Foundation dewatering immediately downstream of the dam is necessary to facilitate seismic retrofit work to be done under USBR’s Safety of Dams Program, which ensures dams are inspected for safety deficiencies and corrective actions are implemented if necessary.
Beginning in May, a pumping discharge system will be constructed and maintained to lower the groundwater level downstream of the dam in preparation for, and throughout, subsequent excavation work in which potentially liquefiable foundation material will be removed and replaced with stronger, denser material. This will enhance the dam’s ability to withstand a significant seismic event.
“Reclamation places a high priority on regularly inspecting and evaluating the safety of our facilities,” said USBR commissioner Michael Connor. “Because many of our dams pre-date contemporary seismic design standards, we continue to make the necessary improvements to provide enhanced stability and ensure public safety.”
USBR began installing numerous dewatering and observation wells to facilitate the seismic retrofit work last year following the completion of a risk-analysis and corrective action study done by USBR and reviewed by a board of independent consultants.
Echo Dam is a 158ft high zoned earthfill structure on the Weber River, upstream from the town of Echo. Part of the Weber River Project, Echo Dam was constructed between 1927 and 1931 to help supply supplemental irrigation water to approximately 109,000 acres of land west of the Wasatch Mountains. Echo Dam is operated by the Weber River Water Users Association.
