Final answer:
Lake Mead's main water source is the Colorado River, fed by snowmelt from the Rocky Mountains. Las Vegas, heavily reliant on Lake Mead for water, may face a crisis due to diminishing water levels and sedimentation issues.
Step-by-step explanation:
The main source of water in Lake Mead is the Colorado River, which originates in the Rocky Mountains. The river's flow is primarily sustained by snowmelt from these mountains. The Hoover Dam plays a crucial role in managing this water, creating Lake Mead, the largest reservoir in the U.S. However, with the ongoing drought and high water demand, Lake Mead's levels have been dropping. This poses a potential water crisis for places like Las Vegas, which relies on the lake for 90% of its drinking water.
Las Vegas has taken measures to conserve water, including increasing water prices and offering incentives to replace lawns with less water-intensive landscaping. Furthermore, the city has reached a remarkable 94% rate of sewage water recycling. Despite these efforts, sedimentation is another challenge Lake Mead faces, with a significant amount of sediment depositing at the bottom of the lake, affecting its capacity.