Despite recent storms to the north and a deep snowpack in the Sierra Nevada, experts are no more encouraged now about the long-term prospects for Southern California's water supply. Lake Powell and Lake Mead remain at low levels after 23 years of drought, the Los Angeles Times reports. "To think that these things would ever refill requires some kind of leap of faith that I, for one, don't have," said Brad Udall of Colorado State University. Lake Mead, on the Colorado River, is at about 30% capacity and Lake Powell, which is upstream, is at 23%.
Southern California relies on water from Colorado River Basin, and the lakes are the largest reservoirs in the nation. The water levels in Lake Powell are trending toward the point where Glen Canyon Dam would not be able to generate electricity. That's also true of Hoover Dam on the Colorado River, per Newsweek. Lake Mead was almost full in 2000; then the drought began. Rising temperatures are lowering water levels and drying up the region. Refilling would require about six straight seriously wet years, experts say. "And I just don't see that even being remotely possible," Udall said. Said Bill Hasencamp of the Metropolitan Water District of Southern California: "The only reason they filled the first time is because there wasn't demand for the water."
A wet spell could happen, Udall said, but that wouldn't change the bleak long-term trends. Water-sharing deals are contributing to the problem. "Climate change is reducing the flow into the Colorado River system, so the agreements are divvying up more water than exists," said David Pierce of Scripps Institution of Oceanography. Just hoping the situation improves won't be enough, experts said; there's every reason to think the warming up and drying out will continue. "A bet on anything other than that seems like water management malpractice," Udall said, adding "we have got to plan for something that looks like a worst-case future." (Read more water supply stories.)