Walterville Hydroelectric Project to remain offline through 2025
The Eugene Water & Electric Board (EWEB) will not be able to repair a leak at the forebay of the Walterville Canal this year. Additional analyses into seismic and flood hazards will be required before EWEB can obtain regulatory approvals for the work. As a result, the project will need to remain offline until at least the fall of 2026.
The Walterville Canal will remain dewatered through the 2025 irrigation season.
“We are disappointed to report that the canal will be empty again this summer. We know that this announcement is hard for our neighbors to hear – especially those who irrigate from the canal. But we cannot return the canal to service until we gain a better understanding of the risks that earthquakes and floods pose to the project,” Generation Manager Lisa Krentz said.
EWEB dewatered the Walterville Canal on February 27, 2024 following an unexpected increase of water seeping through the canal forebay embankment near the Walterville Powerhouse.
Unlike the seepage concerns along portions of the Leaburg Canal that prompted EWEB’s investigation and eventual decision to decommission the Leaburg Hydroelectric Project, the seepage at the Walterville Canal is localized to the forebay. The forebay is the structure at the lower end of the canal that directs water to either drop into the powerhouse to spin a turbine to generate electricity or releases the water through a spillway into the tailrace.
EWEB intends to bring the project back online and is contracting with a company to develop a repair plan for the forebay leak. Pending regulatory approval, EWEB would authorize the firm, Carpi, Inc., to manufacture and install their synthetic liner system to seal the forebay and prevent further seepage.
However, preliminary results from a study into the forebay’s vulnerability to earthquakes indicate that a portion of the forebay could be seismically unstable during a large earthquake. Another study found that extreme flooding of the creeks that feed into the canal could result in overtopping.
As a result, EWEB will need to compile additional information for the Federal Energy Regulatory Commission (FERC) to approve repair plans – delaying the targeted 2025 return-to-service and pushing the date into late 2026.
If approved by EWEB’s regulator, the current repair plan would cost approximately $3 million and the project could recuperate such an expense in two to five years of generation, depending on water availability and energy prices.
“At this point, with the information we have, we will continue working to get the project safely up and running at the earliest opportunity,” Krentz said. “We will continue to communicate our findings regarding the project’s seismic vulnerabilities once we know more.”
