The Corps of Engineers' Nashville District announced Feb. 22 it awarded a contact worth nearly $87.4 million to Kiewit�A.C.T. to install a grout curtain seepage barrier at 135-MW Center Hill Dam, on the Caney Fork River in DeKalb County, Tenn.
Kiewit-A.C.T. of Little Rock, Ark., is a joint venture of Kiewit Southern Co., a subsidiary of Kiewit Corp., and Advanced Construction Techniques Ltd. It was chosen in a Corps solicitation that estimated the cost of the two-year contract would range from $50 million to $100 million. (HNN 8/10/07)
The 250-foot-tall Center Hill Dam consists of a 1,382-foot-long concrete section and 778-foot-long earth embankment. The contractor is to install an 800-foot-long grout curtain into the rock foundation of the main dam embankment, build a work surface near the crest of the earthen embankment portion of the dam, and install a 3,500-foot-long grout curtain into the rock foundation at the left rim of the dam. Kiewit-A.C.T. also is to plug an area beneath the grout line on the left rim.
The dam, near Lancaster, Tenn., has a history of seepage problems that have worsened in recent years. It is among six dams the Corps identified as having a high risk of failure. In 2006, the Corps approved a $240 million rehabilitation plan that includes the grouting work. Work to improve the dam's long-term reliability could be completed in 2014, the Corps said.