Lake Mead is roughly 30% full at 1,055 feet. Another 20-foot drop shuts down twelve of seventeen turbines, and output falls from an already diminished 500-600 megawatts to around 300. The Bureau of Reclamation projects this could happen by fall, after cutting releases from Lake Powell to keep that upstream reservoir alive.
Salt River Project shrugs. Hoover covers half a percent of its load. But Lincoln County Power District No. 1 in rural Nevada draws 70% of its electricity from the dam, serving about 2,000 agricultural customers. General manager Dane Bradfield has been plain about it: replacement power from the open market costs more, and those costs land directly on his ratepayers.