Installing Water Mains

A water main extension (WME) or system improvement will be required if a parcel requesting new water service does not abut a standard distribution or suitable water main. For information on water availability, see CAM 1201. SPU will issue an approved or not approved WAC based on your project’s specific site conditions. You will be required to enter into a water system improvement contract to design and construct the water main system improvement if your project is issued an not approved WAC.

Water main contracting & construction process

Contract initiation phase

1. Contact the DSO when you are ready to initiate the required water system improvements. The DSO can be reached at (206) 684-3333 or
2. SPU will assign a Project Coordinator for the lifecycle of your project.
3. Your Project Coordinator will draft a commitment contract and prepare the invoice for the commitment contract charges.
4. SPU will issue an approved WAC when the contract is fully executed and the invoice is paid.

Design review phase

1. The design review process for a WME project differs on whether it is located within or outside the City of Seattle. If the project is located within Seattle, the design review process is led by the Seattle Department of Transportation (SDOT) through their street use permit process. The design review process is led by the DSO if the project is located outside of Seattle. Both reviews may require reviews at 30%, 60% and 90% design completion based on project complexity.
2. The property owner will work with SPU directly to develop a 30% Alignment Design for the WME requirement and appurtenances.
3. Once review cycles are complete and the plan is approved, SPU and SDOT will sign the mylars.

Pre-construction phase

You must fill these forms out and return them to your Project Coordinator:

Construction phase

1. Your Project Coordinator will prepare the construction contract and the invoice for related fees once the project is at 90% design.
2. Once your project is at 100% approved design a SPU resident engineer will invite all applicable representatives to the pre-construction meeting.
3. Please allow 10 business days for the meeting to be held after you’ve submitted the pre-construction meeting notice document to your SPU Project Coordinator.
4. The SPU resident engineer will guide the project through construction and to completion.

Reconciliation phase

Certain charges will be reconciled against actual costs once the once the WM improvements are complete. If actual costs exceed the deposit, the Property Owner shall remit payment of the difference within 30 days after the transmittal date of an invoice from SPU. If the actual cost is less than the deposit, SPU shall refund any overpayment within 30 days after construction costs have been reconciled. 

Public Utilities

Andrew Lee, General Manager and CEO
Address: 700 5th Avenue, Suite 4900, Seattle, WA, 98104
Mailing Address: PO Box 34018, Seattle, WA, 98124-5177
Phone: (206) 684-3000

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Seattle Public Utilities (SPU) is comprised of three major direct-service providing utilities: the Water Utility, the Drainage and Wastewater Utility, and the Solid Waste Utility.