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1999 Friends of Lake Powell, Inc.
P.O. Box 7007
Page, AZ 86040 USA
(928) 645-2741  Fax: 928-353-2227

Statement of
Arizona Department of Water Resources
Director Rita P. Pearson
before the
House Subcommittees on Water and Power
National Parks and Public Lands

September 23, 1997

I am here today to address the proposal being promoted by the Sierra Club and the Glen Canyon Institute to drain Lake Powell. Lake Powell is a large storage reservoir located on the Colorado River on the Northern Arizona-Utah border in the heart of some of the West's most arid country. This proposal cannot be seriously considered, particularly in light of the potentially devastating effects to local and regional environments, endangered species, water and electrical power supplies, and local and regional economies.

To begin, I would like to provide the Subcommittee with background on the authorization and construction, nearly 40 years ago, of one of the "keystone" facilities used in managing the Colorado River Basin's water and hydroelectric power resources for the benefit of residents in portions of the Rocky Mountain region and the southwestern United States. I will then briefly address the impacts of eliminating this "keystone" facility on the water supply, environment and economy of the Lower Basin states.


On November 24, 1922, representatives of the seven Colorado River Basin states (Arizona, California, Colorado, Nevada, New Mexico, Utah, and Wyoming) and the United States entered into a Congressionally approved interstate compact which apportioned the waters of the Colorado River. Based upon hydrologic records available at the time, the Compact commissioners believed they had approximately 16.5 million acre-feet (mar) to divide. The Basin was divided into upper and lower basins, with Lee Ferry, Arizona, designated as the division point. Each basin was allocated 7.5 maf per year. Additionally, Article III(d) of the Compact obligates the Upper Basin states to ensure that a total of 75 million acre-feet is delivered to the Lower Basin past Lee Ferry for any 10 consecutive years. Another one million acre-feet was reserved for use by the lower basin states, and the Compact acknowledged that Mexico was entitled to some quantity of the flow of the Colorado River. In fact, the 1944 International Treaty with Mexico obligates the United States to annually provide a minimum of 1.5 maf to Mexico, 750,000 acre-feet being provided by each basin. This initial apportionment of the flows of the River led to the passage of the Boulder Canyon Project Act in 1928 authorizing the construction of Hoover Dam and the All American Canal to the Imperial Valley in California.

Unfortunately, based on current records, the average annual amount of Colorado River flow at Lee Ferry is likely closer to 15.2 maf. Over the 90 year period of record there have been annual flows of more than 23 maf and flows as low as 5 maf. Approximately 70% of the annual natural flow occurs in the months of May, June, and July. The Colorado River is one of the most erratic large flowing rivers in the country. The only way it can be managed is through reservoir storage. Currently, reservoirs in the Colorado River Basin can store approximately 60 maf, or about four times the River's average annual yield. To meet the demands placed upon the Colorado River by the Compact, it has become increasingly necessary to conserve the annual flow in this large reservoir system, so supplies can be regulated for distribution throughout the year, and to ensure an adequate supply during drought years.

On April 11, 1956, Congress passed the Colorado River Storage Project Act (CRSP) authorizing the Secretary of Interior to construct, operate, and maintain CRSP units such as dams, reservoirs, powerplants, and transmission facilities, including Curecanti (now the Aspinall Unit), Flaming Gorge, Navajo, and Glen Canyon. The intended purpose of the CRSP was to provide long-term regulatory storage for the Upper Colorado River Basin States allowing them to meet their obligations under the 1922 Compact while utilizing their Colorado River water apportionments.

At maximum capacity, Lake Powell, the reservoir created by the construction of Glen Canyon Dam, is capable of storing approximately 25 maf, and generating more than 1,000 megawatts of hydroelectric power. The Colorado River water stored in the reservoir is utilized by almost 20 million residents in southern California, central and southern Arizona, and southern Nevada. In the three Lower Basin states, the dam and the reservoir have reduced the need to use groundwater, a finite source of water which when depleted causes serious environmental hardships. Hydroelectric energy from Glen Canyon Dam is utilized by cities, towns, Indian communities, rural electric cooperatives and utility companies in Arizona, Colorado, Nevada, New Mexico, Utah, and Wyoming.

While Lake Powell provides enormous benefits to water and power users throughout the Basin, it is also a recreational haven for visitors from around the world. In fact, Page, Arizona is the focal point for millions of tourists annually visiting the myriad of natural and man- made wonders at the national monuments, recreation areas, parks, archeological and historic sites, and other unique features of the Colorado Plateau.

Water Supply Issues

If the storage capabilities of Glen Canyon Dam and Lake Powell are eliminated, future Colorado River water supplies in the Lower Basin states will be severely jeopardized. Without Lake Powell, future Lower Basin supplies are more susceptible to drought. The reduction in the Upper Basin's ability to store Colorado River water results in a dramatic increase in the likelihood that yearly flows at Lee Ferry will be less than 7.5 maf. Overall, this reduces the amount of water that the Lower Basin can expect to receive each year. A reduction in the yearly reliable supply would result in earlier and more frequent shortages.

Without Lake Powell, modeling indicates shortages in the Lower Basin could occur as early as 2006, almost twenty years earlier than had been projected. Moreover, the annual probability that a shortage will occur between 2020 and 2045 is increased by as much as 10%. If storage behind Glen Canyon Dam is not available, the potential is created for catastrophic shortage in the Lower Basin that is otherwise not projected to occur over the next 100 years.

During a catastrophic shortage, the Central Arizona Project (CAP) could see diversions reduced to zero, occurring as early as 2051. The CAP service area includes most of Maricopa, Pinal and Pima Counties. Currently, more than 2.4 million people reside in Maricopa county alone, which is home to Phoenix, Arizona, the sixth largest city in the United States. More importantly, the probability of such an event will continue to increase yearly. During such a shortage, diversions by Southern Nevada Water Authority could also reach zero and the Metropolitan Water District of Southern California would be required to reduce it's diversions significantly. More than 20 million people live in the combined service areas of these three major water providers.

The amount of water stored in Lake Mead in future years is also likely to be less if Lake Powell is not available. Without Lake Powell, there is no reliable source of water supply to annually replenish Lake Mead. Moreover, the effects of drought periods will be more severe without the mitigating effect of Lake Powell. Draining Lake Powell will decrease the long-term reliability of the Colorado River water supply to meet the needs of the Lower Basin states.

Depending upon annual flows of the Colorado River, 65,000 to 100,000 acre-feet of sediment is deposited behind Glen Canyon Dam in Lake Powell each year. If Lake Powell is drained and no longer traps these sediment inputs, the sediment will continue to travel downstream and ultimately be deposited in Lake Mead. This will increase the current Lake Mead sedimentation rate and drastically decrease the life expectancy of this reservoir. Not only will the yearly sediment production of the Upper Basin be transferred to the Lower Basin, but the sediments that have been trapped behind Glen Canyon Dam for more than 30 years will be eroded and transported downstream. The rapid erosion of these sediments will also increase sedimentation in Lake Mead, further decreasing its life expectancy and reducing water conservation storage space. The overall reduction in Lake Mead's conservation storage space will ultimately contribute to an increased risk of shortage to the Lower Basin states.

Environmental Issues

Draining Lake Powell will undoubtedly cause two significant environmental impacts in the Colorado River Basin. First, draining the reservoir will leave about 250 square miles of rock formations that have been bleached through the leaching of mineral and millions of cubic yards of sand and silt deposits trapped behind the dam. Given the arid climate, these sediments will dry out and likely become airborne, circulating during dust storms and summer monsoon events. These airborne sediments would create poor air quality conditions, and could affect visibility in the Grand Canyon National Park. It is highly likely that the condition of Glen Canyon before the construction of the dam will never be restored.

Additionally, the environmental consequences of replacing Glen Canyon Dam's lost energy generation would be significant. Replacement resources, through construction of additional coalfired or natural gas turbines, would be required to make up the more than 1,000 megawatts now generated by the Glen Canyon facility. Construction of new power plants, or generating additional energy at existing power plants will not only be significantly more costly for CRSP power customers, but will also have environmental consequences by negatively impacting regional air quality standards.

By removing the dam, warm water flows would be re-established leading to encroachment of nonnative aquatic species (i.e., carp, catfish, sunfish, etc.) into the Grand Canyon and Marble Canyon reaches. This would increase predation and competition on the few remaining populations of endangered native fishes. Currently, the last remaining population of humpback chub resides near the confluence of the Little Colorado River and the Colorado River. Biologists are extremely concerned about the potential interactions of the humpback chub population with non-native fishes.

Finally, removing 25 maf from storage in the Basin dramatically hinders the management flexibility for endangered species and sensitive habitats. Three years ago, the Lower Basin States, Tribes, several Interior agencies, and environmental organizations initiated an ecosystem-based multi-species conservation planning effort. The plan is intended to provide benefits for over 100 species residing in aquatic, wetland, riparian, and upland habitats along the lower Colorado River corridor from the tailrace of Glen Canyon Dam to the Southerly International Boundary with Mexico. Management flexibility now exists on the timing of releases out of Hoover Dam and other reservoirs lower in the system which enhance habitat conditions for endangered native fishes and birds such as the Yuma clapper rail and southwestern willow flycatcher. For example, the Bureau of Reclamation and Western Area Power Administration operate the elevation of Lake Mohave in order to provide suitable spawning habitat for the largest population of razorback suckers in the Colorado River Basin. If 42% of the Basin's storage is permanently removed, Lake Mead will be the sole reservoir available to meet the demands of the Lower Basin states. Consequently, Lake Mead would have less flexibility in meeting the needs of threatened and endangered species and Lower Basin endangered species management could be seriously jeopardized.

Economic Impacts

Recent data released by the National Park Service suggest current visitation at Glen Canyon National Recreation Area, including Lake Powell, is almost 3 million annually, with the second largest number of overnight stays of any National Park Service area. Revenues from the Glen Canyon National Recreation Area total more than $500 million a year which is ultimately spent throughout the Southwest. Additionally, the number of boating days on Lake Powell is approximately 500,000, with 70,000 people annually visiting Rainbow Bridge National Monument by tour-boat. Not only would the areas surrounding Lake Powell and Glen Canyon Dam face detrimental economic hardships, but the areas outside of the Southwest would feel the effects as well. For example, a company in the State of Michigan exclusively constructs houseboats for use on Lake Powell. Like many other businesses, the company that builds the 'Skipper Liner' houseboats would be put out of business.

In the reach of the Colorado River below Glen Canyon Dam and Lees Ferry, approximately 42,000 people annually float the river. The Arizona Game and Fish Department reports about 30,000 angler-days throughout the world class blue-ribbon Lees Ferry trout fishery. The annual economic impact to the tiny Arizona communities of Marble Canyon and Vermillion Cliffs, associated with the Lees Ferry fishery, is estimated to be $5 million. Draining Lake Powell, or removing Glen Canyon Dam, will completely destroy the Lees Ferry trout fishery.

The draining of Lake Powell would seriously jeopardize water supply availability and reliability for irrigated agriculture throughout Arizona. Agricultural areas in Arizona dependent on Colorado River water supplies generate more than $2.2 billion. If production potential drops, as it would without Lake Powell, land values would also deflate, creating a strain on the property tax base used to finance schools and infrastructure in both Arizona and California.

The Navajo Tribe would also feel a significant loss. The Navajo Project, including the Navajo Generating Station, the Kayenta Mine, and the Scrubber Construction Project, could be shut down with a loss of 1,956 jobs. Of those jobs lost, more than 1,600 would be Indian. The cost of closing the Navajo Project would total more than $2.7 billion. The price of closure would cost more than just the Navajo tribe, more than 300 non-Indians work on the Navajo Project. If the Navajo Project was to remain open, significant costly modifications would need to be made. More than 3 million customers receive electricity produced by the Navajo Project. The electricity is delivered to Phoenix, Tucson, Los Angeles and Las Vegas.

Current Mitigation Efforts

The history of Glen Canyon Dam operations and management of Lake Powell have evolved over several distinct stages. First, the reservoir was filled in a 17-year period, from 1963 until 1980. The dam and reservoir were then managed for full or flood control operations for the next decade until about 1990. The Glen Canyon Environmental Studies, initiated a series of research or test flows, that resulted in the adoption of interim operating criteria and the passage of the Grand Canyon Protection Act of 1992.

The Act required completion of an environmental impact statement (EIS) on the operation and management of Glen Canyon Dam. Following substantial public review and comment of the Draft EIS, the Final EIS was released on March 20, 1995. The preferred alternative of the Final EIS requires reduced daily flow fluctuations from the dam, includes periodic habitat maintenance and beach-building flows, implements adaptive management, reduces flood frequency, and establishes a second breeding population of humpback chub. This major EIS was completed after more than a decade of regional and national debate, public involvement and independent scientific peer review. The adaptive management process and long-term monitoring specified in the EIS will ensure that this state-of-the-art science and technological process can be applied to the management of the dam and reservoir. The State of Arizona supports the process which has been implemented since Secretary of Interior's Record of Decision on the Final Glen Canyon Dam EIS.


To conclude, draining the Lake Powell Reservoir will result in many needless and harmful impacts on the water supplies of 20 million people. There will be adverse impacts to the environment including endangered species, and local and regional economies dependent on the benefits of the dam and the reservoir.

Arizona is a state of diverse interests, and much of its well-being is based upon what has been created historically. When most of the major decisions were made regarding Glen Canyon, the conditions were significantly different from what they are today, and perhaps dramatically different from what they will be tomorrow. We need not look back in time and regret what has been done, but focus on how we can enjoy the beauty we have now. If the original grandeur of Glen Canyon could be restored, and most believe it cannot, significant water supply, environmental and economical impacts would occur. In fact, these impacts would likely be felt across the nation.

As I view it, the challenge now, and that of the future, is to continually re-evaluate Glen Canyon Dam operations by integrating new advances in science and technology, while maintaining a high degree of public and agency involvement in decision-making processes. The key is to manage Glen Canyon Dam and Lake Powell for the benefit of all resources as Congress directed in 1992.

Thank you for the opportunity to address the Joint Subcommittees on Water and Power and National Parks and Public Lands. I would be happy to answer any questions you may have.

For more information contact. friends@lakepowell.org