Updated 9/23/2025

What is changing?

Starting January 1, 2026, Seattle Public Utilities will introduce:

• System Development Charges (SDCs): Updated charge for water and a new charge for wastewater for developments that require a new or larger water connection, and a new SDC for drainage when there is an increase in hard surface. Note: SDCs for wastewater and drainage are only applicable within the City of Seattle.
  • Water service invoices issued on or before December 31, 2025 will include the current SDC (connection charge) for water and are valid until paid or expired.
  • Water service invoices and certain side sewer permit invoices issued after December 31, 2025 will include the updated SDC for water and the new SDCs for drainage and wastewater.
• Participatory Latecomer Program: This program offers a cost-sharing opportunity for developers who are required to install main line extensions (water, wastewater, or drainage) to develop their property. Developers who opt in will be eligible for reimbursement of up to $1,500 per lineal foot (LF) and up to 750 LF.
  • This must be an SPU-required main line extension as required by the Water, Drainage, and Wastewater Availability Certificate (WAC) or SDCI Preliminary Assessment Report (PAR).
• Water Valves Cost Reduction: When valves are authorized by SPU in lieu of a water main line extension or otherwise required by the WAC, SPU will cover up to $25K per valve. Valves and other appurtenances are not eligible for a Participatory Latecomer Agreement, but a Developing Property Owner Latecomer Agreement is permitted.  
• Updated Water Availability Certificate: Current Water Availability Certificates (WAC) only outline water service requirements. Beginning January 1, 2026 they will be called Water, Drainage, and Wastewater Availability Certificates (WAC) and will include drainage and wastewater infrastructure requirements (for projects within the City of Seattle) in addition to water requirements. The application process for a WAC will remain the same.
• Contracts for Drainage and Wastewater Main Line Extensions: We will require contracts for drainage and wastewater (DWW) main line extensions, mimicking the current process we have for water main line extensions. A major difference is that there will be no charges for DWW main line extension contracts.

Why are these changes being made? 

Extending utility mains to undeveloped properties can be costly. The new program is designed to:

• Help developers offset infrastructure costs
• Ensure predictable, long-lasting utility services for future property owners
• Support the City’s goal of building reliable infrastructure

How will these changes to System Development Charges impact me? 

Many factors go into the calculation of the system development charges. If you're planning a development, these changes may affect your development costs, refer to System Development Charge Update (PDF). All charges provided are intended to give developers a general sense of cost and the actual charges will be finalized once your Water Service Application is submitted, approved, and your invoice is issued. For questions and to obtain preliminary charge estimates, feel free to contact michelle.lange@seattle.gov.

How can I opt in to a Participatory Latecomer Agreement (PLA)?  

If your project starts after January 1, 2026, you’ll need to:

• Request a WAC.
• If your WAC requires a water, drainage, and/or wastewater main line extension, submit a Request for Utility Systems Improvement & Latecomer Agreement Contract and select to opt into the Participatory Latecomer Agreement program.
• Be issued a Construction Contract.
  • To participate in a Participatory Latecomer Agreement, you must opt in to the program prior to executing the Construction Contract.

If your Street Improvement Permit was issued before January 1, 2026, but you haven’t had your Preconstruction Meeting, you can still opt in. However, you’ll need to:

• Reapply for a new Water, Drainage, and Wastewater Availability Certificate (WAC) on or after January 1, 2026.
• Submit a Request for Utility Systems Improvement & Latecomer Agreement Contract and select to opt in to the Participatory Latecomer Agreement program.
• Be issued a new Construction Contract (a new Commitment Contract is not required).
  • You must opt in to a Participatory Latecomer Agreement prior to the SDOT Preconstruction Meeting.

In order to participate in the cost-sharing Participatory Latecomer Agreement, you must agree to certain terms, including:

• Submit final construction costs to SPU within 120 days of completion of the utility main line extension construction, including final street restoration. The final costs will be submitted on a form provided by SPU and stamped by an engineer licensed in the State of Washington.
• Pay prevailing wage for the construction of the water, drainage, or wastewater main line extension for which SPU is providing funding, as required by RCW 39.12 (Prevailing Wages on Public Works) and RCW 49.28 (Hours of Labor) as amended or supplemented and in accordance with Washington State Department of Labor & Industries, in addition to filing intents and affidavits, keeping payroll records, and submitting certified payroll records if requested.

Please contact michelle.lange@seattle.gov with questions.

News:

SPU PROPOSES TO UPDATE CHARGES FOR DEVELOPMENT-RELATED SERVICES ON JANUARY 1, 2026

Seattle Public Utilities (SPU) plans to update charges for development-related services, including water service installations (“taps”), water main extensions and improvements, and others.

Charges are being updated to reflect the actual costs for SPU to provide these services in 2026 and ensure that Seattle ratepayers are not subsidizing these individual services.

To update separate charges, SPU will need to adopt a Director’s Rule. The public can comment on the rule during a formal comment period, which ends on November 17, 2025.

If the director’s rule is adopted, revised charges will become effective on January 1, 2026.

Comments can be sent to Julie Vorhes at Julie.Vorhes@seattle.gov.

2026 Separate Charges FAQ (PDF)

Separate Charges – 2026 Proposed Charge Revisions for Development Services (PDF)

Contacts:

You can contact the Development Services Office (DSO) at (206) 684-3333 or SPU_DSO@Seattle.gov. The mailing address for the DSO is:

You can make a secure payment online to the Development Services Office using your 8-digit invoice number. Otherwise, you can mail in your payment.