India, Aug. 17 -- The water level at Lake Powell, the United States' second-largest reservoir, has fallen to a record low, heightening concerns about the crisis in the Colorado River system.

The alarming milestone at Lake Powell, reached Saturday, comes about a week after the river's other major reservoir, Lake Mead, also hit a historic low.

Plummeting water levels pose a major threat to the Colorado River Basin, a key resource for wildlife, hydropower and more than 40 million people in seven US states.

The historic lows come as the federal government and states that rely on the river -- California, Arizona, Nevada, New Mexico, Utah, Wyoming and Colorado -- struggle to reach agreement on a long-term management plan for the dwindling re...