A near failure of Arthur V. Watkins Dam, a leaking U-shaped earth-fill levee structure located 10 miles northwest of Ogden, Utah, is prompting a compressed-schedule repair, squeezing two years of work into one. The dam was within a few days of failure, U.S. Bureau of Reclamation officials say, threatening lives and major flood damage to surrounding property. General contractor Geo-Solutions Inc., New Kensington, Pa., is consequently running double shifts and using specially modified equipment to speed up repair work. It designed a 150-cu-yd-per-hour slurry plant fed by twin 60-ton silos for three times the output of a typical facility. Geo-Solutions additionally customized a Komatsu PC1250 hydraulic excavator with a hybrid boom stick that can extend 85 ft for tough excavations.
The leak was discovered in November 2006 by Bureau of Reclamation officials along the 14.5-mile-long, 36-ft-high dam. Water was seeping at a rate of 100-150 gallons per minute across a 200-ft-long southeastern section. It is unclear when the leak began, but the reservoir was about 80% full at 175,000 acre-ft when it was discovered. Founding Fault.