Lake Powell is a man-made reservoir located in northern Arizona, created when the Glen Canyon Dam was built on the Colorado River in the 1960s. Its hydrology is primarily fed by the Colorado River, but also receives water from several tributaries, including the San Juan and Escalante rivers. The lake plays a critical role in providing water to users in Arizona, California, and Nevada, as well as Mexico. The surface flow of the lake is also affected by snowpack, with the snowmelt from the Rocky Mountains influencing the annual water levels. Lake Powell is used for a variety of purposes, including hydroelectric power, irrigation for agriculture, and recreational activities such as boating and fishing. Despite its importance, the lake faces several environmental challenges, including drought, invasive species, and water quality issues.