articleThe Brief Lake Mead has fallen to its lowest water level in nearly 90 years. Drought, rising temperatures and overuse are straining the Colorado River system. Hamby said it is vital for states that use Colorado River water to reduce water use. The backstory:Years of overuse combined with drought and rising temperatures have been depleting Lake Mead and Lake Powell, the country’s second-largest reservoir. According to modeling done in July, Lake Mead is forecast to continue dropping through much of the rest of the year.