A report by independent consultants says an embankment dam with a water-tight core is the best design for Jordanelle Dam now under construction north of Heber.
The Bureau of Reclamation, building the dam as the main feature of the Central Utah Project's Bonneville Unit, announced earlier it would wait until the dam's foundation was excavated before deciding on a design for the dam structure.The panel of three independent consultants evaluated the results of core drilling at the dam site and found it free of faults and shears that would pose safety problems, according to a reclamation release.
The panel reported that an embankment dam would best survive seismic activity - either from external geologic forces or that induced by pressure from the reservoir - and could survive an earthquake magnitude of 6 to 6.5 directly beneath the dam, the release stated.
The consultants also said the bureau "has adopted an appropriate and credible approach for quantifying the probability of reservoir-induced seismicity."
Final dam design specifics will be the topic of public seminars reclamation plans to schedule in Heber and Provo.