The U.S. Army Corps of Engineers’ Dam Safety team on Monday, Oct. 22, began a geotechnical investigation at Foster Dam that will include boring into the dam’s embankment or rock-fill portion of the dam.
The work is part of a larger geotechnical assessment where data from the borings will provide information on the physical properties of the dam.
The dam safety team will then use the data to study how the dam will perform under various conditions.
Corps staff anticipates completing the drilling by the end of October and the team doesn’t foresee road closures; however, it is possible one lane may be impacted adjacent to the site.
“Drilling is not going to impact the integrity of the dam,” said Matt Chase, Portland District Dam Safety Program Manager. We use these investigations to improve our understanding of the make-up and risks at our dams,” he said.
The Dam Safety Program’s goal is to make Corps dams as safe as possible, and minimize risks to the public.
“We’re conducting this investigation in conjunction with our routine dam safety program which includes inspections, performance monitoring, and risk assessments,” Chase said.
The study will also include Emergency Action Plan exercises, seismic and hydrologic studies.
The U.S. Army Corps of Engineers operates Foster Dam and 12 other dams and reservoirs in the Willamette River Basin.
Each dam contributes to a water resource management system that provides flood risk management, power generation, irrigation, water quality improvement, fish and wildlife habitat and recreation on the Willamette River and many of its tributaries.
Since their completion, the dams have cumulatively prevented more than $20 billion in flood damages to the Willamette Valley, a Corps statement said.