n the spring of this year the Bureau of Reclamation conducted what many call the most ambitious experiment in river restoration ever attempted. On March 26, 1996, an artificial flood was created on the Colorado River through Grand Canyon as 45,000 cubic feet per second (cfs) of water was released from Glen Canyon Dam. Although the release was only half the river’s average annual pre-dam flood, it was not without controversy. It has been hailed as a success by Interior Secretary Babbitt but others are more skeptical, describing the event as everything from a dud to pure hype.
Was the Glen Canyon Dam Beach/Habitat Building Flow really a success? I was fortunate to have been on the river both during and after the flood flow. And, as a long time commercial guide in the Canyon and active in the issues surrounding Glen Canyon Dam, my short answer is yes, the flood was a success. But there is more to understanding what that success really means.
The flood flow successfully substantiated the hypothesis that sand from eroding beaches and canyon tributaries can be stored in the river’s channel during normal dam operations and then redeposited to beaches with higher flows. Large quantities of clean sand were deposited throughout the Canyon. While this may seem obvious to us now, only a few years ago scientists and conservationists alike considered uncontrolled clear water floods as the most damaging of dam operations. The key word is uncontrolled. This flow proved that controlled floods can be a useful tool for managing the river system downstream.
The flood flow was successful as an experiment as well. More than 100 scientists, working under sublime but difficult conditions, collected critical data on the flood. Careful scientific analysis will give us a more complete understanding of the dynamics of the river system and lead to even more effective future floods. Should future floods be higher or lower; will they be longer or shorter? What was the cost to the system? How much of the stored sand was carried down to Lake Mead? Answers to these questions will help us design the next flood.
In my opinion, however, the biggest success of the flood was that it happened at all. In spite of historic conflicts over Colorado River resources, the flood was carried out with the unprecedented cooperation of traditionally contentious interests who chose dialog over litigation. Thanks to direction given by the passage of the Grand Canyon Protection Act and to the patient, hard work of the basin states, federal and state agencies, tribes, power and water users, environmental and recreation interests, the flood was accomplished without litigation or bloodshed. The 13 year effort represents a balance driven by our country’s changing social values.
Once water and power were the sole purpose of these huge reclamation projects. Today these have moved over to accommodate increasing concern over our dwindling natural resources. For the first time environmental concerns of the river ecosystem sat side by side with water and power in the control room at Glen Canyon Dam.
And what of the restoration of the natural and cultural resources of the Colorado River in Grand Canyon? The complete answer to that question awaits analysis of the data collected, to be completed this fall. The primary purpose of the flood was to restore “disturbance” to a river ecosystem stabilized by the workings of man. Some of the new beaches are eroding away, but this is to be expected as the system readjusts to normal dam operations. Healthy system dynamics means active processes of erosion as well as deposition; one depends upon the other. Asked the question, “When will we release another flood?”, one geomorphologist answered, “When we see the erosion rates slow.” How long the new sand bars will last is still unknown. The biological elements may take even longer to respond. We may not see changes in streamside and river habitats and native fish populations for years. And we may find that, in a system which evolved to huge ranges in flow and temperature, our puny efforts have not been enough. There is much we will learn.
This experiment should be looked at in a historic context, recognizing the dramatic change in how we look at our water resources and operate our large dams. The significance shouldn’t escape us: For the first time in history, water was bypassed from a major dam to directly benefit the natural and cultural resources of the downstream ecosystem. This flood represents a change in our societal values that has taken place over the past 30 years, a shift toward recognizing the values of our increasingly scarce natural and cultural resources. Have no doubt that water storage and power generation will continue to be an important consideration, especially here in the arid and growing west. However, the Glen Canyon Dam Beach/Habitat Building Flow has proven that we can successfully balance our societal values and so benefit multiple resources. And we can do so cooperatively without resorting to costly litigation.