Oroville Dam’s spillway fractured last February. Back in the 1960s, a contractor working on the dam told the California Department of Water Resources it needed to dig deeper to find stronger rock.

New research has uncovered that the construction of water dams has shifted Earth's poles in subtle but important ways.

Anatomy of Calaveras Dam. In this cross section (upstream, left), the dam design features a clay-soil core (1), ranging from 200 ft wide at the base to 80 ft wide at the crest.

Crews hired by the contractor Kiewit Corp. will use machinery to excavate the dam’s estimated 1 million cubic yards of earthen material, including rock, sand and clay.

The largest dam removal project in U.S. history has freed the ... Crews hired by the contractor Kiewit Corp. have excavated an estimated 1 million cubic yards of rock, soil and clay at Iron Gate Dam.

The largest dam removal project in U.S. history has freed the ... Crews hired by the contractor Kiewit Corp. have excavated an estimated 1 million cubic yards of rock, soil and clay at Iron Gate Dam.

Remediation consists of building a 275-ft-deep, 3,800-ft-long concrete wall composed of secant piles and rectangular panels installed through the clay embankment and into the rock of the dam ...