The Bureau of Reclamation has awarded an $18.4 million contract to PNK Constructors LLC for dam safety excavation work at Utah's 4.5-MW Echo Dam.
Operated by the Weber River Water Users Association, Echo Dam is a 158-foot-tall zoned earthfill structure that was constructed between 1927 and 1931 as part of the Weber River Project to help supply supplemental irrigation water to 109,000 acres west of the Wasatch Mountains. The bureau awarded a $1.3 million contract in May to Foothill Engineering and Dewatering Inc. of California to dewater the work site to enable excavation for the dam safety work.
Reclamation announced Aug. 26 that PNK, of Coalville, Utah, is to perform major excavation on the downstream side of the dam to replace potentially liquefiable materials in the dam foundation with stronger and denser material. A large stability berm is to be built on the downstream side of the dam while the dam's crest is to be raised three feet. A second stability berm will be added on the upstream side of the dam.
The work is to be performed between October 2011 and winter 2013.
A second contract to modify the spillway is to be awarded in September 2012, with the entire seismic modification project to be completed by the end of 2014.
