Colorado River Story

Colorado River is Critical to Utah’s Water Security

The mighty Colorado River serves 40 million people in seven states and two states in Mexico. It also irrigates 5.5 million agricultural acres of land, including 15% of American agriculture and about 90% of the nation’s winter vegetables.

The Colorado River originates in Rocky Mountain National Park near Grand Lake, Colorado, and is 1,450-miles long. The river has a huge drainage basin that covers 244,000 square miles and ranks about sixth among the nation’s rivers in flow volume.

In 1922, Herbert Hoover (who later became president) and representatives from seven western states signed the Colorado River Compact, which allocates the amount of water that Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming can legally use. Photo credit U.S. Bureau of Reclamation

The Compact divides the states into two basins: the Upper Basin, (CO, NM, UT, WY) and the Lower Basin (AZ, CA, NV). Colorado River water is to be shared equally between the two basins. The Upper Basin is required to deliver the entire 7.5 million acre-feet (or 75 million acre-feet every 10 years) before taking its allocation. The Upper Basin is allocated by percentage to account for uncertainty in water years. California receives 4.4 million acre-feet, Arizona 2.8 million acre-feet and Nevada 300,000 acre-feet, with Mexico apportioned 1.5 million acre-feet per year.

The Colorado River Compact was developed to ensure faster-growing states would not be able to claim all the available basin water at the detriment to slower-growing states. Today, states like Colorado, Wyoming, New Mexico and Utah have not used their full Colorado River allocation and now need the water to support their communities and growth. Photo credit Utah Office of Tourism

Balancing river resources among the states and other interests is an ever-evolving process. In 1948, the Upper Colorado River Commission was created and divided the Upper Basin’s 7.5 million acre-feet among the four Upper Basin states. Colorado (51.75%), New Mexico (11.25%), Utah (23%) and Wyoming (14%). The slice of Arizona in the Upper Basin receives 50,000 acre-feet annually. Photo credit Centerstar

The Colorado River system includes the river and the country’s two largest reservoirs: Lake Mead and Lake Powell. These reservoirs were constructed to store water. (Powell for the Upper Basin and Mead for the Lower Basin). They act as “savings accounts” where water is banked in wet years to use in dry years. Photo credit Centerstar

Standing 710-feet high, the Glen Canyon Dam is the second-largest concrete arch dam in the U.S. Located near Page, AZ, it was completed in 1963 to form Lake Powell. Hoover Dam, which holds back Lake Mead near Las Vegas is the largest. The U.S. Bureau of Reclamation manages both of these massive dams.

About 25 million people rely on water from Lake Mead including residents of Arizona, California, and Nevada. This water is used for municipal, industrial and irrigation purposes as well as for recreation and power generation.

Utah currently does not use all of its Compact allocation. A proposed water delivery project, the Lake Powell Pipeline, would use 5% of Utah’s unused allocation and bring water to 10 communities in southwestern Utah. This project has been part of the state’s water planning for more than 20 years.

Even during drought, the Colorado River has been a reliable source. From 2010-2019, the Upper Basin delivered more than 93 million acre-feet of water to the Lower Basin – 18 million acre-feet more than required by the compact. Six out of 10 of these years, the Upper Basin was in drought.

The Southwest continues to be the fastest growing part of the nation, which is why the basin states work to conserve and stretch existing resources and develop additional water resources to meet the needs of growing communities.

Water officials from the basin states joined representatives from the Department of Interior and Bureau of Reclamation in 2019 to sign drought contingency plans. These plans are designed to minimize risks from ongoing drought and protect the river by requiring tiered reductions in the use of Colorado River water by the Lower Basin when Lake Mead’s water level elevation drops below 1,090 feet. Photo credit Bureau of Reclamation

Much of that growth is projected to occur in southwestern Utah, specifically Washington County. (About 500,000 people by 2065; currently about 200,000.) Photo credit Washington County Water Conservancy District

Traditionally, two-thirds of Utah’s growth has been from “natural increase” from the population having children. This percentage is declining with more people moving in. People have discovered Utah is a great place to live and work. Unfortunately, they don’t bring water with them.

Even though Utah’s Colorado Compact allocation is 1.725 million acre feet, Utah has adjusted its use to account for climate change and hydrology impacts and is planning on 1.4 million acre feet as its “reliable supply.” Utah’s current use is less than 1 million acre-feet but plans are in place for the remaining allocation.

Access to water is at the core of prosperity and growth. Utah’s need has never been more pressing because our population is projected to double by 2065.

Utah looks for multi-faceted solutions like conservation, efficiency, optimization, agriculture conversion and water development. This balanced approach will help meet water needs now and into the future.