Lake Powell, formed by the Glen Canyon Dam, serves as a water 'bank account' for the Colorado River basin. It helps regulate water flow to downstream areas during dry years. However, the reservoir has reached record-low levels due to a combination of climate change-induced drought, rising temperatures, and heavy water usage. The reservoir's water levels have dropped to just under 30 feet above the point where its dam can no longer generate hydropower, posing significant risks to energy production and water supply.