Las Vegas is set in a vast desert, so naturally getting water is one of its primary concerns. Because the leaders of Las Vegas knew that the nearby Colorado River couldn’t match the water needs of planned development, they set up the Southern Nevada Water Authority (SNWA) to buy water rights from surrounding areas, including neighboring states and the Great Basin National Park. This idea held promise because of a trick of nature that formed the giant valley called the Great Basin Desert, inside of which Las Vegas sits.
More than 43 million years ago, a series of volcanic eruptions caused the earth’s mantle to stretch, creating the Great Basin—a group of mountain ranges separated by flat, expansive valleys. Bookended by the Sierras to the west and the Wasatch Range to the east, the Great Basin covers most of Nevada, half of Utah, and dips its topographic toe into California, Idaho, Oregon, and Wyoming. The mountains are impressive but the Basin’s true miracle rests with its water. The precipitation that falls in the Great Basin Desert has “no communication with the sea,” in the words of John C. Fremont, who named the area in 1843. Instead, all of the basins in the 200,000-square-mile area drain internally. The rain and snow that fall here evaporate, pool into lakes, or sink deep into the gravel subsurface, where they recharge aquifers left over from the ice ages. Underground, the water slowly migrates toward the Great Salt Lake and along the way occasionally—almost miraculously—bubbles up through the dry desert as a spring. Nevada is the heart of the Great Basin. It is also at the heart of SNWA’s plan to get more water.