Programs and Communities

The operation of Glen Canyon Dam on the Colorado River affects several downstream resources and water uses including water supply for consumptive uses in Arizona, California, and Nevada, hydroelectric power production, endangered species of native fish, recreational angling for non-native fish, and recreational boating in the Grand Canyon. Decisions about the magnitude and timing of water releases through the dam involve trade-offs between these resources and uses. The numerous laws affecting dam operations create a hierarchy of legal priorities that should govern these decisions. At the top of the hierarchy are mandatory requirements for water storage and delivery and for conservation of endangered species. Other resources and water uses have lower legal priorities. The Glen Canyon Dam Adaptive Management Program ("AMP") has substituted collaborative decision making among stakeholders for the hierarchy of priorities created by law. The AMP has thereby facilitated non-compliance with the Endangered Species Act by the Bureau of Reclamation, which operates the dam, and has effectively given hydroelectric power production and non-native fisheries higher priorities than they are legally entitled to. Adaptive management is consistent with the laws governing operation of Glen Canyon Dam, but collaborative decision making is not. Nor is collaborative decision making an essential, or even logical, component of adaptive management. As implemented in the case of Glen Canyon Dam, collaborative decision making has actually stifled adaptive management by making agreement among stakeholders a prerequisite to changes in the operation of the dam. This Article proposes a program for adaptive, but not collaborative, management of Glen Canyon Dam that would better conform to the law and would be more amenable to adaptation and experimentation than would the current, stakeholder-centered program.

This brief article, written for a symposium on "Collaboration and the Colorado River," evaluates the U.S. Department of the Interior's Glen Canyon Dam Adaptive Management Program ("AMP"). The AMP has been advanced as a pioneering collaborative and adaptive approach for both decreasing scientific uncertainty in support of regulatory decision-making and helping manage contentious resource disputes -- in this case, the increasingly thorny conflict over the Colorado River's finite natural resources. Though encouraging in some respects, the AMP serves as a valuable illustration of the flaws of existing regulatory processes purporting to incorporate collaboration and regulatory adaptation into the decision-making process. Born in the shadow of the law and improvised with too little thought as to its structure, the AMP demonstrates the need to attend to the design of the regulatory process and integrate mechanisms that compel systematic program evaluation and adaptation. As such, the AMP provides vital information on how future collaborative experiments might be modified to enhance their prospects of success.

The Grand Canyon Monitoring and Research Center began long-term planning at its inception and, in May 1997, produced a Long-Term Monitoring and Research Strategic Plan that was adopted by stakeholder groups (the Adaptive Management Work Group and the Technical Work Group) later that year. The Center then requested the National Research Council's (NRC) Water Science and Technology Board to evaluate this plan.

Federal management of water is undergoing a change that involves a drastic reduction in the number of new water projects and an increase in emphasis on the quality of water management. This book summarizes and analyzes environmental research conducted in the lower Colorado River below the Glen Canyon Dam under the leadership of the Bureau of Reclamation. It reviews alternative dam operations to mitigate impacts in the lower Colorado riverine environment and the strengths and weaknesses of large federal agencies dealing with broad environmental issues and hydropower production. While many problems remain to be solved, the Bureau of Reclamation through the Glen Canyon area. The lessons of GCES are transferable to other locations and could be the basis for a new era in the management of western waters.

This book contains 11 papers that review the extant information about the Colorado River from an ecosystem perspective and serve as the basis for discussion of the use of ecosystem/earth science information for river management and dam operations. It also contains a synopsis of the committee's findings and recommendations to the Bureau of Reclamation as the agency seeks to change its direction to the management of natural resources.

River rafting trips and hikers use sandbars along the Colorado River in Marble and Grand Canyons as campsites. The U.S. Geological Survey evaluated the effects of Glen Canyon Dam operations on campsite areas on sandbars along the Colorado River in Grand Canyon National Park. Campsite area was measured annually from 1998 to 2012 at 37 study sites between Lees Ferry and Diamond Creek, Arizona. The primary purpose of this report is to present the methods and results of the project.

Campsite area surveys were conducted using total station survey methods to outline the perimeter of camping area at each study site. Campsite area is defined as any region of smooth substrate (most commonly sand) with no more than an 8 degree slope and little or no vegetation. We used this definition, but relaxed the slope criteria to include steeper areas near boat mooring locations where campers typically establish their kitchens.

The results show that campsite area decreased over the course of the study period, but at a rate that varied by elevation zone and by survey period. Time-series plots show that from 1998 to 2012, high stage-elevation (greater than the 25,000 ft3/s stage-elevation) campsite area decreased significantly, although there was no significant trend in low stage-elevation (15,000–20,000 ft3/s) campsite area. High stage-elevation campsite area increased after the 2004 and 2008 high flows, but decreased in the intervals between high flows. Although no overall trend was detected for low stage-elevation campsite areas, they did increase after high-volume dam releases equal to or greater than about 20,000 ft3/s. We conclude that dam operations have not met the management objectives of the Glen Canyon Adaptive Management program to increase the size of camping beaches in critical and non-critical reaches of the Colorado River between Glen Canyon Dam and Lake Mead.

Between 1999 and 2005, drought in the western United States led to a >44 m fall in the level of Lake Powell (Arizona-Utah), the nation's second-largest reservoir. River discharges to the reservoir were halved, yet the rivers still incised the tops of deltas left exposed along the rim of the reservoir by the lake-level fall. Erosion of the deltas enriched the rivers in sediment such that upon entering the reservoir they discharged plunging subaqueous gravity flows, one of which was imaged acoustically. Repeat bathymetric surveys of the reservoir show that the gravity flows overtopped rockfalls and formed small subaqueous fans, locally raising sediment accumulation rates 10–100-fold. The timing of deep-basin deposition differed regionally across the reservoir with respect to lake-level change. Total mass of sediment transferred from the lake perimeter to its bottom equates to ~22 yr of river input.