Bureau of Reclamation drill crews and geologists will begin seismic stability evaluation work at Combe and Farmington equalizing dams located in Ogden and Farmington canyons respectively, in early December as part of the periodic inspection and safety evaluations conducted under Reclamation's Safety of Dams Program.

The work will focus on analyzing the foundation materials of both dams which consist of clay, silt, sand, and gravel, to determine the potential for these materials to change from a solid into a liquid state during an earthquake. This process of liquefaction could seriously damage the structural integrity of the equalizing dams. The goal of the evaluation work is to ensure early detection of any potential seismic weakness that need to be addressed. Reclamation anticipates the evaluation work will be complete by spring 2013.

The reservoirs impounded behind Combe and Farmington equalizing dams are located along the Weber and Davis Aqueducts. Both dams were constructed as part of the Weber Basin Project between 1953 and 1967 to equalize the pressure inside the aqueducts which convey irrigation and municipal and industrial water in the north to Ogden and adjacent communities and south to North Salt Lake area communities.

Combe Dam is 25 feet high and 500 feet long with a reservoir capacity of 162 acre-feet. Farmington Dam is 30 feet high and 2,140 feet long with a reservoir capacity of 101 acre-feet.