KUNC/LightHawk Lake Powell is impounded by Glen Canyon Dam, near the Utah-Arizona border, shown here in fall 2018. Declining levels at the second-largest reservoir in the U.S. have spurred officials in Colorado, Utah, Wyoming, and New Mexico to search for ways to prop it up. Lake Powell on the Colorado River is dropping rapidly amid one of the southwestern watershed’s driest years on record. It’s currently forecast to be at 29% of capacity by the end of September — the lowest level since the reservoir first started filling in 1963. Its sister reservoir downstream on the Colorado River, Lake Mead, is also approaching a record low this year.