The U.S. Army Corps of Engineers has awarded a contract to Kiewit Infrastructure South Co. to perform the remaining excavation that will allow flows into a new auxiliary spillway at Canton Lake Dam on the North Canadian River in Oklahoma.
The Corps’ Tulsa District took bids for the work in May. Canton Lake Dam, a 68-foot-tall, 15,140-foot-long earthfill embankment, includes a 778-foot-wide service spillway at the right abutment with 16 tainter gates. Corps hydraulic studies found the existing spillway is unable to discharge a probable maximum flood and the dam is likely to fail during a major flood. To address the inadequate spillway capacity, the Corps began construction of an auxiliary spillway at the right abutment.
Under a new $26.99 million contract, Kiewit, of Omaha, Neb., is to carry out Phase 2 of the auxiliary spillway channel excavation to remove the remaining soil plug that prevents lake flows into the new spillway. Work includes reshaping some dam embankment, diaphragm walls, a cofferdam and dewatering.
In 2011, the Corps awarded an initial contract to ASI Constructors Inc. for construction of a concrete weir and hydraulic structures as part of the auxiliary spillway. The Corps chose a Fusegate system from Hydroplus Inc. for the new spillway.