One of the first major efforts to increase farming and encourage habitation in the arid regions of the western United States, the Rio Grande Project was designed to provide reliable irrigation as well as resolve a dispute over water supply with the Republic of Mexico. The project's centerpiece is Elephant Butte Dam, a concrete gravity structure 301 feet high and 1,674 feet wide. Elephant Butte Reservoir - with a surface area of 36,600 acres and a capacity of more than 2.2 million acre-feet - was the largest reservoir in the world at the time of its completion.
In the mid-1800s Virginia City was America's greatest producer of high-grade silver and gold ore. When mining activities began, natural springs provided water to the camps. As the population grew, the Virginia and Gold Hill Water Company was formed to address the need for more water. The company first drew water from tunnels that had been driven into the mountains by prospectors. Water was stored in wooden tanks and sent through pipes into the town.
Four prehistoric reservoirs at Mesa Verde National Park were constructed and used between AD 750 and AD 1180. They are: Morefield Reservoir (in Morefield Canyon), Far View Reservoir (on Chapin Mesa), Sagebrush Reservoir (on an unnamed mesa), and Box Elder Reservoir (in Prater Canyon). These four ancient reservoirs represent extraordinary engineering achievements by the Ancestral Puebloan people. In an arid environment with very little surface water, these prehistoric people found ways to route and capture runoff to create sustainable domestic water supply reservoirs.