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Title image: UC Region Colorado River Storage Project


Life as we know it today in the western United States would be very different without the reality and benefits of the Colorado River Storage Project. This multipurpose project provides many benefits and sustains life and economic well-being in the West. Although the CRSP didn’t become a reality until the authorizing legislation was signed in 1956, the need for the CRSP clearly emerged as the complexities of water development and management began to unfold throughout the 20th century.

The scarcity of water and the challenges of making this vital resource available to support development and growth have always been at the heart of the West’s history. In the Colorado River Basin, the waters of the Colorado River have long been the source of intense debate and negotiation, resulting in a century of federal laws, compacts, court decisions and decrees, treaties, and regulatory guidelines known collectively as the Law of the River. Thus, the Colorado River is considered the most regulated river in the world today. 

photo:Colorado River below Glen Canyon Dam
Colorado River below Glen Canyon Dam

The Law of the River originated with the Colorado River Compact of 1922, which is considered the cornerstone of the Law of the River. The need for this foundation document grew out of early contention over the Colorado River. By the early 1900's, California was rapidly growing and the Imperial Valley in California was already relying heavily on the Colorado River for significant agricultural development. The burgeoning growth of California caused concern for the other Colorado River Basin states for fear that California would establish priority rights to Colorado River water. Because Western water law was based on the doctrine of "prior appropriation" (first in time, first in right) giving highest priority to first users of water, it was entirely possible that a fast growing state like California could establish priority rights before the rest of the basin states could develop what they viewed as their fair share of the river.

graphic image showing Upper and Lower Colorado River Basin

In order to resolve this pivotal issue, discussions for an interstate compact between the Colorado River Basin states began in January 1922 to determine how to equitably divide and apportion the use of the Colorado River’s water among the seven Colorado River Basin states. After nearly a year of negotiations, the provisions of the Colorado River Compact were agreed upon by each of the seven Colorado River Basin states. The compact divided the river system into two sections; the Upper Basin (comprised of Colorado, New Mexico, Utah, and Wyoming and a portion of Arizona) and the Lower Basin (comprised of California, Nevada, and Arizona) with the dividing point at Lee Ferry, Arizona, and established that each basin would receive 7.5 million acre-feet of water annually. It also gave priority to delivery of the Lower Basin’s entitlement requiring the Upper Basin to ensure delivery of 75 million acre-feet to the Lower Basin in any rolling 10-year period regardless of hydrology. Because the flow of the Colorado River is erratic with flows varying from four to 22 million acre-feet annually, this left the Upper Basin to deal with the challenges of uncertain river flows.

Because the issues and interests associated with the Colorado River are complex and extensive, the 1922 compact was only the first of many legal documents to govern the use of the Colorado River. Other important Law of the River documents came about after the 1922 Colorado River Compact that further clarified rights, authorities, obligations, and priorities, and authorized construction of many water development projects. By the early 1950’s, many federal water projects were in place in the Lower Basin, including Hoover Dam, Laguna Dam, Imperial Dam, Parker Dam, Davis Dam, and the All-American Canal. The Upper Basin states, fearing that efforts would be made by the Lower Basin states to claim additional water, initiated development of their water to sustain future growth. This concern, coupled with the undependable nature of Colorado River flows and the Upper Basin’s delivery obligations to the Lower Basin, led to the planning of the multi-purpose Colorado River Storage Project.

The need for the Colorado River Storage Project was actually envisioned at the time of the Colorado River Compact, and it was made possible by the groundwork laid by the 1922 Compact.  With the Upper and Lower Basin distinction established and each basin’s allocation of the Colorado River identified, the Compact set the stage for the development that would be authorized by additional Law of the River legislation, including the CRSP Act.

Authorized by Congress on April 11, 1956, the Colorado River Storage Project Act became an important force in the development and management of water in the Upper Basin. The CRSP was intended to provide water storage in the Upper Basin to allow the Upper Basin to develop its apportionments of the Colorado River while assuring the required water delivery to the Lower Basin. This would be accomplished through construction of four initial storage units: the Wayne N. Aspinall Unit in Colorado (Blue Mesa, Crystal, and Morrow Point Dams), Flaming Gorge Unit in Utah, Navajo Unit in New Mexico, and Glen Canyon Unit in Arizona. The CRSP Act also authorized a number of participating projects to deliver irrigation water to farms and provide municipal and industrial water to many communities.

photo: snowpacked mountain

The CRSP initial stoarage units and participating projects store the limited precipitation which falls principally in the form of snow in the high mountains of the Upper Basin for municipal, industrial, and agricultural use. In addition, the CRSP provides other valuable benefits including flood control, recreation, and hydropower generation which have significant economic impact in the West. The CRSP initial storage units have a combined live storage capacity of 30.6 million acre-feet and power generation capabilities to provide over four billion kilowatt-hours of energy annually.

It has been over 50 years since the Congress authorized the Colorado River Storage Project. Since that time, the foresight of the framers of the CRSP has been demonstrated as the purposes for which the CRSP was built continue to be realized. The importance of the purposes and benefits provided by the CRSP cannot be overstated, particularly in light of the extended periods of drought that have been weathered successfully. Water deliveries to the Lower Basin and Mexico have consistently been made without creating significant shortages in the Upper Basin because of the long-term regulatory storage provided by Glen Canyon Dam and Lake Powell, the principal feature of the CRSP. 

As the population of the West continues to grow, so will the challenges and complexities of western water management. The Colorado River Storage Project has been integral to the development of the arid West, and it will continue to play a vital role in the future of the West. Finding solutions to increasing demands for limited water supplies while providing other important benefits would be more difficult without the CRSP.


Last updated: July 8, 2013