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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
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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
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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
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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.
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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.
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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
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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
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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.
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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.
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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
Representative terms from entire chapter:
canyon dam
