Click for next page ( 2


The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement



Below are the first 10 and last 10 pages of uncorrected machine-read text (when available) of this chapter, followed by the top 30 algorithmically extracted key phrases from the chapter as a whole.
Intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text on the opening pages of each chapter. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

Do not use for reproduction, copying, pasting, or reading; exclusively for search engines.

OCR for page 1
Executive Summary The Colorado River corridor through the Grand Canyon is among the most highly valued natural resources of the Unitecl States. Although the Grand Canyon corridor is a national park and Glen Canyon above it is a national recreation area, the flow of the Colorado River through both of these has been regulated forwater management and power production since 1963, when the Glen Canyon Dam was installed near Page, Arizona. Glen Canyon Dam offers many benefits, including the measured distribution of app- roximately 15 million acre-feet of valuable western water, the generation of hyciropower valued at $50 million to $100 million per year, the maintenance of a prized Goldwater trout fishery below the dam, the control and storage of sediment, and recreation in Lake Powell. Among the environmental costs of the dam, however, are the suppression of native fishes, including endangered fishes native to the Colorado River, erosion of beaches valued as campsites by rafters, support of aquatic and terrestrial organisms, and large daily changes in discharge volume and water level that are potentially harmful to aquatic and riparian communities and are considered aesthetically un- clesirable by most visitors to the river. The daily and seasonal operating regimes of Glen Canyon Dam were challenged in the early 1 980s by constituencies calling for the moderation of operating regimes in recognition of values otherthan hydropower production. Responcling to these challenges, the Bureau of Reclamation (BOR) initiated in 1982 the Glen Canyon Environmental Studies (GOES), which were intended to document the effects of dam operations on resources other than hydroelectric power. In committing itself to analyze the effects of dam operations on all resources downstream of Glen Canyon Dam, the BOR un 1

OCR for page 1
2 River Resource Management in the Grand Canyon dertook some of the most ambitious integrated environmental studies ever conducted under federal sponsorship. The GCES, which extended over an interval of 13 years at a cost of over $50 million, have produced information leading to major changes in the operation of Glen Canyon Dam. The GCES program is important not only in rationalizing changes in the operation of Glen Canyon Dam, but also as a forerunner and prominent example of the challenges that federal agencies face in conducting complex environmental studies that ultimately allow the comparison of costs and benefits across diverse categories of resources. WORK OF THE NRC COMMITTEE In 1986, after Phase I of the GCES was underway, the BOR requested that the National Academy of Sciences appoint, through the National Research Council's Water Science and Technology Board, a committee to oversee and review the GCES. The committee was formed in 1986 and continued its work through the end of GCES in 1995. Between 1986 and 1995, the NRC committee released 12 reports related to GCES (see page 8~. These included a review of the first phase of GCES (NRC, 1987), a review of the envi- ronmental impact statement (EIS) on dam operations (NRC, 1994a), and a review of the draft federal long-term monitoring plan (NRC, 1994b). In addition, the NRC committee convened a symposium to assist the GCES senior scientist in gathering background information on the Colorado River (NRC, 1991 a), sponsored a workshop in 1993 that was to form the basis for a long-term monitoring plan, and sponsored two meetings with the six Native American tribes that were participants in the GCES. The committee's task has been to review research that has been done in connection with the Glen Canyon Environmental Studies and to comment on the application of science in the management program for the Colorado River. OBJECTIVES AND DESIGN OF THE GCES il The objective of GCES was to identify and predict the effects of variations n operating strategies on the riverine environment below Glen Canyon Dam within the physical and legal constraints under which the dam must operate. Critical elements for the development of GCES and other such projects include a list of resources directly or indirectly affected by management, a list

OCR for page 1
Executive Summary 3 of management options, and an ecosystem framework showing the causal connections among system components, potential management strategies that include humans as integral parts of the environment. The GCES ultimately developed each of these elements, but only during the course of study ratherthan priorto it. Future studies could benefit from earlierdefinition of scope. The GCES showed how agency perspectives and their legally defined missions can constrain a list of management options. Becausethe leadership of the GCES program lacked independence and authority within BOR, the valid objectives of other agencies involved in the research did not always recede adequate attention (NRC, 1988b). The BOR, with support from the U.S. Department of Energy's Western Area Power Administration (WAPA), initially argued that flexibility in the operation of Glen Canyon Dam did not extend to any operating regime that would reduce hydropower revenues. The BOR subsequently changed its policy in this regard, thus opening the scope of GCES to a more effective breadth. Future studies should allow definition of management options that occupy the full range of possibilities rather than the preferred operating range of the sponsoring agency. The ecosystem concept is essential in unifying studies of environmental systems. While GCES Phase 11 recognized the importance of the ecosystem concept, the components of GCES already had been identified and were never fully realigned with the ecosystem approach. RESULTS OF THE GCES Although GCES produced numerous useful results, it had not completed any final synthesis or integrated report as of September 1995. It is not clear whether final synthesis will occur, nor was the NRC committee able to review such a synthesis even in draft form. Firm commitments to final synthesis and specific recommendations to management should always be required for future studies of this type. Unless there are compelling reasons not to do so, the synthesis should be completed prior to the time that management decisions are finalized. Final synthesis should reflect uncertainties that remain at the end of the project and show how resource managers can accommodate uncertainty through adaptive management. This section summarizes the general conclusions and recommendations made by the committee. Other more detailed recommendations can be found at the end of Chapters 4, 5, 8, 9 and 10. Chapter 1 1 summarizes the

OCR for page 1
4 River Resource Management in the Grand Canyon lessons learned from the committee's involvement in review of the GCES and provides suggestions to the BOR and other government agencies for future studies of complex environmental systems. Operations of Glen Canyon Dam The BOR, through GCES, was responsible for a number of significant achievements between 1982 and 1995. Information from GCES on the linkage between operations and the transport and distribution of sediment below the Glen Canyon Dam supported specific recommendations for change in operation of the dam. Equally as significant, the BOR facilitated major operational changes in recognition of this new information from GCES and committed itself to the concept of adaptive management, which will involve frequent consideration of adjustments in operations as a means of optimizing the aggregate value of all resources below the dam. For the future, the scope of adaptive management can be extended through installation of a multiple-level outlet withdrawal and possibly by other means as well. Options that now have little support but that may offer some significant advantages need to be explored objectively. These include slurry pipelines for augmentation of sediment supply and a reregulation dam that would allow more complete control of flow for environmental purposes while also allowing maintenance of maximum power revenues. Sediment and Hydrology The GCES provided valuable information on sediment dynamics in the Colorado River between Glen Canyon Dam and Lake Mead. The GCES verified that the supply of sand reaching the Colorado River through tributaries below Lee's Ferry is sufficient to maintain beaches between Lee's Ferry and Lake Mead. GCES also showed that beaches are best protected by operating regimes that avoid great extremes in daily discharge or in the rate of change in daily discharge. Even with protective measures in the form of less extreme daily fluctuations, as adopted by BOR in response to GCES, gradual loss of mass from beaches and gradual sedimentation in backwaters and pools will occur unless occasional high discharges (controlled floods or beach-building flows) are part of the operating regime. These high flows lift sand from pools in the river channel onto the beaches and scour backwaters.

OCR for page 1
Executive Summary 5 GCES also showed that such high flows are critical in moving coarse debris that enters the Colorado Riverwith storm flows from tributaries. Thus, GCES showed the justification for a new operating regime, and the BOR re- commended adoption of this new operating regime through the EIS on the operation of Glen Canyon Dam. The GCES findings on sediment and the BOR's application of these findings are exemplary of an effective interface between environmental analysis and resource management. The new operating regime will result in moderate losses of power revenue but will offer substantial benefits to recreational interests (rafting, fishing); aquatic life, including enclangered species; and nonuse value. The committee recommends several kinds of continuing research and monitoring that will enhance the potential for beneficent management of sediment transport: Study of the rate of sand interchange between the main channel and the eddy systems that create beaches. Development of a mechanism for determining the initiation of beach- building flows. Development of quantification of the magnitude and duration of beach- building flows. ~ Study of the rate at which sand is deposited on beaches during beach- building flows. Creation of a procedure for determining sand budgets in different parts of the canyon downstream from Glen Canyon Dam. Biological Resources . The GCES analysis of biotic components also produced valuable new information, but was notwell integrated. The GCES provided some ofthefirst comprehensive inventories of aquatic life along the Colorado River corridor and resulted in an excellent study of the humpback chub and studies of other endangered species and of trout. While this information is essential in support of ecosystem analysis, GCES failed to progress to a comprehensive view of connections between biotic components, physical or chemical habitat features, and operations. Synthesis was notably absent, and predictive capability was week. Inthefuture, careful planningthat isfocused on specific objectives known in advance to be useful to management will be critical, as will commitment to completion of the advanced phases of ecosystem an- alysis.

OCR for page 1
6 River Resource Management in the Grand Canyon Recreation GCES-supported studies of recreation quantify and explain the changes in economic value associated with rafting under various strategies for operation and management of the dam. GCES also provides predictions related to the trout fishery, but these predictions have an inadequate basis because of the weak understanding of the composite effects of various factors on the trout population. Hydropower Economics Hydropower economics were studied extensively in the late phases of GCES. These studies were strengthened bythe inclusion of external experts in the improvement and constructive critique of modelling for the purpose of projecting the costs of various operational alternatives. Only through studies of this type can the environmental benefits of various operating alternatives for the dam be weighed against hydropower production. For the future, the BOR should sustain these gains by developing analytical modelling cap- abilKies for adaptive management. BOR should maintain a national economic perspective in Rs projections, and should consider costs of short-term flow alternatives in the context of potential long-term benefits. Cultural Resources Cultural resources, which include both sites of cultural significance (historic and prehistoric) and sites of tribal significance not marked by specific artifacts, were originally not accorded appropriate recognition in the GCES study plan. In the late phases of GCES, some of these components, as well as some studies of endangered species, were examined in a manner that did not always address the basic objectives of GCES. Future projects of a similar type should take into account cultural resources from the early planning stages and should constrain studies around the objectives of the project. Institutional Influences on the GCES GCES, although successful in a number of respects, was handicapped

OCR for page 1
Executive Summary by organizational and administrative flaws that are deeply imbedded in the operating traditions of the federal government. I n organizing GCES, the BOR properly convened a group of cooperators consisting of federal agencies with research interests in the Colorado River, a state agency, and, belatedly, Native American tribes having cultural and resource interests in the Colorado River between Glen Canyon Dam and Lake Mead. The GCES project manager was not, however, vested with sufficient authority to override the influence of individual cooperators for the overall benefit of the project. One result was expansion of the scope of work as a reflection of specific agency interests but not always according to the priorities of GCES. Agency personnel also developed strong feelings of entitlement to GCES support, which they reinforced through control over facilities and permitting. This greatly reduced the possibility for diversification of expertise through open solicitation of proposals outside the federal government. The development of agency entitlements also weakened the ability of project management to enforce contractual obligations made by agencies to GCES and increased project costs by diffusing the focus of study. These institutional problems are very likely generic to cooperative ventures involving federal agencies and need to be remedied in future projects through greater independence and authority of project management over project resources. Nonuse Values Nonuse values (values not associated with direct use of the resource) are exceptionally high for the Grand Canyon region because of its aesthetic and cultural appeal regionally, nationally, and internationally. Even so, the BOR resisted for most of the history of GCES any inclusion of nonuse values as a consideration related to operational alternatives. The BOR did, however, ultimately support through GCES a state-of-the-art study of nonuse values, which was appended to the EIS in 1995. Studies of nonuse values show that distinctions among operating alternatives for Glen Canyon Dam are perceived as significant by the public and that the U.S. public's willingness to pay for preferred operating alternatives for the dam is of the order of several billion dollars. This is many times the value of changes in any of the tangible resources affected by the dam's operations, including power production. While the implications of this information for operations are as yet uncertain, their relevance to a broad perspective on operations is unquestionable. Thus, GCES has illustrated the need for inclusion of nonuse value studies in similar

OCR for page 1
8 projects. River Resource Management in the Grand Canyon ACHIEVEMENTS OF GCES The BOR adjusted the scope of GCES inquiry in a manner consistent with the ecosystem concept, thus encompassing, ultimately, all resources and a full range of management options as the basis for analysis of the effects of dam management. While this adjustment came too late to be fully effective for GCES, the conceptual advance itself is highly significant and should be carried forward to other projects. The BOR also developed, over the course of GCES, greatly increased acceptance of external criticism and expertise through its work with the NRC committee as well as its appointment of an external senior scientist for GCES and through formation of an advisory board, increased emphasis on external contracting, and acceptance of external participation in hydropower studies. The BOR has, through GCES, modernized and reformed its strategy for management of Glen Canyon Dam. Similar changes, augmented by lessons from GCES, could inaugurate a new era in the management of western waters by BOR and other federal agencies. LIST OF NRC REPORTS National Research Council. 1987. River and Dam Management: A Review of the Bureau of Reclamation's Glen Canyon Environmental Studies. Washington, D.C.: National Academy Press. National Research Council. 1 988a. Supplementary Report to 1987 River and Dam Management. Water Science and Technology Board, National Research Council, Washington, D.C. National Research Council. 1988b. Letter report to the Honorable Donald Paul Hodel, Secretary, U.S. Department of the Interior, August 1, from G. Richard Marzolf, Chair, Committee to Review the Glen Canyon En- vironmental Studies. Water Science and Technology Board, National Research Council, Washington, D.C.

OCR for page 1
Executive Summary 9 National Research Council. 1991 a. Colorado River Ecology and Dam Man- agement: Proceedings of a Symposium, May 24-25, 1990, Santa Fe, N. Mex. Washington, D.C.: National Academy Press. National Research Council. 1991 b. Review of the Draft Integrated Research Plan for the Glen Canyon Environmental Studies, Phase 11. Washington, D.C.: National Academy Press. National Research Council. 1991c. Letter report to Commissioner Dennis Underwood, August 9, from William M. Lewis, Jr., Chair, Committee to Review the Glen Canyon Environmental Studies. Water Science and Technology Board, National Research Council, Washington, D.C. National Research Council. 1991d. Letter report to the Honorable Manuel Lujan, Office of the Secretary, U.S. Department of the Interior, August 9. Water Science and Technology Board, National Research Council, Washington, D.C. National Research Council. 1 992a. Letter report to Michael Roluti, Bureau of Reclamation, October 21, Committee to Review the Glen Canyon Environmental Studies comments on May 1992 draft report "Power System Impacts of Potential Changes in Glen Canyon Power Plant Operations." Water Science and Technoloov Board National Research Council, Washington, D.C. _~ National Research Council. 1992b. Letter report to David L. Wegner, April 22, assessing proposed GOES studies related to economies, hydropower production, and dam operations. Water Science and Technology Board, National Research Council, Washington, D.C. National Research Council. 1993. Letter report to Tim Randle, Bureau of Reclamation, February 26, Committee to Review the Glen Canyon Environmental Studies comments on January 1993 preliminary draft "Operation of Glen Canyon Dam, Colorado River Storage Project, Arizona." Water Science and Technology Board, National Research Council, Washington, D.C.

OCR for page 1
To RA/er Resounce A{snagemenTA~ age Gassed Canyon Name Re~mh mung. 1~. Ram ~1~ Dam E~l~nma~ - Statement on Operation of Glen Canyon Dam. Washington, D.Cs ~e-P~ Nominal Research Council 19g4b. Rave ~ the Drag Federal Long~rm ~onhoMng Plan for the Colorado River Belch Glen Canyon Dam. Washington, D.C.: Nadonal Academy Press