Lake Powell is one of the most scenic and popular lakes in the world. Formed by the waters of the Colorado River behind Glen Canyon Dam, Lake Powell’s 1,960 miles of winding shoreline (when full) and 186 mile-length make it the second-largest reservoir in the United States. Lake Mead, formed by Hoover Dam approximately 361 river miles downstream of Glen Canyon Dam, is the largest.
Lake Powell began filling on March 13, 1963 following the completion of Glen Canyon Dam and closure of the diversion tunnel gates used to redirect the flow of the Colorado River during the dam’s construction. Lake Powell filled for the first time on June 22, 1980 reaching elevation 3,700 feet above sea level with a total capacity of over 26 million acre-feet of water (24.3 million acre-feet in live storage and 1.9 million in dead storage). Lake Powell extends through the main corridor of Glen Canyon as well as into over 90 side canyons that extend outward.
Named after Major John Wesley Powell who successfully navigated the first expedition down the Colorado River through the Grand Canyon in 1869, Lake Powell offers visitors spectacular scenery and numerous recreational opportunities. For this reason, the lake and over a million acres of beautiful red-rock desert and canyon country were designated as a national recreation area by Congress in 1972. The Glen Canyon National Recreation Area is managed by the National Park Service. Over three million visitors from around the world are drawn to Glen Canyon NRA each year to experience the majestic beauty of this unique area.
In addition to its significant recreation value, Lake Powell functions as a vast ‘bank account’ of water that can be drawn on during dry years. Lake Powell provides long-term carryover water storage that allows the Upper Basin states of Wyoming, Colorado, New Mexico, and Utah to use their share of the Colorado River while still providing the required delivery of water to the Lower Basin states of Arizona, California, and Nevada according to the Colorado River Compact of 1922. As drought conditions persist in the Southwest, the water storage in Lake Powell is especially critical.
As Lake Powell fulfills its intended purposes, it’s natural for the elevation of the lake to fluctuate depending on the amount of spring runoff from the mountains, deliveries to the Lower Basin, and the amount of water carried over from the previous year. Each year, the lake level increases between May and July from runoff followed by a decrease in lake level throughout the remainder of the year, leaving a visible ring along the shoreline. The amount of fluctuation varies each year but during extended periods of drought, Lake Powell’s elevation could drop by more than 200 feet below its maximum elevation.
Because of the many significant benefits provided by Lake Powell, Congress continues to include a direct prohibition concerning any planning actions or expenditure of public funds related to consideration or actions toward draining Lake Powell. Former Reclamation Commissioner, John W. Keys III said, "Previous administrations of both political parties, as well as the U.S. Congress, have said that Glen Canyon Dam is here to stay because it is serving millions of people in the Southwestern United States. Congress, through the passage of the Grand Canyon Protection Act of 1992, clearly stated that the dam and reservoir have a place in the tapestry of the country." Reclamation is committed to operating Glen Canyon Dam in accordance with the Law of the River and all applicable environmental laws.