Saying winter storms had eased drought conditions somewhat in the Colorado River basin, Interior Secretary Gale Norton on Monday ordered federal dam managers to continue making normal water releases from Lake Powell, one of the West's biggest reservoirs.
Norton's decision settles for now a dispute between the upper and lower basin states over levels in Lake Powell, which collects water from Colorado, Wyoming, Utah and northern New Mexico, and its downriver sibling, Lake Mead.
Led by Colorado, the upper basin states wanted the Interior Department to reduce releases from Lake Powell for the first time to slow a dramatic drop in the reservoir's levels. The lower basin states were concerned that if the releases were trimmed and Lake Powell's level increased, it would be at the expense of Lake Mead, which supplies water to Nevada, Arizona and Southern California.
After more than five years of severe drought along the Colorado, Lake Powell is only a third full -- the lowest it has been since it was filled after the 1963 construction of Glen Canyon Dam. Lake Mead, by contrast, is 62% full and has been rising after a series of winter storms doused parts of the Southwest.
The upper basin doesn't use water from Lake Powell. Rather, the reservoir operates as a huge holding tank for Lake Mead, ensuring that the upper basin has enough reserves to meet its legal obligation to send a certain amount of water to the lower basin.
As Lake Powell's level has dropped, those reserves have dwindled, threatening hydropower production, hurting recreation businesses and raising the possibility that if the drought continues, Colorado and other states might be forced to make cuts in their water usage in order to give the lower basin its share.
Representatives from California, Nevada and Arizona had argued against reducing the discharges from Lake Powell, saying the step was unnecessary because runoff had increased throughout the basin.
Releasing less water from Lake Powell would not have affected deliveries in the lower basin. But it would have lowered the level of Lake Mead. That would reduce power generation at Hoover Dam and potentially interfered with the intakes that divert water to Las Vegas. In the long term, lower levels in Lake Mead could trigger shortages.
In declining to reduce Powell's discharges, Norton noted that flows into Powell from the upper basin are expected to be about normal this year thanks to a relatively wet winter. That will boost the lake levels and leave it nearly half full by fall, closing the gap between Lake Powell and Lake Mead.
