SUB to build new facility to draw drinking water from McKenzie River

The Springfield Utility Board is getting closer to establishing a water treatment facility on the McKenzie River in Thurston. 

The utility says the new source of water will help support Springfield’s growing community and will make its system more resilient with multiple sources of drinking water. 

The project is almost three decades in the making. The state granted SUB water rights on the river in 2007. The utility is working with a design firm and pursuing permits. SUB plans for construction on the new plant to begin in 2028, with the facility starting to operate in 2031.

SUB is building the facility near groundwater wells the utility already manages near Thurston Middle School.

The utility’s director, Jeff Nelson, said SUB currently plans for the plant to cost between $135 million and $140 million, which will be financed through a combination of increasing water rates and long-term loans. Current SUB budget projections show water rates increasing 8.5% every year for the next five years. 

Springfield’s drinking water

Currently, most of Springfield’s drinking water comes from six well fields, which tap groundwater from an aquifer of water-bearing sands and gravel under the city. SUB also has a water treatment facility on the Middle Fork of the Willamette River near 28th and M streets that produces 6 million gallons of water per day. The utility built that plant in the early 2000s.

SUB water division director Greg Miller said the new McKenzie River water source will help it meet demand from the community, including the city’s two hospitals. According to SUB, the utility supplied about 3 billion gallons of drinking water to more than 61,000 people in 2024. The utility predicts demand for water will increase 48% over the next 50 years. 

Miller said the new plant will also provide flexibility during natural disasters or other emergencies that could affect the utility’s existing supply. 

Nelson pointed toward Salem, where a planned drawdown at the Detroit Reservoir by the U.S. Army Corps of Engineers is expected to impact the city’s drinking water, according to the Salem Statesman Journal. 

“If something were to happen on either of those rivers (Willamette or McKenzie), we would be in a position to have a surface water source on both of the rivers to be able to address that kind of potential risk,” Nelson said. 

Nelson said SUB also plays an important role in making sure the fire department has water for fighting suburban fires and wildfire. The Holiday Farm Fire in 2020, which devastated the McKenzie River valley and threatened the Thurston neighborhood, showed the importance of fire protection in the community.

Nelson also said that toxic algae blooms in the Willamette River, which are more common during the summer when water demand is higher, sometimes mean pausing surface water intake from the river.

“That puts a bit more stress on our system,” Nelson said. “So having this alternate surface water source would really mitigate that risk.” 

Surface water treatment is generally more cost-effective than treating groundwater for two reasons: Surface water pumps produce more water than groundwater pumps (the new facility is expected to yield 23 million gallons per day once fully operational) and groundwater is more susceptible to PFAS (per- and polyfluoroalkyl substances also referred to as “forever chemicals”), which are costly to remove, Nelson said. 

“Setting aside the issues of resiliency and the need to provide water for the future for the community, we’re also looking at trade-offs in terms of what’s the most cost-effective way to treat water,” he said.

The new plant

The project includes three facilities: water intake and pumps, the filtration facility and underground pipelines. 

The river intake site will be northeast of where the water treatment plant is being planned. Miller said the water intake will be integrated into the riverbank so that it doesn’t obstruct boating or other recreational activity in the river.

The treatment plant will be built on land owned by SUB on 66th Street, northeast of Thurston Middle School.

A conceptual rendering of the site shows sedimentation basins where the water will initially enter and where small particles and suspended solids will settle out of the water. Next the water will go into a building with membrane filters before entering storage tanks with chlorine and UV disinfection. Finally, the water will enter an underground pipeline that will carry it to other parts of Springfield. 

SUB is working with design consultant Stantec and general contractor Slayden Constructors Inc. on the project, Miller said. The project is currently at 30% design, which is the initial project direction and design phase. At 60% design, which SUB anticipates reaching in spring 2026, the utility will have a better idea of the final project cost. 

Nelson said SUB’s current annual budget is about $30 million. He expects the new project to add about $10 million in annual expenditures for loan payments. Customers will see rate increases spread out over time. Nelson said the utility has so far been unsuccessful in securing state and federal grants to help fund the project.

Each year SUB staff reviews its 10-year capital plan and cash flow projections with the utility’s budget committee, which includes board members and customer representatives. A presentation by SUB staff to the budget committee in August projected 8.5% water rate increases every year for the next five years, decreasing to 6% in 2032 and 4% in 2033 through 2035. 

The projected increases include funds for ongoing water operations such as system maintenance, testing, meeting treatment regulations and pipeline construction. 

According to the utility, the typical SUB water customer will pay an additional $4.50 per month or about $54 per year, of which about half would go toward the new filtration facility.

The utility said the rate increases are estimates. SUB’s board will set rates based on recommendations from the budget committee and after public hearings in November and December.

Historic SUB water rates show increases of 5% to 9.5% each year for the past 10 years.