U.S. Department of the Interior
Office of the Secretary

Paul Bledsoe (202)208-4662


For Release: May 22, 1996

The U.S. Interior Department today released initial data from the controlled flooding of the Colorado River and Grand Canyon, describing formation of dozens of new sand beaches, reinvigorated fish habitat, and other indications of the experiment's success.

"By any standard, the flood experiment was a success," Assistant Interior Secretary for Water and Science Patricia J. Beneke said. "Secretary Babbitt's personal observations at the Grand Canyon have led him to believe the flood was a great success. These data back up that observation. We are extremely pleased with these initial results, which indicate a restorative effect on the Grand Canyon. "These positive results are the culmination of the work not only of scientists, but of the many groups with strong interests in the dam and canyon. Indian tribes, river runners, power users, environmentalists--they all came together to help develop consensus."

Scientists from the U.S. Bureau of Reclamation and the U.S. Geological Survey will continue to gather data in the coming weeks. Throughout the summer, the beaches will be monitored to determine their stability and the process by which the river reshapes them. Other areas of study will include the flood's long-term effects on backwater channel habitat for endangered fish species and monitoring of the trout fishery and the trout's food base.

Researchers have also recommended that additional aerial photography be collected in the fall months to allow for evaluation of the response of the sediment deposits to summer operations of the dam. A draft report analyzing the full scientific data will be available at the end of September, with the final report due by the end of the year.

Prior to construction of the Glen Canyon Dam, the Colorado River was a dynamic, sediment-laden river, fluctuating according to the seasons, rainfall, snowmelt, and sediment inflow from side canyons. Construction of Glen Canyon Dam altered the natural dynamics of the river, specifically sediment flow and water quality.

The flood of the Colorado River from Glen Canyon Dam lasted two weeks, from March 22 to April 7. The peak of the flood, in which 45,000 cubic feet per second of water was passing through the dam, lasted one week, from March 26 to April 2. More than 110 billion gallons of water passed through the dam during the whole of the experiment.

The beach and habitat building flood is provided for in the Operation of Glen Canyon Dam Environmental Impact Statement which was completed in 1995. The flows also fit within the intent of the Grand Canyon Protection Act of 1992, which provides for operation of Glen Canyon Dam for environmental purposes in Glen and Grand canyons in addition to traditional water and power generation benefits.

To provide for the test, the 1996 Annual Operating Plan for the Colorado River, signed by Secretary Babbitt, contains terms and conditions for the releases. The Colorado River Basin States consulted with the Secretary, as did public and special interests as provided in the Grand Canyon Protection Act.

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