequate water supply to service each new development project exists.
  • New development projects will not have a negative impact on the existing water supply or other SPU customers.
  • New development projects will utilize their water service in a manner consistent with approved water usage regulations.

Regulation of Water Services

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 supplies in Water Availability Certificate Chapter 246-290.

Information Provided by the Property Owner

Property owners in Seattle can apply for a water availability certificate through SDCI’s permit process. SDCI will pass on the water availability certificate information to SPU and request the certificate on your behalf. Property owners in Shoreline and unincorporated King County must apply for a water availability certificate directly from SPU.

Property owners applying for a water availability certificate should provide the following:

  • A completed water availability certificate request form (doc).
  • A site plan clearly showing what is to be done with the property.
  • A description of the project, to be written on the request form.
  • The address of the project, to be written on the request form.
  • Legal description of the property or the property’s tax ID number, either written on the request form or shown clearly on the site plan.
  • Location, size and type of new water service(s) shown clearly on the site plan.
  • Site plan or civil drawing must show existing water service(s) (size, type and location), and proposed water services (size, type and location).

Responsibilities of the Property Owner

  • The property owner is responsible for providing clear and accurate information to the City of Seattle in a timely manner, outlining the applicant’s water usage requirements.
  • Assure that the water service requested is sufficient to meet all Seattle Fire Department standards for the property. For example, fire sprinkler systems require a separate or larger water service.
  • Hydraulic flow data may be required.

Before Buying a Property for Development

Before purchasing property for development in Seattle or in an SPU service area, verify that water service is available for the project. SPU can issue a water availability inquiry even before the property is purchased.

If a private water service line must pass through a neighboring property, a recorded easement is required prior to ordering a new water service line. If an easement is not obtained, then water is unavailable.

Reduce Delays

  • Do not assume that each property has access to water. Just because other properties in a neighborhood have water does not mean that water service is available to your property. In some cases, the customer might have to make significant improvements to the existing infrastructure to obtain additional service.
  • Changes to a project after a water availability certificate is issued can result in delays or additional costs to your project. Check with the DSO project lead to determine whether project changes will affect your water service.
  • Request a water availability certificate even if a project requires an increased amount of water usage. Property owners need to verify that SPU can provide the increased volume of water to that site.
  • Notify SPU when an extra water service is required. For example, a separate or larger water service is required for a fire sprinkler system.
  • Do not locate water services in driveways or within five feet of trees.


Useful Links

Seattle Public Utilities (SPU) supplies water to 1.3 million people in the region. Nearly all this water is from the 90,000-acre Cedar River Watershed and the 13,300-acre South Fork Tolt River Watershed in eastern King County. Our goal is to provide a reliable source of high quality drinking water, while protecting the environmental resources of our watersheds.

Legal Disclaimer

This Client Assistance Memo (CAM) should not be used as a substitute for codes and regulations. The applicant is responsible for compliance with all code and rule requirements, whether or not described in this CAM.