Glen Canyon Dam A dam in Glen Canyon was studied as early as 1924, but these plans were initially dropped in favor of the Hoover Dam (completed in 1936) which was located in the Black Canyon. By the 1950s, due to rapid population growth in the seven U.S. and two Mexican states comprising the Colorado River Basin, the Bureau of Reclamation deemed the construction of additional reservoirs necessary. However, the USBR faced opposition when it proposed the Echo Park Dam in Utah's Dinosaur National Monument, which the nascent environmental movement saw as a legal threat to the status of protected lands. After a
Glen Canyon Dam long fight, the USBR agreed not to build the dam in Dinosaur National Monument, but only if the environmentalists did not oppose the proposed dam in Glen Canyon. Since first filling to capacity in 1980, Lake Powell water levels have fluctuated greatly depending on water demand and annual runoff. Operation of Glen Canyon Dam helps ensure an equitable distribution of water between the states of the Upper Colorado River Basin (Colorado, Wyoming, and most of New Mexico and Utah) and the Lower Basin (California, Nevada and most of Arizona). During years of drought, Glen Canyon guarantees a water delivery to