2025 Sewer and Stormwater Rate Review
Background
An essential component of municipal services is addressing current infrastructure needs and effective planning to meet future need. Sewer and storm water are essential municipal services, critical to protecting the health and safety of the community.
The sewer system includes pipes and facilities that collect sewage that is then processed at a treatment facility before discharge into the Willamette River. The storm water system includes the conveyance and treatment of water runoff from structures, roads, sidewalks, rooftops, parking lots and the natural environment.
The City adopts Master Plans that articulate the current and future needs of its systems of its utility systems and to assess maintenance and operations requirements to sustain each utility's current level of service over a 20-year period. In 2024, Wilsonville’s City Council adopted updates to both the Wastewater Treatment Plant Master Plan and the Storm Water Master Plan. Collectively, the two plans identified more than $240 million in capital improvements (CIPs) that would be necessary within 5-20 years to maintain these systems and support additional capacity as the City grows over time.
Sewer and Storm Water Rate Review
In August 2024, the City of Wilsonville engaged the services of a financial consultant team, FCS Group, to assess the City’s sewer and storm water utility fees and System Development Charges (SDC) and to recommend rate adjustments to provide funding for the necessary improvements.
Utility fees are those paid each month by every Wilsonville residents and business. These fees help fund maintenance, rehabilitation, and replacement of City infrastructure (i.e. pipes, lift stations, treatment facilities) that collect, clean, and discharge wastewater and storm water runoff, ensuring that the City’s rivers and streams are clean, wastewater doesn’t back up into homes and businesses, and rainfall isn’t flooding neighborhoods or eroding creek channels, helping to maintain a healthy environment.
The City maintains local sewer and storm water utility systems and plans for their eventual replacement (just as a homeowner removes moss from the roof, clears rain gutters, and installs a new roof).
System Development Charges (SDCs) are one-time fees paid by developers at the time of permit issuance as part of new development or redevelopment within the City. These fees help fund expansion and extension of utility infrastructure needed to serve to a growing population. Growth-related infrastructure improvements include upsizing pipelines, expansion of pumping and treatment facilities, and extension of pipelines to serve new development areas. SDCs help make sure that system expansion is paid for by development and not existing residents and businesses.
Recent Project Activity
On April 21, 2025, City staff held a work session with the Wilsonville City Council for an initial discussion of the City’s 5-to-20-year forecast of sewer and storm water capital infrastructure needs and an initial review of the recommended utility rate adjustments.
On June 2, 2025, City staff held a second work session to review recommended sewer and storm water SDC rate adjustments to fund growth-related infrastructure improvements.
Progress & Timeline
The sewer and storm water utility fee and SDC update is proceeding according to the following work plan:
Task 1: Data Collection and Analysis (Complete)
Collection of utility billing and usage data, as well as utility operations, maintenance, and infrastructure improvement needs and estimated costs. This information helps the project team determine the sewer and storm water utility funding needs for the next 10 years.
Task 2: Identify Revenue Requirement (Complete)
Identify the total amount of revenue needed to meet both the sewer and storm water utility’s financial obligations, including operation and maintenance costs, infrastructure improvement needs, and financial policy compliance.
Present recommended rate adjustments to City Council (to be refined as necessary as further analysis is completed).
- Proposed residential sewer fees (presented 4/21/25)
- Proposed residential storm water fees (presented 4/21/25)
Task 3: System Development Charge Rate Review and Adjustment (Complete)
Determine the total amount of revenue needed to expand the sewer and storm utility systems to support future development within Wilsonville. Update the sewer and storm water System Development Charge based on the identified funding needs.
Present recommended SDC adjustments to City Council (to be refined as necessary as further analysis is completed).
Task 4: Utility Fee Cost-of-Service Analysis (April-July 2025)
The cost of sewage treatment and infrastructure (i.e. pipes and lift stations) will be assessed by customer type, including single-family and multi-family residential, public facilities, restaurant, commercial, and industrial, to ensure that the costs are allocated based on actual impact to the sewer system.
Task 5: Public Review & Comment (Summer 2025)
The project team will be considering public comment in advance of the Utility Fee Rate Design. Open Houses are to be scheduled to discuss pending adjustments to utility fees and SDCs.
- A Utility Fee Open House will take place this summer (date TBD)
- A SDC Stakeholder Meeting will take place this summer (date TBD)
Task 6: Utility Fee Rate Design (July-September 2025)
The draft utility rate adjustment presented above will be updated across all customer types after the Cost-of-Service Analysis, yielding a final recommended utility rate schedule and implementation schedule for consideration and adoption by the Wilsonville City Council.
Task 7: Adoption of New Sewer and Storm Water Rates (Fall 2025)
- The adoption of new storm water and sewer SDCs is expected to take place at a September 2025 meeting of the City Council.
- The adoption of new storm water and sewer utility fees is scheduled to take place at an October 2025 meeting of the City Council.
Frequently Asked Questions
Why are the sewer and storm water utility fees and SDC rates being updated?
The Wilsonville City Council and Budget Committee authorized a review of the sewer and storm water utility fees and SDC rates as part of the Fiscal Year 2024-25 Capital Improvement Program. Among the reasons the review was initiated:
- An updated Wastewater Treatment Plant Master Plan was completed and adopted on January 18, 2024. An updated Storm Water Master Plan was completed and adopted on April 1, 2024. These plans assess the staffing, materials, and infrastructure (i.e. pipes, structures, lift stations, treatment systems) needed over the next 20 years to maintain and operate the utility system, replace outdated and worn out utility systems, expand and extend infrastructure to serve anticipated growth, and comply with new and changing regulatory requirements. Collectively, these plans identified future capital projects requiring more than $240 million to complete over the next 20 years. With these updated utility needs identified, the City needs to make sure there is sufficient funding available.
- Between 2020 and 2023, the construction industry experienced unprecedented inflation, increasing construction costs by as much as 53.8% as reported by the Federal Highway Administration: National Highway Construction Cost Index. Because sewer and storm water utility fee studies occurred before 2020 and are not indexed for inflation, this substantial increase in construction costs has significantly affected the City’s ability to fund needed sewer and storm water infrastructure improvement projects.
When were these utility rates last adjusted?
An update to storm water and sewer utility fees is overdue.
The sewer fee was last updated in 2014 to fund a major expansion of the Wastewater Treatment Plant. The rate has not been indexed annually for inflation.
Informed by a study of the storm pipe replacement needs identified in the 2014 Charbonneau Consolidated Improvement Plan, storm water fees were last adjusted in 2021. Like the sewer fee, the storm utility rate has not been indexed for inflation.
Because these fees have not been updated or adjusted for inflation for many years, current funding is insufficient to meet the financial demands of both systems.
Why do these fees need to go up so substantially so quickly?
Several essential capital projects must be completed in the next 5-20 years to meet projected growth, maintain and/or replace failing systems, and meet regulatory requirements. The cost of these projects is projected to exceed more than $240 million. Several of these projects are needed within the next five years, including installation of a new Membrane Bioreactor (MBR) to remove suspended solids, organic matter, and other pollutants from the water system. This project alone is projected to cost $80-90 million. The sooner this and other projects can be funded and completed, the more cost-effective they become because the impact of inflation and debt service can be minimized.
How is the City raising rates without residents having a voice in the discussion?
No rate increase would be adopted until this fall, and rates would not change until 2026. The first discussion among staff, consultants and the City Council about the need for a rate adjustment took place at a City Council work session on April 21, 2025. This was a preliminary discussion to allow the Council to understand the dire need for a significant rate adjustment to generate the necessary funding to support planned growth, maintain existing utility assets, and meet the regulatory requirements that ensure a sound sewer and storm utility program. Before the City Council considers adoption of the fee adjustments this fall, the draft fee schedule may be adjusted in response to further analysis, input from the Council, and a period of public engagement that is to include an open house.
How would the proposed rate increase affect my monthly utility bill?
The City’s Utility Bill is comprised of fees that support six City services: water, sewer, storm water, road maintenance, streetlights, and fire sprinklers (where applicable). Based on the current base rate for single-family homes, the current monthly fee for City utilities is $74.82. Note that some consumers incur monthly charges exceeding the base rate because of higher water usage.
The following table illustrates how this base rate would be impacted by the recommended fee adjustments:
Are current residents footing the bill for plant expansion and other improvements to support future growth?
Ultimately, no. System Development Charges (SDC) that are paid for by developers to fund projects or portions of projects that serve future growth. The portion of projects that serve existing customers are funded through the utility rates. However, SDC revenue is based on the rate of development within Wilsonville and is typically collected after the needed project has already been constructed, as infrastructure that supports growth needs to be built before development occurs. As a result, the utility rate accounts for the lagging SDC revenue and may be used to fund needed capacity projects. However, the utility rate expenses are offset by SDC revenue as development occurs over time, helping to ensure that “growth pays for growth”.
Why wasn’t this increase introduced many years earlier, and over a longer period?
Wilsonville consumers have been the beneficiary of flat sewer rates for more than a decade and until recently, the added revenue from Wilsonville’s growth in residents and businesses has helped the sewer and stormwater utility meet its financial requirements. With a new 20-year assessment of utility maintenance, operations, and infrastructure needs identified through the recently adopted utility master plans, an unprecedented increase in construction costs, and a lack of an inflation adjustment over time necessitates a substantial increase in the utility rates to bring the sewer and stormwater systems back to financial stability. Delaying implementation of the needed utility rate increase, will only cause the backlog of sewer and stormwater needs to increase, resulting in higher cost and utility rates in the future. To help mitigate large fee increases in the future, City Council will be considering application of an annual inflation index to the utility rates as part of the final rate adoption.
Are Wilsonville's rates comparable to those in neighboring cities?
Each City and utility district is unique in the make up of its residents and businesses and the infrastructure needed to provide sewer and stormwater service to its customers. As a result, an “apples to apples” comparison of utility rates and SDC fee between City’s is not productive.
For example, some City’s may have a large portion of residential areas, whereas others may have larger percentage of commercial or industrial businesses. Each has its own unique utility service needs. Likewise, some City’s may have geographic differences, one consisting of hills and steeps slopes, whereas others may be relatively flat with little change in elevation.
One such challenge with Wilsonville is the location of the Wastewater Treatment Plant (WWTP). The WWTP site is limited in size, surrounded on each side by Interstate 5, the Old Town Neighborhood, and Boones Ferry Park. Replacement, upgrade, or expansion of the existing WWTP is not feasible with conventional sewage treatment facilities and necessitates use of smaller, compact treatment processes that are higher in cost.
In addition, any comparison of utility rates and SDC fees represents a snapshot in time and doesn’t reflect where each City or utility district is in the process of updating their fees to meet current and future needs.
Many people are on fixed incomes. Will rate reductions or exemptions be available for qualifying customers?
Wilsonville does not currently offer rate reductions of exemptions for utility rates based on income. The City does offer payment plans for one-time financial events. Additional assistance may be offered by area social service providers.
Why are we paying for a project that serves Beaverton and Hillsboro?
The City's review of sewer/stormwater utility fees is unrelated to the Willamette Water Supply Program and its projects in Wilsonville. Our residents do not contribute financially to water pipeline work currently underway on 95th Avenue and Ridder Road.
What exactly are we paying for? Why is it so essential?
Utility fees help fund maintenance, rehabilitation, and replacement of City infrastructure (i.e. pipes, lift stations, treatment facilities) that collect, clean, and discharge wastewater and storm water runoff, ensuring that the City’s rivers and streams are clean, wastewater doesn’t back up into homes and businesses, and rainfall isn’t flooding neighborhoods or eroding creek channels, helping to maintain a healthy environment.
SDC rates are paid by developers and help fund expansion and extension of utility infrastructure (i.e. pipeline upsizing and extension, pumping and treatment facility expansion) needed to serve a growing population.
Detailed information regarding Wilsonville’s utility system needs can be found at:
Sewer
Storm water
Who can I contact for additional information about sewer and storm water rates?
Should you have any questions, need additional information, or would like to share your thoughts regarding the sewer and storm water utility rate and system development charges, please contact City Engineer, Zach Weigel at 503-570-1565 or by e-mail.
Supporting Documents
DRAFT Sewer SDCs (presented 6/2/25) (841 KB) 