In February 2007, Barber Dam experienced an uncontrolled seepage event. The event caused the 26 foot high, 104 year old timber crib dam to be elevated to a critical dam safety issue with the Federal Energy Regulatory Commission (FERC), the Idaho Department of Water Resources Dam Safety Division, and other agencies.
Deere & Ault staff (formerly with Engineering Science & Construction) was retained by the FERC license holder, Enel Italia North America, to study and manage the repair of the structure.
Deere & Ault prepared a study report on the seepage problem, conducted a FERC Potential Failure Mode Analysis, performed final engineering design, obtained and coordinated all necessary permits, and served as the resident engineers during construction.
It was ultimately determined that the best method of repair would be to replace a 40 foot wide portion of the 400 ft wide spillway using driven pipe piling, hydraulic drains, and a 40 foot wide section of reinforced concrete ogee spillway.
To improve the stability of the structure, eight high-tension rock anchors were placed and tested. Each anchor was tested to a tension of 400,000 lbs.
Client: Enel Italia North America