EWEB 2023 year in review
In 2023, EWEB invested in our community with grants, rebates and an array of other programs and measures aimed at fulfilling our core values of safety, reliability, affordability, environmental responsibility and community/culture.Find Out More
EWEB Recognized with Excellence in Communications Awards from American Public Power Association
We are proud to have been recognized with two Excellence in Public Power Communications Awards for 2023 from the American Public Power Association (APPA).Find Out More
Let's talk turkey. If a disaster strikes, is your family ready?
Many of us avoid discussing politics over the dinner table in the spirit of family peace and harmony. But here's a topic that can bring everyone together: emergency preparedness.Find Out More
EWEB To Hold First of Two Public Hearings on Proposed 2024 Budget and Prices
At the Nov. 7 Board of Commissioners meeting, EWEB staff will present a proposed budget that includes rate increases necessary to support utility operations and make needed infrastructure investments.Find Out More
River Road Substation returns to service after infrastructure upgrades
Supply chain shortages and proactive infrastructure investments, including constructing seismic foundations and implementing control modernization, have played a role in the substation's return-to-service timeline.Find Out More
Public Power Week Poster Contest Winners 2023
The results are in! View the winning posters from EWEB's 2023 Public Power Week Poster Contest.Find Out More
Fall is the perfect time to prepare for winter storm season
Winter is coming, which increases the likelihood of storm-related power outages. It's important to be prepared, and there are simple actions you can take right now.Find Out More
EWEB lead annual "Spill Drill"
EWEB coordinates drill as part of protecting Eugene’s drinking waterFind Out More
EWEB seeks public input on electric vehicle, demand response standards
EWEB is seeking public input on the potential adoption of updated standards for electric vehicles (EVs) and demand response programs. The potential standards are derived from the Public Utility Regulatory Policies Act, or PURPA.Find Out More
Public Power Week Poster Contest 2023
It’s that time of year again! October 1-7 is Public Power Week. To celebrate, EWEB is holding our annual poster contest for fifth graders in our service area. Help us pick the winners.Find Out More
Salmon Return to Finn Rock Reach
Finn Rock Reach and other restoration projects throughout the Middle McKenzie provide conditions to help young fish survive to adulthood.Find Out More
EWEB programs reflect community values
EWEB is here to serve our customer-owners and provides programs that reflect the values of our community.Find Out More
Where is EWEB in planning our future electricity supply?
In August, we reached a milestone: EWEB’s five-member elected Board of Commissioners approved an action plan to guide our energy supply choices for the next 2-3 years. How did we get here?Find Out More
National Preparedness Month: Older adults take control in 1, 2, 3
We know older adults can face greater risks when it comes to the extreme weather events and emergencies we face, especially if they are living alone, are low-income, have a disability, depend on electricity for medical needs, or live in rural areas.Find Out More
Women in STEM: EWEB Engineer Laura Ohman's second degree brings a lifetime of benefits
EWEB Engineer Laura Ohman shares how getting her second degree was one of the most difficult and rewarding things she's ever accomplished.Find Out More
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Monitoring of Trail Bridge Reservoir "Sinkholes" Continues
October 22, 2021
As part of our routine monitoring efforts, EWEB conducted a bathymetric survey of Trail Bridge Reservoir in May 2021. The reservoir is one of three that make up our Carmen-Smith Hydroelectric Project located about 70 miles east of Eugene off of Highway 126 near the headwaters of the McKenzie River.
The results of the survey, which is essentially a map of the topographic features of the reservoir bottom, indicated three "depressions" that required further investigation. One of the depressions was apparent during re-examination of a similar survey performed in 2010.
EWEB conducted follow-up inspections with a remotely operated underwater vehicle along with dye testing by divers in early June 2021. Based on the dye tests, the two larger depressions are actively taking water and are considered sinkholes. Subsequent dye testing and geophysical investigations in July and August indicated that there is no concentrated seepage flow through or under Trail Bridge Dam.
Public safety is EWEB's top priority, and staff are working diligently to manage the safety risk to the public downstream of the dam while actively investigating sinkhole conditions and cause. EWEB's Dam Safety team, along with Generation Operations and Engineering, have been working closely with experienced consultants and the Division of Dam Inspection and Safety of the Federal Energy Regulatory Commission to address the issue and develop a risk mitigation plan.
We have implemented several risk-reduction measures to date, including lowering the Trail Bridge Reservoir level approximately 7 feet below the normal operational elevation, increasing monitoring and surveillance at the dam and downstream, and ensuring effective notification and communication with Emergency Action Plan (EAP) partners.
The decision to lower the reservoir level was made out of an abundance of caution.
EWEB has multiple monitoring devices in place to detect anomalies or any unexpected changes. These include stream flow gauges, reservoir level sensors, groundwater level sensors, turbidity monitoring sensors, remote video cameras with night vision capability and seepage weirs at the toe of Trail Bridge Dam.
"Based on our understanding and the data we have gathered so far, the risk of a catastrophic dam failure is low," said Daniel Huang, EWEB's Chief Dam Safety Engineer. "We will continue our investigation and evaluation, and that could take a year or longer."
Carmen-Smith duty operators conduct daily inspections of the dam, and can further lower the reservoir if any anomalies are detected visually or by the monitoring equipment.
There are plans in place to notify the public, public safety agencies and the U.S. Forest Service should the situation change. There is also a siren at Olallie Campground, downstream of the dam, that EWEB staff can activate should the status of the dam change. The campground was closed in August for the remainder of 2021 due to its close proximity to the Knoll Fire.
The steps EWEB has taken with the increased monitoring and lowering the reservoir level by 7 feet reduce the likelihood of a dam failure. Staff, including engineers, are confident they can quickly intervene if anomalies are detected, which further lowers the likelihood of dam failure.
We will continue to monitor and assess the sinkholes to determine the cause and potential remedies.
Anyone with questions or concerns can contact Joe Harwood at firstname.lastname@example.org.