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 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.

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

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

Even during drought, the Colorado River has been a reliable source. According to the Compact, the Upper Division States “will not cause the flow of the river at Lee Ferry to be depleted below an aggregate of 75 million acre-feet for any period of ten consecutive years….” The Upper Division States have consistently satisfied this obligation and exceeded it. The 72nd Annual Report for Water Year 2020, reports the flow at Lee Ferry during the ten-year period ending on September 30, 2020, was 92,509,400 acre-feet. Provisional data from the USGS for Water Year 2021 suggests the flow at Lee Ferry ending on September 30, 2021, was 88,049,400 acre-feet.

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.

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.

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.