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Colorado River Facts



It is seen by many as the lifeline to the Southwest. Cutting through 1,450 miles of mountains and deserts, the Colorado River supplies water to over 25 million people and helps to irrigate 3.5 million acres of farmland. More water is exported from the Colorado River's 250,000 square-mile basin than from any other river basin in the world. The river's waters are diverted to supply numerous regions including the Salt Lake Valley in Utah; the Rio Grande Basin in New Mexico; Cheyenne, Wyoming; the southern coastal plain and irrigation districts in California; and over the Continental Divide to the city of Denver.

Waters of the Colorado River were first developed by the Anasazi Indians in northwestern New Mexico as early as 600 A.D. followed by Spanish missionaries in the mid-16th century. By the mid-1800s, the Church of Jesus Christ of Latter Day Saints (Mormons) settled in Utah and began developing the Green and Virgin rivers - major tributaries to the Colorado River. In 1869, geologist John Wesley Powell led a party that became the first to successfully explore and map the Green and Colorado rivers. A one-armed Civil War major, Powell led three boats down the Colorado through the Grand Canyon on two expeditions, proving the trip could be accomplished. His explorations helped open the gateway to the West - and development of the Colorado River.

Territories with rights to the Colorado River are divided into the Upper and Lower basins. The Upper Basin states are Utah, Wyoming, Colorado and New Mexico. The Lower Basin states are California, Arizona and Nevada. Each basin is allocated 7.5 million acre-feet (326,000 gallons equals one acre-foot) annually under the Colorado River Compact of 1922. From there, numerous compacts, agreements, treaties and court decisions - known collectively as the Law of the River -- divide the waters of the Colorado even further between the seven states, American Indian Tribes and the country of Mexico.

Because much of the Southwest is located in an arid region, drought could spell disaster to economies and life. The U.S. Bureau of Reclamation began building a series of large dams along the lower Colorado River starting with Hoover Dam in 1931. The dams are intended not only to provide drought protection for cities and farms via their massive storage reservoirs, but safety from the raging floods that affect the river after wet winters. Unfortunately, scientists have come to realize that building the dams has altered river habitat and impacted area fish and wildlife, including four endangered species of fish in the river. Efforts are currently underway to restore damaged habitat and boost the populations of these creatures.

Nothing on the Colorado River is easy and battles over this precious waterway continue today. Cities such as Los Angeles, Phoenix, Tucson and Las Vegas are rapidly growing metropolises located in the middle of deserts. Water is scarce and reliance on the Colorado River is heavy, both for water and the electricity that water can provide in the form of hydropower. Farms, too, rely solely on flows from the Colorado River to keep their soils wet and their crops healthy. To accommodate the growing populations in these desert cities, a trend of transferring water from agriculture to urban areas is seen by some as one way to handle the water crunch. Both of these interests, combined with water owed to the Tribes and the need to protect river habitat and species, create a running battle for the finite amount of water available from the river each year.

Colorado River Materials

The Foundation offers a number of products that can enhance your knowledge and understanding of the issues surrounding the Colorado River. Our Layperson's Guide to the Colorado River is an excellent starting point for those interested in the history, issues and politics of the river. Our Colorado River Water Map gives a thorough overview of the river's geography by demarcating basins, dams, reservoirs, tributaries and boundaries of the Colorado River. The Foundation also offers River Report, a biannual newsletter on the Colorado River, and the 75th Anniversary of the Colorado River Conference Symposium Proceedings. These items can be found in our products page under Colorado River materials.