For 60 years, the town of St. Thomas lay beneath the waters of Lake Mead. In 2002, St. Thomas re-emerged from the shrinking lake and scientists don’t expect the site to ever be under water again. St. Thomas’s appearance offers further evidence of the Southwest’s critical water problem. Lake Mead is one of the largest reservoirs in the world and one of the most important water sources in the western United States, however, over the past few years scarce rain and snow amounts have lowered the lake’s water levels significantly. According to researchers at Scripps Institution of Oceanography, there is a 50 percent chance Lake Mead will be dry by 2021 if climate changes continue as expected and future water usage is not curtailed.