Saturation divers, working one at a time, have begun a repair project on a pumped-storage hydroelectric system at Horse Mesa Dam on the Salt River in central Arizona. The repair will reestablish 115 megawatts of peak-load generating capacity that was lost 13 months ago, when failure of a guide vane sent about 50 tons of concrete shooting down the penstock serving the turbines.
"It is our largest hydro-generation asset on the Salt River," says Roger Baker, principal engineer for hydro-generation at the U. S. Bureau of Reclamation's Salt River Project, which owns and maintains the facility. He says getting it back into service is "critical."