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Return to Previous PageRepairs to improve dam’s spillway

Silver Creek Dam reservoir to close for about 3 weeks

By Danielle Peterson

Repairs that will target weather-related damage are scheduled this month at Silver Creek Dam. City officials said the estimated $30,000 project also will improve the flow of the spillway.

Silverton Public Works Director Rich Barstad said this is the first repair project at the dam , in terms of concrete repairs, since it was constructed about 35 years ago.

Two concrete wall joints on the dam’s spillway will be resurfaced to repair damage from weathering. In addition, the concrete apron at the crest of the spillway will be extended and rounded to prevent debris from building up during storms. City staff designed the extension after discussion with state officials.

"This is standard maintenance that will extend the life of the spillway,” said Andy Peters, Silverton Public Works maintenance supervisor.

During the three-week-long project, the reservoir will be closed to the public, both for safety reasons and to prevent any damage to the work or the contractor’s equipment. A start date for the project has not yet been set, but Barstad anticipates it will begin by the end of this month or in early September.

Specialized Concrete Solutions of Estacada has been contracted to do the work. The project will be paid for through the city’s water fund.

What would happen if Silver Creek Dam failed has been a topic of discussion in Silverton for years.

Studies predict that if there were a catastrophic breach of the dam and the multi-million gallon reservoir it contains were unleashed, downtown Silverton would be flooded by a wave of water 10 feet high in some places.

To address that potential threat, the city adopted an emergency plan and in the future, plans to install an early-warning system that would trigger sirens to alert residents.

"At this time, we have no indications that the dam is in any danger,” Peters said.

Maintenance and monitoring of the dam are performed regularly, he said, and the Oregon Department of Water Resources surveys the dam each year.

The dam, about 2 miles upstream of downtown Silverton, was completed in 1974 and is owned and operated by the city.

This year’s city budget includes a remote monitoring system for the dam.

"The council has indicated that they want to pursue that," Barstad said. " I don’t know exactly what that will entail. It will probably require hiring an engineer to put together the full scope of the project.”

Barstad, who is set to retire at the end of the month, is currently working on a staff report about the remote monitoring system. It may be discussed at the next city council meeting.

"It’s a work in progress,” he said.

Silverton, OR
August 19, 2009

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