Bureau of Reclamation: An Assessment of the Environmental Impact
Statement on the Operations of the Glen Canyon Dam (Chapter Report,
10/02/96, GAO/RCED-97-12).
Since the Glen Canyon Dam, located in northern Arizona, was completed by
the Bureau of Reclamation in 1963, it has been used to generate power
during periods of high demand--commonly known as peaking power. The
fluctuating releases of water associated with the dam's peaking power
operations have raised concerns about the harmful effects such flows
have on downstream areas, particularly the Grand Canyon. In 1989, the
Bureau of Reclamation was directed to prepare an environmental impact
statement that would reevaluate the Glen Canyon Dam's operations. The
purpose of the reevaluation was to determine options for operating the
dam that would minimize the harmful effects on the downstream
environmental and recreational resources, as well as on Native American
interests in the Glen and Grand canyons, while still allowing the dam to
produce hydropower. The Bureau issued its final environmental impact
statement in March 1995. This report examines (1) whether the Bureau's
impact determinations were reasonable and (2) what concerns still exist
about the Glen Canyon Dam's final environmental impact statement.
--------------------------- Indexing Terms -----------------------------
REPORTNUM: RCED-97-12
TITLE: Bureau of Reclamation: An Assessment of the Environmental
Impact Statement on the Operations of the Glen
Canyon Dam
DATE: 10/02/96
SUBJECT: Dams
Endangered species
Environmental impact statements
Flood control
Fishes
Wildlife conservation
Environmental research
Environmental policies
Hydroelectric energy
Water supply management
IDENTIFIER: Grand Canyon National Park (AZ)
Colorado
Colorado River Basin
Colorado River Storage Project
Bureau of Reclamation Adaptive Management Program
Wyoming
Salt River Project (AZ)
Lake Powell (AZ/NV)
Bureau of Reclamation Colorado River Simulation System
Glen Canyon Dam (AZ)
Arizona
Nevada
New Mexico
Utah
California
Glen Canyon National Recreation Area (AZ)
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Cover
================================================================ COVER
Report to Congressional Committees
October 1996
BUREAU OF RECLAMATION - AN
ASSESSMENT OF THE ENVIRONMENTAL
IMPACT STATEMENT ON THE OPERATIONS
OF THE GLEN CANYON DAM
GAO/RCED-97-12
Glen Canyon Dam's Environmental Impact Statement
(140896)
Abbreviations
=============================================================== ABBREV
ABT - Aquatic Biology Team
cfs - cubic feet per second
CROD - Contract Rate of Delivery
CRSP - Colorado River Storage Project
CRSS - Colorado River Simulation System
CVM - contingent valuation method
EGEAS - Electronic Generation Expansion Analysis System
EIS - environmental impact statement
Elfin - Electric Utility Financial and Production Cost Model
EPA - U.S. Environmental Protection Agency
FWCA - Fish and Wildlife Coordination Act
FWS - U.S. Fish and Wildlife Service
GCES - Glen Canyon Environmental Studies
NEPA - National Environmental Policy Act
NOAA - National Oceanic and Atmospheric Administration
SLCA/IP - Salt Lake City Area/Integrated Projects
WAPA - Western Area Power Administration
Letter
=============================================================== LETTER
B-272927
October 2, 1996
The Honorable Frank Murkowski
Chairman
The Honorable J. Bennett Johnston
Ranking Minority Member
Committee on Energy and Natural Resources
United States Senate
The Honorable Don Young
Chairman
The Honorable George Miller
Ranking Minority Member
Committee on Resources
House of Representatives
This report responds to subsection 1804(b) of the Grand Canyon
Protection Act of 1992 (title XVIII of P.L. 102-575), which required
GAO to audit the Bureau of Reclamation's final environmental impact
statement on the operations of the Glen Canyon Dam. The report
discusses (1) whether Reclamation's determination of the impact of
various dam-operating alternatives on selected resources was
reasonable and (2) what, if any, concerns still exist on the part of
key interested parties about the final impact statement.
We are providing a copy of this report to the Secretary of the
Interior, the Assistant Secretary for Water and Power, and the
Commissioner of the Bureau of Reclamation. We will also make copies
available to others upon request.
This report was prepared under the direction of Victor S. Rezendes,
Director, Energy, Resources, and Science Issues, who can be reached
at (202) 512-3841 if you or your staff have any questions. Major
contributors to this report are listed in appendix XIII.
Keith O. Fultz
Assistant Comptroller General
EXECUTIVE SUMMARY
============================================================ Chapter 0
PURPOSE
---------------------------------------------------------- Chapter 0:1
Since the Glen Canyon Dam, located in Page, Arizona, was completed by
the Bureau of Reclamation in 1963, it has been used to generate power
during periods of high demand, commonly known as peaking power. The
fluctuating releases of water associated with the dam's peaking power
operations have caused concerns about the detrimental effects such
flows have on downstream resources, particularly those located in the
Grand Canyon. In response to these concerns, the Secretary of the
Interior, in July 1989, directed the Bureau of Reclamation to prepare
an environmental impact statement that would reevaluate the Glen
Canyon Dam's operations. The purpose of the reevaluation was to
determine specific options for operating the dam that could minimize
the adverse impacts on the downstream environmental and recreational
resources, as well as on Native American interests in the Glen and
Grand canyons, while still producing hydropower.
Figure 1: Location of the Glen
Canyon Dam
(See figure in printed
edition.)
Source: Bureau of Reclamation.
In October 1992, the Congress enacted the Grand Canyon Protection Act
of 1992 (title XVIII of P.L. 102-575), which required the Secretary
of the Interior to complete the environmental impact statement by
October 30, 1994. The act also required that GAO audit the costs and
benefits of the various operating alternatives identified in the
final environmental impact statement. In preparing the statement,
Reclamation studied the potential impact of various flow alternatives
on selected resources. Reclamation reported the results of these
studies in the final environmental impact statement on March 21,
1995. As discussed with the responsible congressional committees,
for the purpose of this audit, GAO examined (1) whether Reclamation's
impact determinations were reasonable and (2) what, if any, concerns
still exist about the Glen Canyon Dam's final environmental impact
statement. The act also requires that on the basis of the findings,
conclusions, and recommendations made in the environmental impact
statement and the GAO audit report, the Secretary is to adopt
criteria and operating plans for the dam.
BACKGROUND
---------------------------------------------------------- Chapter 0:2
Before the construction of the Glen Canyon Dam, the Colorado River's
sediment-laden flows fluctuated dramatically during different seasons
of the year. Annual daily flows of greater than 80,000 cubic feet
per second were common during the spring runoff. In contrast, flows
of less than 3,000 cubic feet per second were typical throughout the
late summer, fall, and winter. Water temperatures ranged from near
freezing in the winter to more than 80 degrees Fahrenheit in the
summer. The construction of the Glen Canyon Dam altered the natural
dynamics of the Colorado River corridor through the Glen and Grand
canyons. The dam replaced the dramatic seasonal flow variations with
significant daily fluctuations, greatly reduced the amount of
sediment in the water, and resulted in nearly constant water release
temperatures of about 46 degrees Fahrenheit.
As early as 1982, the Secretary of the Interior initiated the Glen
Canyon Environmental Studies of the effects of the dam. These
studies were led by Reclamation and conducted by a number of
different agencies. In 1989, the Secretary designated Reclamation as
the lead agency in preparing an environmental impact statement.
Other agencies and individuals participated in these efforts,
including federal and state resource agencies, Indian tribes, private
consultants, universities, and river guides. To protect the
downstream resources until the completion of the impact statement and
the adoption of a new operating plan for the dam, in November 1991
Reclamation implemented interim operating criteria. The interim
operating criteria reduced the maximum peak releases and daily
fluctuations. With the passage of the Grand Canyon Protection Act of
1992, the Congress required that the Glen Canyon Dam be operated to
protect and restore the downstream resources of the Grand Canyon
National Park and the Glen Canyon National Recreational Area.
The National Environmental Policy Act of 1969 (42 U.S.C. 4321 et
seq.) requires that a detailed environmental impact statement be
prepared for every major federal action that may significantly affect
the quality of the human environment. The act and its implementing
regulations set forth the requirements for preparing an impact
statement. Among other things, a statement must (1) address the
purpose of and need for the action, (2) describe the environment that
will be affected, (3) identify alternatives to the proposed action,
(4) present the environmental impacts of the proposed action
(including the direct, indirect, and cumulative impacts), and (5)
identify the agency's preferred alternative. The act does not
require, and Reclamation did not perform, a cost and benefit analysis
of the proposed action.
In preparing the environmental impact statement for the operation of
the Glen Canyon Dam, Reclamation identified 11 resources affected by
the dam's operations to be analyzed in detail: water, sediment,
fish, vegetation, wildlife and habitat, endangered and other
special-status species, cultural resources, air quality, recreation,
hydropower, and non-use value. (Non-use values have been defined as
those values that people may receive from the knowledge that such
things as rare plants and unspoiled natural environments exist, even
if people do not consume or use these goods directly.)
In addition, the impact statement identified nine alternative
operational scenarios to be studied in detail. These alternatives
can be divided into three descriptive categories: unrestricted
fluctuating flows (two alternatives, including the no-action
alternative); restricted fluctuating flows (four alternatives); and
steady flows (three alternatives).
In the final impact statement, Reclamation recommended the Modified
Low Fluctuating Flow as the preferred alternative. This alternative
was developed to reduce daily flow fluctuations well below the dam's
previous operating levels and to provide periodic high, steady
releases of short duration; the goal of this alternative was to
protect or enhance downstream resources while allowing limited
flexibility for power operations.
RESULTS IN BRIEF
---------------------------------------------------------- Chapter 0:3
In general, Reclamation used appropriate methodologies and the best
available information in determining the potential impact of the
dam's various flow alternatives on selected resources. GAO
identified some shortcomings and controversy in Reclamation's
application of certain methodologies, and some of the data that
Reclamation used in making its impact determinations were dated,
preliminary, or incomplete. These limitations, combined with the
inherent uncertainty associated with making forecasts, reduces the
precision of the impacts contained in the statement, and some
uncertainty, such as the impact of steady flows on fish resources,
remains. Nonetheless, according to GAO's analysis and the opinions
of experts, these limitations are not significant enough to alter the
relative ranking of the flow alternatives nor render the final
environmental impact statement unusable as a decision-making
document. Furthermore, Reclamation recognizes that uncertainties
still exist. To address these concerns, Reclamation intends to
initiate a process of "adaptive management" that would provide for
long-term monitoring and research to measure the actual effects of
the selected alternative. The results of this effort would form the
basis for possible future modifications of the dam's operations.
Many of the key interested parties affected by the Glen Canyon Dam's
environmental impact statement support the process used by
Reclamation to develop the impact statement as well as the
implementation of the preferred alternative. However, while
expressing their support, some interested parties raised specific
concerns that still exist about the final environmental impact
statement, including (1) the manner in which compliance with the
Endangered Species Act will be achieved, (2) the economic impact of
reducing the Glen Canyon Dam's hydroelectric power capacity, (3) the
consideration of other possible causes of adverse downstream impacts,
(4) the difficulties in measuring the impact of changes in the dam's
operations, (5) the adequacy of the measures for reducing the
frequency of unscheduled floods, (6) the need for installing
multilevel water intake structures (selective withdrawal structures)
on the dam to raise the downstream water temperature, and (7) the
implementation of the Adaptive Management Program.
PRINCIPAL FINDINGS
---------------------------------------------------------- Chapter 0:4
IMPACT DETERMINATIONS ARE
USABLE FOR DECISION-MAKING
-------------------------------------------------------- Chapter 0:4.1
In preparing the environmental impact statement, Reclamation used a
variety of methodologies and data sources to study the impact of the
various dam flow alternatives on hydropower, non-use values and other
resources located below the dam. Generally, GAO found the
methodologies used to be reasonable and appropriate. For example,
the power analysis was conducted by a committee of specialists
representing the federal government, the utility industry, private
contractors, and the environmental community. This committee used
utility-specific data and state-of-the-art simulation models to
estimate the economic impact of the alternative dam flows on large
regional utilities.
In assessing Reclamation's implementation of the various
methodologies, GAO did note several shortcomings and controversy over
the methodology used to estimate non-use values. For example, in the
hydropower analysis, Reclamation's assumptions do not explicitly
include the mitigating effect of higher electricity prices on
electricity demand (price elasticity). GAO also found that
Reclamation's assumptions about future natural gas prices were
relatively high and that two computational errors were made during
the third phase of the power analysis. These limitations suggest
that the estimated economic impacts for power are subject to
uncertainty. However, Reclamation and many experts associated with
the process do not believe that these limitations make the results of
the analysis unusable. For example, an association that represents
the affected power utilities, which has maintained throughout the
power studies process that the impact statement understates the costs
to the power system, does not believe that Reclamation's cost
estimate is understated by a large magnitude. To quantify the impact
of various dam flow alternatives on recreation and non-use value,
Reclamation used a methodology called contingent valuation. The use
of contingent valuation studies, which rely on surveys to elicit
information from consumers to estimate how much they would be willing
to pay for something is controversial. Although contingent valuation
is currently the only known approach for estimating non-use values,
some prominent economists question whether this methodology can
accurately elicit the value consumers place on non-use goods.
However, many economists and survey researchers working in the
natural resource and environmental areas have developed and used this
methodology. Although these shortcomings affect the estimates for
the alternatives, it is unlikely that they would alter the relative
ranking of the fluctuating and steady flow alternatives.
GAO also found that Reclamation generally used the best available
data in making its impact determinations. For example, for
information on cultural resources and properties, Reclamation went
beyond the federal requirements for the development of an impact
statement by performing assessments of all previously identified
archeological sites within the Colorado River corridor in the Glen
and Grand canyons. According to many experts, when completed, this
effort generated the best and most current scientific information
available. However, GAO also found some limitations in the data used
in the development of the impact statement. Specifically, some of
the information was dated, some was preliminary, and some was
incomplete. For example, to assess the economic impact of the
alternative flows on recreational activities, Reclamation used a 1985
survey of a sample of anglers, day-rafters, and white-water boaters
that asked about their experiences on the Colorado River and what
effect, if any, different streamflows would have on their
recreational experiences. Although Reclamation updated some of the
data to 1991, it acknowledges that the survey information is
generally dated. The National Research Council generally found the
analysis to be adequate.
Many of the results of the sediment studies at Glen Canyon were
preliminary, were in draft form, and had not been published at the
time that the draft or even the final impact statement was written.
However, according to the researchers that GAO interviewed, no new or
additional information on sediment impacts has been obtained that
would alter the information or conclusions presented in the final
impact statement.
Finally, the information on some resources is incomplete, as is the
knowledge of how changes in the Glen Canyon Dam's operations will
affect those resources. For example, in part because of incomplete
data, the experts' opinions vary on the interactions between native
and nonnative fish and how operational changes would affect these
interactions and, ultimately, fish populations. In its final
biological opinion, the U. S. Fish and Wildlife Service stated that
Reclamation's preferred alternative for the dam's future operations,
the Modified Low Fluctuating Flow alternative, is likely to
jeopardize the existence of two native endangered fish species (the
humpback chub and the razorback sucker). The Service identified
actions that would modify the preferred alternative with seasonally
adjusted steady flows. The Service and Reclamation agreed to
categorize these flows as experimental, or research flows. The
purpose of this research is to study the effects of steady flows on
endangered and native fish.
Reclamation recognizes that many uncertainties about the actual
impact of the various flow alternatives still exist. To address such
concerns, Reclamation intends to initiate a process of "adaptive
management" that would provide for long-term monitoring, research,
and measurement of the effects of the selected alternative. The
results of this effort would form the basis for future modifications
of the dam's operations.
MOST KEY PARTIES SUPPORT THE
PREFERRED ALTERNATIVE, BUT
SOME CONCERNS REMAIN
-------------------------------------------------------- Chapter 0:4.2
The process for selecting a preferred alternative for the future
operations of the Glen Canyon Dam considered many factors, such as
protecting natural and cultural resources and maintaining hydropower
generating capability, and involved many parties with diverse
interests. Reclamation's goal was to select an alternative
dam-operating plan that would permit downstream resources to recover
to acceptable long-term management levels while maintaining some
level of hydropower flexibility. Reclamation believes that it
accomplished this goal by selecting the Modified Low Fluctuating Flow
as the preferred alternative. According to Reclamation, this flow
alternative was developed to reduce daily flow fluctuations well
below the dam's historic operations and to provide periodic high,
steady water releases of short duration with the goal of protecting
or enhancing the downstream resources while allowing limited
flexibility for power operations. This alternative has the same
annual and essentially the same monthly water releases as the dam's
historic operations but would restrict daily and hourly water
releases more than previously.
GAO judgmentally selected 37 key interested parties and surveyed them
on whether they supported Reclamation's preferred alternative and
whether they have any remaining concerns about implementing this
alternative as the future operating plan for the Glen Canyon Dam.
GAO's judgmental sample consisted of all of the organizations and
individuals that Reclamation identified as providing significant
comments on the draft impact statement, any organizations that were
considered cooperating agencies in the impact statement's development
process, and other key interested parties. Over 83 percent (25 of
30) of the respondents to GAO's survey supported the preferred
alternative, and many expressed support for the process used by
Reclamation to develop the impact statement. Of the five remaining
respondents, three stated that they had no position on the issue,
while two, the San Juan Southern Paiute Tribe and the Grand Canyon
River Guides, believed that the current interim operating criteria
would be more protective of resources and, therefore, more consistent
with the intent of the Grand Canyon Protection Act.
Other interested parties, although supporting the preferred
alternative, believed that several areas of concern still remain.
For example, one organization stated that the final impact statement
assumes that the dam's operations are the only cause of the impacts
on downstream resources and, therefore, that changing the dam's
operations is the only technique available for managing and enhancing
those resources. The organization noted other causes of downstream
impacts, including the introduction of nonnative fish and human
usage. Still other organizations believed that there is a potential
for negative impacts that will be difficult to measure because,
between the draft and the final impact statement, Reclamation revised
the preferred alternative to simultaneously increase two of the dam's
operating parameters: the maximum daily peak releases and the upramp
rate (the hourly rate of increase). Others stated that they were
concerned about flood protection measures. Also, concerns were
expressed about the future implementation of Reclamation's Adaptive
Management Program, including its continued monitoring and research
efforts.
RECOMMENDATIONS
---------------------------------------------------------- Chapter 0:5
GAO is making no recommendations in this report.
AGENCY COMMENTS
---------------------------------------------------------- Chapter 0:6
GAO provided copies of a draft of this report to the Department of
the Interior for its review and comment. Interior generally agreed
with the information presented in the report and stated that they
were impressed with the quality of the product developed by the audit
team. Interior also provided several technical clarifications to the
draft, which have been incorporated into the report as appropriate.
Interior's comments and GAO's responses are included in appendix XII.
INTRODUCTION
============================================================ Chapter 1
The Glen Canyon Dam was completed by the Bureau of Reclamation in
1963 as a multipurpose facility. It is the key feature and major
storage unit of the Colorado River Storage Project. The Colorado
River Storage Project was authorized in 1956 to develop and use the
water resources in the Upper Colorado River Basin. The operations of
the Glen Canyon Dam and its reservoir, Lake Powell, enable the
Colorado River Storage Project to fulfill the downstream water
release requirements while the runoff from the Upper Basin is stored
and used for irrigation, recreation, and municipal and industrial
purposes.
The powerplant at the Glen Canyon Dam has been used primarily for
generating power during high-demand periods (peaking power). The
fluctuating releases of water associated with peaking power
operations have caused concern among federal, state, and tribal
resource management agencies; river users who fish in Glen Canyon or
take white-water raft trips in the Grand Canyon; and Native American
and environmental groups, in connection with the detrimental effects
that such water releases have on the cultural resources and the
downstream plants, animals, and their habitats.
OPERATION OF THE GLEN CANYON
DAM'S POWERPLANT
---------------------------------------------------------- Chapter 1:1
The Glen Canyon Dam powerplant has eight generators with a maximum
combined capacity of 1,288,000 kilowatts at a 95-percent power
factor. The maximum combined discharge capacity of the eight
turbines is approximately 33,200 cubic feet per second (cfs) when
Lake Powell is full; however, Reclamation has limited such releases
to 31,500 cfs. Fluctuations within a day have typically ranged from
12,000 cfs in October to about 16,000 cfs in January and August.
Although water can be released from the dam through the powerplant,
the outlet works, or the spillways, discharging water through the
powerplant's turbines is the preferred method because electricity and
its associated revenue can be produced. The power generated by the
Glen Canyon Dam is marketed principally in a six-state area--Arizona,
Colorado, Nevada, New Mexico, Utah, and Wyoming. Figure 1.1 shows
the various release capacities for the Glen Canyon Dam.
Figure 1.1: Water Release
Capacities of the Glen Canyon
Dam's Powerplant, Outlet Works,
and Spillways
(See figure in printed
edition.)
Source: Bureau of Reclamation.
Historically, the Glen Canyon Dam, as part of the Colorado River
Storage Project, was operated to produce the greatest amount of firm
capacity and energy practicable while adhering to the releases
required under the "Law of the River." The Law of the River--a
collection of federal and state statutes, compacts, court decisions
and decrees, federal contracts, a treaty with Mexico, and formally
determined long-range operating criteria--defines the operation and
management of the Colorado River. The operating criteria for the dam
were established under the "Criteria for Coordinated Long-Range
Operation of Colorado River Reservoirs" (Long-Range Operating
Criteria), which include the criteria for annual operations. The
Annual Operating Plan, which is prepared under the Long-Range
Operating Criteria, addresses monthly operations while interagency
agreements control the dam's hourly operations.
The annual volume of releases from the dam is based on the water
inflow to Lake Powell and the remaining space in Lake Powell and Lake
Mead. The annual release volumes vary greatly, but all adhere to the
Long-Range Operating Criteria's objectives of an
8.23-million-acre-feet\1 minimum annual release and equalized storage
between the two reservoirs. From 1968 to 1989, the annual releases
ranged from 8.23 million acre-feet to 20.4 million acre-feet. Annual
releases greater than the minimum were permitted to avoid anticipated
spills (excess annual releases that cannot be used for project
purposes) and to equalize storage. The minimum release occurred in
about half the years.
The volume of water released from Lake Powell each month depends on
the forecasted inflow, existing storage level, monthly storage
targets, and annual release requirements. Demands for electrical
energy, fish and wildlife needs, and recreation needs are also
considered and accommodated as long as the risk of spilling and
storage equalization between Lakes Powell and Mead are not affected.
Power demand is highest during the winter and summer months, and
recreation needs are highest during the summer. Therefore,
higher-volume releases are scheduled during these months whenever
possible. Each month during the inflow forecast season (January to
July), the volume of water to be released for the rest of the year is
recomputed on the basis of updated streamflow forecast information.
The Scheduled releases for the remaining months are adjusted to avoid
anticipated spills and maintain conservation storage in accordance
with the Long-Range Operating Criteria.
Hourly releases from the dam are set to reach monthly release
volumes, to maintain established minimum flow rates, and to follow
energy demand. Hourly power operations are most flexible during
those months with moderate release volumes. The need to maintain
minimum flows in the months with low release volumes limits the
flexibility to accommodate changing hourly power demands. If the
reservoir is nearly full and the inflow is extremely high, the
monthly releases are scheduled at or near the maximum capacity most
of the time, again leaving little flexibility for the hourly releases
to change in response to power demand.
To the extent possible, the Glen Canyon Dam follows these guidelines
in producing hydropower:
-- Maximize water releases during the peak energy demand periods,
generally Monday through Saturday between 7 a.m. and 11 p.m.,
-- Maximize water releases during peak energy demand months and
minimize during low demand months,
-- Minimize and, to the extent possible, eliminate powerplant
bypasses.
--------------------
\1 An acre-foot is the amount of water needed to cover 1 acre of land
to a depth of 1 foot--or about 326,000 gallons.
GLEN CANYON'S ENVIRONMENTAL
STUDIES AND ENVIRONMENTAL
IMPACT STATEMENT
---------------------------------------------------------- Chapter 1:2
Before the construction of the Glen Canyon Dam, the Colorado River's
sediment-laden flows fluctuated dramatically during different seasons
of the year. Flows of greater than 80,000 cfs were common during the
spring runoff. In contrast, flows of less than 3,000 cfs were
typical throughout the late summer, fall, and winter. Water
temperatures ranged from near freezing in the winter to more than 80
degrees Fahrenheit in the summer. The construction of the Glen
Canyon Dam altered the natural dynamics of the Colorado River. The
dam replaced seasonal flow variations with daily fluctuations,
greatly reduced the amount of sediment in the river, and resulted in
nearly constant water release temperatures of about 46 degrees
Fahrenheit.
In response to the concerns of federal, state, and tribal agencies
and the public about the negative effects of the dam's operations, in
December 1982 the Secretary of the Interior directed Reclamation to
initiate a series of interagency scientific studies. These studies
were to examine the short- and long-term effects of the dam's
historic, current, and alternative operations on the environmental
and recreational resources of the Glen and Grand canyons. The
studies became known as phase I of the Glen Canyon Environmental
Studies. From 1982 through 1987, 39 technical reports were prepared
evaluating terrestrial biology, aquatic biology, sediment and
hydrology, recreation, and the dam's operations. However, no studies
were conducted on the economic impact to hydropower from changes in
the dam's operations. According to Reclamation, of primary
importance in the Glen Canyon Environmental Studies was the research
connected with endangered fish. The existence and operations of the
dam were believed to be important factors involved in the extinction
of two fish species (the Colorado squawfish and bonytails) from the
river corridor. The dam and its operations were also considered to
present survival problems for the existing populations of the
humpback chub and razorback sucker as well as other native fish
species. Therefore, according to Reclamation, the biological opinion
issued by the U.S. Fish and Wildlife Service in 1994 was an
important factor in the ultimate formulation of the preferred
alternative in the environmental impact statement (EIS).
The Glen Canyon Environmental Studies technical reports were
concurrently reviewed by the National Research Council and the
Executive Review Committee. The Executive Review Committee was made
up of policy-level representatives from Reclamation, the National
Park Service, the U.S. Fish and Wildlife Service, the Department of
the Interior's Office of Environmental Policy and Compliance, and the
Western Area Power Administration. This Committee then prepared a
report\2 in January 1988 on the findings and conclusions of phase I
of the Glen Canyon Environmental Studies and made recommendations and
suggested options for revising the dam's operations.
In June 1988, phase II of the Glen Canyon Environmental Studies was
initiated to gather additional data over a 4- to 5-year period on the
dam's specific operational elements. Phase II was to further define
the impacts on the natural environment, public uses associated with
recreation, cultural resources, and power-generation economics. At
the urging of the National Research Council, an entity of the
National Academy of Sciences, non-use values were incorporated into
the studies. "Non-use value" is the term used to describe the
monetary value that non-users place on the status of the environment.
For example, the values that people may receive from the knowledge
that such things as rare plants, animals, and unspoiled natural
environments exist are defined as non-use values. A number of
federal and state resource agencies, Indian tribes, private
consultants, universities, and river guides participated in phase II
of the Glen Canyon Environmental Studies.\3 Funding for these studies
was provided mainly from the revenue derived from the sale of
electricity generated by the Glen Canyon Dam.
In July 1989, the Secretary of the Interior decided that Reclamation
should prepare an environmental impact statement to reevaluate the
operations of the Glen Canyon Dam. The purpose of the EIS was to
determine specific options for operating the dam that could minimize
the adverse impacts on the downstream environmental and cultural
resources, as well as on the Native American interests in the Glen
and Grand canyons, while still producing hydropower. Reclamation was
designated by the Secretary to be the lead agency responsible for
preparing the EIS; other participants were the following cooperating
agencies: the Bureau of Indian Affairs, the National Park Service,
the U.S. Fish and Wildlife Service, the Western Area Power
Administration, and the Arizona Game and Fish Department. In 1989,
after the EIS process started, Reclamation also made the following
Native American tribes cooperating agencies: the Hopi Tribe, the
Hualapai Tribe, the Navajo Nation, the Pueblo of Zuni, the San Juan
Southern Paiute Tribe, and the Southern Paiute Consortium. Officials
from many of these same agencies and tribes participated in the Glen
Canyon Environmental Studies, which formed the basis for the analyses
of alternatives for the EIS.
The EIS was designed primarily to focus on the Colorado River
corridor from the Glen Canyon Dam in northwestern Arizona, southward
through the Glen and Marble canyons and westward through the Grand
Canyon to Lake Mead. The map in figure 1.2 shows the area of study
under the Glen Canyon Environmental Studies and the EIS for the Glen
Canyon Dam.
Figure 1.2: Map of the Study
Area of the Glen Canyon Dam's
Environmental Studies and
Environmental Impact Statement
(See figure in printed
edition.)
Note: RM - River Mile.
Source: Bureau of Reclamation.
The requirement to prepare an EIS accelerated the scheduled
completion of the research studies in phase II of the Glen Canyon
Environmental Studies to provide more timely data for the EIS. This
acceleration was accomplished by designing special "research flows,"
a series of carefully designed discharges of water and data
collection programs conducted in June 1990 through July 1991. Each
research flow lasted 14 days and included 3 days of steady 5,000 cfs
flows and 11 days of either steady or fluctuating flows. The
research flows provided a means to evaluate the short-term responses
of certain resources to a variety of discharge parameters, including
minimum and maximum flows, the rate of change in flow, and the range
of daily fluctuations.
To protect downstream resources until the completion of the EIS and
the formal adoption of new operating criteria for the Glen Canyon
Dam, Reclamation implemented the interim dam operations on November
1, 1991. The interim operating criteria were purposely designed to
be conservative for the protection of natural and cultural resources.
Specifically, the interim criteria reduced peak water releases from
the approved maximum of 31,500 cfs to 20,000 cfs; restricted daily
fluctuations in releases to between 5,000 cfs and 8,000 cfs; and
restricted the rate of change in releases (ramp rates) to 2,500 cfs
per hour when increasing and to 1,500 cfs per hour when decreasing.
While these limitations were imposed, the interim criteria met the
minimum annual release of 8.23 million acre-feet in accordance with
the 1970 Long-Range Operating Criteria. Although the interim
operating criteria could be modified on the basis of new information,
they were to remain in effect until the EIS and the Secretary's
Record of Decision for new operating criteria for the dam were
completed.
--------------------
\2 The Glen Canyon Environmental Studies Final Report, U.S.
Department of the Interior, 1988.
\3 Agencies participating in phase II of the Glen Canyon
Environmental Studies included Reclamation, the National Park
Service, the Western Area Power Administration, the U.S. Geological
Survey, the U.S. Fish and Wildlife Service, the Hopi Tribe, the
Hualapai Tribe, the Navajo Nation, the Pueblo of Zuni, the San Juan
Southern Paiute Tribe, the Southern Paiute Consortium, and the
Arizona Game and Fish Department.
GRAND CANYON PROTECTION ACT OF
1992
---------------------------------------------------------- Chapter 1:3
Subsequent to Reclamation's initiation of the EIS process, on October
30, 1992, the Congress enacted the Grand Canyon Protection Act of
1992 (title XVIII of P.L. 102-575). The act addresses the
protection of the Grand Canyon National Park, the Glen Canyon
National Recreational Area, the interim operating criteria for the
dam until the EIS is completed, long-term monitoring and research,
and the replacement of lost power from any changes to the dam's
operation. The act requires that the Glen Canyon Dam be operated to
protect, mitigate adverse impacts to, and improve the downstream
resources of the Grand Canyon National Park and the Glen Canyon
National Recreational Area. The act also required the Secretary of
the Interior to complete a final environmental impact statement for
the Glen Canyon Dam's operations by October 30, 1994. Furthermore,
the act required GAO to audit the costs and benefits of the various
operating alternatives identified in the final environmental impact
statement. On the basis of the findings, conclusions, and
recommendations made in the EIS, other relevant information, and our
audit report, the Secretary is to issue a Record of Decision adopting
future operating criteria and operating plans for the Glen Canyon
Dam.
NATIONAL ENVIRONMENTAL POLICY
ACT
---------------------------------------------------------- Chapter 1:4
The National Environmental Policy Act of 1969 (NEPA) (42 U.S.C. 4321
et seq.) establishes the national environmental policy and goals for
protecting, maintaining, and enhancing the environment, and it
provides a process for implementing these goals within federal
agencies. The act requires, among other things, that the applicable
federal agency prepare a detailed EIS for every major federal action
that may significantly affect the quality of the human environment.
The EIS is designed to ensure that important environmental impacts
will not be overlooked or underestimated before the government
commits to a proposed action. The act also established the Council
on Environmental Quality, which oversees the NEPA process.
The Council on Environmental Quality's Regulations for Implementing
the Procedural Provisions of the National Environmental Policy Act
(40 C.F.R. 1502.4) provide federal agencies with a process for
determining whether or not to prepare an EIS. If it is determined
that an EIS is necessary, regulations require, among other things,
that the EIS must (1) address the purpose of and need for the action,
(2) describe the environment that will be affected, (3) identify
alternatives to the proposed action, (4) present the environmental
impacts of the proposed action (including the direct, indirect, and
cumulative impacts), (5) identify any adverse environmental impacts
that cannot be avoided should the proposed action be implemented, and
(6) identify any irreversible and irretrievable commitment of
resources that would occur should the proposed action be implemented.
The regulations also require each federal agency to identify the
agency's preferred alternative or alternatives, if one or more
exists, in the draft and the final EIS. In addition, before making a
decision, the responsible agency must solicit comments from the
public and from other government agencies that may have jurisdiction
by law or expertise with respect to any environmental impacts.
Under section 309 of the Clean Air Act, the Environmental Protection
Agency (EPA) is required to review and publicly comment on the
environmental impacts of major federal actions, including actions
that are the subject of a draft or final EIS. EPA reviews and
comments on both the adequacy of the analyses and the environmental
impacts of the proposed action. If the Administrator, EPA,
determines that the action is environmentally unsatisfactory from the
standpoint of the public's health or welfare or environmental
quality, this determination shall be published and the matter will be
referred to the Council on Environmental Quality. If the action
involves a federal project located at a specific site, the
appropriate EPA regional office has the jurisdiction and delegated
responsibility for carrying out the section 309 review and working
with the proposing federal agency to resolve any problems. EPA's
Region IX in San Francisco, California, was the region responsible
for reviewing the draft and final EIS for the operation of the Glen
Canyon Dam.
RECLAMATION'S PROCESS FOR
COMPLETING THE GLEN CANYON
DAM'S EIS
---------------------------------------------------------- Chapter 1:5
The preparation of the Operation of Glen Canyon Dam Final
Environmental Impact Statement was a cooperative effort involving
Reclamation, the cooperating agencies, the participants in the Glen
Canyon Environmental Studies program, and the representatives of an
interagency EIS team. Although Reclamation was designated to be the
lead agency responsible for preparing the EIS, its objective was to
obtain substantial input from these organizations during the
decision-making process, and its goal was to build a consensus for
the ultimate decision of recommending a preferred alternative in the
EIS.
The group of cooperating agencies, which prior to the development of
the formal EIS included only federal agencies, was established in
July 1989. This group ultimately included representatives from
Reclamation, the Bureau of Indian Affairs, the Environmental
Protection Agency, the National Park Service, the U.S. Fish and
Wildlife Service, the Western Area Power Administration, the Arizona
Game and Fish Department, the Hopi Tribe, the Hualapai Tribe, the
Navajo Nation, the San Juan Southern Paiute Tribe, the Southern
Paiute Consortium, and the Pueblo of Zuni. The EIS team was
established in mid-1990 and included representatives from
Reclamation, the National Park Service, the U.S. Fish and Wildlife
Service, the Western Area Power Administration, the U.S. Geological
Survey, the Arizona Game and Fish Department, the Hopi and Hualapai
Tribes, the Navajo Nation, and a private consulting firm.
Reclamation charged the EIS team with formulating alternatives for
operating the dam and assessing their impacts on the environment.
For resources that were to be studied in detail, subteams were formed
to make the impact determinations, document their findings, and draft
that particular section of the EIS. For the other resources,
individuals with expertise in a particular field were assigned the
responsibility for determining the impacts and preparing the
documentation. Figure 1.3 shows some of the key dates in the
preparation of the Glen Canyon Environmental Studies and the EIS.
Figure 1.3: Key Dates in the
Environmental Studies and the
Environmental Impact Statement
Processes for the Glen Canyon
Dam
(See figure in printed
edition.)
Source: GAO's presentation of the Bureau of Reclamation's data.
SCOPING PHASE
---------------------------------------------------------- Chapter 1:6
The initial step in preparing an EIS involves a scoping phase that
provides for the early identification and consideration of
environmental issues and alternatives. In February 1990, Reclamation
published a notice in the Federal Register announcing the opening of
the scoping phase of the Glen Canyon Dam's EIS. This phase included
environmental scoping meetings to obtain public comments and
determine the appropriate scope of the EIS. The comment period,
initially established for March 12 through April 16, 1990, was
extended to May 4, 1990, in response to comments by the public.
Reclamation provided opportunities for public participation in the
scoping phase through news releases, mailings, legal notices, and
contacts with media, organizations, and individuals. Throughout the
process, the EIS team periodically reported the results of its
analyses to the cooperating agencies and the public. The cooperating
agencies acted as a steering committee and provided input to
Reclamation on both the EIS process and the EIS document after a
period of review and discussion.
More than 17,000 comments were received during the scoping period.
Numerous comments were received about suggested alternatives and
factors to be considered in the development of alternatives. These
comments ranged from general suggestions about the management of the
dam to specific flow release recommendations. As a result of the
analyses and the categorization of the oral and written scoping
comments by a Reclamation contractor, the EIS team consolidated and
refined the public's issues of concern. The following resources were
identified to be analyzed in detail in the EIS: water, sediment,
fish, vegetation, wildlife and their habitat, endangered and other
special-status species, cultural resources, air quality, recreation,
hydropower, and non-use value.
In July 1990, representatives from the cooperating agencies and
various interest groups participated in a "brainstorming" workshop to
fully consider all concepts and suggestions in formulating
alternatives for the dam's operations. On the basis of the results
of the workshop, scoping comments, and the Glen Canyon Environmental
Studies phase I report, the interdisciplinary EIS team formulated 10
preliminary alternative flow scenarios. Some of these alternatives
would provide for warmer water release temperatures in the summer,
add sediment to the river below the dam, or reregulate releases to
provide steady flows downstream. The EIS team presented these
alternatives to the cooperating agencies and, following their
approval, presented them to the public in March 1991.
The public was asked to comment on the range of preliminary
alternatives as part of the EIS scoping process. The predominant
public comment was the need to separately consider alternatives that
deal with the operations of the dam from those considering changes to
the structure of the dam. Using the additional input received from
the public, professional judgment, and analysis of interim flows, the
EIS team reviewed and revised the preliminary alternatives. Seven
alternatives were then identified for detailed analysis. Later, to
present a full range of reasonable operations for study in the EIS,
two more alternatives were formulated. These included the Maximum
Powerplant Capacity alternative, which was developed to allow use of
the powerplant's maximum discharge capacity of 33,200 cfs, and the
eventual preferred alternative--the Modified Low Fluctuating Flow
alternative. The Modified Low Fluctuating Flow alternative was
similar to the Interim Flow but included a habitat maintenance flow.
Habitat maintenance flows are high, steady releases of water within
the powerplant's capacity for 1 or 2 weeks in the spring. The
purpose of these flows is to reform and rejuvenate backwaters and
maintain sandbars, which are important for native fish habitat.
Table 1.1 presents the nine alternative flows studied in detail in
the Glen Canyon Dam's environmental impact statement. These
alternatives can be categorized as follows: unrestricted fluctuating
flows, restricted fluctuating flows, and steady flows.
Table 1.1
Alternative Operating Procedures Studied
in the Glen Canyon Dam's EIS
--------------------------------------- ------------------------------------------------
Unrestricted fluctuating flows The two unrestricted fluctuating flow
alternatives would allow flows to vary, as
necessary, for power generation purposes.
No-Action Maintain historic fluctuating releases the same
as they were from 1964, when the dam was placed
in hydropower operation, until the research
flows began in June 1990. The maximum allowable
discharge during these fluctuations would be
31,500 cfs.
Maximum Powerplant Capacity Permits use of full powerplant capacity (33,200
cfs).
Restricted fluctuating flows The four restricted fluctuating flow
alternatives would provide a range of downstream
resource-protection measures, while offering
varying amounts of flexibility for power
operations.
High Slightly reduce daily fluctuations from historic
no-action levels.
Moderate Moderately reduce daily fluctuations from
historic no-action levels; includes habitat
maintenance flows, which are short-duration high
releases during the spring that allow sand to be
transported and deposited for maintaining
camping beaches and fish and wildlife habitat.
Modified Low (preferred alternative) Substantially reduce daily fluctuations from
historic no-action levels; includes habitat
maintenance flows.
Interim Low Substantially reduce daily fluctuations from
historic no-action levels; same as interim
operations.
Steady flows The three steady flow alternatives would provide
a range of downstream resource-protection
measures by minimizing daily release
fluctuations. Flows would be steady on either a
monthly, seasonal, or year-round basis.
Existing Monthly Volume Provide steady flows that use historic monthly
release strategies.
Seasonally Adjusted Provide steady flows on a seasonal or monthly
basis; includes habitat maintenance flows.
Year-Round Provide steady flows throughout the year.
-----------------------------------------------------------------------------------------
RESOURCE PROTECTION MEASURES
(COMMON ELEMENTS)
---------------------------------------------------------- Chapter 1:7
All of the restricted fluctuating flow and steady flow alternatives
include elements designed to provide additional resource protection
or enhancement. Since these elements were common to all such
alternatives, they became known as the "common elements." Each impact
analysis includes these common elements. The common elements include
adaptive management, monitoring and protecting cultural resources,
flood frequency reduction measures, beach/habitat-building flows,
further study of selective withdrawal structures, measures to
increase populations of an endangered fish--the humpback chub,\4 and
emergency operating exception criteria.
--------------------
\4 Measures to provide protection for, or enhancement of, populations
of the razorback sucker are not specifically included as a common
element because currently very few of the species exist in the
mainstream Colorado River and no reproduction is known to occur.
ADAPTIVE MANAGEMENT
------------------------------------------------------ Chapter 1:7.0.1
The concept of adaptive management is based on the recognized need
for operational flexibility to respond to future monitoring and
research findings and varying resource conditions. The purpose of
the Adaptive Management Program would be to develop future
modifications to the dam's operating criteria if monitoring and/or
research results indicate a need for change. Long-term monitoring
and research would measure how well the selected alternative meets
the resource management objectives. The basis for any decision would
be linked to the response of the resources to the operations of the
dam. (Further details on the Adaptive Management Program are
provided in ch. 2.)
MONITORING AND PROTECTING
CULTURAL RESOURCES
------------------------------------------------------ Chapter 1:7.0.2
The existence and operation of Glen Canyon Dam has had an effect on
the historic properties within the Colorado River corridor of the
Glen and Grand canyons. These properties include prehistoric and
historic archeological sites and Native American traditional cultural
properties and resources. Impacts are likely to occur to some of
these historic properties regardless of the EIS alternative chosen
for implementation. The National Historic Preservation Act, as
amended in 1992, instructs federal agencies to develop measures to
avoid or minimize the loss of historic properties resulting from
their actions.
FLOOD FREQUENCY REDUCTION
MEASURES
------------------------------------------------------ Chapter 1:7.0.3
Under this common element, the frequency of unscheduled flood flows
greater than 45,000 cfs would be reduced to no more than once in 100
years as a long-term average. This would allow management of certain
other common elements--habitat maintenance flows and
beach/habitat-building flows.
The two separate methods of reducing flood frequency that were
identified include (1) increasing the capacity of Lake Powell by
raising the height of the spillway gates by 4.5 feet and (2) reducing
the volume of the lake by 1 million acre-feet from its current
capacity in the spring until the runoff peak has clearly passed.
BEACH/HABITAT-BUILDING
FLOWS
------------------------------------------------------ Chapter 1:7.0.4
Sandbars above the river's normal peak stage will continue to erode,
and backwater habitat within the river's flow will tend to fill with
sediment under any EIS alternative. Beach/habitat-building flows
involve controlled high releases of water greater than the
powerplant's capacity for a short duration; they are designed to
rebuild high-elevation sandbars, recycle nutrients, restore backwater
channels, and provide some of the dynamics of a natural system.
FURTHER STUDY OF
SELECTIVE WITHDRAWAL
STRUCTURES
------------------------------------------------------ Chapter 1:7.0.5
Reclamation would perform a study to determine if structures that
would allow the withdrawal of water from various depths of the
reservoir should be installed at the Glen Canyon Dam. Currently,
water released from the dam to produce hydropower is withdrawn from
the cold depths of Lake Powell, averaging 230 feet below the water's
surface when the reservoir is full. This withdrawal process is
accomplished by a series of eight 15-foot-diameter intake pipes that
provide the water directly to the dam's eight turbines. This water
withdrawal process results in the river water temperature downstream
of the dam being a nearly constant year-round average of about 46
degrees Fahrenheit. Many native fish species cannot reproduce and
survive in these constant cold temperature conditions. Increasing
mainstream water temperatures by means of selective withdrawal
structures offers the greatest potential for creating new spawning
populations of humpback chub and other native fish in the Grand
Canyon. Multilevel intake structures (a means of selective
withdrawal) could be built at Glen Canyon Dam to provide seasonal
variation in the water temperature. A structure would be attached to
each of the eight existing intake pipes to withdraw warmer water from
the upper levels of the reservoir. However, the cost of installing
multilevel intake structures at the Glen Canyon Dam has been
estimated at $60 million.
NEW POPULATION OF
HUMPBACK CHUB
------------------------------------------------------ Chapter 1:7.0.6
With the assistance of the U.S. Fish and Wildlife Service, the
National Park Service, the Arizona Game and Fish Department, and
other land management entities, such as the Havasupai Tribe,
Reclamation would make every effort--through funding, facilitating,
and technical support--to establish a new population of humpback chub
within the Grand Canyon. The humpback chub is currently a listed
species under the federal Endangered Species Act of 1973 (16 U.S.C.
1532 et seq.) and is one of the native fish species that faces
continued ecological health problems due to the cold water
temperatures of the Colorado River. Such cold temperatures are not
conducive to the humpback chubs' spawning or the survival of eggs and
young.
EMERGENCY EXCEPTION
CRITERIA
------------------------------------------------------ Chapter 1:7.0.7
Normal operations described under any alternative could be altered
temporarily to respond to power and water emergencies, such as
insufficient generating capacity, the restoration of the electrical
system, or search and rescue operations. These changes in operations
would be of short duration (usually less than 4 hours) and would be
the result of emergencies at the dam, downstream, or within the
interconnected electrical system.
DRAFT EIS AND PUBLIC COMMENTS
---------------------------------------------------------- Chapter 1:8
On January 4, 1994, Reclamation filed a draft EIS with EPA. The
Draft EIS presented the impacts of the nine flow alternatives,
including the No-Action alternative (historic operations) that
provided a baseline for comparison, on the 11 resources that could be
affected by the various dam-operating regimes. Over 33,000 written
comments were received on the draft EIS. More than 2,300 separate
issues and concerns were extracted from an analysis of the comments.
EPA's Region IX supported the preferred alternative (Modified Low
Fluctuating Flow) selected by Reclamation in the draft EIS. However,
EPA gave the draft EIS a qualified rating based on insufficient
information on two issues. First, EPA expressed concern about the
lack of information on the impacts of raising the dam's spillway
gates as a flood frequency reduction measure and recommended that the
final EIS include a more thorough evaluation of the flood frequency
reduction options. Second, EPA recommended that the final EIS
contain further discussion of Reclamation's Adaptive Management
Program and how it plans to implement beach/habitat-building flows.
PRELIMINARY FINAL EIS
---------------------------------------------------------- Chapter 1:9
Reclamation issued a preliminary final EIS for the operations of the
Glen Canyon Dam in December 1994. The preliminary final EIS also
took into consideration the discussions with the U.S. Fish and
Wildlife Service (FWS) in connection with the consultation
requirements of the Endangered Species Act and with the provisions of
the Fish and Wildlife Coordination Act. Section 7 of the Endangered
Species Act, as amended (16 U.S.C. 1536), requires federal agencies
to consult with FWS to ensure that the actions they authorize, fund,
or carry out are not likely to jeopardize the continued existence of
a species listed under the act as endangered or threatened. If the
action would jeopardize a listed species, FWS suggests a reasonable
and prudent alternative that the federal agency can implement to
minimize and/or mitigate the activity's impact on the species or
their critical habitat. The Fish and Wildlife Coordination Act of
1958 (16 U.S.C. 661 et seq.) was enacted to ensure that fish and
wildlife receive equal consideration during the planning and
construction of federal water projects. FWS prepares a Fish and
Wildlife Coordination Act report that contains nonbinding
recommendations for actions that would be beneficial to fish and
wildlife. The cooperating agencies and the EIS team reviewed the
preliminary final EIS, and additional changes were made to the EIS on
the basis of that review.
FINAL EIS
--------------------------------------------------------- Chapter 1:10
On March 21, 1995, Reclamation filed the final EIS with EPA. In June
1995, EPA informed Reclamation that it continues to support the
preferred alternative and was pleased that Reclamation had addressed
EPA's concerns about the draft EIS. Specifically, the final EIS
states that Reclamation will conduct a detailed evaluation of the
flood frequency reduction measures before a decision is made and
provides more information on the approach that Reclamation will use
to implement an Adaptive Management Program and conduct
beach/habitat-building flows. EPA applauded the efforts made by all
of the agencies, tribes, organizations, and individuals involved in
the research, scoping, and preparation of the EIS. EPA summarized
that the dedication to sound science and cooperative relations was
critical to developing a preferred alternative (including adaptive
management), which it believes will protect and enhance the
environmental and cultural resources downstream from the Glen Canyon
Dam.
RECLAMATION'S PREFERRED
ALTERNATIVE FOR FUTURE
OPERATIONS OF THE GLEN CANYON
DAM
--------------------------------------------------------- Chapter 1:11
In the Glen Canyon Dam's final environmental impact statement,
Reclamation recommends the Modified Low Fluctuating Flow as the
preferred method for the future operations of the Glen Canyon Dam.
According to the final EIS, the Modified Low Fluctuating Flow
alternative was developed to reduce daily flow fluctuations well
below no-action levels and to provide periodic high, steady releases
of short duration, with the goal of protecting or enhancing
downstream resources while allowing limited flexibility for power
operations. This alternative would have the same annual and
essentially the same monthly operating plan as under the No-Action
alternative but would restrict daily and hourly water releases.
Specifically, minimum flows would be no less than 8,000 cfs between 7
a.m. and 7 p.m. and 5,000 cfs at night. The maximum rate of
release would be limited to 25,000 cfs during fluctuating hourly
releases. Ramp rates would be limited to 4,000 cfs per hour for
increasing flows and 1,500 cfs per hour for decreasing flows. Daily
fluctuations would be limited to 5,000, 6,000, or 8,000 cfs depending
on the monthly release volume.
The preferred alternative also included periodic habitat maintenance
flows, which are steady high releases within the powerplant's
capacity for 1 to 2 weeks in the spring. The purpose of these flows
is to rejuvenate backwater channels that are important to fish
habitat and maintain sandbars that are important for camping.
Habitat maintenance flows differ from beach/habitat-building flows in
that they would be within the powerplant's capacity and would occur
nearly every year when the reservoir's volume is low. According to
Reclamation, when the reservoir is low, water flows normally would
not exceed about 22,000 cfs, and the probability of an unscheduled
spill is small. Therefore, the habitat maintenance flows would be
scheduled in those years. Habitat maintenance flows would not occur
in years when a beach/habitat-building flow is scheduled.
Beach/habitat-building flows are controlled floods with scheduled
high releases of water greater than the powerplant's capacity for a
short duration, designed to rebuild high elevation sandbars, deposit
nutrients, restore backwater channels, and provide some of the
dynamics of a natural river system.
According to Reclamation, instead of conducting the beach/habitat
building flows in years in which Lake Powell storage is low on
January 1, it has been agreed to modify the preferred alternative in
the Record of Decision to accomplish the flows in high reservoir
years when bypassing the powerplant would be necessary for safety
purposes at the dam. In the spring of 1996, Reclamation conducted
its first experiment of the controlled flood concept. The controlled
experiment commenced with 4 days of constant flows at 8,000 cfs.
Flows began to increase incrementally on March 26, 1996, until they
reached a maximum of 45,000 cfs, where they remained for 7 days.
After 7 days of high flows, the releases were reduced, gradually, to
a constant flow of 8,000 cfs for 4 days of evaluation. According to
Reclamation, the preliminary results indicate that the release
increased sandbars in the Glen and the Grand canyons by as much as 30
percent and also created numerous backwaters for fish.
OBJECTIVES, SCOPE, AND
METHODOLOGY
--------------------------------------------------------- Chapter 1:12
Subsection 1804(b) of the Grand Canyon Protection Act states that the
Comptroller General shall (1) audit the costs and benefits to water
and power users and to natural, recreational, and cultural resources
resulting from the management policies and dam operations identified
pursuant to the environmental impact statement and (2) report the
results of the audit to the Secretary of the Interior and the
Congress.
While the act states that GAO should audit the "costs and benefits"
of various alternative dam operations identified in the EIS, the
National Environmental Policy Act does not require, and Reclamation
did not perform, a cost and benefit analysis. In preparing the
impact statement, Reclamation studied the impact of nine
dam-operating alternatives on 11 resources. In the absence of a cost
and benefit analysis, we determined that the statute does not require
us to conduct our own cost and benefit analysis. As discussed with
the staff of the Majority and Ranking Minority members of the Senate
and House committees having jurisdiction over these matters, to
fulfill the requirements of the act, we examined
-- whether Reclamation's determination of the impact of various
flow alternatives on selected resources was reasonable and
-- what, if any, concerns still exist on the part of key interested
parties about the final EIS.
To assess whether Reclamation's impact determinations were
reasonable, we assessed for each resource, the methodologies and data
used to make the impact determinations, how the methodologies were
implemented, and the results achieved. The details of our analysis,
and a comprehensive list of individuals contacted and key studies
identified, are contained in appendixes I through X of this report.
The title of each appendix is the designation (name) of the resource,
and they are numbered in alphabetical order. We combined our
analysis of the vegetation and wildlife/habitat impact determinations
into one appendix--appendix IX. We made this choice because (1)
similar indicators were studied in making the impact determinations
for these resources, (2) the riparian vegetation that developed along
the Colorado River corridor plays an important role as habitat to
support the diversity of wildlife within the Glen and the Grand
canyons, and (3) the same EIS team member was responsible for the
impact determinations of both resources.
For three resources--hydropower, recreation, and non-use
values--Reclamation quantified the economic impact of the cost or
benefit that the various flow alternatives would have on the
resource. For these resources, we also reviewed the documentation on
the modeling techniques and economic assumptions used to make the
impact determinations. For example, for Reclamation's power
methodology, we reviewed key economic assumptions, results, and
documentation, including reports entitled Power System Impacts of
Potential Changes in Glen Canyon Power Plant Operations, [Phase II]
Final Report, October 1993, and Power System Impacts of Potential
Changes in Glen Canyon Power Plant Operations, Phase III Final
Report, July 1995. These reports were prepared by the Power
Resources Committee, a subgroup of the EIS team which included
experts from the federal government, the utility industry, and the
environmental community. This committee was charged with determining
the impact of the nine flow alternatives on hydropower.
We interviewed members of the Power Resources Committee, including
the Reclamation officials who served as Chairman and economist, and
representatives from the Western Area Power Administration, the
Colorado River Energy Distributors Association, the Environmental
Defense Fund, and the Reclamation contractor that conducted the
studies.
In addition, to assess the methodology used, economic assumptions,
and results, we reviewed federal guidance on water resource projects
entitled Economic and Environmental Principles and Guidelines for
Water and Related Land Resources Implementation Studies, U.S. Water
Resources Council, March 10, 1983; public comments on the draft and
final EIS, and comments provided by three energy consultants retained
by HBRS, Inc. to review the power analysis. HBRS, Inc. (now called
Hagler Bailly Consulting), was Reclamation's primary contractor for
conducting the power analysis. Also, we reviewed the comments
provided by the National Research Council on the power analyses in
the draft and final EIS. We used standard microeconomic principles
to assess the reasonableness of key economic assumptions. Our
assessment of the reasonableness of Reclamation's methodology was
limited to a review of the general analytical framework and an
assessment of the reasonableness of the key assumptions and data. We
did not evaluate the Power Resources Committee's calibration of the
power simulation models used or the spreadsheet models used, nor did
we verify the accuracy of all data inputs.
For both the recreation and non-use methodologies, we reviewed the
literature and research principles on the contingent valuation method
to assess the reasonableness of the methodology, assumptions used,
and results in conjunction with standard economic principles.
Economists and survey researchers working in the natural resource and
environmental areas have developed the theory and practice of
contingent valuation to estimate non-use values.
To gain an understanding of Reclamation's recreational methodology,
key assumptions, and results, we reviewed documentation that
describes these in detail, including the EIS. We also interviewed
members of the Recreation subgroup, including Reclamation officials
and their contractors, as well as representatives from the National
Park Service and the Arizona Game and Fish Department. In addition,
we interviewed academic experts in the field and a member of the
National Academy of Sciences' team that reviewed the EIS.
To gain an understanding of Reclamation's non-use value study
methodology and results, we reviewed the final report entitled GCES
Non-Use Value Study, dated September 8, 1995. We interviewed
Reclamation officials responsible for the preparation of the report,
and a Senior Associate at Hagler Bailly Consulting, who was a primary
contributor to the development of the report. To evaluate
Reclamation's non-use study, we made use of some general guidelines
that focus on the quality of a contingent valuation study and on the
underlying survey research. Specifically, to assess the contingent
valuation study, we relied on general guidelines developed by a panel
of prominent researchers convened by the National Oceanic and
Atmospheric Administration. The panel's report was published in the
Federal Register on January 15, 1993. To assess the total design
method for conducting mail surveys used by Reclamation in the non-use
study we used the most widely accepted written standards for mail
questionnaires published by Don A. Dillman in 1978. We also
interviewed a number of the Non-Use Value Committee members to obtain
their opinion of the methodologies and data used and the results
achieved. The Committee included members from the power industry,
environmental groups, Native American tribes, and federal agencies.
The Committee was tasked to consider interim study results and
provide input to the study process.
For the eight resources whose impact determinations were not
economically quantified, to determine the methodology and data used
to make an impact determination, we obtained and reviewed the
following documents: the draft EIS and associated appendixes, the
preliminary final EIS, the final EIS, public comments on the draft
EIS, Reclamation's analysis of and responses to these comments,
copies of the minutes of EIS team meetings, summaries of the
cooperating agency meetings, and Reclamation's newsletters on the EIS
process. We also obtained and reviewed the U.S. Fish and Wildlife
Service's draft biological opinion and final biological opinion on
the Glen Canyon Dam's EIS, Reclamation's comments and responses to
the biological opinions, and the U.S. Fish and Wildlife Service's
report required by the Fish and Wildlife Coordination Act. Also, we
reviewed numerous scientific studies related to each of the resources
that were identified by EIS team members as the most useful in
developing the impact determinations for the respective resources.
To obtain a better understanding of other issues related to the EIS
process, we also reviewed the Colorado River Simulation System
Overview, the Final Analysis Report on Scoping Comments, and the Glen
Canyon Dam EIS Preliminary Alternatives Report. Other documents
reviewed included the draft and final environmental assessment of the
spring 1996 beach/habitat-building test flow and papers presented at
a 1991 National Research Council Symposium on the Glen Canyon
Environmental Studies.
Because certain parameters included in the preferred alternative were
changed, we reviewed a document entitled "Assessment of Changes to
the Glen Canyon Dam Environmental Impact Statement Preferred
Alternative from Draft to Final EIS," issued by Reclamation in
October 1995. This paper explained the background and scientific
basis of the changes to the preferred alternative between the draft
and final EIS. A comprehensive list of the documents we reviewed is
contained in the discussion of each of the 11 resources in appendixes
I through X (vegetation and wildlife/habitat are both discussed in
appendix IX).
To assess the reasonableness of the impact determinations for the
eight resources that were not economically quantified, we interviewed
the EIS team members and/or subgroup members who had the primary
responsibility for making the impact determinations, writing sections
of the draft EIS, and revising the EIS following the receipt of
public comments. We also spoke with scientists identified by EIS
team members and members of EIS subgroups who commented on issues in
their area of expertise. Finally, we interviewed other agency
officials with information on the EIS and Glen Canyon Environmental
Studies processes. For each of these resources, we obtained his or
her views on the reasonableness of the methodology and data used in
making the impact determinations, how well the methodologies were
implemented, and the reasonableness of the results achieved.
To obtain information on what, if any, concerns still exist on the
part of key interested parties about the final impact statement,
including how many supported the preferred alternative, we surveyed
37 key organizations and individuals knowledgeable about the EIS and
its development. Our judgmental sample included officials of federal
agencies, state agencies, Indian tribes, environmental organizations,
water and power suppliers and users, and individuals involved in the
development of the EIS. Specifically, among the 37 organizations and
individuals we asked to respond to our survey, 23 were organizations
and individuals that provided what Reclamation considered to be the
most substantive comments on the draft EIS. These agencies and
individuals include the Navajo Nation, Hualapai Tribe, Hopi Tribe,
Bureau of Indian Affairs, National Park Service, Arizona Game and
Fish Department, U.S. Fish and Wildlife Service, Western Area Power
Administration, Plains Electric Generation and Transmission Coop,
Inc., Environmental Protection Agency, Environmental Defense Fund,
National Research Council, Upper Colorado River Commission,
Department of the Interior's Office of Environmental Policy and
Compliance, Salt River Project, Colorado River Energy Distributors
Association, Grand Canyon Trust, American Rivers, Sierra Club Legal
Defense Fund, American Fisheries Society, Grand Canyon River Guides,
and Dr. Larry Stevens. Dr. Stevens is considered by many to be the
leading authority on vegetation in the Grand Canyon region. He was a
major contributor of research on both the vegetation and
wildlife/habitat resources for the EIS. We also contacted Mr. David
Marcus, whom Reclamation stated also provided substantive comments on
the draft EIS. However, Mr. Marcus stated that he worked as a
consultant for American Rivers and that he preferred to provide us
with his comments through that organization, not as an individual.
As such, we did not include Mr. Marcus as part of our survey
universe.
We also contacted the three cooperating agencies (Pueblo of Zuni,
Southern Paiute Tribe, and Southern Paiute Consortium) that were not
among the 22 above. Furthermore, the seven Colorado River Basin
states (Arizona, California, Colorado, Nevada, New Mexico, Utah, and
Wyoming) were asked to respond to our survey. In addition, another
five environmental groups with interests in the Glen Canyon Dam area
(Sierra Club, Arizona Flycasters, Friends of the River, America
Outdoors, and Trout Unlimited) were also contacted. We received
responses from 30 of the 37 (81 percent) organizations and
individuals we contacted. The seven nonrespondents did not represent
any particular interest group. Specifics on how the 37 organizations
and individuals responded to our survey are provided in chapter 3 of
this report.
We conducted our work from January 1995 through September 1996 in
accordance with generally accepted government auditing standards.
We provided copies of a draft of this report to the Department of the
Interior for its review and comment. Interior generally agreed with
the information presented in the report and stated that they were
impressed with the quality of the product developed by the audit
team. Interior also provided several technical clarifications to the
draft, which have been incorporated into the report as appropriate.
Interior's comments and our responses are included in appendix XII.
RECLAMATION'S IMPACT
DETERMINATIONS ARE USABLE FOR
DECISION-MAKING
============================================================ Chapter 2
In preparing the Glen Canyon Dam's environmental impact statement,
Reclamation studied the impact of the dam's various flow alternatives
on hydropower, non-use values, and other selected resources located
below the dam. To make these impact determinations, Reclamation used
a variety of methodologies and data sources. Generally, we believe
the methodologies used to be reasonable and appropriate and the data
used to be the best available at the time. Some prominent
economists, however, question the credibility of results obtained
from the methodology Reclamation used to derive non-use values. We
also noted some shortcomings in some of Reclamation's economic
assumptions and its application of certain methodologies. In
addition, we found that some of the data used in the resource
analyses were dated, preliminary, or incomplete. Overall, these
limitations reduce the precision of the estimated impacts contained
in the EIS. In addition, there is general agreement that as a result
of incomplete information, the impact of steady flow alternatives on
fish resources remains uncertain. Nonetheless, our work disclosed no
evidence that these limitations would alter the relative ranking of
the fluctuating and steady flow alternatives. Therefore, we believe
that these limitations are not significant enough to render the final
impact statement unusable to the Secretary of the Interior as a
decision-making document.
Generally, Reclamation and other experts associated with the
development of the Glen Canyon Dam's environmental impact statement
believe that the impact determinations are reasonable. At the same
time, they recognize that there are limitations to the EIS. However,
they believe that these limitations are not significant enough to
make the results unusable. Furthermore, Reclamation recognizes that
many uncertainties still exist. To address these uncertainties,
Reclamation intends to initiate a process of "adaptive management"
that would provide for long-term monitoring and research to measure
the actual effects of the selected alternative. The results of this
effort would form the basis for possible future modifications of the
dam's operations.
METHODOLOGIES USED TO MAKE
IMPACT DETERMINATIONS WERE
GENERALLY REASONABLE
---------------------------------------------------------- Chapter 2:1
We found that, in general, the variety of methodologies and research
techniques used by Reclamation to make impact determinations were
reasonable and appropriate. For most resource assessments,
Reclamation relied on multidisciplinary subteams consisting of
experts representing federal and state governments, tribal interests,
academic and scientific communities, the electric utility industry,
environmental organizations, and the recreation industry. The exact
makeup of each team depended on the resource and the area of concern.
In addition, for each resource, the subteam assessed, either
quantitatively, qualitatively or both, how alternative flows would
affect the resource relative to a No-Action (base case) flow. The
EIS teams generally used state-of-the-art modeling techniques and/or
the latest scientific research to make the impact determinations.
Furthermore, the methods used and results achieved were reviewed by
peers and outside experts, including the Glen Canyon Environmental
Studies Review Team and the National Academy of Sciences.
To conduct the impact analyses of various flows on hydropower,
Reclamation established the Power Resources Committee--a group of
electricity and modeling experts from Reclamation, the Western Area
Power Administration, the electric utility industry, private
contractors, and the environmental community. Using a 50-year
analysis period (1991-2040) and the No-Action Flow alternative
(historic operations) as the base case, the Committee assessed how
various flow alternatives would affect hydropower production and then
projected the subsequent economic costs that would be incurred by
regional utilities and end-users to replace the dam's forgone power
production. The Committee considered the fixed costs associated with
the existing generating capacity in the region to be "sunk" costs
and, hence, excluded them from the economic cost calculations. The
Committee also used two state-of-the-art modeling techniques and
detailed utility-specific data to quantify the economic impacts. In
addition, the Committee used sensitivity analysis to test the impact
of changes in key economic assumptions. The results of the power
study were then incorporated into the draft EIS for public comment.
The Committee solicited and received an independent review of the
power study from three energy experts. On the basis of the comments
received from the public and outside experts, the Committee partially
revised its initial power study. For example, the Committee updated
the projected costs of building gas-combustion powerplants, revised
its retail rate analysis, and conducted additional sensitivity
analyses. The results of both power studies were incorporated into
the final EIS. (See app. V for details on the results of the power
study.)
For fish resources, numerous public comments were received by
Reclamation expressing concern about the impact determinations
presented in the draft EIS. To respond to these concerns,
Reclamation formed an Aquatic Biology Team workgroup. This work
group consisted of EIS team members representing Reclamation, the
U.S. Fish and Wildlife Service, the Arizona Game and Fish
Department, and two Indian tribes. The workgroup was tasked to
respond to comments and to reorganize and rewrite the fish section of
the final EIS. Individual workgroup members were given specific
assignments, interactive discussions were held, and decisions were
made through consensus. As a result of this effort, several major
changes were made to the final EIS, including more explicit
recognition of the uncertainty and disagreement that exist among
scientists about the response of fish to the steady flow
alternatives. (See app. IV for details on the results of the fish
impact determinations.)
To assess the impact of various flow alternatives on water and
sediment, Reclamation's EIS team used the Colorado River Simulation
System (CRSS) to project the long-term (50 years) and short-term (20
years) impacts on annual and monthly streamflows, floodflows and
other water spills, water storage, water allocation deliveries, and
Upper Colorado River Basin yields. CRSS is a package of computer
programs and databases designed to assist water resource managers in
performing comprehensive long-range planning and operations studies
that arise from proposed changes in the Colorado River's operations,
proposed development of the Colorado River Basin, or changes in
present water use throughout the basin. The development of CRSS took
place over a 10-year period and stemmed from the need for a
comprehensive model of the Colorado River Basin that would
incorporate all areas of interest, including legislative
requirements. According to Reclamation and other experts, CRSS is
the most comprehensive and detailed simulation of the Colorado River
system that exists. (See app. VIII and app. X for details on the
results of the sediment and water analyses, respectively.)
To quantify the economic impact of the dam's various flow
alternatives on non-use values and recreation, Reclamation primarily
relied on a methodology called contingent valuation. Social
scientists and economists have long acknowledged the existence of
non-use values--the monetary value placed on the status of the
environment by people who never visit or otherwise use these
features. Contingent valuation relies on public surveys to elicit
information from consumers and estimate how much they would be
willing to pay for a non-use good. For valuing most goods and
services, economists are able to rely on people's actual purchases of
goods in markets. However, by definition people do not purchase
non-use goods, and some prominent economists question whether the
contingent valuation method can accurately elicit the values
consumers place on non-use goods. For example, Peter A. Diamond and
Jerry A. Hausman state, "We believe that contingent valuation is a
deeply flawed methodology for measuring non-use values, one that does
not estimate what its proponents claim to be estimating."\1 Still
many economists and survey researchers working in the natural
resource and environmental areas have developed and used this
methodology, and it is currently the only known approach for
estimating non-use values. (See app. VI for details on the results
of the non-use value study.) Economists generally have fewer
questions about the application of the contingent valuation
methodology in measuring the value of goods and services that
consumers actually purchase. Therefore, there are fewer questions
about the usefulness of this approach for measuring the values
associated with recreational activities. (See app. VII for details
on the results of the recreation studies.)
--------------------
\1 Peter A. Diamond and Jerry A. Hausman, "Contingent Valuation:
Is Some Number Better than No Number?" Journal of Economic
Perspectives, 8(4), Fall 1994, pp. 45-64. (quotation on p. 62).
SHORTCOMINGS NOTED IN
RECLAMATION'S ECONOMIC
ASSUMPTIONS AND
IMPLEMENTATION OF CERTAIN
METHODOLOGIES
-------------------------------------------------------- Chapter 2:1.1
In light of the results of our work and the opinions of the experts
we contacted, we believe the methodologies used by Reclamation and
its EIS teams to make impact determinations were generally
reasonable. We did note, however, some shortcomings in the economic
assumptions used in the hydropower analysis and in Reclamation's
implementation of certain methodologies. Specifically, in the
hydropower analysis, the assumptions used do not explicitly include
the mitigating effect that higher electricity prices would have in
reducing the demand for electricity (that is, price elasticity). For
example, the Power Resources Committee assumed that both the demand
for and price of electricity would continue to rise over the planning
period. However, we believe the rise in the price of electricity
would likely induce some electricity consumers (both wholesalers and
end-users) to consume less electricity or switch to cheaper
alternative suppliers, which is not taken into account in the
analysis. Consequently, fewer resources would be needed to replace
forgone power at the Glen Canyon Dam, and the subsequent economic
impacts would be lower than estimated (all else being the same).
In addition, the Committee's assumptions about future natural gas
prices are relatively high. The Committee assumed that the average
gas price would increase annually by 8 percent from 1991 through
2010. In 1994, industry forecasters projected that the price of
natural gas would increase by about 6 percent for the same time
period, and in 1995, forecasts assumed that prices will rise by only
5 percent. The higher escalation rates could affect the power
analysis by overstating the economic cost of replacing the Glen
Canyon Dam's power.
We also found that Reclamation's staff made two computational errors
during the revision of the initial power analysis. The Power
Resources Committee acknowledged these errors in its final report and
stated that the errors affected the results in opposite directions,
that is, one error may have overstated costs while the other error
may have understated costs. The Committee was unable to correct the
errors in the report because of time and funding constraints.
These shortcomings, combined with the inherent uncertainty in making
economic forecasts, reduce the precision of the estimated economic
impacts. However, an association that represents the affected power
utilities, while maintaining that the costs to the power system are
understated, does not believe that Reclamation's analysis is
inaccurate by a large magnitude. Furthermore, because these
shortcomings affect the estimated economic impact of all alternatives
equally, we believe that addressing these shortcomings would not
alter the relative ranking of the fluctuating and steady flow
alternatives.
Although we believe the recreation impacts methodology is generally
reasonable, we noted several limitations. For example, the survey
data used as the basis of the analysis were gathered during an
unusually high-water year; therefore, some respondents may not have
actually experienced how various alternative flows would have
affected their recreational experience, which is what they were being
asked to value. In addition, the survey was designed well before the
flow alternatives to be studied in the Glen Canyon Dam's EIS were
finalized. As a result, the survey scenarios do not systematically
correspond to the flow alternatives presented in the EIS. Finally,
although researchers tested proposed questions to determine which
ones offered the highest response rate, they did not adequately
pretest some survey instruments to detect wording, construction, and
presentation defects or other inadequacies. Because the recreation
economic model used the results of these survey instruments as a
basis for the analysis, the estimated dollar value of the benefits
may not be very precise. Reclamation and National Park Service
officials involved in the process acknowledged that the recreation
analysis has limitations but stated that these limitations would not
affect the ranking of the alternatives. They also noted that the
estimated recreation benefits identified by this research were not a
key element in the selection of the preferred alternative.
In addition to the shortcomings in the hydropower and recreation
analyses, we also noted that there was no formal opportunity for
affected parties as well as the general public to offer comments on
the Glen Canyon non-use value study. Although the final EIS notes
that the non-use value is positive and significant, the actual
quantified results are not included in the final EIS. Reclamation
did not include the non-use value study results because they were not
available when the final EIS was published. The non-use study was
completed as a separate Glen Canyon Environmental Studies report and,
according to Reclamation, will be attached to the Record of Decision
package sent to the Secretary of the Interior. In that way, it will
become part of the final decision-making process. Reclamation noted
that although the non-use study did not go through the public comment
process, the study team solicited and received peer review at various
key decision points and that the final results of the non-use value
study received a positive review by the National Academy of Sciences
and the Office of Management and Budget. Reclamation also noted that
interests likely to be affected by any changes in the operations of
the Glen Canyon Dam, such as power groups and environmental groups,
were involved in the non-use value study process. In addition, there
were scoping sessions and focus groups that were derived from members
of the general public. The results of these sessions were used to
assist in the development of the content of the survey and the
relevant issues to be addressed.
DATA USED IN IMPACT
DETERMINATIONS WERE THE BEST
AVAILABLE
---------------------------------------------------------- Chapter 2:2
Reclamation's National Environmental Policy Act Handbook requires
that all EIS analyses be based on the best reasonably obtainable
scientific information. According to Reclamation and other experts
who developed the Glen Canyon Dam's environmental impact statement,
the data used to make the impact determinations were the best
available at the time. For example, for the impact of various flow
alternatives on nonfish endangered species, one researcher said the
terrestrial and bird-related research used as a basis for making
impact determinations was "top notch." Another researcher who worked
on endangered species stated that when they were clarifying
information or needed data to fill gaps, the EIS team contacted
researchers directly to get the latest available data. For
information on cultural resources and properties, members of that
resource team believe that Reclamation went beyond federal
requirements for the development of an impact statement by performing
assessments of all previously identified archeological sites within
the Colorado River corridor in the Glen and Grand canyons. According
to many experts, when completed, this effort generated the best and
most current scientific information available.
For some resources, we found that although the data were the best
available, they had limitations. Some of the data used in making the
impact determinations were dated, preliminary, or incomplete. For
example, Reclamation used survey data collected in 1985 to assess the
economic impact of alternative dam flows on recreational activities.
Reclamation's contractor surveyed a sample of anglers, day-rafters,
and white-water boaters about their recreational experiences on the
Colorado River and what effect, if any, different streamflows would
have on their recreational experiences. However, because the survey
was undertaken in 1985, it may not represent more recent trends in
recreational experiences. For example, the number of angling trips
on the Colorado River more than doubled between 1985 and 1991 (the
base year used by Reclamation in preparing the draft EIS), which may
influence the value of each trip. Reclamation updated some of the
data to 1991 but acknowledges that the survey data were generally
dated. Reclamation stated, however, that the recreation analysis was
adequate to present a good picture of the potential impact of
alternative flows on various recreational experiences and that
because of the limited impact of alternative flows on recreation,
limited research funds could be better used to improve other
analyses. The National Research Council generally found the
recreation analysis to be adequate.
In addition, the estimated non-use values for the steady flow
alternatives could be overstated because of new information that was
not available at the time the survey instruments were developed. The
non-use value surveys described the environmental impacts based on
information that was the best available at the time. This
information indicated that improvements would be obtained for fish
resources under fluctuating and steady flow alternatives. However,
after the development of the survey instruments, the fish section of
the EIS was revised to recognize the uncertainty that exists about
the impact of steady flow alternatives. To the extent that the
non-use value surveys did not capture this degree of uncertainty, the
precision of the non-use value estimates could be reduced.
Many of the results of the Glen Canyon sediment studies were
preliminary, in draft form, and had not been published at the time
that the draft impact statement or the final impact statement was
written. In addition, in some cases definitive information on the
impact of a specific flow alternative was not available. Therefore,
the EIS team had to extrapolate from the existing data using their
professional judgment to estimate the potential impact of a specific
alternative. The EIS team told us that they always verified the
reasonableness of their conclusions and extrapolations with the
researchers. However, they believed that if finalized data had been
available, the reasons for the selection of the preferred alternative
would have been more clearly supported. These researchers added that
no new or additional information on sediment impacts has been
obtained that would alter the information or conclusions presented in
the final impact statement.
Finally, information on some resources is incomplete, as is the
knowledge of how changes in the Glen Canyon Dam's operations will
affect those resources. For example, the experts' opinions vary, in
part because of incomplete data, on how native and nonnative fish
interact and how changes to the dam's operations would affect these
interactions. Many researchers and EIS team members we interviewed
expressed regret about the lack of coordinated time frames between
the completion of the Glen Canyon Environmental Studies and the
development of the Glen Canyon Dam EIS. The leader of the workgroup
responsible for developing the EIS impact determinations for fish
stated that this difference in time frames was especially problematic
when the preferred alternative was selected. At that point,
decisions had to be made, but data and analyses were not complete.
Reclamation explicitly acknowledges the uncertainty that exists about
the impact of the steady flow alternatives on fish resources in the
final EIS. In its final biological opinion, the U.S. Fish and
Wildlife Service stated that Reclamation's preferred alternative is
likely to jeopardize the existence of two native endangered fish
species (the humpback chub and the razorback sucker). In general,
the biological opinion's "reasonable and prudent alternative" would
modify the preferred alternative by including seasonally adjusted
steady flows. The U.S. Fish and Wildlife Service and Reclamation
have agreed to categorize these flows as experimental and include
them as part of the Adaptive Management Program.
THE RESULTS OF THE GLEN CANYON
DAM'S EIS ARE GENERALLY
REASONABLE, BUT FUTURE STUDIES
WILL BE NEEDED
---------------------------------------------------------- Chapter 2:3
Reclamation and other experts associated with the development of the
Glen Canyon Dam's EIS generally believe that the impact
determinations presented in the final EIS are reasonable. (A summary
of Reclamation's comparison of alternatives and impacts is presented
in app. XI of this report.) They recognize that there are
limitations to the results, but they believe that these limitations
are not significant enough to make the impact determinations unusable
for the Secretary's decision-making. For example, one EIS team
member stressed that in the process of scientific decision-making and
economic forecasting, complete and certain information is never
available. Furthermore, Reclamation noted that the Congress had
mandated that the final EIS be issued within a certain time frame;
therefore, decisions had to be made on the basis of the best
information available at the time.
Reclamation recognizes that uncertainties still exist about the
impact of the various flow alternatives on resources. To address
these uncertainties, Reclamation intends to initiate a process of
"adaptive management."
IMPACT DETERMINATIONS IN THE
GLEN CANYON DAM'S EIS ARE
GENERALLY REASONABLE
-------------------------------------------------------- Chapter 2:3.1
We discussed the results of the impact determinations for each
resource with Reclamation and other experts involved in the
development of the Glen Canyon Dam's EIS. Although these individuals
recognized that there were some shortcomings in the analyses, they
generally agreed that the results of the impact determinations as
presented in the Glen Canyon Dam's final EIS were reasonable. For
example, although some researchers described the model used (the
sand-mass balance model) to determine the impact of various flows on
sediment as "simplistic" compared with models that are currently
being developed by U.S. Geological Survey researchers, none of the
preliminary results from the new models contradict the conclusions
reached by the sand-mass balance model. Another researcher who
worked on the vegetation and wildlife resources told us that although
the EIS may have been based on incomplete information, subsequent
science supports it. The researcher further added that the results
of the EIS were right on track with the best scientific evidence
available at the time.
The results of some impacts, however, such as how steady flows will
affect fish, are still uncertain. The individual responsible for
leading the fish impact determinations process stated that the lack
of final results from the fish research studies was frustrating and
that the limited data allowed differences of opinion and scientific
interpretation to arise about the impacts on fish resources.
However, he added that he believed that if final data had been
available, they would have refined the EIS team's conclusions but
would not have changed the impact determinations or the preferred
alternative.
Although there is general agreement that the results of the Glen
Canyon Dam's EIS are reasonable, there is also general agreement that
additional research is needed to further refine or, in the case of
fish resources, define the impact on resources of changes to the
dam's operations. For example, impacts to some archeological and
cultural properties are bound to occur regardless of the flow
alternative chosen. To avoid or minimize the loss of historic
properties and comply with the requirements of the National Historic
Preservation Act, Reclamation developed a programmatic agreement
between federal and state agencies as well as affected Native
American tribes. Implemented in 1994, the agreement led to numerous
monitoring trips and site-stabilization efforts, but all parties
involved believe that more research is needed to understand how water
flow affects cultural resources. Furthermore, several sediment
researchers we interviewed stated that they supported the impact
determinations and the preferred alternative. However, one stated
that as more information is obtained about the various systems in the
canyon, the preferred alternative may become less restrictive in
terms of the allowed water releases for hydropower use.
RECLAMATION'S PROPOSED
ADAPTIVE MANAGEMENT PROGRAM
-------------------------------------------------------- Chapter 2:3.2
Reclamation recognizes that uncertainties exist about the downstream
impacts of water releases from the Glen Canyon Dam. To address these
uncertainties, Reclamation plans to initiate an Adaptive Management
Program. The concept of adaptive management is based on the
recognized need for ongoing operational flexibility to respond to
future monitoring and research findings and varying resource
conditions. The objective of the Adaptive Management Program is to
establish and implement long-term monitoring programs that will
ensure that the Glen Canyon Dam is operated, consistent with existing
law, in a manner that will protect, mitigate adverse impacts to, and
improve the values for which the Glen Canyon National Recreational
Area and the Grand Canyon National Park were established. According
to Reclamation, long-term monitoring and research are essential to
adaptive management. Reclamation believes that such an effort is
needed to measure the performance of any selected EIS alternative.
In this way, managers can determine whether the alternative is
actually meeting resource management objectives and obtain an
additional understanding of the resources' responses to the dam's
operations.
Under Reclamation's current proposal, the Adaptive Management
Program, which would be under the direction of the Secretary of the
Interior, would be facilitated through an Adaptive Management Work
Group. The Adaptive Management Work Group, chartered under the
Federal Advisory Committee Act, would include representatives from
each of the EIS cooperating agencies, the basin states,\2 contractors
for the purchase of federal power, recreation interests, and
environmental organizations. The work group would:
-- develop proposals for (1) modifying the operating criteria,
(2)research under the long-term monitoring program, and (3)
other mitigation actions as appropriate and
-- facilitate technical coordination and input from interested
parties.
The Adaptive Management Work Group would be supported by a monitoring
and research center and a technical work group. The Monitoring and
Research Center would manage and coordinate monitoring activities,
research, and inventory programs and maintain a scientific
information database. The technical work group would include
technical representatives from federal, state, and tribal governments
and their contractors. This work group would translate the policy
and goals of the Adaptive Management Work Group into resource
management objectives and establish criteria and standards for
long-term monitoring and research. The independent scientific review
panel would include scientific experts not otherwise participating in
the long-term monitoring and research studies. The responsibilities
of this review panel would include reviewing scientific study plans,
resource reports, and scientific logic and protocols.
--------------------
\2 The basin states consist of Arizona, California, Colorado, Nevada,
New Mexico, Utah, and Wyoming.
MOST KEY INTERESTED PARTIES
SUPPORT RECLAMATION'S PREFERRED
ALTERNATIVE FOR THE DAM'S
OPERATIONS, BUT SOME CONCERNS
REMAIN
============================================================ Chapter 3
Since December 1982, Reclamation has been studying the effects of the
Glen Canyon Dam on various resources within the Glen and the Grand
canyons. According to Reclamation, during this 14-year period, over
$75 million was spent initially on the Glen Canyon Environmental
Studies and then on the Glen Canyon Dam's EIS. This research and
analysis was aimed at providing sufficient information to recommend
an operating plan for the dam that would permit the recovery of
downstream resources while maintaining some level of hydropower
flexibility. Still, after all this time and money, the process of
selecting a preferred alternative involved not only scientific
evidence but also trade-offs and compromise. This occurred because
no one alternative could maximize benefits to all resources and
because the impacts of some of the flow alternatives remain
uncertain. Nevertheless, over 83 percent of the key interested
parties who responded to our survey support Reclamation's preferred
alternative as a good starting point for the future operations of the
Glen Canyon Dam. In addition, many respondents supported the process
used to develop the Glen Canyon Dam's EIS. However, while expressing
their support, some organizations still had concerns about the final
EIS.
RECLAMATION'S PROCESS FOR
SELECTING A PREFERRED
ALTERNATIVE
---------------------------------------------------------- Chapter 3:1
The selection of a preferred alternative for the future operation of
the Glen Canyon Dam involved a repetitive sequence of comparisons of
the effects that each of the nine flow alternatives would have on the
11 resources studied in the EIS. All resources were evaluated in
terms of whether each flow alternative had a positive or an adverse
effect. Reclamation's goal was to find an alternative dam-operating
plan that would permit downstream resources to be maintained and if
possible recover to acceptable long-term management levels while
maintaining some flexibility in hydroelectric power capability. The
EIS team, which included up to 25 individuals representing 11 of the
cooperating agencies, the U.S. Geological Survey, and a private
consultant, was primarily responsible for initially recommending a
preferred alternative to the cooperating agencies. This team, which
also had been responsible for the scientific and technical
development of the resource impact determinations, realized very
early in the process that they would have to make trade-offs in the
selection of a preferred alternative. None of the alternatives could
maximize potential benefits to all of the resources. The Grand
Canyon Trust environmental organization told us that
"The Glen Canyon Dam EIS was a lengthy, complex process with
many individuals and interests involved. It is safe to say that
the preferred alternative will not completely satisfy any one
group, however it represents a balance of interests and a
reasonable starting point for future dam operations."
Another factor that the EIS team considered was that some affected
resources were renewable, while others were viewed as nonrenewable.
They avoided recommending an alternative dam-operating procedure that
would result in significant loss of any existing nonrenewable
resource and tried to minimize the adverse impacts to most renewable
resources. They eliminated the No-Action, Maximum Powerplant
Capacity, and High Fluctuating Flow alternatives from consideration
as a preferred alternative because the data indicated that while
these alternatives were beneficial to hydropower, they would either
increase or maintain conditions that result in adverse impacts to
nonrenewable downstream resources.
The EIS team also eliminated the Year-Round Steady Flow alternative
from consideration as the preferred alternative. This alternative
exhibited the highest probability for net gain in riverbed sand, had
the largest potential for expanding riparian vegetation, and received
the highest ranking among all alternatives for white-water boating
safety benefits. However, the EIS team believed that the alternative
probably exceeded sediment protection requirements for long-term
management and would result in the lowest-elevation sandbars. The
team was also concerned that a completely stable flow alternative
would permit vegetation to adversely affect camping beaches and over
time reduce the value of wildlife habitat. In addition, a stable
flow may increase the negative interaction between native fish and
predator and competitor nonnative fish. Finally, the team eliminated
this alternative because they believed that it did not provide
benefits that could not be provided by other alternatives, yet it
would cause large adverse effects to hydroelectric power generation.
Of the remaining alternatives, the Existing Monthly Volume Steady
Flow alternative was eliminated for reasons similar to those
discussed for the Year-Round Steady Flow alternative. The Low
Fluctuating Flow alternative was eliminated to reduce
redundancy--Reclamation considered the Modified Low Fluctuating Flow
alternative an improved version of the Low Fluctuating Flow
alternative.
The EIS team considered the impacts associated with the three
remaining alternatives (Moderate Fluctuating Flow, Modified Low
Fluctuating Flow, and Seasonally Adjusted Steady Flow), although they
were substantially different from the effect of the No-Action
alternative, to be very similar in their assumed benefits to most
downstream resources. Reclamation's former NEPA Manager for the Glen
Canyon Dam's EIS advised us that from an ecosystem perspective,
sediment was identified as the key resource in the selection of a
preferred alternative. Riverbed sand and sandbars were the sediment
resources of primary interest affected by riverflows below the dam.
For sandbars to exist, sufficient amounts of sand must be stored on
the riverbed. Because the dam traps 90 percent of the sediment, the
sand supply is currently limited to whatever is contributed by
downstream tributaries and hundreds of side canyons. Of equal
concern is the river's capacity to transport sediment. Riverflows
must be large enough to move and deposit sediment but not so large as
to carry the sediment out of the canyon ecosystem. Frequent high
flows, either from floods or large daily fluctuations, can transport
greater amounts of sand than are contributed, causing a net decrease
in both the amount of stored riverbed sand and the size of sandbars.
Water release patterns modify the natural process of sandbar
deposition and erosion. Rapid drops in the level of the river drain
groundwater from sandbars, thus accelerating sandbar erosion. The
EIS team concluded that any of these three alternatives were very
similar in their assumed benefits to most downstream resources.
The effects on native fish did, however, vary among the three
remaining alternatives. The Moderate Fluctuating Flow alternative
provides potential minor benefits to native fish over no-action
conditions. The benefits from the Seasonally Adjusted Steady Flow
alternative were uncertain given the improvement in habitat
conditions that this alternative would provide for predator and
competitor nonnative fish. The team also determined that seasonally
adjusted steady flows would create conditions significantly different
from those under which the current aquatic ecosystem had developed
since the construction of the dam. Finally, for hydropower, the team
determined that the Seasonally Adjusted Steady Flow alternative would
have the highest economic cost of any alternative, estimated at about
$124 million annually. Ultimately, the EIS team decided to recommend
the Modified Low Fluctuating Flow for the preferred alternative in
the draft EIS. The members believed that this alternative would
create conditions that permit the recovery of downstream resources to
acceptable management levels while maintaining a level of
hydroelectric power flexibility. The EIS team presented this
recommendation to the cooperating agencies. Most cooperating
agencies concurred, and the group recommended that this alternative
be adopted by Reclamation. The draft EIS was issued by Reclamation
in January 1994 with the Modified Low Fluctuating Flow identified as
the preferred alternative.
After the draft EIS was provided for public comment but before the
issuance of the final EIS, Reclamation changed two parameters of the
preferred alternative. Specifically, the draft EIS' preferred
alternative had a maximum release level of 20,000 cfs and a maximum
upramp rate of 2,500 cfs per hour. In the final EIS, Reclamation
modified the preferred alternative to provide a maximum release level
of 25,000 cfs and a maximum upramp rate of 4,000 cfs per hour. The
primary reason for these changes was to benefit hydropower. The
preferred alternative presented in the draft EIS had the same maximum
release rate and upramp rate as the interim operating criteria.
Reclamation stated that the interim operating criteria were based on
the results of phase I of the Glen Canyon Environmental Studies and
professional judgment and were designed to be environmentally
conservative over the interim period. With the benefit of the
additional phase II results of the Glen Canyon Environmental Studies
and EIS impact analyses, Reclamation stated that the upramp rate and
maximum flow criteria were found to be overly conservative for the
long term and that the two changes would not cause adverse impacts to
downstream resources. As a result, with the concurrence of the
cooperating agencies, the preferred alternative was modified in the
final EIS.
In July 1995, Reclamation issued a document entitled Flow
Modifications to the Glen Canyon Dam Environmental Impact Statement
Preferred Alternative. Those who commented on that document
expressed concern that no studies on the specific upramp and maximum
flow criteria had been conducted. In October 1995, Reclamation
issued a new report entitled Assessment of Changes to the Glen Canyon
Dam Environmental Impact Statement Preferred Alternative from Draft
to Final EIS. This report provided a more detailed and focused
assessment of the impacts associated with the increased upramp rate
and maximum flow criteria. While acknowledging that no new studies
were conducted, Reclamation pointed out that the same was true for
the parameters of the interim flows when they were selected and
implemented. Furthermore, Reclamation stated it was possible to
determine the effects of these changes by using the extensive amount
of knowledge gained from both phase I and phase II of the Glen Canyon
Environmental Studies. Reclamation concluded that the analyses were
fully adequate to justify the change.
SUPPORT FOR PREFERRED
ALTERNATIVE IS SIGNIFICANT
---------------------------------------------------------- Chapter 3:2
The respondents to our survey of key parties interested in the Glen
Canyon Dam's EIS overwhelmingly supported Reclamation's preferred
alternative--the Modified Low Fluctuating Flow operating regime. We
surveyed 37 key organizations and individuals about whether they
support the preferred alternative and what, if any, remaining
concerns they may have about implementing this alternative as the
future operating plan for the Glen Canyon Dam. Our judgmental sample
included federal and state resource agencies, American Indian tribes,
water and power suppliers and users, and environmental groups.
Specifically, Reclamation identified 23 of these organizations and
individuals as providing the most substantive comments on the draft
EIS. We excluded David Marcus from our survey analysis because he
had commented on the draft EIS as a consultant to American Rivers and
preferred to provide us with his comments through that organization.
In addition, we surveyed any other organizations that were considered
to be cooperating agencies in the development of the impact statement
as well as other key interested parties. We also queried the seven
Colorado River Basin states: Arizona, California, Colorado, Nevada,
New Mexico, Utah, and Wyoming.
Over 83 percent (25 of 30) of the respondents to our survey supported
the preferred alternative. Of the five remaining respondents, three
organizations stated that they had no position on the issue, while
two, the San Juan Southern Paiute Tribe and the Grand Canyon River
Guides, believe that the current interim flows would be more
protective of resources and, as such, consistent with the intent of
the Grand Canyon Protection Act. Table 3.1 provides details on whom
we surveyed and their response, if any.
Table 3.1
Key Interested Parties' Responses on
Support of the Preferred Alternative
Support preferred Other alternative
Respondents alternative supported
------------------------- ------------------------- --------------------------
Federal agencies
--------------------------------------------------------------------------------
U.S. Fish and Wildlife Yes Modified Low Fluctuating
Service Flow as modified by the
reasonable and prudent
alternative
Environmental Protection Yes None
Agency
National Park Service Yes None
Department of the No position
Interior -Office of
Environmental Policy and
Compliance
Bureau of Indian Affairs Yes Interim Low Fluctuating
Flow and Seasonally
Adjusted Steady Flow
National Research Council Nonrespondent
Western Area Power Yes None
Administration
State agencies
Arizona Game and Fish Yes None
Department
Colorado River Board of No position
California
Colorado River Commission Nonrespondent
of Nevada
Arizona Department of Yes None
Water Resources
New Mexico Interstate Yes Modified Low Fluctuating
Stream Commission Flow as modified by
adaptive management
Colorado Department of No position
Natural Resources
Utah Division of Water Yes None
Resources
Wyoming State Engineer's Yes None
Office
Indian tribes
Hopi Tribe Yes None
Hualapai Tribe Nonrespondent
Navajo Nation Yes None
San Juan Southern Paiute No Interim Low Fluctuating
Tribe Flow
Pueblo of Zuni Yes None
Southern Paiute Yes None
Consortium
Water and power
suppliers, users,
associations, etc.
Colorado River Energy Yes None
Distributors Association
Plains Electric Nonrespondent
Generation and
Transmission Coop, Inc.
Salt River Project Yes None
Upper Colorado River Yes Modified Low Fluctuating
Commission Flow as modified by
adaptive management
Interest groups
America Outdoors Yes Seasonally Adjusted Steady
Flow
American Fisheries Nonrespondent
Society
Arizona Flycasters Nonrespondent
American Rivers Yes None
Environmental Defense Yes None
Fund
Trout Unlimited (Arizona Yes None
Council)
Friends of the River Nonrespondent
Grand Canyon River Guides No Interim Low Fluctuating
Flow
Grand Canyon Trust Yes None
Sierra Club Legal Defense Yes None
Fund
Sierra Club Yes None
Individual
Dr. Larry Stevens Yes None
--------------------------------------------------------------------------------
RESPONDENTS ALSO SUPPORT
RECLAMATION'S EIS PROCESS
---------------------------------------------------------- Chapter 3:3
Many respondents to our survey supported the process used by
Reclamation to complete the EIS. In fact, many respondents commended
Reclamation for its efforts to produce a comprehensive EIS. For
example, the National Park Service stated that the EIS process was
directed very well by Reclamation and that alternatives for the
operation of the dam were fully explored. American Rivers, an
environmental interest group, stated that the EIS is a high-quality
document that reflects a process that was exemplary in its scope,
thoroughness, and overall achievement. The Grand Canyon Trust stated
that the EIS represents a significant and productive effort to
understand the complexities of the river's ecosystem below Glen
Canyon Dam and to include broad participation by the public and
parties vitally interested in the issue. They further stated that in
addition to increasing the scientific understanding of the Colorado
River system, a great deal of trust and good faith were created
between traditionally contentious interest groups. The Navajo Nation
stated that overall, they were very pleased with the EIS process,
citing that Native American concerns were taken into account by
Reclamation and that the affected tribes had real input into the
development of the EIS.
SEVERAL CONCERNS REMAIN ABOUT
THE IMPLEMENTATION OF THE DAM'S
NEW OPERATING PROCEDURES
---------------------------------------------------------- Chapter 3:4
While respondents to our survey were generally positive about the
selection of a preferred alternative and the process used by
Reclamation to develop the EIS, some were still concerned about the
preferred alternative and the Glen Canyon Dam's final environmental
impact statement. These concerns focus on the manner in which
compliance with the Endangered Species Act will be achieved, the
economic impact of reducing the Glen Canyon Dam's hydroelectric power
capacity, the lack of consideration in the EIS of other causes of
downstream adverse impacts other than water releases from Glen Canyon
Dam, the simultaneous changing of two of the dam's operating
parameters very late in the EIS process, the adequacy of the flood
frequency reduction measures, the need for selective withdrawal
structures, and issues related to adaptive management, including
future research and monitoring.
The U.S. Fish and Wildlife Service supports the preferred
alternative as modified by its reasonable and prudent alternative.
FWS's biological opinion expressed concern that the preferred
alternative recommended flows would likely jeopardize the continued
existence of two endangered species, the humpback chub and the
razorback sucker. The biological opinion's reasonable and prudent
alternative would modify the preferred alternative with seasonally
adjusted steady flows about 25 percent of the time. FWS and
Reclamation agreed to categorize these flows as experimental, or
research flows, so that studies could be conducted to verify an
effective dam-operating plan and to include those flows with another
element of the reasonable and prudent alternative, adaptive
management. However, there are concerns on the part of the Colorado
River Energy Distributors Association, which represents over 140
nonprofit utilities that purchase power from the Western Area Power
Administration (WAPA), that the implementation of endangered fish
research flows will proceed regardless of the outcome of the Adaptive
Management Program. The association strongly supports the EIS
preferred alternative as a reasonable point to begin modified dam
operations and adaptive management. However, the association also
believes that an important part of the adaptive management process is
that if an analysis of a research proposal indicates an inappropriate
risk to the endangered fish or other resource, the Secretary could
decide not to pursue this element of the preferred alternative. As
such, the association objects to the language in the final EIS and
the final biological opinion that indicates that the research flows
will go forward regardless of the outcome of the adaptive management
research design and risk assessment.
The Colorado River Energy Distributors Association and the Salt River
Project, an agricultural improvement district that provides
electrical service to various counties in the state of Arizona, are
concerned that the economic cost of reducing the hydroelectric power
capacity of the Glen Canyon Dam is understated in the EIS. Both the
association and the Salt River Project believe that the preferred
alternative does not adequately address the economic cost to power
users of research flows. In addition, the Salt River Project
believes that the EIS does not analyze the full economic impact of
the preferred alternative on Salt River and its customers and on WAPA
and its customers, resulting from WAPA's being unable to fulfill its
obligations under an exchange agreement. The exchange agreement
obligated Salt River to build and operate power generation facilities
near customers in Colorado and New Mexico and to deliver the power
produced by those facilities to WAPA to serve those customers. In
exchange, WAPA was obligated to deliver a like amount of power to the
Salt River Project from the Glen Canyon Dam.
WAPA stated that the EIS assumes that the dam's operations (water
releases) are the only cause of the adverse impacts on the downstream
resources and that, therefore, changing the dam's operations is the
only technique or method available for managing and enhancing those
resources. WAPA believes that other causes of downstream impacts
include lack of sediment, cold water temperatures, nonnative fish
species, and human usage. Accordingly, they believe that changing
the operations at Glen Canyon Dam is not the only, or necessarily the
best or lowest-cost, means of achieving positive resource changes.
WAPA believes that a more holistic approach to the management of the
downstream resources should be taken and supports the investigation
of both operational and nonoperational management techniques,
practices, and programs. Although WAPA supports the preferred
alternative, it stated that the concepts of pumping sand, protecting
beaches with native materials, augmenting sediment, managing
vegetation, restricting human use, restricting raft moorings,
reducing the competition for native fish, developing new tributary
habitats for native fish, and using a reregulation dam (build another
dam below the Glen Canyon Dam to regulate river flow) are all valid
management techniques that merit detailed investigation and
consideration.
Several environmental and recreational organizations, although
supporting the preferred alternative, were concerned that Reclamation
changed certain parameters of the preferred alternative very late in
the EIS process. Specifically, the draft EIS' preferred alternative
had a maximum release level of 20,000 cfs and a maximum rate of
increase (upramp rate) of 2,500 cfs per hour. In the final EIS,
Reclamation modified the preferred alternative to allow for a maximum
release level of 25,000 cfs and a maximum upramp rate of 4,000 cfs
per hour. Two basic concerns exist about this change: (1) the
higher parameters were substituted in the final EIS without adequate
scientific evidence that such flows would not negatively affect the
downstream resources of the Glen and Grand canyons and (2) two
parameters were changed simultaneously, which could compromise the
ability to scientifically monitor and assess the future impacts of
these flow parameters in the proposed adaptive management framework.
Reclamation believes that it has adequately addressed both of these
concerns by conducting an assessment of the proposed changes. Some
agencies, including the Wyoming State Engineer's Office, America
Outdoors, American Rivers, and the Sierra Club Legal Defense Fund
still believe that adequate specific scientific testing was not done
to fully evaluate the effect of changing these flow parameters.
However, these groups still support the preferred alternative at this
time because of Reclamation's proposed Adaptive Management Program.
The New Mexico Interstate Stream Commission believes that the
spillway gates on the Glen Canyon Dam must be increased in height by
about 4.5 feet to add the flexibility to accomplish flood protection
without reducing the water supply available to the Upper Colorado
Basin. The Commission, which supports the preferred alternative,
also believes that the selective withdrawal outlet proposal for Glen
Canyon Dam has not been adequately justified; the estimated cost of
$60 million needs to be arrayed against the resulting benefits; and
an assessment needs to be made of the potential adverse impacts
associated with increasing water temperature.
Future monitoring and research efforts were a concern of several
groups, including federal agencies, Native American tribes, and an
environmental group. For example, American Rivers urged Reclamation
to do everything in its power to ensure that an effective Adaptive
Management Program be in place or sufficiently delineated in scope
and substance and that a specific long-term monitoring program be
identified that will quantify any impacts before the proposed flow
changes are implemented.
AIR QUALITY
=========================================================== Appendix I
In the Glen Canyon Dam's environmental impact statement (EIS), air
quality is identified as an issue for both the immediate vicinity of
the Grand Canyon and the surrounding six-state area, including parts
or all of Utah, Wyoming, Colorado, Arizona, New Mexico, and Nevada.
The power needs of this area are served by the Salt Lake City Area
Integrated Projects, a group of power generation facilities that
include the Glen Canyon Dam. Although the Glen Canyon Dam's
hydroelectric powerplant does not cause air pollution, a change in
its operations would affect the regional electrical power system.
The Glen Canyon Dam has historically been used to generate power
during periods of high demand for electricity, commonly known as
peaking power. The loss or reduction of that capability would mean
that another source of peaking power would be required. If that
alternative source of power used fossil fuel, there would be a net
change in the power system's emissions. Fossil fuels contain
hydrocarbons, whose combustion can result in emissions of such
atmospheric pollutants as sulfur dioxide and nitrogen oxides.
Reclamation found that the region's air quality would improve under
all restricted fluctuating and steady flow alternatives for operating
the dam. Generally, this would occur because the sources of
replacement power would produce less emissions than the sources of
power used by the current Integrated Projects System. According to
Reclamation and the EIS team member who was responsible for the air
quality impact determination, the process used to come to this
conclusion was appropriate, the data used were the best scientific
information available at the time, and the results were reasonable.
DESCRIPTION OF THE RESOURCE
--------------------------------------------------------- Appendix I:1
While the Grand Canyon region enjoys some of the cleanest air in the
lower 48 states, the visual range is affected by haze. This haze is
generally at its worse during the summer months. Air is carried into
the Grand Canyon area from the south and west, where it picks up
pollutants from urban and industrial areas. As a result, during the
summer, the average visibility is only 100 miles, and it drops below
68 miles 10 percent of the time. Sulfates, which are produced from
sulfur dioxide, are the major contributors to haze in the Grand
Canyon. The Navajo Generating Station near Page, Arizona, has been
identified as a major source of sulfates in the vicinity of the Grand
Canyon.
During the winter, strong cold fronts bring in clean air from
sparsely populated areas. The average visibility during these months
is 158 miles, but it reaches more than 211 miles 10 percent of the
time. Between the passages of cold fronts, however, the air
stagnates, and pollution from local sources sinks into the canyon.
The pollution can be trapped by strong inversions until another cold
front again brings in clean air.
EFFECTS OF PRE- AND POSTDAM
CONDITIONS ON AIR QUALITY
--------------------------------------------------------- Appendix I:2
Although power production at the Glen Canyon Dam has had no direct
effect on air quality at the Grand Canyon or in the region, an
analysis of the impacts on air quality was included in the EIS
because the Glen Canyon hydroelectric facility is part of a regional
utility system that has some sulfate-producing facilities. The
region's air quality is affected by the operation of these
interconnected powerplants. For example, the National Park Service
identified the Navajo Generating Station as a major source of
sulfates in the Grand Canyon's air. In response to the Park
Service's findings, the Environmental Protection Agency mandated
modifications to reduce the plant's emissions. Although the Navajo
Generating Station is independent of the Glen Canyon Dam's operations
and modifications will be made to it regardless of which EIS
operating alternative is selected, the air quality in the Grand
Canyon would likely improve because of the modifications.
The changes in the operations at the Glen Canyon Dam might indirectly
affect the region's air quality by forcing reliance on other types of
power-generating facilities. For example, if power generated in the
marketing area served by the Salt Lake City Area Integrated Projects
were changed from older existing powerplants to new, cleaner-burning
facilities, there would be less emissions, all else being the same.
Conversely, if the reductions in power production from hydroelectric
plants are replaced with power from existing powerplants that burn
coal, there would be an increase in the amount of sulfur dioxide and
nitrogen oxide emissions in the region.
ISSUE
--------------------------------------------------------- Appendix I:3
The final EIS considers how the dam's operations affect other
electricity-producing facilities in the area, including those that
have impacts on air quality.
INDICATORS
--------------------------------------------------------- Appendix I:4
The resource indicators considered in the EIS were the amount of
sulfates in the Grand Canyon's air and the tons of sulfur dioxide and
nitrogen oxides in the region's air.
METHODOLOGY USED TO MAKE IMPACT
DETERMINATION
--------------------------------------------------------- Appendix I:5
Reclamation assigned the responsibility for the development of the
air quality section of the EIS to a member of the National Park
Service, who at the time was assigned to the Grand Canyon National
Park. The impacts on the air quality in the Grand Canyon's immediate
vicinity and across the region served by Salt Lake City Area
Integrated Projects' power-marketing system were evaluated for each
of the dam's operating alternatives. Reclamation used the same
power-modeling data used to analyze hydropower impacts to determine
the amount of sulfur dioxide and nitrogen oxide emissions that may
occur under the dam's various operating scenarios. (See app. V of
this report for details on Reclamation's hydropower analysis). For
the final EIS, these studies indicate that the region's air quality
will improve under the four restricted fluctuating and three steady
flow alternatives. Because these emissions analyses included
assumptions for long-term (50-year) power system expansion plans,
some of the impacts are based on specific assumptions about power
generation technology, demand for power, public attitudes, and
political and economic climates.
In making the air quality impact determinations, Reclamation made a
number of key assumptions. For example, the analysis assumes that
any loss of power generation at the Glen Canyon Dam will be partly
absorbed by currently available generation at other plants in the
region. The analysis further assumes that, over time, gas combustion
turbines will be added to the system to replace older, inefficient
facilities. Because natural gas is a cleaner-burning energy source
than coal, emissions will be reduced over the short term. However,
as the demand for electric power increases in the future, new
powerplants will be needed. These newer plants, it is assumed, will
produce less emissions than the existing plants because existing
clean air standards are more stringent than those in effect when the
older plants were constructed. There would have to be a relaxing of
current environmental laws and regulations to invalidate these
assumptions.
The air quality impact analyses determined that any one of the steady
or restricted fluctuating flow alternatives was acceptable. However,
the EIS air quality team leader favors the preferred alternative
because, in his opinion, it has the least detrimental impact when the
entire ecosystem of the Glen and Grand canyons is considered.
EFFECTS OF THE FLOW
ALTERNATIVES ON AIR QUALITY
--------------------------------------------------------- Appendix I:6
According to the final EIS, the amount of Glen Canyon Dam hydropower
that would need to be replaced varies under each of the dam-operating
alternatives in the EIS. The net effect on the region's air quality
under each alternative would be a slight reduction in emissions.
Under the No-Action alternative, it was anticipated that gas
combustion turbines, which are cleaner burning than coal-burning
systems, will soon be added to the regional power system to replace
older and more inefficient coal facilities. These additions should
reduce the system's emissions over the first 5 years of operation.
The assumptions under the Maximum Powerplant Capacity alternative
would be essentially the same as those under the No-Action
alternative.
Under the restricted fluctuating and steady flow alternatives, the
amount of electrical energy produced at the dam during the day would
be reduced, whereas the amount of energy produced at night would
increase. Under this scenario, as the demand for electrical energy
increases, especially during daytime hours, additional powerplants
would be needed sooner than under the No-Action alternative. These
new powerplants would produce less emissions than older,
less-efficient existing plants because of today's more stringent
emissions standards and because some of these plants would burn
natural gas.
ASSESSMENT OF IMPACT
DETERMINATIONS
--------------------------------------------------------- Appendix I:7
During our review, we did not receive any negative comments about
Reclamation's air quality impact determinations. However, the draft
EIS generated 29 public comments related to concerns about air
quality. The comments varied from observations and concerns about
the analysis methods used, to the need for further details and
support for some statements. For example, there was some concern
that the EIS did not do a good job of identifying as speculative its
projections of the potential developments in power generation
technologies, future demand for power, public attitudes, and
political and economic climates. Reclamation agrees that forecasts
over a 50-year period are speculative, but it also believes that the
results of the hydropower-modeling studies provide the best available
information on the powerplants' impacts on air quality.
Another concern expressed was that the lost generating capacity at
the Glen Canyon Dam would have to be replaced by the use of
fossil-fueled powerplants or other sources that are more expensive,
nonrenewable, and polluting. Reclamation told us that the hydropower
studies, which looked at all affected utilities, concluded that there
would be a decline in emissions under several alternatives, including
the preferred alternative.
The individual who was responsible for the air quality section of the
EIS told us that he believed that
-- the process used in making the air quality impact determinations
was reasonable,
-- the methodologies employed in this process were adequate for the
decision-making process, and
-- the results of the analysis were reasonable.
However, he stated that he could not judge the overall quality of the
data used in the analysis because it was proprietary and he did not
have access.
SCOPE AND METHODOLOGY
--------------------------------------------------------- Appendix I:8
To identify how Reclamation determined the impact of various flow
alternatives on air quality, we reviewed the scientific studies and
research materials that were used by Reclamation in making its impact
determinations.
KEY STUDIES IDENTIFIED
------------------------------------------------------- Appendix I:8.1
We identified the following studies as the primary scientific sources
of the data included in the air quality section of the EIS:
-- Electric Utility Financial and Production Cost Model (prepared
by the Environmental Defense Fund).
-- Material prepared by Mike Roluti, Bureau of Reclamation.
-- Preliminary Research Findings - Glen Canyon Environmental
Studies, by Duncan Patten and Dave Wegner, dated September 11,
1992.
-- Stone and Webster Power Modeling Reports (prepared for the
Western Area Power Administration).
In addition, to determine what, if any, concerns were expressed about
the air quality analysis presented in the draft EIS, we reviewed the
Bureau of Reclamation's Operation of Glen Canyon Dam Draft
Environmental Impact Statement: Public Comments Analysis Report
prepared by the Bear West Consulting Team for the Bureau of
Reclamation. To determine other concerns that were expressed about
air quality issues in the preparation of the EIS, we also reviewed
the Final Analysis Report on Scoping Comments, Bureau of Reclamation,
dated March 12-May 4, 1990, Bear West Consulting Team.
OFFICIALS INTERVIEWED
------------------------------------------------------- Appendix I:8.2
In order to assess the methodology used, how well it was implemented,
the quality of the data used, and the reasonableness of the results
of the air quality segment of the EIS, we obtained the views of Mr.
Jerry Mitchell, the official responsible for developing the air
quality impact determination. We also spoke with members of the
Power Resource Committee who performed the hydropower analysis, which
was the basis for the air quality analysis. The names of these
individuals and details on the hydropower analysis are contained in
appendix V of this report.
CULTURAL RESOURCES
========================================================== Appendix II
Cultural resources include archeological sites and Native American
traditional cultural properties and resources. The affected area
containing these sites and properties includes a 255-mile section of
the Colorado River corridor within the Glen and the Grand canyons and
lands adjacent to the Navajo Nation, the Havasupai and Hualapai
Reservations, and the Lake Mead National Recreation Area. The tribes
that have ancestral claims to the Grand Canyon and that continue to
use the area today include the Havasupai, the Hopi, the Hualapai, the
Navajo, the Southern Paiute, and the Zuni.
The Glen Canyon Dam changed the pattern of sediment deposition,
erosion, and flooding through the Glen and Grand canyons. As a
result, archeological sites that were once protected by sandbars and
terraces have become increasingly exposed, making them vulnerable to
erosion, deterioration, and ultimate destruction. While erosion will
continue to occur under any operating alternative selected, some flow
alternatives are more favorable for enhancing the long-term
preservation of cultural resources than others.
According to representatives of Native American groups, the
information used to analyze cultural resources issues was the best
and most up to date available. In addition, many researchers and
representatives of Indian tribes believe that Reclamation went beyond
the requirements of the National Environmental Policy Act (NEPA) in
preparing the cultural resource impact determination. Those involved
in the process were also highly complimentary of Reclamation's
efforts to include Native American tribes in making the impact
determinations. As a result of the cooperation of all parties
involved, the cultural resources team was able to reach a consensus
on the impacts that various flow alternatives would have on the
resources. Also, although not tasked to reach a consensus on a
preferred alternative, the individual cultural resource team members
each agreed on the Modified Low Fluctuating Flow alternative as the
preferred dam operating regime.
DESCRIPTION OF THE RESOURCE
-------------------------------------------------------- Appendix II:1
All natural resources are considered sacred by Indian tribes, and
some resources are considered vital for the continuation of
traditional cultural practices. The cultural resources in the EIS
study area include prehistoric and historic archeological sites,
traditional cultural properties, and other resources that are
important to Native Americans in maintaining their cultural heritage,
lifeways, and practices. A variety of archeological sites were
identified--for example, pueblos (habitation sites of four or more
contiguous rooms); storage sites (granaries or cists); sherd and
lithic scatter (scatter or concentration of ceramic sherds and debris
from making stone tools); rock art (pecked, incised, scratched, or
painted designs, symbols, or figures on rock); and burial sites.
Many of these sites were determined to be eligible for inclusion on
the National Register of Historic Places.
Also, many properties and resources within the Colorado River
corridor, despite not being archaeologically significant, are
culturally significant to Native American beliefs and practices. The
culturally significant sites include plant-gathering areas,
landforms, springs, prayer-offering sites (shrines), and mineral
deposits. Also significant to some Native American tribes are
willows, giant reeds, and many birds, including yellow warblers and
yellow throats.
EFFECTS OF PRE- AND POSTDAM
CONDITIONS ON CULTURAL
RESOURCES
-------------------------------------------------------- Appendix II:2
Until the mid-1980s, it was generally thought that cultural resources
were not affected by the operation of the Glen Canyon Dam. The
belief was that archeological remains would not be found below the
historic high-water mark in the river corridor. This belief was
based on two assumptions: (1) that prehistoric people were aware of
the river's flood potential and would thus build above the floodplain
and (2) that any cultural remains close to the river would have been
washed away over the past thousands of years.
In 1989, the National Park Service and the U.S. Geological Survey
conducted a pilot research project to evaluate erosion at
archeological sites in the Grand Canyon. The project's results
suggested that the operation of the Glen Canyon Dam contributed to
ongoing site erosion. The dam affected sediment deposition, erosion,
and flooding through the Glen and Grand canyons. As a result,
river-deposited sandbars and high terraces (the surface form of a
high sediment deposit having a relatively flat surface and a steep
slope facing the river) have been eroded and, in some cases,
destroyed. The archeological sites once protected by these sediment
deposits have become increasingly exposed to erosion and ultimate
destruction.
ISSUE
-------------------------------------------------------- Appendix II:3
The issue presented in the final EIS for cultural resources is how do
the dam's operations affect the continued existence of cultural
resources in the Glen and Grand canyons?
INDICATORS
-------------------------------------------------------- Appendix II:4
The indicators studied for cultural resources and listed in the final
EIS were
-- the number of archeological sites directly, indirectly, or
potentially affected and
-- the number of Native American traditional cultural properties
and resources directly, indirectly, or potentially affected.
METHODOLOGY USED TO MAKE IMPACT
DETERMINATIONS
-------------------------------------------------------- Appendix II:5
To provide baseline cultural resource information for inclusion in
the Glen Canyon Dam's EIS, Reclamation contracted with the National
Park Service to conduct an archeological inventory in August 1990.
The inventory, which was conducted by staff from the National Park
Service and Northern Arizona University, was completed in May 1991.
The inventory gathered basic information on the numbers, types,
locations, National Register eligibility, and physical conditions of
all cultural resources within the area that have been or could be
affected by the operations of the Glen Canyon Dam. The inventory
identified 475 sites in the Colorado River corridor, 336 of which had
been or could be affected by the existence and operation of the dam.
The remaining 139 sites did not exhibit any effects from the dam's
operations and were excluded from further study. The EIS summarized
these impacts, as shown in table II.1.
Table II.1
Glen Canyon Dam's Impacts on
Archeological Sites
Type of impact Number of sites
-------------------------------------------------- ------------------
Direct--site erosion immediately caused by river 33
flows
Indirect--sediment loss at the site or arroyo 124
cutting near the site
Potential--loss of site due to catastrophic event 179
such as unexpectedly high flows
----------------------------------------------------------------------
In addition to the 336 sites, many Native American cultural
properties and resources, especially plant and animal species that
depend on sandbars and high terraces, have been adversely affected by
the flows from the Glen Canyon Dam. According to the cultural
resource writing team leader, the information on cultural resources
and properties was obtained from research conducted by the following
Native American tribes: Hopi, Hualapai, Southern Paiutes, Navajo,
and Zuni.
The National Historic Preservation Act requires that an impact
determination be made when any action by a federal agency could
affect sites included in or eligible for the National Register of
Historic Places. The process for such determinations is spelled out
in 36 C.F.R. 800 and requires that a determination of "effect" or
"no effect" be made. When there is an effect, a "finding of no
adverse effect" or "finding of adverse effect" is required.
Mitigating measures must be taken when there is a "finding of adverse
effect."
Because dam-related impacts to archaeological sites would continue
regardless of the alternative flow patterns, the operations of the
Glen Canyon Dam were considered to have an adverse effect on cultural
resources located on the terraces that have formed along the river
corridor. However, the rate at which impacts would occur could be
affected by alternative operations, principally through flood
frequency reduction measures.
To assess the impacts of various alternatives on cultural resources,
Reclamation established a cultural resource team. The team leader
was an archeologist with the National Park Service. The team leader
was primarily responsible for cultural resource analysis, including
archeological and tribal issues and compliance with the National
Historic Preservation Act. The team members included representatives
of the Hualapai Tribe, the Navajo Nation, and the Hopi Tribe.
The team was asked to analyze the archeological data and cultural
resource issues and determine how various flow alternatives for the
dam affected these resources. The team was not required to arrive at
one specific preferred alternative.
In addition, tribal representatives from other interested tribes
would periodically attend various EIS meetings to discuss the
cultural resources issues. The cultural resource information for
tribes that did not have representation on the team was prepared for
them by the cultural resource team.
EFFECTS OF THE FLOW
ALTERNATIVES ON CULTURAL
RESOURCES
-------------------------------------------------------- Appendix II:6
According to the final EIS, the dam's operations influence the rate
at which archeological sites and cultural resources are affected.
Flow alternatives that maintain the sand balance and allow for its
distribution along the river corridor would enhance the long-term
preservation of cultural resources. The most favorable operation
alternatives are those which produce a positive net sand balance in
the river system while maintaining a higher elevation of sand
deposits. Of the nine alternatives, six (Moderate Fluctuating,
Modified Low Fluctuating, Interim Low Fluctuating, Existing Monthly
Volume Steady, Seasonally Adjusted Steady, and Year-Round Steady
flows) cause moderate impacts on the sites but nevertheless allow for
a net positive sediment balance in the system and potential sediment
redeposition in areas that would protect cultural resources. The
No-Action and the Maximum Powerplant alternatives were shown to have
major impacts affecting all of the archeological sites, and the High
Fluctuating Flow alternative was found to have the potential to have
major adverse impacts on 263 sites.
NEED FOR CONTINUED STUDIES OF
CULTURAL RESOURCES
-------------------------------------------------------- Appendix II:7
The assessment of impacts on cultural resources will be an ongoing
endeavor. The National Historic Preservation Act, as amended in
1992, requires federal agencies to develop measures to avoid or
minimize the loss of historic properties resulting from their actions
and recommends a long-term monitoring program to assess the changing
conditions of cultural resources. In addition, long-term monitoring
is required by the Grand Canyon Protection Act of 1992.
To comply with these requirements, Reclamation and the National Park
Service developed a programmatic agreement for the continued
monitoring of cultural resources and for the mitigation of the
adverse effects of the dam on threatened cultural resources. The
programmatic agreement stipulates that these long-term
responsibilities will be outlined in a Historic Preservation Plan to
be developed for cultural resources along the river corridor. The
following are signatories to the programmatic agreement.
Advisory Council on Historic Preservation
Arizona State Historic Preservation Officer
Bureau of Reclamation
Hopi Tribe
Hualapai Tribe
Kaibab Paiute Tribe
National Park Service
Navajo Nation
Paiute Indian Tribe of Utah for the Shivwits Paiute Tribe
San Juan Southern Paiute Tribe
Zuni Pueblo
At the time of our review, the Havasupai Tribe was also expected to
be a signatory to the programmatic agreement. The agreement was
officially implemented in February 1994, and numerous
river-monitoring trips, site-stabilization efforts, and periodic
meetings among the signatories have already been held. The agreement
calls for continued monitoring within the river corridor.
ASSESSMENT OF IMPACT
DETERMINATIONS
-------------------------------------------------------- Appendix II:8
The cultural resource writing team members and several of the
representatives from the cooperating agencies who were concerned
about the cultural resource issues were complimentary of
Reclamation's effort to solicit information from and include Native
American tribes in the EIS process. There was a consensus that the
data used to address the impacts on the cultural/archeological
resources were the best and most up to date that were available.
Several comments commended Reclamation for conducting an open and
well-researched and well-documented EIS process. For example, one
commenter stated that Reclamation went beyond the requirements of
NEPA by funding new research used to make impact determinations.
According to the leader and other members of the cultural resource
team, there was consensus among the members on how to present
cultural resource issues. The tribes also presented a unified
position. A representative from the Bureau of Indian Affairs noted
that he was not aware of any disagreement from any tribes about the
EIS process. According to most representatives of the Native
American groups we interviewed, the scientific data used in the
archeological and cultural resource sections of the EIS were the most
recent data available. Furthermore, many representatives stated that
all relevant information available at the time was sought out and
used and that the data presented in the EIS are factual and do not
contradict historical tribal information or other known data. While
most of the information used in the cultural resources section of the
EIS was in draft form, no new or additional data have emerged that
would change or contradict the information in the EIS.
The cultural resource team members, as well as most representatives
from the Native American tribes, support the preferred alternative
(the Modified Low Fluctuating Flow).
The cultural resources team leader's overall position was that
-- the process used in making cultural resource impact
determinations was reasonable,
-- the methodologies employed in this process were appropriate,
-- the data used were the best available, and
-- new information that had been obtained at the time of our audit
work did not alter the facts used in arriving at the impact
determinations in the final EIS.
SCOPE AND METHODOLOGY
-------------------------------------------------------- Appendix II:9
In addition to identifying how Reclamation determined the impact of
various flow alternatives on cultural resources, we evaluated the
scientific foundations, the study review process, the EIS work
groups, and the impact determinations. We also gathered studies and
research materials that were instrumental to Reclamation in making
the EIS decisions.
KEY STUDIES IDENTIFIED
------------------------------------------------------ Appendix II:9.1
We identified the following studies as the primary scientific
foundations for the data included in the cultural resources section
of the EIS:
-- Big River Canyon: Southern Paiute Ethnographic Resource
Inventory and Assessment for Colorado River Corridor, Glen
Canyon National Recreation Area, Utah and Arizona, and Grand
Canyon National Park, Arizona, June 1994, and Storied Rocks:
Southern Paiute Rock Art in the Colorado River Corridor,
September 1995. These reports were prepared by the Southern
Paiute Consortium and the University of Arizona. According to
the consortium, research data collected for the studies were
used in preparing the EIS. The fieldwork for the ethnographic
resource study began in July 1992. We did not obtain data on a
peer review of the reports.
-- The Grand Canyon River Corridor Survey Project: Archeological
Survey Along the Colorado River Between Glen Canyon Dam and
Separation Canyon prepared in cooperation with the Glen Canyon
Environmental Studies Cooperative Agreement No. 9AA-40-07920.
Although this study was not published until December 1994,
research conducted for it was used in preparing the EIS. The
researchers for the study included professional staff from the
National Park Service and Northern Arizona University. The
fieldwork commenced August 30, 1990, and was completed May 10,
1991. Peer review was performed by the Arizona State Historical
Office, the University of Cincinnati, the University of Arizona,
the National Park Service regional archeological staff in Denver
and San Francisco, and affected Native American tribes.
-- The River of Neverending Life: Navajo History and Cultural
Resources of the Grand Canyon and the Colorado River. Navajo
Nation Historic Preservation Department. August 9, 1995. A
draft version of the report as well as basic research were used
in preparing the EIS. The fieldwork for this report was begun
in May 1992. We did not obtain information on a peer review of
the report.
-- Surficial Geology, Geomorphology, and Erosion of Archaeologic
Sites along the Colorado River, Eastern Grand Canyon, Grand
Canyon National Park, Arizona. U.S. Geological Survey,
Open-File Report 93-517, prepared in cooperation with the Bureau
of Reclamation-Glen Canyon Environmental Studies. This report,
released in 1993, acknowledges a number of individuals for
critical review and comments.
-- Zuni and the Grand Canyon: A Glen Canyon Environmental Studies
Report, July 21, 1995, Zuni GCES Ethnohistorical Report prepared
by the Institute of the North American West. The research data
on which this report is based were used in the EIS. The
research was initiated in 1993. We did not obtain information
on a peer review of the report.
In addition to these studies, which dealt specifically with cultural
resources, we examined other relevant documents to determine the
significance of cultural resource concerns expressed or addressed
prior to the preparation of the EIS. These other documents included
the following:
-- Final Analysis Report on Scoping Comments, prepared by Bear West
Consulting Team, March 12-May 4, 1990, and
-- Preliminary Research Findings, Glen Canyon Environmental
Studies, presented to the Bureau of Reclamation and Western Area
Power Administration in Denver by Duncan Patten and David
Wegner, September 11, 1992.
OFFICIALS INTERVIEWED
------------------------------------------------------ Appendix II:9.2
To assess the procedures followed and obtain views on the quality of
the data used in preparing the cultural resource issues, we
interviewed the four members of the cultural resource writing team.
We asked the team leader for the cultural resources workgroup to
review our description of the resource impact determination process
for factual accuracy. She agreed that the information presented is a
good summary of the process, methodology, and scientific basis used
to determine the impacts on the cultural resources from the Glen
Canyon Dam's operations. We also contacted representatives of
several cooperating agencies, primarily Native American tribes, to
obtain their perspectives on and concerns about the
archeological/cultural resources addressed in the EIS. The following
officials were contacted.
Roger Anyon, Pueblo of Zuni
Janet Balsom, National Park Service - Grand Canyon
Clay Bravo, Hualapai Tribe
Angelita Bulletts, Southern Paiute Consortium
Gary Cantley, Bureau of Indian Affairs
Kurt Dongoske, Hopi Tribe
Alan Downer, Navajo Nation
Loretta Jackson, Hualapai Tribe
Leigh Jenkins, Hopi Tribe
Signa Larralde, Bureau of Reclamation
Johnny Lehi, San Juan Southern Paiute Tribe
Alexa Roberts, Navajo Nation
John Thomas, Navajo Nation
Michael Yeats, Hopi Tribe
Also, members of the following cooperating agencies were involved in
the analysis and development of the cultural resource issues
addressed in the EIS: Bureau of Indian Affairs, National Park
Service, Hopi Tribe, Hualapai Tribe, Navajo Nation, Pueblo of Zuni,
San Juan Southern Paiute Tribe, and Southern Paiute Consortium.
ENDANGERED SPECIES
========================================================= Appendix III
The historic operations of the Glen Canyon Dam have negatively
affected some wildlife resources while enhancing others. Among the
wildlife that inhabit the Glen and Grand canyon river corridor, there
are seven nonfish endangered species.\6 The impacts of the various
flow alternatives on these endangered species are mostly indirect and
were analyzed through linkages to other resources, such as fish and
vegetation. The U.S. Fish and Wildlife Service (FWS) determined
that the proposed operation of the Glen Canyon Dam under the Modified
Low Fluctuating Flow preferred alternative, is not likely to
jeopardize the continued existence of the bald eagle, Kanab
ambersnail, or peregrine falcon. The FWS addressed only species that
were listed as endangered by the federal government. When the final
EIS was issued, the southwestern willow flycatcher was only a
candidate for listing. It has subsequently been listed as an
endangered species. In addition, the bald eagle has been
reclassified from endangered to threatened. The belted kingfisher,
osprey, and southwestern river otter are Arizona species of concern.
Therefore, they were addressed in the EIS but not by the FWS. In
general, nonfish endangered species issues were not controversial in
the preparation of the Glen Canyon Dam's EIS, and few concerns exist
about the process used or the data relied upon for making the
endangered species impact determinations.
--------------------
\6 In this appendix, the term "endangered species" is used for all
special-status species addressed in the final EIS, including
endangered species, candidate species, and Arizona species of
concern. In the final EIS, Reclamation revised the fish section to
include the discussion of endangered fish species. This appendix
follows the same approach. That is, only nonfish endangered species
are discussed in this appendix. Endangered fish species are
discussed in app. IV.
DESCRIPTION OF THE RESOURCE
------------------------------------------------------- Appendix III:1
Wildlife is diverse and abundant along the river corridor through the
Glen and the Grand canyons. Riparian (near water) vegetation, which
developed along the river after the construction of the Glen Canyon
Dam, plays an important role as habitat to support this diversity and
abundance. The variety of animals present in the river corridor,
their habitats, and how they use their habitats form a complex system
that is difficult to evaluate in detail. However, like other
resources, this system is linked to the river and ultimately to the
operations of the Glen Canyon Dam.
Both aquatic and terrestrial endangered species occupy or use the
river corridor. The seven nonfish endangered species considered in
this appendix include five birds, one terrestrial snail, and one
mammal now presumed extinct. Specifically, these species are the
bald eagle, peregrine falcon, southwestern willow flycatcher, belted
kingfisher, osprey, Kanab ambersnail, and southwestern river otter.
A brief description of each of these species follows.
BALD EAGLE
----------------------------------------------------- Appendix III:1.1
The bald eagle was listed as endangered in 1978 but has since been
reclassified as threatened. The Colorado River corridor through the
Grand Canyon is used by migrating bald eagles in the winter. While
eagles are capable of taking fish from a river system with
characteristics identical to those of the Colorado River before the
construction of the Glen Canyon Dam, they were not often observed in
the Grand Canyon until after the rainbow trout fishery was
established.
The bald eagle's use of the river corridor is opportunistic and
currently concentrated around Nankoweap Creek, where they use
winter-spawning trout as a food source. The use of the river by
eagles may increase and eventually expand to other locations. For
example, bald eagles are regularly located along the river corridor
above the Little Colorado River and occur around Lake Powell.
PEREGRINE FALCON
----------------------------------------------------- Appendix III:1.2
Peregrine falcons were listed as endangered in 1970 but have
generally increased nationwide since the prohibition on the use of
certain pesticides. The Grand Canyon and the surrounding areas
support the largest known breeding population of peregrine falcons in
the contiguous United States. The birds using the Grand Canyon
appear to be part of an increasing peregrine falcon population on the
Colorado Plateau.
Although relationships are still under investigation, it is assumed
that the peregrine falcon's success in the area is at least partially
due to the abundance of birds and bats. These prey species are
plentiful because of large insect populations produced in the clear
river water. The relationships between aquatic productivity,
insects, prey species, and peregrine falcons are largely speculative.
No specific data are available that refute or confirm the above
relationships, and no data are available on the activities of
peregrine falcons in the Grand Canyon before the construction of the
Glen Canyon Dam.
SOUTHWESTERN WILLOW
FLYCATCHER
----------------------------------------------------- Appendix III:1.3
The southwestern willow flycatcher is a riparian bird found in
Arizona, New Mexico, and southern California. At the time the final
EIS was released, this species was a candidate for listing. It has
since been listed as an endangered species.
Southwestern willow flycatchers have always occupied the river
corridor. Nesting pairs of this species increased in the Grand
Canyon following the completion of the Glen Canyon Dam. Researchers
attribute this response to increases in riparian vegetation following
reduced flood discharges. However, a 1991 survey found only two
pairs of nesting birds. The most probable reason for this apparent
decline is the brown-headed cowbird. These birds lay their eggs in
other species' nests, usually at the expense of their hosts' young.
One researcher speculated that a possible reason for the decline in
the numbers of this species is habitat fragmentation caused by floods
and fluctuating river flows. Fluctuating flows contribute to the
erosion of terrestrial habitats, resulting in a decrease in the size
of contiguous vegetation patches. However, the required patch size
for nesting southwestern willow flycatchers is not known. Although
the southwestern willow flycatcher has traditionally been associated
with willows and other native vegetation, all of the nests located in
the Grand Canyon have been located in tamarisk, even though native
vegetation was available.
BELTED KINGFISHER
----------------------------------------------------- Appendix III:1.4
The belted kingfisher is considered a candidate species for listing
by the state of Arizona. This bird is found in low numbers
year-round in the Grand Canyon and its tributaries. This species is
restricted to habitats with permanent, fish-inhabited waters.
OSPREY
----------------------------------------------------- Appendix III:1.5
The osprey is a fall, spring, or accidental transient in the Grand
Canyon and is listed by the state of Arizona as a "state threatened"
bird species. Osprey are primarily found in coniferous forests
around lakes, and it is assumed that they use the river as a travel
lane to other habitat.
KANAB AMBERSNAIL
----------------------------------------------------- Appendix III:1.6
Only three populations of this snail are known to exist--two near
Kanab, Utah, and one in the Grand Canyon. Since the listing of this
species as endangered in 1992, one of the Utah populations is now
believed to be extirpated (extinct in that area). The Grand Canyon
population was discovered in 1991 by researchers surveying mollusks
in conjunction with the Glen Canyon Environmental Studies program.
Although officially a terrestrial animal, the Kanab ambersnail is
really an amphibious creature found in wet or moist environments,
such as marshes and seeps located at the bases of sandstone cliffs.
Vegetation cover is necessary for this mollusk. The vegetation in
the Grand Canyon associated with the Kanab ambersnail is the cardinal
monkey flower and water cress. The availability of the cardinal
monkey flower and other vegetation near the river in the Grand
Canyon, as well as the presence of rock ledges, influence the
distribution of the Kanab ambersnail. Since the implementation of
the interim flows for the Glen Canyon Dam in 1991, the Kanab
ambersnail's habitat has become available at lower elevations, closer
to the river.
SOUTHWESTERN RIVER OTTER
----------------------------------------------------- Appendix III:1.7
The southwestern river otter is considered an endangered species by
the state of Arizona. River otters have always been considered rare
in the Grand Canyon; the last sighting was reported in 1983.
Unconfirmed reports of their presence continue to be received from
several localities, but extensive surveys have not resulted in
sightings. The species is generally believed to be extinct.
EFFECTS OF PRE- AND POSTDAM
CONDITIONS ON ENDANGERED
SPECIES
------------------------------------------------------- Appendix III:2
The Grand Canyon ecosystem originally developed in a sediment-laden,
seasonally fluctuating environment. The construction of Glen Canyon
Dam altered the natural dynamics of the Colorado River. The
interruption in riverflow and the regulated releases of lake water
now support aquatic and terrestrial systems that did not exist before
the Glen Canyon Dam. The historic operations of the dam negatively
affected some wildlife resources while enhancing others. The impacts
of the dam's operations on the various endangered species also vary.
ISSUE
------------------------------------------------------- Appendix III:3
As defined in the final EIS, the issue for endangered species is how
do dam operations affect the populations of endangered and other
special-status species throughout the Glen and the Grand canyons?
INDICATORS
------------------------------------------------------- Appendix III:4
Because the seven nonfish endangered species that inhabit the river
corridor occupy diverse niches in the Grand Canyon ecosystem, no
single resource could be used as an indicator of impacts for
endangered species as a whole. Therefore, the EIS team utilized an
analytical approach which considered linkages among resources. The
team identified the following indicators for individual species:
-- for the bald eagle: trout and the aquatic food base;
-- for the belted kingfisher: the aquatic food base;
-- for the southwestern willow flycatcher: the area of woody
plants; and
-- for the Kanab ambersnail: maximum river flow.
METHODOLOGY USED TO MAKE IMPACT
DETERMINATIONS
------------------------------------------------------- Appendix III:5
EIS team members told us that the EIS was developed through a dynamic
process involving three main groups--the EIS team, Glen Canyon
Environmental Studies officials and researchers, and representatives
of the cooperating agencies. The EIS team was responsible for the
technical development of alternatives and impact determinations,
while the cooperating agency group was a policy-level review body.
The nonfish endangered species impacts and issues were primarily
developed by two EIS team members assigned to that task on the basis
of their areas of expertise. Unlike the groups formed to address
economic issues, no formal endangered species workgroup existed and
no formal reports were produced.
These two team members developed their sections of the EIS through an
iterative process of drafting, discussions, and formal and informal
presentations to, and review by, the EIS team, as well as through
input from key researchers and colleagues with whom they shared their
work and from whom they solicited feedback. Additionally, the team
members presented impact assessments to the cooperating agency group.
Decisions on endangered species issues were handled through voting;
the goal was to obtain consensus on the results of the work. The
formal minutes of the EIS team meetings were kept as a record of key
decisions.
Reclamation received approximately 33,000 public comments on the
draft EIS, 1,826 of which related to endangered species. However,
only 31 comments specifically focused on nonfish endangered species.
On the basis of new scientific information, the public comments, and
the comments received from internal reviews, the EIS team as a whole
made changes to the endangered species section of the EIS. These
changes included the addition of a new indicator for the impact
analysis related to the Kanab ambersnail, changes to the text, and
modifications to the endangered species impact matrix. Both minor
and major changes were made. An example of a minor modification is
the change of status in the matrix for the southwestern river otter
from presumed "extirpated" to presumed "extinct." A more major
addition/modification pertains to the inclusion of updated
information on, and an expanded treatment of, the Kanab ambersnail in
the final EIS.
According to the principal author of the revised endangered species
section, new information received after the release of the draft EIS
indicated that the Kanab ambersnail responded to interim flows at the
dam by moving into lower elevations than it had inhabited under the
dam's historic operations. Kanab ambersnails residing in these
locations would be affected by flows higher than 20,000 cubic feet
per second (cfs) and the associated habitat maintenance and
beach/habitat-building flows.
Because this population survived the 1983-86 floodflows of about
90,000 cfs, the EIS team assumed that infrequent flows of about
45,000 cfs would not jeopardize the continued existence of the
population. However, some unavoidable mortality, or "incidental
take," would occur. As a result of this information, changes were
made to the discussion in the text of the Kanab ambersnail, and the
impact determinations in the associated matrix were modified from "no
effect" to "some incidental take."
DATA USED FOR MAKING IMPACT
DETERMINATIONS
----------------------------------------------------- Appendix III:5.1
The research studies used to support the impact determinations on
endangered species are listed in the final EIS bibliography. Because
of linkages to the fish and vegetation resource areas, the studies
done in these fields are pertinent to endangered species. The
studies include Glen Canyon Environmental Studies phase I and phase
II research, as well as research developed by various state and
federal agencies involved in endangered species work. Those studies
deemed most useful by a key member of the EIS team who worked on
endangered species issues are noted later in this appendix.
EFFECTS OF FLOW ALTERNATIVES ON
ENDANGERED SPECIES
------------------------------------------------------- Appendix III:6
Details of the anticipated impacts of the nine flow alternatives on
endangered species are found in the final EIS. However, the
following general statements can be made about these impacts:
-- The Kanab ambersnail is the only species expected to be
adversely affected by any of the flow alternatives. Some
mortality, or "incidental take," would occur under all
alternatives, although the continued existence of the population
would not be jeopardized.
-- Three species will be unaffected by changes in the dam's
operations--the peregrine falcon, the osprey, and the
southwestern river otter (which is presumed extinct).
-- Habitat conditions for the bald eagle and belted kingfisher
would remain stable or potentially improve under all
alternatives.
-- The southwestern willow flycatcher would experience an
"undetermined increase" in habitat under all alternatives except
the No-Action and Maximum Powerplant Capacity alternatives.
U.S. FISH AND WILDLIFE
SERVICE'S FINAL BIOLOGICAL
OPINION
------------------------------------------------------- Appendix III:7
The U.S. Fish and Wildlife Service's 1994 final biological opinion
found that the proposed operation of the Glen Canyon Dam under the
preferred alternative is not likely to jeopardize the continued
existence of the bald eagle, the peregrine falcon, or the Kanab
ambersnail. Few of the researchers and EIS team members we spoke
with commented on the biological opinion as it related to nonfish
endangered species. When asked about this, two EIS team members said
that the "no jeopardy" finding was key to the lack of controversy on
endangered species issues in team discussions. Another EIS team
member added that the no jeopardy finding probably did allow the team
to target their discussions and efforts on those endangered fish
which had a jeopardy finding. Still, another team member told us
that the team was not surprised by FWS' no jeopardy finding and knew
even before the opinion was released that fish would be the primary
concern.
ASSESSMENT OF IMPACT
DETERMINATIONS
------------------------------------------------------- Appendix III:8
Nonfish endangered species were not a controversial issue in the
preparation of the Glen Canyon Dam's EIS. This is particularly true
in comparison to fish, which generated a great deal of controversy
and difference of opinion. When asked to comment on "endangered
species," most researchers we spoke with talked only about endangered
fish.
Several EIS team members pointed to the indirect impacts of the dam's
operations on most endangered species as a key reason for this lack
of controversy. A few EIS team members noted that nonfish species
represent only a small percentage of the endangered species in the
canyon and that concern about nonfish species was low compared to
fish because of these small populations. One EIS team member used as
an example of this the fact that only two nesting pairs of
southwestern willow flycatchers are in the affected area. However,
another EIS team member disputed the view that the smaller numbers of
endangered species made them less controversial. This individual
stressed that the smaller numbers actually made it even more crucial
that these species be protected and taken very seriously in the EIS
process. One researcher noted that there is a long history of fish
research in the canyon but that there is no such research history for
other species. This individual said that of the nonfish endangered
species, most interest focused on the Kanab ambersnail and the
southwestern willow flycatcher. Another researcher simply stated
that "the fish drive the system" in the canyon and are more
politically important than the other species. Furthermore, he said
that the connection between fish and the dam's operations can be
easily seen, while this connection is harder to see with terrestrial
species.
REASONABLENESS OF THE
METHODOLOGY
----------------------------------------------------- Appendix III:8.1
Few concerns exist among the experts we interviewed about the process
used in making the endangered species impact determinations. Most
EIS team members we interviewed were satisfied with the process of
analyzing the linkages among resources in determining impacts.
However, one EIS team member noted that analyzing linkages was only
one way to look at impacts on endangered species. The member noted
that while analyzing linkages was an acceptable and reasonable
approach, it was not necessarily the best or the worst way to
proceed.
EIS team members acknowledged that because some linkages were quite
indirect, professional judgment was important in this process. They
stressed, however, that professional judgment was supported by the
best available data.
One researcher expressed some dissatisfaction with this process.
This individual said that, on the basis of his experience in the
canyon observing the connections among bird species and other
terrestrial resources, the connections are more direct than they were
represented in the final EIS. He felt that although the team claimed
to have looked at linkages, they did not do as thorough a job as they
say and looked more at the impacts that could be directly ascribed.
OPINIONS ON DATA USED FOR
IMPACT DETERMINATIONS
----------------------------------------------------- Appendix III:8.2
Individuals we interviewed had few concerns about the data used in
making the impact determinations for nonfish endangered species. One
EIS team member told us that with the possible exception of the Kanab
ambersnail and the southwestern willow flycatcher, endangered species
were not controversial in terms of the data or the process used in
making the impact determinations. In fact, one researcher with whom
we spoke characterized the terrestrial and bird-related research used
as a basis for these determinations as "top notch." Nevertheless, one
EIS team member said that the data used for endangered species were
even less solid than they were for fish.
A researcher who was also a member of the EIS team told us that while
professional judgment played a role in their decision- making, the
team worked hard to collect all of the information available. This
person said that when necessary, to fill in data gaps, the team
contacted researchers directly and asked them to provide information
in the form of written communications that could then be cited as
documentation.
Another member of the EIS team told us that, in his opinion, the data
on the bald eagle were "adequate," data on the southwestern willow
flycatcher were "on the cusp," and much of the new data on the Kanab
ambersnail became available only after the EIS process was
substantially complete. This individual went on to say, however,
that the data available to the team on most species provided adequate
information to make informed decisions. He stressed that complete
information is never available in the process of scientific
decision-making.
RESPONSE TO THE ISSUES
RAISED
----------------------------------------------------- Appendix III:8.3
The principal author of the endangered species section of the final
EIS provided us with detailed comments on and responses to each of
the issues noted above. He agreed with some statements or positions
and disagreed with others. For example, he disagreed that the data
available on which to base impact determinations were less solid than
those for fish. He noted that because impacts based on linkages are
difficult to quantify, they can give the impression that they are
less solid. However, he stressed that linkages are a legitimate and
useful scientific approach and that they yield useful information.
Moreover, he agreed that the data available on the various species
produced reasonable results that were adequate for informed
decision-making.
SCOPE AND METHODOLOGY
------------------------------------------------------- Appendix III:9
To determine the data and process used in developing endangered
species issues, we identified and reviewed the following documents:
the draft EIS and associated appendixes; the preliminary final EIS;
the final EIS; public comments on the draft EIS; Reclamation's
analysis of and the EIS team's responses to these comments; copies of
the minutes of the EIS team meetings; summaries of the meetings of
the cooperating agencies; and Reclamation's newsletters on the EIS
process. We also obtained and reviewed FWS' draft biological opinion
and final biological opinion on the operation of Glen Canyon Dam,
Reclamation's comments on the draft biological opinion and official
response to the final biological opinion, and FWS' Fish and Wildlife
Coordination Act report. (See below for a list of related documents
and full citations.)
We obtained a copy of the final EIS bibliography from Reclamation,
with titles sorted by each resource area. The endangered species
bibliography contains 29 titles; however, most of these titles relate
to endangered fish. The wildlife and habitat bibliography also
contains 29 titles, several of which specifically relate to nonfish
endangered species. We asked the EIS team member recommended to us,
as a key initial contact on nonfish endangered species issues, to
identify those studies which had been the most useful in developing
the impact determinations. This individual was also one of the two
individuals primarily responsible for writing the endangered species
section of the final EIS.
To assess the procedures followed and obtain views on the quality of
the data used in preparing the endangered species impact
determinations, we interviewed the EIS team members who had primary
responsibility for writing this section of the draft EIS, as well as
several other members of the EIS team. We spoke with several
scientists identified by team members and others as having done key
research used by the team in developing the endangered species
section of the EIS. We also interviewed other agency officials with
information on the EIS and the Glen Canyon Environmental Studies
processes.
Finally, we asked the principal author to review our description of
the endangered species impact determination process for factual
accuracy. He agreed that our description was generally accurate but
made some suggestions for changes. We have incorporated these
changes into our description of the process. We also presented him
with our preliminary findings on endangered species in order to
provide him an opportunity to comment on and respond to the various
issues raised through our audit work. He generally agreed with the
facts as presented.
KEY STUDIES IDENTIFIED
----------------------------------------------------- Appendix III:9.1
The following are key titles selected from the endangered species
bibliography not related to fish.
"Biological Opinion of the Effects of Glen Canyon Dam on the Colorado
River as It Affects Endangered Species." Memorandum from Regional
Director, U.S. Fish and Wildlife Service, Albuquerque, New Mexico,
to Acting Regional Director Harl Noble, Bureau of Reclamation. Salt
Lake City, Utah: U.S. Fish and Wildlife Service, 1978.
Clarke, A.H., "Kanab Amber Snail--Oxyloma Haydeni Kanabinsis,
Pilsbry, 1948," Status Survey of Selected Land and Freshwater
Gastropods in Utah. Denver, Colorado: Prepared by Ecosearch, Inc.,
Portland, Texas, for the U.S. Fish and Wildlife Service, 1991, pp.
23-36.
Handbook of Federally Endangered, Threatened, and Candidate Plants of
Arizona, S. Rutman, compiler. Phoenix, Arizona: U.S. Fish and
Wildlife Service, 1990a.
Influences of Glen Canyon Dam Fluctuating Flows on Spawning Rainbow
Trout and Wintering Bald Eagles, With Observations on the Effects of
Human-Bald Eagle Interactions on the Colorado River in Grand Canyon
National Park. Final Report from Northern Arizona University to
Grand Canyon National Park, National Park Service, 1992.
Unitt, P. "Empidonax Trailli Extimus: An Endangered Species,"
Western Birds, Vol. 18, No. 3, pp. 137-162, 1987.
The following titles were selected from the wildlife and habitat
bibliography related to nonfish endangered species.
Brown, B.T. Abundance, Distribution, and Ecology of Nesting
Peregrine Falcons in Grand Canyon National Park, Arizona. Final
report submitted to Grand Canyon National Park, Grand Canyon,
Arizona, 1991b.
Brown, B.T. "Monitoring Bird Population Densities Along the Colorado
River in Grand Canyon," Glen Canyon Environmental Studies Technical
Report. Salt Lake City, Utah: Bureau of Reclamation, 1987.
Brown, B.T. "Status of Nesting Willow Flycatchers Along the Colorado
River From Glen Canyon Dam to Cardenas Creek, Arizona," Endangered
Species Report No. 20. Phoenix, Arizona: U.S. Fish and Wildlife
Service, 1991a.
Brown, B.T., and R.R. Johnson. "The Effects of Fluctuating Flows on
Breeding Birds," Glen Canyon Environmental Studies Executive
Summaries of Technical Reports. Salt Lake City, Utah: Bureau of
Reclamation, 1988.
Brown, B.T., and W.C. Leibfried. "The Effect of Fluctuating Flows
from Glen Canyon Dam on Bald Eagles and Rainbow Trout at Nankoweap
Creek in Grand Canyon National Park, Arizona," Glen Canyon
Environmental Studies Phase II Draft Integrated Research Plan, Vol.
2. Salt Lake City, Utah: Bureau of Reclamation, 1990.
Brown, B.T., R. Mesta, L.E. Stevens, and J. Weisheit. "Changes in
Winter Distribution of Bald Eagles Along the Colorado River in Grand
Canyon, Arizona," Journal of Raptor Research, Vol. 23, No. 3, pp.
110-113, 1989.
Brown, B.T., G.S. Mills, R.L. Glinski, and S.W. Hoffman. "Density
of Nesting Peregrine Falcons in Grand Canyon National Park, Arizona,"
Southwestern Naturalist, Vol. 37, No. 2, pp. 188-193, 1992.
Brown, B.T., and L.E. Stevens. Written communication, National Park
Service, 1991.
Brown, B.T., and M.W. Trosset. "Nesting Habitat Relationships of
Riparian Birds Along the Colorado River in Grand Canyon, Arizona,"
Southwestern Naturalist, Vol. 34, No. 2, pp. 20-270, 1989.
Spamer, E.E., and A.E. Bogan. "Mollusca of the Grand Canyon and
Vicinity, Arizona: New and Revised Data on Diversity and
Distributions, With Notes on Pleistocene-Holocene Mollusks of the
Grand Canyon," Proceedings of the Academy of Natural Sciences in
Philadelphia, Vol. 144, pp. 21-68, 1993.
Threatened Native Wildlife in Arizona. Phoenix, Arizona: Arizona
Game and Fish Department, 1988.
In addition to the studies identified above from the final EIS
bibliography, other documents are relevant to endangered species
issues.
Carothers, S.W., and B.T. Brown. The Colorado River Through Grand
Canyon: Natural History and Human Change. Tucson, Arizona:
University of Arizona Press, 1991. The coauthors of this book were
both key researchers identified in our work. Furthermore, Dr.
Carothers was a member of the EIS team and the Aquatic Biology Team
workgroup. Portions of this book address fish and endangered species
issues, drawing from Glen Canyon Environmental Studies research.
Final Biological Opinion: Operation of Glen Canyon Dam as the
Modified Low Fluctuating Flow Alternative of the Final Environmental
Impact Statement, Operation of Glen Canyon Dam. (2-21-93-F-167) U.S.
Fish and Wildlife Service, Dec. 21, 1994. The Final Biological
Opinion and its related Reasonable and Prudent Alternative were
developed by FWS in response to Reclamation's request for formal
consultation under section 7 of the Endangered Species Act. The
Final Biological Opinion states that the Modified Low Fluctuating
Flow preferred alternative is likely to jeopardize the continued
existence of the humpback chub and razorback sucker but is not likely
to jeopardize the bald eagle, peregrine falcon, or Kanab ambersnail.
Glen Canyon Dam: Beach/Habitat-Building Test Flow, Final
Environmental Assessment and Finding of No Significant Impact, Bureau
of Reclamation, Feb. 1996. This report presents the findings of the
required environmental assessment prepared prior to implementing the
spring 1996 "spike" flow.
Operation of Glen Canyon Dam - Fish and Wildlife Coordination Act
Report, U.S. Fish and Wildlife Service, June 28, 1994. In
accordance with the Fish and Wildlife Coordination Act, FWS submitted
this report to Reclamation with recommendations in connection with
the Glen Canyon Dam's operations. The act does not require
Reclamation to accept the recommendations; however, reasonable and
practicable recommendations will be implemented. The act ensures
that fish and wildlife receive equal consideration during the
planning and construction of federal water projects.
"Organisms and Biological Processes," River Resource Management in
the Grand Canyon, pp. 84-117. National Research Council, Committee
to Review the Glen Canyon Environmental Studies, 1996. This is a
chapter of a National Research Council committee report on the Glen
Canyon Environmental Studies. The purpose of this report and the
committee's task was to review research that was done in connection
with the Glen Canyon Environmental Studies and to comment on the
application of science in the management program of the Colorado
River.
"Response to the Final Biological Opinion on the Operations of Glen
Canyon Dam," Bureau of Reclamation, Apr. 6, 1995. This is
Reclamation's official response to, and addressing of, the issues
presented in the Final Biological Opinion. In its response,
Reclamation states that it does not agree with all the points made or
positions taken by FWS but will take steps to comply with them.
OFFICIALS INTERVIEWED
----------------------------------------------------- Appendix III:9.2
We interviewed the following individuals about endangered species and
other related Glen Canyon Dam EIS issues.
Michael Armbruster, Bureau of Reclamation, principal author of
the endangered species section of the EIS
Frank Baucom, U.S. Fish and Wildlife Service
Debra Bills, U.S. Fish and Wildlife Service
Byran Brown, SWCA, Inc.
Christine Karas, Bureau of Reclamation
Dennis Kubly, Arizona Game and Fish Department
William Leibfried, SWCA, Inc./Hualapai Tribe
Gordon Lind, Bureau of Reclamation
Margaret Matter, Western Area Power Administration
Debra McGuinn-Robbins, Arizona Game and Fish Department
Anthony Morton, Western Area Power Administration
Ronald Moulton, Western Area Power Administration
S. Clayton Palmer, Western Area Power Administration
Timothy Randle, Bureau of Reclamation
Lawrence Riley, Arizona Game and Fish Department
David Wegner, Bureau of Reclamation, Glen Canyon Environmental
Studies
FISH
========================================================== Appendix IV
The construction of the Glen Canyon Dam altered the natural dynamics
of the Colorado River, including the downstream aquatic system. The
predam aquatic system supported an array of native and nonnative
fish. The decline of the native fish in the Glen and Grand canyons
is attributed to the presence of nonnative competitors and predators
and to subsequent postdam river conditions that affected habitat and
redefined the relationship between native and nonnative fishes.
Scientific opinions differ about the potential impacts on fish
resources of the flow alternatives addressed in the Glen Canyon Dam
environmental impact statement.
The U.S. Fish and Wildlife Service's (FWS) final biological opinion
expressed concern that the Modified Low Fluctuating Flow, the EIS's
preferred alternative, would jeopardize the continued existence of
two endangered fish species, the humpback chub and the razorback
sucker. The biological opinion's reasonable and prudent alternative
identified actions that would modify the preferred alternative with
seasonally adjusted steady flows about 25 percent of the time. FWS
and Reclamation agreed to categorize these flows as experimental, or
research, flows so that studies could be conducted to verify an
effective dam flow regime and to include those flows with another
element of the reasonable and prudent alternative, "adaptive
management." Reclamation intends to initiate a process of adaptive
management that would provide for long-term monitoring and research
to measure the actual effect of the selected dam-operating criteria.
The results of this effort would form the basis for possible future
modifications of the dam's operations and, with other conservation
measures, may lead to the removal of the jeopardy opinion.
EIS team members and resource scientists express a variety of
opinions about the process and data used in making the impact
determinations for fish. Because of incomplete information, as
stated in the final EIS, the impact of steady flows on fish is still
uncertain.
DESCRIPTION OF THE RESOURCE
-------------------------------------------------------- Appendix IV:1
Several elements comprise the aquatic ecosystem downstream of the
Glen Canyon Dam. These elements include the aquatic food base,
native fishes, and nonnative fishes. Nonnative fishes include
warmwater, coolwater, and coldwater species. Due to the very limited
data collected before the construction of the dam, the predam
distribution and relative abundance of native and nonnative fish are
largely unknown and subject to speculation.
In general, the ability of fish populations to persist and thrive
depends on how well their life requirements are met. Life
requirements include food supply, habitat, and the ability to avoid
or minimize competition and predation.
Before the dam was closed, the aquatic food base for fish was founded
on coarse organic material carried into the river from the drainage
basin. Today, this coarse material is trapped above the dam in Lake
Powell. Algae in the river (especially the filamentous green alga
Cladophora glomerata) has now become an important part of the aquatic
food base, along with associated diatoms (microscopic, single-celled,
or colonial algae) and invertebrates (especially insects and the
amphipod Gammarus lacustris).
The predam aquatic ecosystem contained eight native fish species and
several introduced species such as the channel catfish and the carp.
The eight native species were the humpback chub, razorback sucker,
Colorado squawfish, bonytail chub, roundtail chub, flannelmouth
sucker, bluehead sucker, and speckled dace. The Colorado squawfish,
the roundtail chub, and the bonytail chub are considered extirpated
(i.e., extinct in a given area) from the Grand Canyon, and the
razorback sucker is very rare. The population of humpback chub in
the Grand Canyon is the largest of five remaining populations and the
only population of the species in the Lower Colorado River Basin.
Warmwater nonnative fish species began to be introduced into the
river system possibly as early as the late 1800s. About the time
that the dam was completed, warmwater nonnative fish found near the
dam site included channel catfish, carp, fathead minnow, green
sunfish, killifish, largemouth bass, mosquito fish, and red shiner.
Coolwater nonnative fishes introduced into the river include striped
bass, smallmouth bass, and walleye. In addition to these warmwater
and coolwater nonnatives, coldwater nonnative trout species were
introduced for sport purposes beginning in the 1920s. Rainbow trout
make up the major part of the sport fishery, but brook trout, brown
trout, and cutthroat trout also have been stocked in the river.
The variety of native and nonnative fish present in the system leads
to the issue of "interactions" among them. Interaction in the form
of competition from, and predation by, nonnative fish has been cited
along with habitat modification as causes of the decline of native
fish in the Colorado River system. Potential competitors for habitat
with native fish include carp, fathead minnow, killifish, rainbow
trout, and red shiner. Species cited as predators on native fish
include striped bass, channel catfish, brown trout, and possibly
rainbow trout. Because of limited data, opinions vary about
interactions between native and nonnative fish and how operational
changes would affect these interactions.
EFFECTS OF PRE- AND POSTDAM
CONDITIONS ON FISH
-------------------------------------------------------- Appendix IV:2
The aquatic ecosystem originally developed in a sediment-laden,
seasonally fluctuating river environment. The construction of the
Glen Canyon Dam altered the natural dynamics of the Colorado River.
Today, the ecological resources of the Glen and Grand canyons depend
on the water releases from the dam and the sediment that comes from
tributaries below the dam. Lake Powell traps water, sediment, and
the associated nutrients that previously traveled down the Colorado
River.
The interruption of riverflow and regulated release of lake water now
support aquatic and terrestrial systems that did not exist before the
Glen Canyon Dam. The predam aquatic system supported an array of
native and nonnative fish. Native fish evolved in a river that
carried large amounts of sediment and was subject to extreme seasonal
variability in flow and temperature. The construction of the dam
created a relatively clear river with near constant year-round cold
temperatures. These water temperatures limit the possibility of
successful reproduction by warmwater fish, including the five native
fish still present in this portion of the Colorado River system. The
decline of the native fish in the Glen and Grand canyons is
attributed to the presence of nonnative competitors and predators and
to postdam river conditions. The tributaries of the Colorado River
in the Grand Canyon are used by native fish species for spawning and
rearing young.
ISSUE
-------------------------------------------------------- Appendix IV:3
As defined in the final EIS, the issue of concern for fish resources
is how do dam operations affect fish--their food base, life cycles,
habitat, and ability to spawn?
INDICATORS
-------------------------------------------------------- Appendix IV:4
The indicators for fish resources listed in the final EIS are the
-- abundance of Cladophora and associated diatoms for the aquatic
food base;
-- reproduction, recruitment(survival to adulthood), and growth of
native fish;
-- reproduction, recruitment, and growth of nonnative warmwater and
coolwater fish; and
-- level of interactions between native and nonnative fish.
Both the biological productivity of the aquatic food base and the
physical characteristics of the environment (temperature, reliable
flow, turbidity, etc.) determine the limits of fish development.
Therefore, the EIS team's assessments of impacts on fish included
both of these areas. The analysis of impacts on the food base
focused on Cladophora production and used changes in the length of
wetted perimeter (the productive band of shoreline) to demonstrate
the differences between the alternatives.
The analyses of the impacts of the alternatives on native and
nonnative fish addressed (1) direct sources of mortality, (2)
potential for reproduction and recruitment, and (3) potential for
growth. The analysis factors included the temperature of the water
in the mainstem and access to tributaries for reproduction, food base
and stable nearshore and backwater environments for recruitment and
growth, flood frequency reduction measures, and
beach/habitat-building flows. The evaluation of native and nonnative
interactions was qualitative and focused on the effects of each
alternative on nearshore and backwater habitats used by native and
nonnative fish.
METHODOLOGY USED TO MAKE IMPACT
DETERMINATIONS
-------------------------------------------------------- Appendix IV:5
EIS team members told us that the EIS was developed through a dynamic
process involving three main groups--the EIS team, Glen Canyon
Environmental Studies officials and researchers, and representatives
of the cooperating agencies. Researchers provided data to the EIS
team that was responsible for the technical development of
alternatives and impact determinations, while the cooperating agency
group was a policy-level review body.
The initial impact determinations for fish and endangered fish were
primarily developed by two EIS team members assigned to that task on
the basis of their areas of expertise. These team members were from
the Arizona Game and Fish Department and FWS. No formal fish
subgroup or workgroup existed at that time and no formal reports were
produced.
These two team members developed their sections of the EIS through an
iterative process of drafting, discussions, and formal and informal
presentations to, and review by, the whole EIS team, as well as
through input from key researchers and colleagues with whom they
shared their work and from whom they solicited feedback.
Additionally, presentations of the impact assessments were made to
the cooperating agency group.
The EIS team's decision-making on fish issues was handled through
voting; the goal was a consensus-based product. Formal minutes of
the EIS team meetings were kept as a record of key decisions.
After public comments were received on the draft EIS, the Aquatic
Biology Team (ABT) workgroup was formed by Reclamation to respond to
the comments and to reorganize and rewrite the fish and endangered
species sections of the final EIS. This workgroup consisted of the
two original individuals and five additional EIS team members
representing Reclamation, the Hopi Tribe, the Hualapai Tribe, and the
Arizona Game and Fish Department. The workgroup was formed because
of the controversy and diametrically opposed positions of many of the
comments pertaining to aquatic biology. All members of the workgroup
participated in discussions and consensus decision-making on fish
issues and revised impact determinations; however, two individuals
were principally responsible for the rewrite of the sections under
review, with assistance and input from other EIS team and ABT
workgroup members. Of the 33,000 comments received on the draft EIS,
291 related to fish and 1,826 related to endangered species.
However, the vast majority of endangered species comments focused on
endangered fish.
The ABT did its work through an iterative process similar to that
used by the EIS team as a whole. Individuals were given assignments,
interactive discussions were held, and decisions were made through
consensus. According to ABT workgroup members, no official
documentation of the discussions and decisions of this group were
kept. Rather, information was shared among members through personal
communications, working meetings, and other collegial interactions.
Some information relevant to fish resources is contained in the
official minutes of the EIS team meetings.
On the basis of the comments received on the draft EIS and the
internal review, the EIS team/ABT workgroup made several major
changes to the fish section of the final EIS. Specifically:
-- In order to make the document less confusing and to facilitate
better integration of material, the fish section was
substantially revised and reorganized to include new information
and to integrate the extensive treatment of endangered fish
previously covered in the endangered species section of the EIS.
-- In response to the comments received and ongoing discussions,
Reclamation and FWS jointly agreed to move the endangered fish
research flows identified in FWS's reasonable and prudent
alternative from the preferred alternative to the Adaptive
Management Program. The EIS team implemented this change.
-- In response to the comments and concerns about interactions
between native and nonnative fish, information on competition
and predation and the predam fish population was expanded in the
final EIS. Information on nonnative fish and native/nonnative
interactions was added to the summary table of impacts.
-- In order to more explicitly recognize the uncertainty and
disagreement that exist among resource scientists about the
responses of fish to steady flow alternatives, the final EIS
describes those areas of uncertainty and includes reference to
this uncertainty in the matrix of potential impacts.
Because final results were not available to the ABT from many of the
phase II fish studies for the Glen Canyon Environmental Studies,
professional judgment was an important factor in developing fish
impact determinations for the final EIS. However, as one ABT member
stressed, these impact determinations were criterion based, using
important resource indicators as the basis for judgment. The ABT
workgroup and EIS team thus used a combination of available data and
professional judgment in developing the impact determinations for
fish.
DATA USED FOR MAKING IMPACT
DETERMINATIONS
------------------------------------------------------ Appendix IV:5.1
The research studies used to support the impact determinations on
fish resources are listed in the bibliography of the final EIS.
These studies include Glen Canyon Environmental Studies research, as
well as research developed by various state and federal agencies
involved with fish resources. Those studies deemed most useful by
several members of the EIS team who worked on fish issues are noted
in the Key Studies Identified subsection of this appendix.
EFFECTS OF FLOW ALTERNATIVES ON
FISH
-------------------------------------------------------- Appendix IV:6
Details of the anticipated impacts of the nine flow alternatives on
fish resources are found in the final EIS. However, the following
general statements can be made about the impacts of restricted
fluctuating flows versus steady flows on fish:
-- Fluctuating releases may affect fishes' access to tributaries
and backwater habitat and destabilize these backwaters by
alternately draining and refilling them with cold water from the
Colorado River mainstem.
-- Daily fluctuations in water level and cold water temperatures
would continue to suppress reproduction and recruitment of
nonnative warmwater fishes in the mainstem.
-- Fluctuations may increase turbidity (cloudiness) of the water,
which may provide cover for native fish and a degree of
protection from predation. Increased turbidity could also
provide foraging opportunities for the adult chub.
-- Steady flows would allow for increased warming of backwaters,
which would benefit young native fish. However, such improved
habitat conditions for native species might also benefit
nonnative species that are competitors or predators of these
native endangered fish. The potential for increased interaction
between native fish and their competitors and predators is
greatest under steady flows.
-- Steady flows might adversely affect maintenance of backwaters,
allowing them to become isolated and filled with sediment.
-- Steady flows could reduce the availability of fish forage and
slow its transport downstream.
The final EIS points out that any change in the dam's daily
operations or other management actions that result in improved
habitat conditions for native fish also would improve conditions for
nonnative warmwater and coolwater fish. Resource scientists are not
in agreement about what improving habitat conditions means in terms
of interactions between native and nonnative fish.
U.S. FISH AND WILDLIFE
SERVICE'S FINAL BIOLOGICAL
OPINION
-------------------------------------------------------- Appendix IV:7
The U.S. Fish and Wildlife Service conditioned its support of the
preferred alternative in the Glen Canyon Dam's EIS on the basis that
Reclamation would agree to additional research on the impact of
steady flows on fish as part of the Adaptive Management Program. In
December 1994, FWS issued its final biological opinion on the
operations of the Glen Canyon Dam, as required by section 7 of the
Endangered Species Act. In its final opinion, FWS supports a flow
regime that includes steady flows, and especially the Seasonally
Adjusted Steady Flow alternative, on the basis of the supposed
benefits for native fish. The final biological opinion concludes
that the Modified Low Fluctuating Flow preferred alternative is
likely to jeopardize the continued existence of the humpback chub and
the razorback sucker. Therefore, FWS issued a "jeopardy opinion"
concerning the EIS preferred alternative for those fish species.
In support of its 1994 opinion and findings, FWS states that "the
preferred alternative (without a selective withdrawal structure) does
not remove the issue of coldwater temperatures on reproductive
success in the mainstem...." Furthermore, FWS asserts that
"fluctuating flows limit solar warming of backwaters, flush
organisms and nutrients important as food resources, and force
earlier life stages of endangered and other native fishes out of
quiet protected waters into unfavorable mainstem conditions.
These conditions might include increased exposure to predation
and debilitating effects of cold water and increased
velocities."
Regulations implementing section 7 of the Endangered Species Act
state that a "reasonable and prudent alternative" to the recommended
action can be identified during the formal consultation process. For
the Glen Canyon Dam's EIS, FWS' reasonable and prudent alternative
recommends further studies of the effects of steady flows on
endangered and native fish, otherwise known as endangered fish
research flows. When implemented, these research flows would require
as many as 5 low release years (annual water releases at or near 8.23
million acre-feet). Because low water release years are expected to
occur only about half the time, it is uncertain how many total years
it would take to complete the research program. However, it is
likely that research flows could be completed within 10 years.
Endangered fish research flows would likely be between 8,000 cfs and
20,000 cfs with a spring through fall pattern and monthly releases
similar to the Seasonally Adjusted Steady Flow alternative. The
results from the research program would be monitored, and corrective
action would be taken if adverse effects on endangered species were
identified. Upon completion of the research flows and analysis of
the data, Reclamation is to implement, through the Adaptive
Management Program, any necessary changes in dam-operating criteria
necessary to comply with the Endangered Species Act. Reclamation and
FWS are to meet at least annually to coordinate reasonable and
prudent alternative activities and ensure that sufficient progress is
being made to remove the jeopardy opinion for the endangered species
that are affected by the operation of the Glen Canyon Dam. FWS
agreed to support the preferred alternative as modified by the
reasonable and prudent alternative.
Reclamation does not agree with FWS' jeopardy opinion on the
preferred alternative. In its comments on a draft version of the
biological opinion, Reclamation presented its concerns about FWS'
support of steady flows by noting that "scientific experts on native
fishes in the Colorado River system who were convened to discuss the
merits and detriments of flow alternatives on March 2, 1994, were not
totally supportive that the draft biological opinion flow scenario
will provide quantifiable benefit to native fish without additional
temperature modification." Furthermore, Reclamation was also
concerned that
"the logic for identifying the effects of steady flows as
related to the Colorado River system in the Grand Canyon is not
well supported. Data coming from the GCES program and in other
research programs on Southwestern ecosystems consistently point
to the importance of disturbance in maintaining the native
species assemblages. The statement that the ecology of the
Grand Canyon will be supported by steady flows is not supported
in the document or in the literature."
Nevertheless, Reclamation has agreed to implement elements of FWS'
reasonable and prudent alternative, including continued study of the
effects of steady flows on fish.
ASSESSMENT OF IMPACT
DETERMINATIONS
------------------------------------------------------ Appendix IV:7.1
EIS team and ABT workgroup members told us that they were pleased
with the process used in developing the EIS, believed that this
process was "reasonable," and were satisfied with their product.
Several noted the professional and open-minded approach brought to
the work by most of the team members. FWS representatives to the
team also said that they were pleased with the process up to the
point where the draft EIS and the draft biological opinion were
released. However, with the formation of the ABT workgroup, they
said, the focus shifted to a concern for supporting the preferred
alternative and "discrediting" the Seasonally Adjusted Steady Flow
alternative. Other EIS team/ABT workgroup members took exception to
this assertion, with one member stating that the preferred
alternative was not forced upon FWS. Another team member stated that
when it comes to the operations of the Glen Canyon Dam, NEPA (the
EIS) and the Endangered Species Act (the reasonable and prudent
alternative) did not complement each other very well.
REASONABLENESS OF THE
METHODOLOGY
------------------------------------------------------ Appendix IV:7.2
We received a variety of comments on the implementation of the fish
impact determination methodology. For example, many interviewees
expressed regret about the lack of coordinated time frames between
the completion of Glen Canyon Environmental Studies research and the
EIS development schedule, because the timing problem led to the use
of incomplete data for the fish resources.
One of the ABT workgroup's tasks was to explicitly deal with the
uncertain impacts of steady flows on fish resources. The leader of
the ABT workgroup told us that there were significant disagreements
among team members about how to handle this uncertainty, and that the
FWS representatives held a different opinion from other members of
the ABT. As with other decisions, this disagreement was handled
through open discussion with the goal of establishing consensus.
Many interviewees expressed the belief that the final EIS' increased,
explicit acknowledgement of uncertainty about flow impacts on the
fish resources was an important improvement in the document. Some of
these individuals told us that this change to the fish resource
section accurately reflects the disagreements and uncertainties
within the scientific community.
EIS team members told us that an important component of the process
of developing the impact determinations was the team's contacts with
Glen Canyon Environmental Studies officials for updates on research
results and the team's interactive relationship with key researchers.
However, while some of the key researchers with whom we talked
acknowledged that they had worked with EIS team members in this way,
others told us that the EIS team's contact with them had been minimal
or even nonexistent.
Some interviewees expressed the belief that private consultants
should not have been included on the EIS team because their loyalty
may be to present or future clients rather than to objective science.
On the other hand, one consultant was also mentioned by several
interviewees as one of the most knowledgeable individuals on fish and
other resource issues in the canyon. Furthermore, several
individuals expressed high regard for the work done by another
consultant on some of the key Glen Canyon Environmental Studies
research on the humpback chub.
Some EIS team members were also researchers whose work was being
reviewed for the EIS. One EIS team member expressed the belief that
this dual role was beneficial to the team because of their knowledge
about the latest scientific findings as they developed. Two
researchers, however, told us that they were troubled by this dual
role for EIS team members. One suggested that it constituted a
conflict of interest; the other was concerned that having individuals
reviewing their own work might have affected the objectivity with
which the research was examined.
OPINIONS ON DATA USED FOR
IMPACT DETERMINATIONS
------------------------------------------------------ Appendix IV:7.3
Limited data permit opinions to vary among members of the scientific
community on a number of issues related to fish. Some of these
differences occur because of disagreements over scientific
interpretations and viewpoints; others reflect personal,
institutional, and academic affiliations and rivalries. Differences
of opinion also exist on the issues related to the development of the
impact determinations on fish for the final EIS.
A number of the individuals we talked with both inside and outside of
the EIS preparation process expressed frustration that the final
results from many of the Glen Canyon Environmental Studies phase II
fish studies were not available to the EIS team and the ABT workgroup
for the development of the impact determinations in the final EIS.
According to several interviewees, this lack of final results--or
"hard data," as one EIS team member not on the ABT called
it--inevitably lead to an increased reliance on professional judgment
in developing impact determinations related to fish.
Opinions varied as to whether the lack of final results from some
phase II studies constituted a "limitation" on or simply a
"hindrance" to the development of the impact determinations. Some
interviewees told us that while it was unfortunate that final results
from phase II were not in, this was not a limitation on the
usefulness of the available data or the conclusions drawn from them.
They believed that if the final data had been available, the team's
determinations might have been more refined or supported, but their
conclusions (and the preferred alternative) would have remained the
same. Others believed that the lack of final results represented a
significant limitation on the impact determinations. Some of these
even suggested that the determinations or decisions might have
changed on the basis of these final research results or that if the
EIS team had used all the science available to them, "they would have
come up with a different alternative."
Despite these differences, most of those who expressed an opinion to
us said that the EIS team had used the "best available data" in
determining the impacts on fish. One said that the best available
data were used, although these data were not complete. Another told
us that while the best available data were used, other, better data
might have been available had the EIS time frames been changed to
accommodate the completion of the Glen Canyon Environmental Studies.
This individual further stated that the EIS team had developed
"reasonable interpretations from unreasonable data." Even some of
those individuals critical of the overall process agreed that the
"best available data" had been utilized.
PEER REVIEW OF STUDIES
------------------------------------------------------ Appendix IV:7.4
Reclamation and Glen Canyon Environmental Studies officials and
researchers told us that a three-tiered review process was developed
for all Glen Canyon Environmental Studies, regardless of resource
area. This process included (1) internal agency/organizational
review by the research entity, (2) Glen Canyon Environmental Studies
office review, and (3) external peer review under the auspices of the
Senior Scientist. However, a number of the researchers that we
interviewed were critical of the actual review process. Furthermore,
the individual responsible for overseeing this process told us that
only about 30 to 35 out of approximately 140 anticipated Glen Canyon
Environmental Studies had actually undergone the complete three-step
review.
RESULTS OF THE PROCESS
------------------------------------------------------ Appendix IV:7.5
As to the results of the process, the views on the preferred
alternative varied among interviewees. Several supported the
preferred alternative, especially when combined with the
beach/habitat-building "spike" flow. Others supported flow regimes
that include the Seasonally Adjusted Steady Flow alternative favored
by FWS. Some interviewees told us that they were originally inclined
to support steady flows but changed their views in favor of
fluctuating flows on the basis of the developing data. Two
interviewees endorsed a flow regime that closely resembles the
"natural hydrograph," including floods and low flows. Some
researchers told us that they had not read or reviewed the final EIS
and were unfamiliar with the specifics of the flow alternatives.
ABT WORKGROUP LEADER'S
RESPONSES TO THE ISSUES
RAISED
------------------------------------------------------ Appendix IV:7.6
The leader of the ABT workgroup provided us with detailed comments on
and responses to each of the issues noted above. He agreed with some
statements or positions and disagreed with others. For example, he
agreed that the lack of final results from the fish research studies
was frustrating and that the limited data allow differences of
opinion on and scientific interpretation of the impacts on fish
resources. However, he disagreed with the statement that had final
results been available, the impact determinations might have been
different. Rather, he said the final data would have refined the EIS
team's understanding of the issues and supported their conclusions
but would not have changed the impact determinations or the preferred
alternative.
His overall position, taking into consideration the various
perspectives and opinions expressed, was that
-- the process used in making the impact determinations on fish
resources was reasonable,
-- the methodologies employed in this process were appropriate,
-- the data used were the best available, and
-- the results of the impact determinations are reasonable.
SCOPE AND METHODOLOGY
------------------------------------------------------ Appendix IV:7.7
To determine the data and process used in developing the impacts on
fish resources, we identified and reviewed the following documents:
the draft EIS and associated appendixes; the preliminary final EIS;
the final EIS; the public comments on the draft EIS; Reclamation's
analysis of and the EIS team's responses to these comments; copies of
minutes of the EIS team meetings; summaries of the meetings of the
cooperating agencies; and Reclamation's newsletters on the EIS
process. We also obtained and reviewed FWS' draft biological opinion
and final biological opinion on the operation of the Glen Canyon Dam,
Reclamation's comments on the draft biological opinion and official
response to the final biological opinion, and FWS' Fish and Wildlife
Coordination Act report (see list of related documents below for full
citations).
We obtained a copy of the final EIS bibliography from Reclamation,
with titles sorted by each resource area. The fish bibliography
contained 57 titles, while the endangered species bibliography
contained 29 titles. We asked three EIS team members recommended to
us as key initial contacts on fish and endangered species issues to
review the titles related to these resources and to point out those
studies they believed had been most useful in developing the impact
determinations.
To assess the procedures followed and obtain views on the quality of
data used in preparing fish issues, we interviewed the EIS team
members who had primary responsibility for writing the fish and
endangered species section of the draft EIS, as well as all other
members of the ABT workgroup, which was formed to revise and
reorganize these two sections following the receipt of public
comments on the draft EIS. Additionally, we met with several other
members of the EIS team, including two EIS team members not on the
ABT workgroup who requested the opportunity to discuss fish and
endangered species issues with us. We spoke with several scientists
identified by team members and others as having done key research
used by the workgroup and the full EIS team in developing the fish
impact determinations. We interviewed other agency officials with
information about the EIS and Glen Canyon Environmental Studies
processes.
Finally, we asked the leader of the ABT workgroup to review the
factual accuracy of our description of the process for developing the
impact determinations for fish resources. He agreed that our
description was generally accurate but made some suggestions for
changes. We have incorporated these changes into our description of
the process. We also presented him with our preliminary findings on
fish resources in order to provide him with an opportunity to comment
on and respond to the various issues raised through our audit work.
KEY STUDIES IDENTIFIED
------------------------------------------------------ Appendix IV:7.8
The following are titles from the fish bibliography selected by at
least two of the three key initial contacts recommended to us.
Angradi, T.R., R.W. Clarkson, D.A. Kinsolving, D.M. Kubly, and
S.A. Morgensen. "Glen Canyon Dam and the Colorado River: Responses
of the Aquatic Biota to Dam Operations," Glen Canyon Environmental
Studies Technical Report. Phoenix, Arizona: Arizona Game and Fish
Department, 1992.
Glen Canyon Environmental Studies Phase II 1992 Annual Report.
Prepared for the Bureau of Reclamation, Glen Canyon Environmental
Studies. Phoenix, Arizona: Arizona Game and Fish Department, 1993.
Gorman, O.T., S.T. Leon, and O.E. Maughan. "Habitat Use by
Humpback Chub, Gila Cypha, in the Little Colorado River and Other
Tributaries of the Colorado River in the Grand Canyon," Glen Canyon
Environmental Studies Phase II Annual Report. Prepared for the
Bureau of Reclamation by the U.S. Fish and Wildlife Service,
Pinetop, Arizona, and the Arizona Cooperative Fish and Wildlife
Research Unit, Tucson, Arizona, 1993.
Leibfried, W.C. "Utilization of Cladophora Glomerata and Epiphytic
Diatoms as a Food Resource by Rainbow Trout in the Colorado River
Below Glen Canyon Dam in Arizona," Masters Thesis. Flagstaff,
Arizona: Northern Arizona University, 1988.
Leibfried, W.C., and D.W. Blinn. "The Effects of Steady Versus
Fluctuating Flows on Aquatic Macroinvertebrates in the Colorado River
below Glen Canyon Dam, Arizona," Glen Canyon Environmental Studies
Technical Report. Salt Lake City, Utah: Bureau of Reclamation,
1987.
Maddux, H.R., D.M. Kubly, J.C. DeVos, Jr., W.R. Persons, R.
Staedicke, and R.L. Wright. "Effects of Varied Flow Regimes on
Aquatic Resources of Glen and Grand Canyons," Glen Canyon
Environmental Studies Technical Report. Phoenix, Arizona: Arizona
Game and Fish Department, 1987.
McGuinn-Robbins, D.K., Comparison of the Number and Area of
Backwaters Associated With the Colorado River in Glen and Grand
Canyons, Arizona. Phoenix, Arizona: Arizona Game and Fish
Department, 1994.
Suttkus, R.D., G.H. Clemmer, C. Jones, and C.R. Shoop. Survey of
Fishes, Mammals and Herpetofauna of the Colorado River in Grand
Canyon. National Park Service, Colorado River Research Series
Contribution no. 34, 1976.
Usher, H.D., D.W. Blinn, G.C. Hardwick, and W.C. Leibfried.
Cladophora Glomerata and Its Diatom Epiphytes in the Colorado River
Through Glen and Grand Canyons: Distribution and Desiccation
Tolerance. National Technical Information Service No.
PB88-183454/AS, 1986.
Weiss, J. "The Relationship Between Flow and Backwater Fish Habitat
of the Colorado River in Grand Canyon" (draft report), Glen Canyon
Environmental Studies Technical Report. Flagstaff, Arizona: Bureau
of Reclamation, 1993.
Weiss, S.J. Spawning, Movement, and Population Structure of
Flannelmouth Sucker in the Paria River. Masters Thesis. Tucson,
Arizona: University of Arizona, 1993.
Titles related to fish selected from the endangered species
bibliography by at least two of these contacts were as follows.
Kubly, D.M., The Endangered Humpback Chub (Gila Cypha) in Arizona: A
Review of Past Studies and Suggestions for Future Research (draft
report). Salt Lake City, Utah: Prepared by the Arizona Game and
Fish Department for the Bureau of Reclamation, 1990.
Tyus, H.M., and C.A. Karp. "Habitat Use and Streamflow Needs of
Rare and Endangered Fishes, Yampa River, Colorado," Fish and Wildlife
Service Biological Report, vol. 89, no. 14. Vernal, Utah: 1989.
Valdez, R.A. Life History and Ecology of the Humpback Chub in Grand
Canyon. Logan, Utah: BIO/WEST, 1994.
Valdez, R.A., and M. Hugentobler (editors). Characterization of the
Life History and Ecology of the Humpback Chub (Gila Cypha) in the
Grand Canyon. Annual Report 1992 to Bureau of Reclamation. Logan,
Utah: BIO/WEST Report No. TR-250-06, 1993.
Valdez, R.A., W.J. Masslich, and W. Leibfried. Characterization of
the Life History and Ecology of the Humpback Chub (Gila Cypha) in the
Grand Canyon. Annual Report to the Bureau of Reclamation. Logan,
Utah: BIO/WEST Report no. TR 250-04, 1992.
Valdez, R.A., A. Wasowicz, and W. Leibfried. Characterization of
the Life History and Ecology of the Humpback Chub (Gila Cypha) in the
Grand Canyon. Logan, Utah: BIO/WEST Trip Report no. 7-1992, 1992.
In addition to the studies identified above from the final EIS
bibliography, other documents are relevant to fish issues. These
documents include the following.
Carothers, S.W., and B.T. Brown. The Colorado River Through Grand
Canyon: Natural History and Human Change. Tucson, Arizona:
University of Arizona Press, 1991. The coauthors of this book were
both key researchers identified in our work. Furthermore, Dr.
Carothers was a member of the EIS team and the Aquatic Biology Team
workgroup. Portions of this book address fish and endangered species
issues, drawing from GCES research.
Clarkson, R.W., O.T. Gorman, D.M. Kubly, P.C. Marsh, and R.A.
Valdez. "Management of Discharge, Temperature, and Sediment in Grand
Canyon for Native Fishes." Mar. 1994. A "white paper" provided to
the EIS team, written by a number of key fish researchers from
various agencies/organizations. In it, the researchers present their
thoughts on native fish management issues. This document was
mentioned by EIS team members as influential in their early
discussions on fish issues. However, it does not appear in the final
EIS bibliography.
Colorado River Endangered Fishes Critical Habitat Draft Biological
Support Document. U.S. Fish and Wildlife Service, Sept. 3, 1993.
Critical habitat must be designated for endangered species. This
document was mentioned by one researcher with whom we spoke as an
example of how agencies should handle scientific data in
environmental policy papers.
Draft Recovery Implementation Program for Endangered Fish Species in
the Upper Colorado River Basin. U.S. Fish and Wildlife Service,
Sept. 3, 1993. This document is not directly related to activities
at the Glen Canyon Dam but contains information about the recovery of
endangered fish in the Colorado River Basin.
Final Biological Opinion: Operation of Glen Canyon Dam as the
Modified Low Fluctuating Flow Alternative of the Final Environmental
Impact Statement (2-21-93-F-167). U.S. Fish and Wildlife Service,
Dec. 21, 1994. The final biological opinion and its related
reasonable and prudent alternative were developed by FWS in response
to Reclamation's request for formal consultation under section 7 of
the Endangered Species Act. The final biological opinion states that
the preferred alternative is likely to jeopardize the continued
existence of the humpback chub and razorback sucker and is likely to
destroy or adversely modify designated critical habitat. FWS'
position is that the Seasonally Adjusted Steady Flow alternative may
be more beneficial for these endangered native fish.
Glen Canyon Dam: Beach/Habitat-Building Test Flow, Final
Environmental Assessment and Finding of No Significant Impact.
Bureau of Reclamation, Feb. 1996. This report presents the findings
of the required environmental assessment prepared prior to
implementing the spring 1996 "spike" flow.
Glen Canyon Dam Discharge Temperature Control Draft Appraisal Report.
Bureau of Reclamation, June 14, 1994. This draft report discusses
options for studying and implementing temperature controls at the
Glen Canyon Dam, including building a selective withdrawal structure.
Minckley, W.L. "Native Fishes of the Grand Canyon Region: An
Obituary?" Colorado River Ecology and Dam Management. Proceedings of
a Symposium, May 24-25, 1990, Santa Fe, New Mexico, pp. 124-177.
Washington, D.C.: National Academy Press, 1991. This paper is
listed in the final EIS bibliography. It is a part of the book
developed from a symposium sponsored by the National Research
Council's Committee to Review the Glen Canyon Environmental Studies.
This paper is an overview of native fish issues by a recognized
expert in the field.
Operation of Glen Canyon Dam - Fish and Wildlife Coordination Act
Report. U.S. Fish and Wildlife Service, June 28, 1994. In
accordance with the Fish and Wildlife Coordination Act, FWS submitted
this report to Reclamation with recommendations in connection with
the dam's operations. The Fish and Wildlife Coordination Act does
not require Reclamation to accept the recommendations; however,
Reclamation has agreed that reasonable and practicable
recommendations will be implemented. The Fish and Wildlife
Coordination Act ensures that fish and wildlife receive equal
consideration during the planning and construction of federal water
projects.
"Organisms and Biological Processes," River Resource Management in
the Grand Canyon, pp. 84-117. National Research Council Committee
to Review the Glen Canyon Environmental Studies, 1996. This is a
chapter of a National Research Council Committee report on GCES. The
purpose of this report and the committee's task was to review
research that was done in connection with the GCES and to comment on
the application of science in the management program of the Colorado
River.
Response to the Final Biological Opinion on the Operations of Glen
Canyon Dam. Bureau of Reclamation, Apr. 6, 1995. This is
Reclamation's official response to, and addressing of, the issues
presented in the final biological opinion. In it, Reclamation states
that it does not agree with all the points made or positions taken by
FWS but will take steps to comply with them.
Threatened Native Wildlife in Arizona. Phoenix, Arizona: Arizona
Game and Fish Department, 1988. This publication presents
information on a variety of species and subspecies including fish,
amphibians, reptiles, birds, and mammals.
OFFICIALS INTERVIEWED
------------------------------------------------------ Appendix IV:7.9
We interviewed the following individuals about the fish impact
determinations and the related Glen Canyon Dam EIS issues.
Michael Armbruster, Bureau of Reclamation
Frank Baucom, U.S. Fish and Wildlife Service
Debra Bills, U.S. Fish and Wildlife Service
Bryan Brown, SWCA, Inc.
Steven Carothers, SWCA, Inc., Hopi Tribe
Michael Douglas, Arizona State University
Owen Gorman, U.S. Fish and Wildlife Service
David Harpman, Bureau of Reclamation
Christine Karas, Bureau of Reclamation
Dennis Kubly, Arizona Game and Fish Department
William Leibfried, SWCA, Inc., Hualapai Tribe
Gordon Lind, Bureau of Reclamation
Paul Marsh, Arizona State University, Center for
Environmental Studies
Margaret Matter, Western Area Power Administration
Debra McGuinn-Robbins, Arizona Game and Fish Department
Wendell Minckley, Arizona State University
Anthony Morton, Western Area Power Administration
Ronald Moulton, Western Area Power Administration
Clayton Palmer, Western Area Power Administration
Timothy Randle, Bureau of Reclamation
Lawrence Riley, Arizona Game and Fish Department
John Thomas, SWCA, Inc., Navajo Nation
Harold Tyus, University of Colorado, Boulder
Richard Valdez, BIO/WEST, Inc.
David Wegner, Bureau of Reclamation, Glen Canyon
Environmental Studies
Judy Weiss, Former Glen Canyon Environmental Studies
Researcher (currently not active in the research community)
HYDROPOWER
=========================================================== Appendix V
The purpose of this appendix is to review the methodology and key
assumptions that the Bureau of Reclamation used to estimate the
economic impact on hydropower of alternative water releases at the
Glen Canyon Dam. The Glen Canyon Dam, which began producing power in
1964, is part of the Colorado River Storage Project, a federal
project for water development in the Upper Colorado River Basin.
Reclamation's purpose in analyzing hydropower issues in the EIS was
to determine the impacts on the power system of potential changes in
the Glen Canyon power plant operations. We found that Reclamation's
methodology for estimating the economic cost of changing the dam's
operations is reasonable and that Reclamation used the best available
information at the time of the study.
Reclamation has estimated that the annual economic cost of changing
the operations at the dam could range from -$1.5 million under the
Maximum Powerplant alternative to $123.5 million under the Seasonally
Adjusted Steady Flow alternative (in 1991 dollars, relative to the
No-Action alternative). We found shortcomings in several of the
assumptions Reclamation used in the power analysis, inconsistencies
in some results, and two phase III computational errors, which
suggest that the estimated economic impacts may be either overstated
or understated. Because future events are inherently uncertain and
because the actual cost of changing the dam's operations could also
depend on factors yet to be determined, such as whether or not an
Endangered Fish Research Program is implemented and the pace of
deregulation in the electric utility industry, the actual economic
impacts on power users may differ from those estimated. However,
because the shortcomings we identified generally affect the estimates
for all of the alternatives, we do not believe that addressing the
shortcomings would alter the relative ranking of the fluctuating and
steady flow alternatives. Furthermore, Reclamation and
representatives of the power industry believe that the results of the
hydropower analysis presented in the final EIS are reasonable and
usable. As a result, we believe that Reclamation's estimated
economic impacts can be used to compare in a general way the economic
trade-offs that are associated with the various flow alternatives.
INTRODUCTION
--------------------------------------------------------- Appendix V:1
The Glen Canyon Dam is owned, operated, and maintained by the Bureau
of Reclamation. The Western Area Power Administration (WAPA)--a
power-marketing administration established in the Department of
Energy Organization Act of 1977--markets and transmits the power
produced at the dam (that is, power in excess of that used by
projects involving irrigation and flood control). WAPA, in
compliance with the Colorado River Storage Project (CRSP) Act of
1956, is obligated to provide first priority to the power needs of
CRSP Participating Projects (for example, Reclamation's irrigation
projects). Power that is surplus to this "project use" requirement
is then marketed by WAPA to wholesale firm-power customers entitled
to preference allocations (for example, municipal and county
utilities, rural electric cooperatives, and other nonprofit
organizations financed under the Rural Electrification Act of 1936).
WAPA generally enters into long-term contracts with its preference
customers to sell firm power (that is, long-term capacity and energy)
at a rate that is limited to the recovery of its costs and all costs
assigned to power for repayment, including that portion of irrigation
costs beyond the ability of the user to repay per the CRSP Act (this
rate is referred to as the Salt Lake City Area/Integrated
Projects--SLCA/IP--rate). If its customers require additional energy
and additional energy is available, WAPA may sell short-term power to
them at a price ranging from the SLCA/IP rate to the spot market
rate, depending on market conditions. If WAPA's generation exceeds
the needs of Reclamation's project use requirements and of the
SLCA/IP's firm-power customers, energy may be exchanged with other
suppliers or may be sold on the spot market. On the other hand, if
WAPA's generation is less than the long-term firm-power commitments,
WAPA must purchase replacement power on the spot market, make
short-term contractual purchases, or exchange energy from other
suppliers to make up the deficit.
Historically, maximum power production at the dam has been limited to
1,300 megawatts, which corresponds to a water release of 31,500 cubic
feet per second. Power production (that is, instantaneous output,
measured in watts) is a function of reservoir head, flow, and the
generating capacity of the dam's turbines. The dam has eight
electric generators that were originally installed when the dam was
constructed and "uprated" to 1,356 megawatts during the 1980s.
Energy production (that is, power produced over time, measured in
watt-hours) is a function of capacity over time or the amount of
water released over time. During a typical year, water releases
average about 10 million acre-feet, corresponding to an average
annual energy production of about 5 million kilowatt hours.\1
Currently, WAPA markets power from the Glen Canyon Dam to
approximately 180 preference customers located mainly in Colorado,
New Mexico, Arizona, Utah, Nevada, and Wyoming. These customers sell
electricity to about 1.7 million residential, commercial, industrial,
and agricultural customers. Since November 1, 1991, the Department
of the Interior has operated the dam under an interim flow regime,
whereby water releases are generally limited to a maximum of 20,000
cubic feet per second (cfs).
Reclamation's purpose in preparing the Glen Canyon Dam's
environmental impact statement was to determine specific options that
could be implemented to minimize the adverse impacts on the
downstream resources and Native American interests in the Glen and
Grand canyons. In connection with hydropower production, the key EIS
issue was to determine the impacts on the power system of potential
changes in the Glen Canyon power plant's operations. Reclamation was
responsible for evaluating the economic, project repayment, and rate
impacts of changing the magnitude and timing of water releases from
the Glen Canyon Dam. To make its assessment, Reclamation identified
power operations flexibility (for example, the ability of WAPA to
provide services to its customers) and power-marketing resources (for
example, capacity and energy), costs, and rates as EIS indicators.
Reclamation examined the effect that nine different alternative flow
regimes could have on the EIS indicators. However, only the impact
on the power- marketing indicator was quantified; the impact on power
operations flexibility was assessed qualitatively.
Under each of the nine alternative flow regimes, the total volume of
water released annually would be the same and would depend on a
number of factors, including long-range operating criteria, such as
an annual minimum flow of 8.23 million acre-feet and balanced storage
between Lake Powell and Lake Mead (formed by the Hoover Dam).
However, the nine alternatives would differ in terms of their daily,
monthly, and seasonal flows.
The nine alternative flow regimes can be grouped into three main
categories: (1) unrestricted fluctuating flows, (2) restricted
fluctuating flows, and (3) steady flows. The unrestricted
fluctuating flow alternatives include the No-Action and Maximum
Powerplant regimes. The No-Action alternative, which reflects
pre-1991 historic operations, would allow daily fluctuations up to
30,500 cfs, depending on the season. The Maximum Powerplant
alternative would allow daily fluctuations up to 32,200 cfs, also
depending on the season.
The restricted flow alternatives include the high, moderate, modified
low, and interim low fluctuating flow regimes. In general, the
restricted fluctuating flow alternatives would restrict ramping
(increases or decreases in cfs per hour) and daily fluctuations (cfs
per 24 hours) and increase the daily minimum release. In general,
maximum releases would be no greater than 31,500 cfs for the high and
moderate flow alternatives, 25,000 cfs for the modified low flow
alternative, and 20,000 cfs for the interim low flow alternative.
The steady flow alternatives include the existing monthly volume,
seasonally adjusted, and year-round steady flow regimes. In general,
the steady flow alternatives would restrict daily fluctuations to
plus or minus 1,000 cfs, providing steady flows on either a monthly,
seasonal, or year-round basis. Under the seasonally adjusted flow
alternative, the highest releases (that is, no greater than 18,000
cfs) would occur in May and June, and the lowest releases would occur
between August and December.
Under habitat maintenance flows, however, releases could be greater
than 31,500 cfs under the Moderate Fluctuating Flow alternative,
greater than 25,000 under the Modified Fluctuating Flow alternative,
and greater than 18,000 cfs under the Seasonally Adjusted Steady Flow
alternative.
One of the key attributes of hydropower is that it can be turned on
and off relatively quickly, allowing operators to respond to daily,
hourly, or instantaneous fluctuations in the demand for electricity.
Demand is typically highest during on-peak periods (for example,
Monday through Saturday, 7 a.m. to 11 p.m.) and lowest during
off-peak periods. Operationally, hydropower generators can respond
to changes in load more easily than most other types of generation,
which makes hydropower operationally more valuable any time load
following (power generation that instantaneously rises and falls in
response to the demand for electricity) is required. As a result of
the operating constraints under the restricted and steady flow
regimes, the maximum flows would generally be lower during on-peak
periods, reducing on-peak energy production. Consequently, in
general, the flexibility of power operations would be reduced under
the restricted and steady flow alternatives. In addition, capacity
(that is, instantaneous output) would be lower, generally speaking,
under the restricted and steady flow alternatives, leading utilities
to seek alternative and potentially higher-cost sources of peaking
capacity. However, the total energy produced at the Glen Canyon Dam
would not change--energy production would simply be shifted from the
on-peak demand periods when it is most valuable to off-peak periods
when it is less valuable. The additional energy produced during the
off-peak periods would be available for sale in regional and other
electricity markets.
--------------------
\1 A kilowatt hour is the amount of electrical energy involved in a
demand or requirement for 1 kilowatt over a period of 1 hour.
RECLAMATION'S POWER IMPACTS
METHODOLOGY IS GENERALLY
REASONABLE
--------------------------------------------------------- Appendix V:2
We found that Reclamation's methodology for estimating the economic
impact of alternative water releases at the dam is generally
reasonable. For example, a strength of Reclamation's power analysis
is that it was conducted by a committee of specialists from the
federal government, the utility industry, and the environmental
community, and as a result, the analysis reflects a broad range of
views. Other key features of the power analysis that we found
appropriate include the use of a detailed analysis to determine the
impact of alternative flows on hydropower production at the dam, a
national perspective to estimate economic impacts, utility-specific
data to determine the economic impact to the regional power system,
and a sensitivity analysis to test the impact of key assumptions.
Finally, Reclamation was responsive to the comments received on the
draft EIS and partially revised the power analysis for the final EIS.
POWER RESOURCES COMMITTEE
CONDUCTED POWER STUDY
------------------------------------------------------- Appendix V:2.1
To draw on expertise from the federal government, the utility
industry, and the environmental community, Reclamation created a
Power Resources Committee (the Committee) in 1989 to study the
impacts of the various flow alternatives on the power system. Under
Reclamation's lead, the Committee's responsibility was to define the
scope of analysis, select modeling techniques, make basic
assumptions, review preliminary analyses, and report findings. The
Committee included representatives from the Colorado River Energy
Distributors Association, the Environmental Defense Fund, and WAPA.
In addition, Reclamation's primary contractor--HBRS, Inc. (now
Hagler Bailly Consulting)--subcontracted with Stone & Webster
Management Consultants, Inc., to serve as technical advisor to the
Committee, collect data, run simulation models, synthesize findings,
and write and prepare the Committee's reports. Another
subcontractor, EDS Management Consulting Services, Inc., was involved
in later phases of the power analysis. We found that the Committee
conducted a comprehensive analysis of the impacts on the power
system.
Using federal principles and guidelines for water resource projects
and the professional judgments of its members, the Committee
conducted an extensive analysis of the potential impacts on the power
system from alternative water releases at the dam. For example, the
Committee analyzed the impact on the regional power market that
receives power from the dam, involving utilities in Arizona, New
Mexico, Nevada, Utah, Colorado, and Wyoming. In addition, using
historic operations as a base case or "No-Action" alternative, the
Committee estimated the economic impacts of several different
alternative flow regimes on the dam's power output and the regional
power system over a 50-year period beginning in 1991.
POWER RESOURCES COMMITTEE
CONDUCTED DETAILED ANALYSIS
OF IMPACTS ON POWER
PRODUCTION
------------------------------------------------------- Appendix V:2.2
The Committee conducted a detailed analysis to determine the
potential impact of the alternative water releases on the dam's power
production. For example, the Committee used future projections of
hydrologic conditions at the dam, two different marketing approaches,
and standard microeconomic principles to estimate the amount of power
that would be available for sale under each alternative flow regime
over the 50-year analysis period.
To develop long-term monthly projections of water releases and power
and energy production at the dam, the Committee used Reclamation's
Colorado River Simulation System. This system projects future water
conditions at the dam on the basis of historic water conditions. In
addition, the Committee used two marketing approaches to estimate the
power and energy that could be marketed over the analysis period.
One marketing approach--the Contract Rate of Delivery (CROD)--is
based on the current marketing practices used by WAPA to market the
dam's power and assumes that a fixed amount of power would be
available for marketing. The other approach--the Hydrology
approach--assumes that a variable amount of power would be available
for marketing, depending on the actual hydrologic conditions at the
dam. In general, the Committee found that more capacity is forgone
under the CROD approach than under the Hydrology approach in moving
from the No-Action alternative to the fluctuating and steady flow
alternatives.
Under the CROD approach, the power available under each alternative
flow regime would be fixed at an amount that could be expected to be
available roughly 9 years out of 10.\2 During periods when less power
is available, WAPA is responsible for purchasing the replacement
power needed to meet its contract commitments.
By contrast, the Hydrology marketing approach assumes that the power
and energy available for marketing would depend on the actual
hydrologic conditions at the dam, which could vary monthly, daily, or
hourly, depending on streamflow and reservoir storage conditions.
WAPA's customers would be responsible for purchasing additional power
during periods when the dam's production is insufficient to meet
their needs.
The Committee used two different methods to estimate the capacity and
energy that would be available under the CROD and Hydrology marketing
approaches for the fluctuating flow alternatives. The geometric
method was used to estimate the power and energy available under the
CROD. The peak-shaving algorithm was used to estimate the capacity
and energy available under the Hydrology marketing approach. The
geometric method uses geometric principles to approximate hourly
operational constraints and calculate the amount of capacity and
energy available on a daily basis. By contrast, the peak-shaving
algorithm uses load projections, which vary hourly, daily, and
seasonally, and operational constraints to optimally allocate water
releases during periods of peak demand. The resulting estimates of
capacity and energy represent the amount that would be available for
each marketing arrangement for each of the alternatives.\3
In general, less capacity is available for the No-Action alternative
under the Hydrology approach than under the CROD approach. For
example, the Committee found that the marketable capacity during the
winter under the CROD would be about 1,058 megawatts compared to an
average of 923 megawatts under Hydrology.
--------------------
\2 The CROD level is based on WAPA's desire to reduce the risk of not
being able to provide a reliable level of power and energy.
\3 Both the geometric method and the peak-shaving algorithm have
limitations. The geometric method assumes load does not vary on a
daily basis, and thus may not accurately capture daily changes in
load, and the peak-shaving algorithm assumes perfect knowledge of
future hourly demand, and thus may overoptimize the hydro dispatch.
POWER RESOURCES COMMITTEE
USED NATIONAL PERSPECTIVE TO
ESTIMATE ECONOMIC IMPACTS
------------------------------------------------------- Appendix V:2.3
The Committee followed federal principles and guidelines for water
resources planning where applicable in developing the analysis of the
impacts to the power system. For example, consistent with the
federal principles and guidelines, the Committee used a "federal
economic analysis" approach to estimate the economic costs to society
from changing water releases at the federally owned Glen Canyon Dam.
The Committee also analyzed the financial impacts on individual
utilities using a "utility economic analysis" approach, and the
impact on the retail rates of selected end-users.
Federal principles and guidelines state that the federal objective of
water and related land resources planning is to contribute to the
national economic development consistent with protecting the
environment, pursuant to national environmental statutes, applicable
executive orders, and other federal planning requirements.\4 The
principles and guidelines further state that contributions to
national economic development are increases in the net value of the
national output of goods and services, expressed in monetary units.
Consistent with this guidance, the Committee included in its economic
analysis only those costs associated with constructing and operating
new generating resources and operating those existing generating
resources that would be needed to replace forgone power at the dam.
The Committee excluded other costs--referred to as "transfer
payments"--from the economic analysis. Transfer payments, including
the fixed capital costs of currently operating powerplants, reflect a
redistribution of income from one group in society to another and, as
a result, do not reflect a net cost to society. For example, when a
utility purchases power from another utility to replace forgone power
at the dam, the appropriate measure of costs for the national
economic perspective is the marginal cost of production. The fixed
capital cost of the existing powerplant is considered a "sunk" cost.
Because the decision to build the existing powerplant was made before
the decision to change the dam's operations, the fixed costs of the
existing plant are not an economic impact of changes in the dam's
operations.
Because the regional power system currently has excess generating
capacity, the economic impacts of the alternative flow regimes are
lower during the early years of the 50-year analysis period.
Economic costs rise over time, however, as the region's excess
capacity is used up and new resources are constructed to replace
forgone capacity at the dam.
In addition to the federal economic analysis, the Committee also
measured the financial cost to individual utilities in a utility
economic analysis. In estimating the financial impact on utilities,
the Committee included transfer payments that incorporate such costs
as the fixed costs of existing powerplants. In general, the
financial impacts are substantially higher than the economic impacts
because they include transfer payments between utilities. The
Committee also examined the impact of higher financial costs on the
retail rates of some end-use customers.
--------------------
\4 Economic and Environmental Principles and Guidelines for Water and
Related Land Resources Implementation Studies, U.S. Water Resources
Council, Mar. 10, 1983.
POWER RESOURCES COMMITTEE
CONDUCTED DETAILED ANALYSIS
OF IMPACTS ON LARGE
UTILITIES
------------------------------------------------------- Appendix V:2.4
The Committee conducted a detailed analysis of the impact of
alternative flows on seven utilities from the regional power
market.\5 In addition, the Committee used state-of-the-art and
industry-standard simulation models to project the power resource
additions and the production costs that the large utilities would
incur to replace forgone power at the dam. In addition to the
large-utility analysis, the Committee also estimated the impact of
the alternative flow regimes on about 100 smaller utilities, using a
spreadsheet model.
The Committee divided the regional power market into two basic
groups: (1) seven large utilities, which own generating resources
and sell power to other utilities and which represent about one-half
of the regional power market, and (2) about 100 small utilities,
which rely primarily on other utilities to generate their power
needs.
From the large utilities, the Committee collected detailed data such
as load and peak demand forecasts, the capacity and the operating
costs and operating life of each generating unit, firm load purchases
and sales, and the current and projected demand-side management
programs.\6 In addition, the Committee developed assumptions about
future prices for natural gas, oil, coal, and nuclear power and the
future costs of adding new generating resources.
On the basis of the utility-specific data and using the Electric
Generation Expansion Analysis System (EGEAS), the Committee
calculated for the base case and each alternative flow regime each
large utility's future expansion plan. The expansion plans represent
the least-cost combination of new generating resources (or
demand-side management programs) and purchased power that each
utility would need to meet future demand for electricity.\7 In
addition to the EGEAS model, the Committee used the Electric Utility
Financial and Production Cost Model (Elfin) to cross-check the
production cost estimates. The Committee used a 20-year planning
period, beginning in 1991, to develop the expansion plans; a 30-year
extension period was added on to complete the 50-year analysis
period. Under the extension period, load was held constant but costs
were allowed to escalate.
To model the large utilities in an integrated way, the Committee used
several interconnected utility systems--consisting of a large utility
and other utilities that sell or purchase power from the large
utilities--to determine the effect of resource coordination on the
selection of future generating resources by the large utilities. The
large utilities were modeled to use their own generation resources to
meet load demand. However, a utility was allowed to meet deficits or
surpluses by purchasing energy from or selling it to its
interconnected system.
Because most of the modeled small utilities rely on other utilities
to generate their power needs, the Committee used historic load data
from the small utilities, replacement costs from the large-utility
analysis, and a spreadsheet model to estimate the economic impact on
small utilities over the analysis period. For example, the cost to a
small utility of replacing forgone capacity was calculated as the
increase in capacity and/or production costs incurred by the small
utility's alternate supplier (that is, large utility). Unlike the
large-utility analysis, however, the estimated costs for small
utilities may not necessarily reflect the least-cost approach for
replacing forgone power. For example, demand-side management
programs were not considered as an option that small utilities could
use to replace forgone power.
For both large and small utilities, the Committee calculated the
economic costs for the base case and each alternative flow regime,
under both the CROD and Hydrology marketing approaches. A discount
rate of 8.5 percent was used to convert the annual stream of future
economic costs to 1991 present valued dollars.\8 The Committee also
"levelized" the total present-value cost estimate over the 50-year
period to determine the annual levelized costs.
The difference between the base case and each alternative flow regime
reflects, essentially, the cost of adding new generating capacity to
replace forgone peaking power, and the cost of operating new and
existing generating units to replace the energy shifted from on-peak
periods to off-peak periods. A simplified representation of the
Committee's methodology is shown in figure V.1.
Figure V.1: Simplified
Representation of the Power
Resource Committee's Power
Systems Economic Impact
Methodology
(See figure in printed
edition.)
(See figure in printed
edition.)
GAO presentation of the Bureau of Reclamation's data.
--------------------
\5 One of the seven large utilities is no longer in existence.
\6 Demand-side management programs are used by utilities to promote
more efficient energy use and include, for example, rebating or
subsidizing the purchase of more efficient home appliances.
\7 The expansion plans were determined on the basis of the impacts of
each alternative for the CROD marketing approach. The Committee used
the expansion plans developed for the CROD approach to analyze the
impacts of each alternative under the Hydrology marketing approach.
\8 The Committee measured costs in nominal terms (that is, including
inflation) partly because the federal discount rate policy for water
resources planning requires the use of a nominal discount rate. The
Committee also conducted a separate analysis using inflation-adjusted
dollars and the nominal rate; however, this analysis is inconsistent
because it uses a nominal rate to discount inflation-adjusted
dollars.
POWER RESOURCES COMMITTEE
USED SENSITIVITY ANALYSIS TO
TEST IMPACT OF KEY
ASSUMPTIONS
------------------------------------------------------- Appendix V:2.5
The Committee assessed the impact of changes in several key
assumptions on the estimated economic costs. For example, for the
large-utility analysis, the Committee assessed the impact of changes
in assumptions about load growth, capital costs, fuel costs and
escalation rates, environmental costs, hydrologic conditions,
demand-side management program costs, and the potential for a
curtailment in electricity transmission between WAPA and the Salt
River Project (Salt River) in Phoenix, Arizona. WAPA and Salt River
currently have an agreement for the exchange of surplus Glen Canyon
Dam generation.
In addition to the large-utility analysis, the Committee also
assessed the impact on the small systems of changes in the
assumptions about escalation rates for electricity prices paid by the
small utility to their alternate supplier.\9 The sensitivity analysis
for the large utilities indicated that in particular the results for
the Hydrology marketing approach are very sensitive to changes in
load growth and in the level of curtailment in the WAPA-Salt River
exchange agreement.
To conduct the sensitivity analysis, the Committee selected several
variables that were the most influential in determining economic
impacts. In addition, the Committee evaluated the effect of changes
in these variables on the No-Action, Low Fluctuating Flow, and
Seasonally Adjusted Steady Flow alternatives. For each variable, the
Committee assumed low and high values. For example, zero annual
growth was used for the low load-growth scenario, and double the
medium load growth (medium annual growth was assumed to average 1.5
percent) was used for the high load-growth scenario.
To examine the effect of alternative curtailment levels on the Salt
River exchange agreement with WAPA, the Committee assumed that a
curtailment in the transmission of electricity between Salt River and
WAPA would occur more or less frequently than the base case,
depending on the scenario. Salt River entered into an agreement with
the United States in 1962 to exchange surplus Glen Canyon Dam
generation. Under the agreement, and when generation at federally
owned facilities is sufficient, WAPA exchanges surplus Glen Canyon
generation with Salt River for thermal generation at three units in
which Salt River owns shares.\10 In addition, under certain
conditions, WAPA wheels power generated at Salt River's units to its
main customer base in Arizona. However, because power generation
would be reduced at Glen Canyon Dam under many of the flow
alternatives, WAPA may be unable to continue to meet its load
commitments and also continue to exchange generation with Salt River.
To approximate the potential for a curtailment in the exchange of
electricity between WAPA and Salt River, the Committee assumed that
Salt River's generation shares in the three generating units would
undergo periodic nonscheduled shutdowns. In the sensitivity
analysis, the Committee increased the probability of a shutdown for a
high forced-outage-rate scenario and decreased the probability of a
shutdown for a low forced-outage-rate scenario, relative to the base
case.
The sensitivity analyses indicated that alternative assumptions in
load growth and in transmission curtailment can have a large impact
on the estimated economic impacts, depending on the alternative and
the marketing approach. For example, the Committee found that under
a high-load growth forecast, on average, the 50-year economic cost of
the Low Fluctuating Flow alternative using the Hydrology marketing
approach would be higher by about $1.5 billion, compared to the
No-Action alternative. Similarly, under a high probability of
curtailment in the WAPA-Salt River exchange agreement in the
Seasonally Adjusted Steady Flow alternative under the CROD marketing
approach, on average, the 50-year economic cost would be higher by
about $620 million, relative to the No-Action alternative.\11
--------------------
\9 Because the sensitivity analysis was conducted separately for the
large and small systems using different sensitivity variables, the
analysis does not fully capture the potential impact of changes in
the key variables.
\10 Salt River has generation rights at Craig (29 percent of Units 1
and 2) and Hayden (50 percent of Unit 2) in Northern Colorado, and
Four Corners (10 percent of Units 4 and 5) in New Mexico.
\11 The Committee's transmission exchange analysis is based on an
assumption that WAPA would continue to market load at 1991 levels
even though less Glen Canyon Dam capacity would be available for
marketing under most of the alternatives. Because WAPA's load
requirements would be lower than assumed, the likelihood and
subsequent cost of a curtailment would be less, all else being the
same.
POWER RESOURCES COMMITTEE
PARTIALLY REVISED POWER
ANALYSIS FOR FINAL EIS
------------------------------------------------------- Appendix V:2.6
The Committee's initial analysis of the impacts on the power system,
published in October 1993 and referred to as the phase II study, was
included in the draft EIS. Reclamation received numerous comments on
the draft EIS' power analysis. In addition, the Committee solicited
additional review from three external energy experts, and Reclamation
partially modified the draft EIS' preferred alternative. As a
result, the Committee partially revised the power analysis in a phase
III study, which was published in July 1995. For example, the
Committee updated the projected costs of building gas-combustion
powerplants, conducted additional sensitivity analyses, and revised
the retail rate analysis.\12 However, because of Reclamation-imposed
funding constraints, the Committee was able to revise the economic
impacts only for the No-Action and the Modified Low Fluctuating Flow
(preferred alternative) alternatives.
Furthermore, before the release of the draft EIS, but too late for
inclusion in the phase II power analysis, Reclamation modified the
characteristics of the Moderate Fluctuating Flow and Seasonally
Adjusted Steady Flow alternatives to include beach-building flows and
habitat maintenance flows. To include the impact of these
modifications in the final EIS, the Committee used phase II cost and
capacity data and a regression model to project the annual economic
impacts of the two alternatives.
In addition, to develop comparable results between the phase II
alternatives and the revised preferred alternative, the Committee
also used the regression approach and phase II data to estimate the
annual economic impact of implementing the preferred alternative.
Before the release of the final EIS, Reclamation modified the
preferred alternative to include a higher maximum release, a greater
allowable daily increase in releases from the dam, and beach-building
and habitat maintenance flows. Because this revised preferred
alternative was not analyzed in the phase II study, comparable
results with the other phase II alternatives were not available. As
a result, the Committee used the regression approach to derive the
economic impacts for the preferred alternative.
Consequently, the economic impacts for all nine alternatives shown in
table IV-26 in Reclamation's final EIS (see page 300) are based on
the phase II analysis and are generally comparable. The revised
phase III power analysis for the preferred alternative is discussed
separately on page 312 in the EIS under the description of the
preferred alternative. Because the phase III results reflect a
revised methodology and updated data, they are not comparable with
the phase II results.
Although the phase III analysis reflects an improvement in
methodology and in some data, it is of limited use in assessing the
economic trade-offs between alternatives because only the No-Action
and Modified Low Fluctuating Flow alternatives were modeled.
Consequently, to show the impacts across alternatives, we display in
table V.1 the estimated marketable resource and the comparable phase
II economic results (that is, the point estimates) for the No-Action,
High Fluctuating Flow, Modified Low Fluctuating Flow, and Seasonally
Adjusted Steady Flow alternatives under the CROD marketing approach.
Table V.1
Projected Impacts of Operational Changes
at Glen Canyon Dam on Hydropower Over
the Period 1991-2041
Modified Seasonally
High Low Adjusted
Glen Canyon Dam Fluctuatin Fluctuatin Steady
hydropower\a No Action g Flow g Flow Flow
---------------------- ---------- ---------- ---------- ----------
Annual energy 6,010 6,010 6,018 6,123
(gigawatt-hours)
Winter capacity 1,407 1,383 965 640
(megawatts)
Summer capacity 1,315 1,272 845 498
(megawatts)
Change in annual $0 $2,500,000 $44,200,00 $123,500,0
economic costs (1991 0 00
nominal $), compared
to No-Action
alternative
----------------------------------------------------------------------
Source: Bureau of Reclamation.
\a Energy and capacity estimates are for WAPA's Salt Lake City
Area/Integrated Projects facilities in total, including Glen Canyon
Dam, which represents about 72 percent of WAPA's Salt Lake City
Area/Integrated Projects generating resources. The change in annual
economic costs are only for the operation of the Glen Canyon Dam.
--------------------
\12 In the phase III sensitivity analysis, the Committee tested the
impact of changing the base year to 1995. The 1995 base year results
indicated that the economic impact would be higher than the 1991 base
year results, due partly to lower amounts of excess generating
capacity.
ESTIMATED IMPACTS ON THE POWER
SYSTEM COULD BE OVER- OR
UNDERSTATED
--------------------------------------------------------- Appendix V:3
We found shortcomings in certain phase II and phase III assumptions,
inconsistencies in some phase II results, and computational errors
made by Reclamation during the phase III analysis. For example, the
Committee did not explicitly consider in either the phase II or phase
III analysis the effect that higher electricity prices would have in
reducing the demand for electricity and the need to replace forgone
power at the dam. In addition, the Committee's escalation rates for
future natural gas prices are relatively high, potentially increasing
the cost of replacing forgone power. These shortcomings would
suggest that the estimated economic impacts may be overstated.
However, we also found that in the phase III analysis the Committee
did not incorporate the possibility of a curtailment in the Salt
River exchange agreement with WAPA. This factor (all else being the
same) would tend to understate the estimated economic costs to
hydropower because a curtailment in the exchange agreement might
require Salt River to purchase additional higher-cost capacity.
Because of the time and expense that would be required to recompute
the results with revised methodology and data, we did not determine
the net effect of these factors on the estimated economic impacts.
SHORTCOMINGS IN THE
COMMITTEE'S ASSUMPTIONS
------------------------------------------------------- Appendix V:3.1
Price elasticity effects were not explicitly incorporated into either
the phase II or phase III analysis.\13 The Committee assumed that
both load demand and electricity price would continue to rise over
the planning period. However, the rise in electricity price would
likely induce some electricity consumers (wholesale and end-use) to
consume less electricity or switch to cheaper alternative suppliers.
Consequently, fewer resources would be needed to replace forgone
power at the dam, and the subsequent economic impacts would be lower
than estimated (all else being the same). The Committee attempted to
approximate the effects of price elasticity by using a low
load-growth scenario in the sensitivity analysis. However, the
inclusion of price elasticity effects in the base-case assumptions
would give a more accurate picture of the potential economic impact
of the alternative flow regimes.
Relatedly, demand-side management programs were not included as an
option available to small utilities for replacing forgone power. The
Committee assumed that the small systems would replace forgone power
by purchasing power from their alternative supplier (that is, a large
utility). Because this approach limits the choices that small
utilities have in replacing forgone power, it may not reflect the
least-cost option of replacing forgone power at the dam. Small
utilities, for example, could also implement demand-side management
programs as a way to mitigate the impact of forgone power, possibly
at a lower cost.
We also found that the estimated economic impact of the preferred
alternative in the phase III analysis does not incorporate the
possibility of a curtailment in the Salt River exchange agreement
with WAPA. During the phase III study, the Committee initially
assumed that the preferred alternative (that is, the Modified Low
Fluctuating Flow) would not affect the transmission exchange
agreement between WAPA and Salt River, on the basis of the phase II
analysis conducted for the draft EIS. However, some Committee
members later revised their original assessment after Reclamation
modified the preferred alternative to incorporate an increase in the
maximum release and upramp rates and the beach-building and habitat
maintenance flows. Implementation of beach-building and habitat
maintenance flows could negatively affect the exchange agreement by
effectively reducing water releases and subsequent power production
during the summer months, when the demand for electricity is fairly
high and when Salt River's system is at its peak. As a result, the
economic impact could be greater because a curtailment in the
exchange could require Salt River to add additional higher-cost
capacity. The key consultant who directed the power analysis told us
that if curtailments increase in the summer months the impact on
economic costs would be significant. According to some Committee
members, a lack of time prevented the contractor from including these
potential impacts in the phase III analysis.
In addition, the Committee's escalation rates, used to project future
natural gas prices in the phase II and phase III analyses, are
relatively high. The Committee used the escalation rates from
DRI/McGraw-Hill's fourth-quarter 1991 forecast to project gas prices
for the western states over the 50-year analysis period (the same
escalation rates were used for the base case and the alternative
cases). DRI has since revised downward its price forecast for
natural gas. Despite comments from several reviewers that these
escalation rates were too high, the Committee did not revise its
analysis. For example, using DRI's 1991 forecast for Arizona and New
Mexico, the Committee assumed that the average gas price would
increase annually by 8 percent from 1991 through 2010. By contrast,
DRI's 1994 forecast projected that gas prices would increase by about
6 percent annually from 1991 through 2010. Its 1995 forecast assumes
that prices will rise by only 5 percent annually over the forecast
period. Similar to hydropower, some gas-powered resources can be
ideal as peaking resources because they can be turned on and off
relatively quickly to meet fluctuations in demand. The higher
escalation rates could affect the power analysis in two ways: (1)
gas resources are selected later than they would be if fuel were
cheaper and (2) gas resources are more expensive to operate than they
would be under a lower gas-price trend. The Committee tested the
impact of lower escalation rates in the phase II sensitivity
analysis. However, the inclusion of the lower gas-price trend in the
base-case assumptions would give a more accurate picture of the
potential economic impact of the alternative flow regimes.
Finally, the Committee did not give full credit to the value of
off-peak energy in mitigating the on-peak demand and energy costs in
the small-utilities analysis in the phase II analysis. In general,
the alternatives shift energy production from the on-peak period to
the off-peak period. Even though less energy is produced during
on-peak periods when it is more valuable, additional energy
production during the off-peak period may help offset the cost of the
forgone energy during the on-peak period. In the phase II analysis,
however, the Committee essentially assigned a value of zero to some
of the off-peak energy in the small-utilities analysis. In a
separate exercise, the Committee estimated that the value of the
off-peak energy could reduce annual economic costs by as much as $19
million, depending on the alternative and the unit price of the
energy.\14
--------------------
\13 The price elasticity of demand is a measure of the percentage
change in the quantity demanded resulting from a percentage change in
price. For example, assuming an estimated price elasticity of demand
for electricity of -0.4, if the price of electricity rose by 1
percent, the quantity demanded for electricity would be expected to
fall by 0.4 percent.
\14 Power System Impacts of Potential Changes in Glen Canyon Power
Plant Operations, Final Report (phase II) (Oct. 1993), page ES-17.
INCONSISTENCIES IN THE
COMMITTEE'S RESULTS
------------------------------------------------------- Appendix V:3.2
We found two inconsistencies in the Committee's results. First, the
economic results for the large utilities and the fluctuating flow
alternatives under the Hydrology marketing approach are inconsistent
in the phase II analysis. For example, in the phase II analysis the
Committee found that on average less capacity is lost under the
Hydrology marketing approach than under the CROD approach. However,
the economic impacts are higher for the fluctuating flow alternatives
under the Hydrology approach than for the fluctuating flow
alternatives under the CROD approach. The key consultant who
directed the power analysis told us that the inconsistency is due to
the Committee's use of the CROD-based utility expansion plans to
represent expansion plans in the Hydrology marketing approach.
However, even though the expansion plans are least-cost under a CROD
marketing approach, they may not reflect least-cost conditions under
a Hydrology approach.
In addition, some of the phase II sensitivity analysis results are
inconsistent. For example, the Committee found that under a wide
range of possible expansion plans, the economic impact of the Low
Fluctuating Flow alternative versus the No-Action alternative would
be approximately $173,923,000 under the "all medium" scenario (all
variables held at expected values) and about $143,170,000 under the
"high-load forecast" scenario. This result is inconsistent because
we would expect that the impact of the Low Fluctuating Flow
alternative versus the No-Action alternative would be greater under a
future scenario of high-load growth than a future scenario in which
all variables were held at their expected values. The key consultant
who directed the power analysis agreed that this result is
inconsistent and stated that the most likely explanation is that more
inefficient generation is replaced in the high-load forecast
scenario.
COMPUTATIONAL ERRORS IN THE
COMMITTEE'S ANALYSIS
------------------------------------------------------- Appendix V:3.3
Computational errors were made by the Reclamation staff during the
phase III analysis. The Committee acknowledged these errors in its
phase III report and stated that the errors affected the results in
opposite ways. For example, in revising the monthly hydrologic
release volumes, Reclamation incorrectly assumed that the
beach-building flows would occur every year rather than every so many
years, as is planned. As a result, more water was projected to flow
through the spillways and less capacity and energy would be available
for marketing purposes. The Committee stated that this error may
have overstated the economic and financial impact of the preferred
alternative. In another case, instead of using the average
hydrological sequence (that is, the average of dry and wet years) to
calculate future hydrological conditions and the impact on power
production at the dam, the Committee used a different hydrological
sequence. The Committee stated that this error may have understated
the economic impact of the preferred alternative under the Hydrology
marketing approach. The Committee was unable to correct these errors
because of time and resource constraints and, consequently, was
unable to determine the effect of the errors on the estimated
economic and financial impacts.
POWER RESULTS CAN BE USEFUL
DESPITE LIMITATIONS
--------------------------------------------------------- Appendix V:4
Because future events are inherently uncertain and the actual cost of
changing the dam's operations could also depend on factors yet to be
determined, such as whether or not an Endangered Fish Research
Program is implemented and the pace of deregulation in the electric
utility industry, the actual economic impacts on power users may
differ from those estimated. Often a point-estimate forecast is used
to represent the most likely or expected outcome. In the case of the
Committee's hydropower analysis, however, the limitations we have
identified indicate that the point estimates lack precision. As a
result, it should not be anticipated that the actual impacts will
equal the estimated impacts. However, because the shortcomings we
identified generally affect the point estimates for all of the
alternatives, we do not believe that addressing the shortcomings
would alter the relative ranking of the fluctuating and steady flow
alternatives. In addition, we do not believe that addressing the
inconsistency in the Hydrology marketing analysis (for example, using
Hydrology-based expansion plans in the expansion analysis) would
alter the relative ranking of the fluctuating and steady flow
alternatives. Moreover, the inconsistency noted in the sensitivity
analysis does not affect the phase II point estimates. Because the
phase III analysis was limited to an assessment of the impacts of the
No-Action and preferred alternative, the computational errors have no
impact on the relative ranking of the phase II alternatives.
Furthermore, Reclamation and representatives of the power industry
believe that the results of the hydropower analysis presented in the
final EIS are reasonable and usable. As a result, we believe that
the estimated economic impacts can be used to compare in a general
way the economic trade-offs that are associated with the various flow
alternatives.
Consequently, we believe that Reclamation's estimated economic
impacts are useful for comparing the economic trade-offs that may be
associated with the fluctuating and steady flow alternatives. The
Committee's analysis indicates that the estimated impacts are robust
across alternatives; that is, the relative ranking of the fluctuating
and steady flow alternatives is consistent even when taking into
account changes in key assumptions such as load growth. Thus, in
making a determination about the future operational plan for the dam,
a decision maker can anticipate that, for example, a Seasonally
Adjusted Steady Flow alternative would cost substantially more than a
Modified Low Fluctuating Flow alternative. Furthermore, officials
from Reclamation and the electric utility industry believe that the
results are reasonable and usable. The Reclamation economist who
served on the Power Resources Committee stated that he generally
agreed with our observations but believed the methodology and the
results are reasonable and should be useful in comparing economic
trade-offs between alternatives. Similarly, an official from a
regional utility who also served on the Committee said that the
methodology and results are reasonable. Although the association
that represents the affected power utilities maintained throughout
the power studies process that the costs to the power system are
understated, the association does not believe that Reclamation's cost
estimate is understated by a large magnitude. The Salt River Project
has also maintained that the estimated costs do not fully account for
the higher costs that Salt River could incur as a result of a
curtailment in the exchange agreement. However, the Salt River
Project did not provide us with documentation supporting its
position.
As indicated by the Committee's sensitivity analysis, changes in
variables such as load growth can have a substantial impact on the
estimated impacts. Economic impacts could also be affected by other
factors yet to be determined, including whether or not an Endangered
Fish Research Program (fish research) is implemented, and the pace of
deregulation in the electric utility industry. For example, fish
research could require higher-than-average water releases in the
spring and summer months periodically to enable scientists to conduct
fish research. As a result, water releases and power production
during the other half of the year--between September and
February--will be lower than average. Consequently, WAPA and its
customers may have to seek alternative power supplies during certain
periods, possibly at higher cost. In addition, the impact of fish
research on Salt River could be substantial, because the decrease in
the capacity available in the summer could limit the Salt River-WAPA
electricity exchange agreement when the Salt River system peaks. As
indicated by the Committee's sensitivity analysis, the economic costs
of changes in the dam's operations increase substantially under
assumptions of a greater probability of a curtailment in the Salt
River-WAPA exchange agreement. According to the draft EIS, the
economic impact of implementing fish research would fall within the
range of impacts identified for the Modified Low Fluctuating Flow
alternative and the Seasonally Adjusted Steady Flow alternative. The
former alternative does not include the potential impact of fish
research, and thus it represents the minimum potential impact. On
the other hand, the latter alternative would involve flows similar to
fish research flows but on a seasonal and annual basis; thus, it
represents the maximum potential impact.
Finally, partly as a result of the Energy Policy Act of 1992, more
opportunities for producing and delivering low-cost power to
customers could emerge in the regional power market, which could help
mitigate some of the economic burden that some small utilities in
particular may bear as a result of changes in the dam's operations.
For example, under the act, electricity generators (utilities,
alternative energy producers) can use a competitor's transmission
grid to wheel power directly to other utilities. As a result, small
utilities may have access to alternative power sources that may be
cheaper than their traditional suppliers.
SCOPE AND METHODOLOGY
--------------------------------------------------------- Appendix V:5
To gain an understanding of the Bureau of Reclamation's power
methodology, key economic assumptions, and results, we reviewed
documentation that describes the methodology, economic assumptions,
and results, including reports by the Power Resources Committee,
entitled Power System Impacts of Potential Changes in Glen Canyon
Power Plant Operations, Final Report (phase II) (Oct. 1993), and
Power System Impacts of Potential Changes in Glen Canyon Power Plant
Operations, Phase III Final Report (July 1995). Also, we interviewed
members of the Power Resources Committee, including the Reclamation
officials who served as Chairman and economist; representatives from
the Western Area Power Administration, the Colorado River Energy
Distributors Association, and the Environmental Defense Fund; and
representatives from the primary contractor, HBRS, Inc., and
subcontractor Stone & Webster Management Consultants, Inc. We also
interviewed Ms. Leslie Buttorff who directed the power analysis for
Stone and Webster.
To assess the reasonableness of the power methodology, economic
assumptions, and results, we reviewed federal guidance on water
resource projects entitled Economic and Environmental Principles and
Guidelines for Water and Related Land Resources Implementation
Studies (U.S. Water Resources Council, Mar. 10, 1983); public
comments on the draft and final EIS; and comments by three energy
consultants retained by HBRS, Inc., to review the power analysis.
Also, we reviewed comments by the National Research Council on the
power analyses in the draft and final environmental impact
statements. In addition, we interviewed members of the Power
Resources Committee, including representatives from Reclamation, the
Western Area Power Administration, the Environmental Defense Fund,
the Salt River Project, and the Platte River Power Authority, as well
as officials from the Colorado River Energy Distributors Association,
HBRS, Inc., Stone & Webster Management Consultants, Inc., the
National Research Council's EIS review team, and several regional
utilities. Finally, we used standard microeconomic principles to
assess the reasonableness of the Power Resource Committee's
methodology, analytical framework, economic assumptions, and results.
Our assessment of the reasonableness of Reclamation's methodology was
limited to a review of the general analytical framework and an
assessment of the reasonableness of key assumptions and data. We did
not evaluate the Committee's calibration of the EGEAS and Elfin power
simulation models or the small systems spreadsheet model, nor did we
verify the accuracy of data inputs.
The organizations and individuals we contacted include those in the
following list.
Arizona Public Service Company, Phoenix, Arizona
Bureau of Reclamation, Denver, Colorado
Buttorff, Leslie, A.T. Kearney, Inc., Englewood, Colorado
Colorado River Energy Distributors Association, Salt Lake City,
Utah
Environmental Defense Fund, Oakland, California
Goodman, Ian, The Goodman Group, Boston, Massachusetts
HBRS, Inc., Madison, Wisconsin
Marcus, David, Berkeley, California
National Research Council, Washington, D.C.
Plains Electric Generation and Transmission Cooperative, Inc.,
Albuquerque, New Mexico
Platte River Power Authority, Fort Collins, Colorado
Salt River Project, Phoenix, Arizona
Stone & Webster Management Consultants, Inc., Englewood, Colorado
Tucson Electric Power Company, Tucson, Arizona
Western Area Power Administration, Salt Lake City, Utah
NON-USE VALUE
========================================================== Appendix VI
The construction and operation of the Glen Canyon Dam changed river
flows and the environment along the Colorado River, affecting, among
other things, fish populations, beach and wildlife conditions, and
sites of archeological significance in and near the Glen and the
Grand canyons. The values that people may receive from the knowledge
that such things as, for example, rare plants, animals, and unspoiled
natural environments exist, even if people do not consume or use
these goods directly, have been defined as "non-use values." The
non-use value concept, which is generally attributed to economist
John Krutilla,\1 can be relevant in natural resource and
environmental policy settings that focus on proposals to develop the
natural environment or to mitigate prior resource damage. In the
context of the Glen Canyon Dam's EIS, individuals suffered losses in
non-use values to the extent they valued the natural resources that
were affected negatively by the changes in river flows after the
construction of the dam. Conversely, the changes in the operation of
the Glen Canyon Dam that are currently under consideration could
result in environmental improvements in downstream riparian resources
and hence gains in non-use values. At the urging of the National
Research Council, an entity of the National Academy of Sciences,
Reclamation undertook the non-use value study as part of the Glen
Canyon Dam's EIS to provide estimates of the non-use values placed on
changes in environmental quality that may be expected to result from
particular operating changes at the Glen Canyon Dam.
The purpose of this appendix is to review the methodology and
economic assumptions that Reclamation used to estimate non-use values
and the reasonableness of the results. A key aspect of Reclamation's
non-use value study\2 is its use of the "contingent valuation" method
(CVM) to estimate economic impacts. While CVM is currently the only
known method of estimating non-use values empirically, some prominent
economists question the usefulness of the estimates of non-use values
produced by contingent valuation studies. We are not taking a
position on the appropriateness of contingent valuation generally.
The Glen Canyon Dam's EIS non-use value study was carried out in a
manner consistent with contingent valuation and survey research
guidance developed to produce high-quality contingent valuation
studies. Non-use values were estimated for the level of change
associated with each examined alternative compared to the no-action
base case. As such, no estimate for the level of non-use values
associated with the No-Action Flow alternative is provided. The
study produced results that suggest that there are substantial
non-use values associated with each of the examined alternatives to
current operations at the Glen Canyon Dam. However, the results of
the non-use value study were not available at the time the Glen
Canyon Dam's final EIS was issued; therefore, the study did not
receive public comment. Reclamation noted that although the non-use
study did not go through the public comment process, the study team
was comprised of interests that will be affected by changes to the
Glen Canyon Dam, such as power groups and environmental groups.
Furthermore, Reclamation stated that the study team received peer
review at various key decision points in the process and that the
final results received a positive review by the National Research
Council.\3
--------------------
\1 "Conservation Reconsidered," American Economic Review, vol. 57,
Sept. 1967, pp. 777-786.
\2 The term non-use value applies to the value an individual places
on a resource without directly or indirectly using that resource.
The term total value applies to the value an individual places on a
resource, including non-use and use components. According to
Reclamation's non-use value study, the study actually measures total
values. That is, a respondent to the non-use value survey could have
been motivated by an experience of direct use (such as rafting or
fishing) or indirect use of the natural resources in the study area,
and thus the estimates may include values associated with recreation.
Reclamation states, however, that the estimated total values are
likely to consist primarily of non-use values.
\3 River Resource Management in the Grand Canyon, Committee to Review
the Glen Canyon Environmental Studies, National Research Council,
Washington, D.C.: National Academy Press, 1996, p. 135.
RECLAMATION USED THE CONTINGENT
VALUATION METHOD AS BASIS FOR
ESTIMATING ECONOMIC IMPACTS
-------------------------------------------------------- Appendix VI:1
While economists have traditionally preferred to rely on information
on what people do rather than on what they say they would do,
economists and survey researchers working in the natural resource and
environmental areas have developed the theory and practice of
contingent valuation to estimate non-use values.\4
Non-use values are typically expressed in terms of willingness to pay
by individuals or households for a specified environmental
improvement. Typically, economists are more accustomed to
calculating willingness-to-pay measurements for marketed goods
because, in markets, information on how consumers value goods can be
determined by their purchases of goods and services. Because by its
definition a non-use good is not used, information from market
transactions in which consumers reveal information about how much
they are willing to pay for the good is not available. Contingent
valuation methods currently offer the only known method of estimating
non-use values empirically.
Contingent valuation studies rely on surveys to elicit information
from consumers to estimate how much they would be willing to pay for
a non-use good. In an overview of contingent valuation practice, a
leading resource economist described three general features typically
contained in contingent valuation studies.\5 First, a contingent
valuation study contains descriptions of the policy or program at
issue and the likely environmental effects so that respondents can
understand the good they are valuing. Second, a contingent valuation
study contains a framework or mechanism for eliciting willingness to
pay. Several mechanisms have been used in contingent valuation
studies, such as open-ended questions (How much would you be willing
to pay?) and referendum formats (Would you vote for the described
proposal if your taxes increase by $10?). Third, a contingent
valuation study gathers information on socioeconomic variables and
attitudes about the environment. This information is used in
estimating willingness-to-pay functions using econometric techniques.
Some prominent economists have voiced strong criticisms of contingent
valuation methods.\6 One of the main concerns about contingent
valuation methods is the ability of survey research and statistical
techniques to adequately capture true estimates of willingness to
pay. Particularly with respect to non-use values, critics argue that
it can be very difficult for individuals to comprehend a particular
environmental or resource valuation issue, or to distinguish what
researchers envision as a well-defined specific issue from a more
general "warm glow" effect. Furthermore, some critics argue that the
statistical estimation process by which willingness-to-pay estimates
are produced from survey responses can be very imprecise.\7
Nonetheless, the contingent valuation method has become a standard
tool for analyzing many natural resource issues.
--------------------
\4 See, for example, Using Surveys to Value Public Goods: The
Contingent Valuation Method, by Robert Cameron Mitchell and Richard
T. Carson, Resources for the Future, 1989.
\5 Paul R. Portney, "The Contingent Valuation Debate: Why
Economists Should Care," Journal of Economic Perspectives, 8(4), Fall
1994, pp. 3-17.
\6 A collection of studies critical of contingent valuation can be
found in Jerry A. Hausman, Contingent Valuation: A Critical
Assessment. Amsterdam: North Holland Press, 1993; and also Peter A.
Diamond and Jerry A. Hausman, "Contingent Valuation: Is Some Number
Better Than No Number?," Journal of Economic Perspectives, 8(4), Fall
1994, pp.45-64.
\7 Daniel McFadden, "Contingent Valuation and Social Choice,"
American Journal of Agricultural Economics, 76(4), Nov. 1994, pp.
689-708.
DEVELOPING CRITERIA TO EXAMINE
RECLAMATION'S NON-USE VALUE
STUDY
-------------------------------------------------------- Appendix VI:2
To evaluate Reclamation's Glen Canyon non-use value study, we made
use of some general guidelines that focus on the quality of a
contingent valuation study and on the underlying survey research.
Specifically, we relied on (1) the statement of a panel of prominent
researchers convened by the National Oceanic and Atmospheric
Administration (NOAA) to develop some general guidelines applicable
to conducting contingent valuation studies\8
and (2) the total design method for conducting mail surveys developed
by Dillman.\9
--------------------
\8 The panel's report was published in the Federal Register. See 58
Fed. R. 4601, Jan. 15, 1993.
\9 The most widely accepted written standards for mail questionnaires
are presented by Don A. Dillman in Mail and Telephone Surveys, the
Total Design Method (1978).
NOAA PANEL DEVELOPED GENERAL
GUIDELINES
------------------------------------------------------ Appendix VI:2.1
As part of a process by which it developed regulations related to oil
spill damages,\10 NOAA convened an advisory panel to address such
issues as whether the contingent valuation method was capable of
providing reliable estimates of non-use values for use in resource
damage assessments.\11 The panel stated that contingent valuation
"can produce estimates reliable enough to be the starting point of a
judicial process of damage assessment, including lost passive-use
(non-use) values," listed some guidelines for producing credible
studies, and noted concerns about some past studies.
The panel suggested (1) using probability sampling and appropriate
statistical sampling procedures, (2) subjecting the survey
instruments to pretesting, and (3) taking steps to reduce nonresponse
rates. Additionally, the panel suggested that contingent valuation
studies disclose information on the sample selection process and
provide information on survey instruments and responses. The panel
also suggested that the use of the referendum format, as opposed to
open-ended elicitation, was desirable.
The panel suggested that respondents be provided with a reminder that
paying for the non-use good at issue would result in a smaller budget
to spend on other goods and services and that they be told of any
available substitutes. In this way, the decisions made by the
respondents may more closely resemble market transactions in which
consumers make choices in the face of budget constraints.
The panel stated a preference for the use of in-person surveys as
superior to telephone or mail surveys. The panel's report stated
that it is "unlikely that reliable estimates of values could be
elicited with mail surveys." This guideline in particular has been
criticized by some contingent valuation practitioners, who argue that
the use of large-scale, in-person surveys can dramatically increase
the cost of conducting contingent valuation studies.
The NOAA panel echoed the concern that estimated willingness-to-pay
figures be consistent with common notions of rationality. One aspect
of rationality is that, generally speaking, people are willing to pay
more for greater amounts of a good. The panel was troubled by
evidence presented in one contingent valuation study finding that
estimated willingness to pay "for the cleanup of all lakes in Ontario
was only slightly more than willingness to pay for cleaning up lakes
in just one region" and in another study that "willingness to pay to
take measures to prevent 2,000 migratory birds (not endangered
species) from dying in oil-filled ponds was as great as that for
preventing 20,000 or 200,000 birds from dying." The sensitivity of a
study to these so-called scope effects can be important in evaluating
its credibility.
--------------------
\10 The Oil Pollution Act of 1990, Pub. L. No. 101-380, 104 Stat.
484, required NOAA, within the Department of Commerce, to develop
regulations for use by natural resource trustees in assessing damages
due to oil spills.
\11 The panel was composed of Kenneth Arrow, Robert Solow
(co-chairs), Edward Leamer, Roy Radner, Howard Schuman, and Paul
Portney. Schuman is a prominent survey researcher, and the others
are economists. Arrow and Solow are Nobel laureates.
DILLMAN'S STANDARDS REFLECT
A TOTAL SURVEY DESIGN METHOD
------------------------------------------------------ Appendix VI:2.2
While the usefulness of contingent valuation methodology has been
debated, survey research, a key component of contingent valuation
studies, is itself a mature discipline with an accepted set of
standards. For example, Dillman's "total design method" has become
an accepted standard in survey research for maximizing the quality
and quantity of responses to mail questionnaires.
By maximizing the quality of responses, researchers can have greater
confidence in the validity of their work; that is, they can be surer
that they are measuring what they intend to measure. By maximizing
the quantity of responses they can have greater confidence in the
reliability of their work; that is, repeated investigations will come
up with similar results. Dillman's method provides a comprehensive
approach that spans the design and implementation of mail
questionnaires. From the wording of the questions to the pretest
regimen to the design of the survey package and, finally, to the
timetables for mailing and following up on the mailing, Dillman has a
proven set of techniques that have been embraced by the survey
research community.
RECLAMATION'S NON-USE VALUE
STUDY FINDS SUBSTANTIAL NON-USE
VALUES ASSOCIATED WITH CHANGES
IN OPERATIONS AT GLEN CANYON
DAM
-------------------------------------------------------- Appendix VI:3
Using a contingent valuation study, Reclamation estimated non-use
values for the environmental improvements associated with changing
the operations at Glen Canyon Dam. These estimates, which ranged
from less than $15 per household annually to almost $30 per household
annually, depending on, among other things, the specific
dam-operating alternative under consideration, indicate the large
non-use values associated with environmental improvements and are
consistent with the idea that some change in the dam's operations
will lead to these improvements. Furthermore, although the EIS
included a discussion of non-use values, the results of the non-use
value study were not formally included as part of the EIS and thus
were not subject to the same set of formal comments from interested
parties.
AN OVERVIEW OF THE GLEN
CANYON NON-USE VALUE STUDY
------------------------------------------------------ Appendix VI:3.1
The Glen Canyon non-use value study was one of the economic studies
Reclamation carried out as part of the Glen Canyon Environmental
Studies.\12 As part of the study process, a non-use value committee,
including representatives from the power industry, environmental
groups, Native American tribes, and federal agencies, met to consider
interim results and to provide input to the research team.
Additionally, the study team received peer review at various key
decision points.
The researchers addressed some important preliminary issues in a
qualitative research phase designed to establish whether a contingent
valuation study would be likely to produce meaningful results.
First, the researchers determined that representative individuals
were able to distinguish the Colorado River environment in the Grand
Canyon from the Grand Canyon itself. This was important because
changes in the Glen Canyon Dam's operations would not affect the
existence of the Grand Canyon itself. Rather, they would change
aspects of the riparian environment along the Colorado River in and
around the Grand Canyon. Importantly, if people were unable to
distinguish changes to aspects of the riparian environment from broad
changes to the Grand Canyon itself, then it would be impossible to
provide meaningful estimates of non-use values related to operational
changes at the Glen Canyon Dam. The researchers were convinced that
people were able to make these distinctions and, moreover, were
likely to care about, or to place meaningful values on, these
resources.
The researchers also determined that people living far away from the
Glen Canyon Dam were likely to care about the affected resources.
This is important in estimating aggregate non-use value because an
average willingness-to-pay estimate is multiplied by the number of
individuals or households believed to have non-use values. Because
there are close to 100 million households in the United States, an
average household's willingness to pay estimated to be $5 per year
yields an aggregate non-use value of $500 million annually.
A pilot test phase was initiated in early 1994. A key research
objective of this phase was to investigate whether willingness-to-pay
estimates were sensitive to the various flow regimes under
consideration, that is, whether non-use values were likely to
increase in measurable ways related to the different river flows
resulting from the different dam-operating alternatives. The pilot
test included a series of nine versions of survey questionnaires
given to separate samples of 250 respondents. Three of these
versions were sent to national samples of households, with each
version describing one river flow alternative and its likely effects
on the affected resources. The three versions were the moderate
fluctuating flow; the low fluctuating flow; and the seasonally
adjusted steady flow. In general, the moderate fluctuating flow
version describes the smallest improvement in environmental
conditions, and the seasonally adjusted steady flow describes the
biggest improvement. The surveys also describe adverse impacts on
power customers, with more severe effects described in the seasonally
adjusted steady flow version. Two versions, one describing the
moderate fluctuating flow and one describing the seasonally adjusted
steady flow, were sent to marketing area households.\13 The other
four survey versions were sent to national samples and were used to
address other methodological issues.
The qualitative research and pilot study phases included a thorough
development and pretesting strategy, as well as peer and other
reviews. During the qualitative research phase, researchers held 15
focus groups in which various methodological issues were
investigated. In particular, focus groups were held in New York,
Tennessee, and Nebraska to examine the geographic extent to which
people living at some distance from the study area were likely to
care about these resources.
The final phase of the non-use value study, built upon the knowledge
developed during earlier phases, was designed to estimate non-use
values. The researchers selected two samples--a national sample and
a marketing area sample--and developed seven versions of a mail
questionnaire. Multiple versions of the instrument permitted the
researchers to investigate the differences in non-use values
associated with the differences in river flow conditions. While the
overall Glen Canyon Environmental Studies examined nine alternatives,
three flow alternatives were considered in the non-use study:
moderate fluctuating flow; low fluctuating flow; and seasonally
adjusted steady flow. According to the non-use study, these
alternatives "covered most of the range of alternative dam operations
being studied and were considered to include the set of alternatives
most likely to contain the eventual preferred alternative."
--------------------
\12 The study was performed by Hagler Bailly Consulting under
contract to Reclamation.
\13 The marketing area refers to the geographic area in which
individuals are served by utilities receiving power produced at Glen
Canyon Dam.
ESTIMATES OF WILLINGNESS TO
PAY FOR ENVIRONMENTAL
IMPROVEMENTS ASSOCIATED WITH
CHANGES IN THE OPERATION OF
GLEN CANYON DAM
------------------------------------------------------ Appendix VI:3.2
Non-use values were based on estimates of willingness to pay for the
described flow alternatives. Respondents were provided with
background information on a proposal to change the dam's operations
and the likely downstream environmental effects and were asked how
they would vote on the proposal if it were to cost them nothing. If
they indicated they would vote yes, they were then asked another
voting question, but this time the proposal was tied to a specified
annual dollar amount and to a specified "payment vehicle." This form
of contingent valuation study is known as the referendum format. The
payment vehicle for respondents in the national sample was a tax
increase, and the payment vehicle for respondents in the marketing
area sample was a utility bill increase. Each respondent was
assigned one of the following eight dollar amounts: $5, $15, $30,
$60, $90, $120, $150, and $200.
Willingness to pay was then estimated using a logistic regression
based on the resulting "yes or no" answers to the voting question. A
variable, referred to here as BID, is defined as the specific dollar
amount associated with the cost of the referendum proposal presented
to the respondent. A variety of other explanatory variables were
derived from the survey responses. For example, four variables
describing the respondent's environmental attitudes were constructed
using factor analysis of a variety of environmental attitude
questions provided in the questionnaire. Also, a score variable was
calculated from a portion of the survey used to test how well the
respondent understood the proposal.
The form of the logistic cumulative density function is:
probability(yes vote)=1/(1 + exp((-� i*Xi ) -
BID*BID)), (1)
where the i are the coefficients for the explanatory
variables and BID is the coefficient on the BID variable
specifically. An expression for mean willingness to pay (WTP) is
derived from the following formula suggested by Hanemann\14 :
WTP = ln (1 + exp � i*Xi) / -BID. (2)
The samples were split to focus on the different operating
alternatives under consideration. The national sample was split four
ways, examining two versions of the seasonally adjusted steady flow
alternative along with the moderate and low fluctuating flow
alternatives--and the marketing area sample was split three ways.
For analytical purposes, a set of 0-1 dummy variables were included
to indicate the different versions.\15
The non-use questionnaires did not ask a binary "yes or no" vote
question but used a scale which included "definitely yes" and
"probably yes." The researchers investigated two definitions of yes
votes for use in the logistic regressions: using "definitely yes" as
the definition of yes, and alternatively with "definitely/ probably
yes" as the definition of yes. "Definitely yes" models generated
mean willingness-to-pay values in the $20 to $38 range across all
flow alternatives and for both the national and marketing area
samples. "Definitely/Probably yes" models generated mean
willingness-to-pay values of $100 to about $130. The researchers
believe that the "definitely yes" definition provides better
estimates than the use of binary "yes or no" definition. They also
believe the "definitely yes" definition yielded lower
willingness-to-pay estimates.
To generate population willingness to pay, the researchers had to
address additional issues. The regression-derived mean
willingness-to-pay values apply to those respondents who voted for
the specified proposal when it was presented to them with the
condition that they would not have to pay for it. However, some
people did not respond to the survey, some respondents did not vote
on the referendum question, and some respondents did not vote for the
proposal at zero cost. In this study, the respondents who did not
vote and those who voted no were both assigned a willingness to pay
of $0. The researchers gathered information on nonrespondents using
follow-up telephone interviews.\16 \17 The assumed or estimated
values for each of the groups were averaged together on the basis of
their proportion of the sample. Table VI.1 presents the resulting
willingness-to-pay values for the "definitely yes" version (dollars
per household per year).
Table VI.1
Population Average Willingness to Pay,
Definitely Yes Model With Imputed Values
for Nonrespondents (1991 Nominal Dollars
per Household per Year)
National Marketing area
Riverflow sample sample
-------------------------------------- -------------- --------------
Moderate fluctuating $13.65 $22.06
Low fluctuating $20.15 $21.45
Seasonally adjusted steady $20.55 $28.87
Seasonally adjusted steady $23.79 ----
(but describing lower power cost
effects)
----------------------------------------------------------------------
In general, the results indicate that individuals have a significant
willingness to pay for the environmental improvements associated with
a change from the no-action alternative to each of the other flow
alternatives (i.e., the moderate fluctuating, low fluctuating, and
seasonally adjusted steady flow alternatives). In addition, the
national sample results indicate that individuals are willing to pay
more for the environmental improvements associated with the
seasonally adjusted steady flow alternative, compared to the moderate
fluctuating flow alternative, and that the difference is
statistically significant. The results also indicate that
individuals are willing to pay more for the environmental
improvements associated with the low fluctuating flow alternative,
compared to the moderate flow alternative; however, this difference
is not statistically significant. Consequently, we have less
confidence in the precision of the estimate for the low fluctuating
flow alternative.
Researchers provided ranges around the average willingness-to-pay
values to reflect the statistical uncertainty surrounding the
estimates. These ranges were calculated using repeated sampling from
the estimated distributions of the parameters generated by the
logistic regressions. In essence, the researchers calculated 3,000
estimates of mean willingness-to-pay for each alternative, arrayed
them from lowest to highest, and reported the values as the lower and
upper limits associated with a 95-percent confidence interval. Table
VI.2 presents these results for the national sample and table VI.3
presents these results for the marketing area sample.
Table VI.2
Population Weighted Average Willingness
to Pay, Definitely Yes Model With
Imputed Values for Nonrespondents and
the Associated 95-Percent Confidence
Interval, National Sample (1991 Nominal
Dollars per Household per Year)
Populati
on
weighted Lower Upper
Riverflow average limit limit
---------------------------------------- -------- -------- --------
Moderate fluctuating $13.65 $9.27 $20.39
Low fluctuating $20.15 $14.22 $29.29
Seasonally adjusted steady $20.55 $14.57 $29.84
Seasonally adjusted steady $23.79 $17.17 $33.39
(but describing lower power cost
effects)
----------------------------------------------------------------------
Table VI.3
Population Weighted Average Willingness
to Pay, Definitely Yes Model With
Imputed Values for Nonrespondents and
the Associated 95-Percent Confidence
Interval, Marketing Area Sample (1991
Nominal Dollars per Household per Year)
Populati
on
weighted Lower Upper
Riverflow average limit limit
---------------------------------------- -------- -------- --------
Moderate fluctuating $22.06 $16.68 $29.39
Low fluctuating $21.45 $15.84 $29.28
Seasonally adjusted steady $28.87 $22.50 $37.24
----------------------------------------------------------------------
Researchers calculated aggregate willingness-to-pay values on the
basis of the population averages. This involved gathering estimates
of the number of households in the United States and in the marketing
area as well as population growth rates nationally and for a set of
states to approximate future growth in the marketing area.\18 A
50-year period (1991-2040) was used. Levelized annual aggregate
willingness-to-pay values were calculated using a discount rate of
8.5 percent. The results are presented in table VI.4.
Table VI.4
Annual Aggregate Willingness to Pay,
Definitely Yes Model With Imputed Values
for Nonrespondents (Millions of 1991
Nominal Dollars)
National Marketing area
Riverflow sample sample
-------------------------------------- -------------- --------------
Moderate fluctuating $2,286.4 $62.2
Low fluctuating $3,375.2 $60.5
Seasonally adjusted steady $3,442.2 $81.4
Seasonally adjusted steady (but $3,984.8 ----
describing lower power cost effects)
----------------------------------------------------------------------
A range of annual aggregate values calculated using the lower and
upper limits of the 95-percent confidence intervals for the
population weighted averages are provided in table VI.5 for the
national sample and in table VI.6 for the marketing area sample.
Table VI.5
Range of Values for Annual Aggregate
Willingness to Pay, Definitely Yes Model
With Imputed Values for Nonrespondents,
National Sample (Millions of 1991
Nominal Dollars)
Populati
on
weighted Lower Upper
Riverflow average limit limit
---------------------------------------- -------- -------- --------
Moderate fluctuating $2,286.4 $1,552.7 $3,415.4
Low fluctuating $3,375.2 $2,381.9 $4,906.2
Seasonally adjusted steady $3,442.2 $2,750.3 $4,998.4
Seasonally adjusted steady $3,984.8 $2,875.8 $5,592.7
(but describing lower power cost
effects)
----------------------------------------------------------------------
Note: Lower and upper limits refer to the lower and upper limits of
the 95-percent confidence interval for the population weighted
average.
Table VI.6
Range of Values for Annual Aggregate
Willingness to Pay, Definitely Yes Model
With Imputed Values for Nonrespondents,
Marketing Area Sample (Millions of 1991
Nominal Dollars)
Populati
on
weighted Lower Upper
Riverflow average limit limit
---------------------------------------- -------- -------- --------
Moderate fluctuating $62.2 $47.0 $82.9
Low fluctuating $60.5 $44.7 $82.6
Seasonally adjusted steady $81.4 $63.4 $105.0
----------------------------------------------------------------------
Note: Lower and upper limits refer to the lower and upper limits of
the 95-percent confidence interval for the population weighted
average.
--------------------
\14 W. Michael Hanemann, "Welfare Evaluations in Contingent
Valuation Experiments With Discrete Responses," American Journal of
Agricultural Economics, vol. 66, Aug. 1984, pp. 332-341.
\15 In other words, the explanatory variables (the Xi) include a set
of intercept dummies which permits different willingness-to-pay
amounts to be determined for the different dam operation
alternatives. BID is estimated for the whole sample, but
the � i*Xi component in expression (2) above will be
different depending on which flow alternative (survey version) is
being considered.
\16 The follow-up information was used to estimate willingness to pay
on the basis of the characteristics derived through this process in
conjunction with the results of a model using the mail survey
respondents to predict the likelihood of voting for the proposal at
zero cost.
\17 Estimates were provided for population average willingness to pay
calculated with the assumption that nonrespondents had zero
willingness to pay. These estimates were in the range of 15 to 20
percent less than the corresponding estimates with imputed values for
nonrespondents.
\18 These states were Wyoming, Utah, Colorado, New Mexico, Arizona,
and Nevada.
EVALUATING THE NON-USE VALUE
STUDY USING THE NOAA PANEL
AND DILLMAN'S FINDINGS
------------------------------------------------------ Appendix VI:3.3
We evaluated Reclamation's non-use study on the basis of issues
considered by the NOAA panel and Dillman's total design methods as
described above.\19 Most of the NOAA panel's suggested practices were
part of the design and implementation of the Glen Canyon non-use
value study, including those related to the sampling, pretesting, and
reporting of results. Samples were based on commercially available
sampling frames and were augmented with motor vehicle and postal
service address update information. The researchers took random
samples proportionate to the number of households in each state for
the national sample and proportionate to the number of households in
zip codes for the marketing area sample.\20 Respondents to the
national survey had higher average levels of educational attainment
and household income than the underlying population. It is likely
that these characteristics are positively associated with willingness
to pay for environmental improvements and thus increase non-use
values. However, the magnitude of the effect is uncertain. During
the qualitative research phase, draft questionnaires were pretested
with six focus groups and six in-depth personal interviews. The
questionnaires were reproduced in the report, along with responses to
the various questions.
The study used the referendum format in preference to open-ended
elicitation, and questionnaires emphasized the consumer's budget
constraint, consistent with suggestions by the NOAA panel.\21
The study also provided a test on a respondent's level of
understanding of the issue at hand.
A notable exception to the NOAA panel's suggested practices is that
the Glen Canyon non-use value study used mail surveys. The panel
strongly favored the use of in-person surveys. The Glen Canyon
researchers maintain that well-designed mail surveys are capable of
producing reliable results.
With respect to the design and implementation of the mail survey, we
found that, except for one component, the researchers followed the
total design method to the letter. Everything from the size and
shape of the documents to the timing and amount of follow-up material
was as Dillman suggested, and in general, the questionnaires were
designed and implemented with extremely high standards. The
researchers made a great effort to ensure that the questions both met
the needs of the research design and were easily understood by the
respondents.
Only the length of the instrument exceeded the maximum suggested by
Dillman. The questionnaires were 18 pages, and according to Dillman,
10 to 12 pages is the maximum length for a questionnaire if a
researcher does not want reduced response rates. Nonetheless, the
average of 74 percent of the usable sample responding to the mail
surveys and an average of 83 percent responding to the mail and
follow-up telephone surveys is commendable given the nature of
general public surveys. Although a shorter instrument may have led
to higher response rates, the researchers faced a trade-off between
the amount of background information and environmental attitude
questions on the one hand and response rates on the other.
--------------------
\19 The NOAA panel's findings have no bearing on the Glen Canyon
non-use study, and indeed were not published until after the Glen
Canyon study was well under way. We refer to them because we believe
that the NOAA panel's deliberations represent valuable critical and
impartial thinking related to contingent valuation.
\20 The national sample size was 3,400 individuals, and the marketing
area sample size was 2,550. Each of the seven survey versions was
administered to 850 individuals. In the national sample, two
versions pertained to the Seasonally Adjusted Steady Flow alternative
and differed not in their descriptions of environmental impacts but
in their descriptions of possible electricity price impacts on users
of Glen Canyon power.
\21 Respondents in the national sample were asked to answer the
following question: "If this proposal passes and you had to pay $xxx
every year for the foreseeable future, on what sorts of things would
you spend less money in order to pay for the cost of this proposal?"
In the marketing area survey, respondents were asked a similar
question about monthly increases in utility bills. The next question
then provided an opportunity for the respondent to change his or her
vote. (Emphasis is contained in the questionnaires.)
EVALUATING SCOPE EFFECTS IN
THE GLEN CANYON NON-USE
VALUE STUDY
------------------------------------------------------ Appendix VI:3.4
Scope effects were of concern to the NOAA panel. Scope effects,
broadly interpreted to mean that changes in estimated willingness to
pay vary in ways that seem consistent with the changes in the degree
of environmental improvement, are at the center of the Glen Canyon
non-use value study because willingness to pay for the environmental
effects of different river flows should differ to the extent that the
effects differ. The researchers investigated scope effects in their
discussion of the "construct validity" of the non-use value study.\22
Scope tests can be considered a form of theoretical construct
validity, in which hypotheses based on economic theory are addressed.
For instance, one potentially important construct validity test is
whether income is positively related to measured willingness to pay.
In their summary of various construct validity issues, the
researchers stated that they believed the national sample results
provided the highest level of credibility, but that the marketing
area sample results were a little less credible.
Scope issues were examined using both the pilot and final versions of
the survey. Compared to the pilot version, the final survey's
descriptions of the environmental effects differed less sharply
across the various flow alternatives because, over time, scientific
assessments carried out in the Glen Canyon Environmental Studies did
not support such sharp distinctions.\23 Thus, the pilot test language
permitted a somewhat cleaner test of the general issue of whether
respondents were able to distinguish among the various degrees of
environmental improvement associated with the different flow
alternatives. Additionally, some versions of the pilot survey used a
multiple-bounded rather than a single-bounded referendum format.
This permitted greater statistical precision in testing for scope
effects.\24
Some scope tests are provided by the voting behavior of those
respondents who voted for the proposal facing them at zero cost.
According to the study, "the portion of respondents who would support
proposals if the cost to them were zero varied significantly across
proposals in ways that were consistent with prior expectations."
Generally, respondents appeared willing to pay more for the
environmental improvement associated with the Seasonally Adjusted
Steady Flow alternative than for that associated with the Moderate
Fluctuating Flow alternative.\25
Direct tests for scope effects are accomplished by examining the
dummy variables indicating the various survey versions. In the
regressions, each dummy variable can be interpreted as an additional
willingness-to-pay contribution for the additional environmental
improvement associated with that flow version over the environmental
effects associated with the examined reference case, moderate
fluctuating flow.\26 One complicating factor, however, is that the
different versions can involve trade-offs. Specifically, the
seasonally adjusted steady flow version describes a greater
environmental improvement but a more serious adverse effect on power
customers.\27 To focus more clearly on willingness to pay for
environmental improvement, researchers developed two versions of the
seasonally adjusted steady flow survey, which differed only in the
description of the adverse effects on power customers.\28 This
permits some disentangling of an environmental improvement scope
effect from the combined effect of environmental improvement and
adverse power impacts.\29
Because each survey version designated with a dummy variable offers
greater environmental improvement compared to the moderate
fluctuating flow version, expectations are that the parameter
estimates for variables representing alternative flows should be
positive. For the preferred "definitely yes" model, four of the five
key parameter estimates are of the correct sign. However, only the
coefficients for the two seasonally adjusted steady flow alternatives
in the national sample are statistically significant (i.e., different
from zero, using a one-tailed test at the 90-percent confidence
level). The study acknowledges that the results of these scope tests
are mixed but suggests that the totality of evidence (including pilot
test versions and the "definitely and probably yes" models) are
relevant for discussions of scope tests, and much of that evidence is
stronger.
--------------------
\22 Drawing on methods developed by psychologists, contingent
valuation researchers often examine three issues relevant to a
study's reliability. These are content validity, construct validity,
and criterion validity.
\23 For instance, the pilot survey proposal describing the Seasonally
Adjusted Steady Flow alternative stated that "There would be a major
improvement in conditions for native fish. Populations of most
native fish, including one of the species in danger of extinction,
would increase." The final survey proposal describing this flow
alternative stated that "There would be a major improvement in
conditions for fish. Native fish, including one of the endangered
species, would most likely increase in numbers. However, competition
from non-native fish may still limit the growth of native fish
populations."
\24 Because the multiple-bounded approach was new, the researchers
decided to use the more traditional single-bounded form in the final
versions. Using an additional bound would allow a finer partition of
the willingness-to-pay range. For instance, if a respondent
indicates a willingness to pay $10 but an unwillingness to pay $20,
the upper bound has been established. The concern with providing the
respondent with another dollar amount is that it may provide a
valuation cue to the respondent and thereby introduce a response
bias.
\25 Additionally, in the national sample pilot test, survey versions
were similar except that one mentioned improved conditions for fish
while the other did not produce different willingness-to-pay
estimates.
\26 In a regression, one of a set of mutually exclusive and
exhaustive dummy variables is omitted as an explanatory variable. In
this way, the "omitted" category can be thought of as the reference
case. In the Glen Canyon study, the moderate fluctuation flow
version is the reference case.
\27 In the national sample, the referendum proposal described effects
on households and farmers using power generated at Glen Canyon Dam.
The fluctuating flow versions contained the following language: "The
average electric bill would increase by $3 per month for 1.5 million
households receiving power from Glen Canyon Dam. This average
reflects a maximum increase of $9 per month for 3,600 households and
a minimum of no increase for 800,000 households. On average, farm
incomes would not change significantly. However, about 300 farmers
in southern Utah would see their incomes drop by 3%." The steady flow
version stated: "The average electric bill would increase by $9 per
month for 1.5 million households receiving power from Glen Canyon
Dam. This average reflects a maximum increase of $21 per month for
3,600 households to a minimum of no increase for 300,000 households.
On average, farm incomes would not change significantly. However,
about 300 farmers in southern Utah would see their incomes drop by
6%."
\28 Specifically, the second version of the steady flow proposal
included descriptions of the adverse effects on power customers and
farmers that were identical to those used in the fluctuating flow
versions.
\29 The use of two survey versions describing the seasonally adjusted
steady flow also permits investigation into whether a description of
the power impacts possibly provides a cue to respondents in answering
the referendum question. For example, the value of the dummy with
the higher power impacts would be greater in magnitude than the dummy
with the lower power impacts if respondents interpreted the larger
dollar impacts on power users as an indication of the magnitude of
the environmental problem. Conversely, if respondents empathized
with the plight of power users, the results would be the opposite.
RESULTS OF THE NON-USE VALUE
STUDY COULD BE SIGNIFICANT IN
THE DECISION-MAKING PROCESS
-------------------------------------------------------- Appendix VI:4
Non-use values represent the highest estimated economic impact from
changing the Glen Canyon Dam's operations. Non-use values were based
on estimates of the public's willingness to pay for downstream
environmental improvement that would likely result from changes in
the dam's operations. Willingness-to-pay estimates for the national
sample ranged from less than $15 per household annually to about $20
per household annually. Because there are close to 100 million
households in the United States, an average household's willingness
to pay estimated to be $15 per year yields an aggregate non-use value
of $1.5 billion annually, which is very large when compared to the
estimated annual power costs.
Although the final EIS discusses non-use values and notes that they
are positive and significant, the actual quantified results are not
included in the final EIS. Reclamation did not include the non-use
value study results in the final EIS because they were not available
when the final EIS was published. Nonetheless, the non-use value
study will be among the materials provided to the Secretary and, as a
result, could be used in the final decision-making. In fact, the
National Research Council in its 1996 report stated that the non-use
value study results "deserve full attention as decisions are made
regarding dam operations."\30
Because the actual quantified results of the non-use value study were
not in the draft or final EIS, they were not available to the general
public to offer comments similar to other EIS results. While
acknowledging the lack of formal public comment, Reclamation
officials point out that the non-use value study was subjected to
extensive peer review at key decision points in the process and that
the final non-use value study received a positive review by the
National Research Council. Reclamation also states that interests
likely to be affected by the changes in the Glen Canyon Dam, such as
power groups or environmental groups, were involved in the non-use
value study process.
--------------------
\30 River Resource Management in the Grand Canyon, Committee to
Review the Glen Canyon Environmental Studies, National Research
Council, Washington, D.C. National Academy Press, 1996, p. 135.
SCOPE AND METHODOLOGY
-------------------------------------------------------- Appendix VI:5
To gain an understanding of Reclamation's non-use value study
methodology and results, we reviewed the final report GCES Non-Use
Value Study, September 8, 1995. We also reviewed the economics
literature on non-use values and the contingent valuation method for
estimating them. We interviewed the principal author of the report,
a Senior Associate at Hagler Bailly Consulting. We examined reports
prepared by peer reviewers and we also discussed the study with some
members of the non-use value committee.
The following is a list of individuals we contacted.
David Harpman, Natural Resource Economist, Bureau of Reclamation
Michael P. Welsh, Hagler Bailly Consulting
Bruce Brown, ECOPLAN Consultants
RECREATION
========================================================= Appendix VII
The purpose of this appendix is to review (1) the methodology and key
assumptions that the Bureau of Reclamation used to estimate the
economic impact on recreation of alternative water releases at Glen
Canyon Dam and (2) the reasonableness of the estimated impacts. The
section of the Colorado River below the dam is used by a variety of
recreationists, including anglers, boaters, day-rafters, campers, and
hikers. We found that the methodology that Reclamation used to
estimate the economic impact of alternative flows on recreational
activities is generally reasonable. For example, recreationists were
surveyed to assess the impact of changes in the dam's operations on
recreation activities. In addition, modeling was used to estimate
the economic benefits accruing to the national economy from
recreational activities under the different flow regimes.
Reclamation has estimated that the economic impact on recreational
activities of changing the operations at the dam could range from $0
under the Maximum Powerplant Capacity and High Fluctuating Flow
alternatives to benefits of $4.8 million under the Seasonally
Adjusted Steady Flow alternative (in 1991 nominal dollars, relative
to a No-Action alternative). However, we found several limitations
in Reclamation's recreation analysis that suggest that the estimated
economic benefits could be over- or understated. For example,
because the initial recreation study was completed in 1985 and some
recreation conditions have changed since then, some of the study's
data may not reflect more recent trends in recreational activities
below the dam. Also, recreationists were surveyed during an
unusually high water year, limiting the ability of the researchers to
capture representative recreational experiences, and some of the
survey instruments were not adequately pretested to minimize bias and
confusion on the part of survey participants. In addition, anglers
who fish within the Grand Canyon were not included in the survey.
Because of the inherent uncertainty associated with future events,
the actual economic impacts on recreation may differ from those
estimated. Nonetheless, despite these limitations, we believe that
the estimated impacts can be useful for generally assessing the
impacts that may be associated with moving from a No-Action
alternative to a fluctuating or steady flow alternative. Moreover,
Reclamation and National Park Service officials told us that they
were generally aware of the limitations in the recreation analysis
but believe that revising the study would not change the basic
conclusions of the EIS, the preferred alternative, or the ranking of
alternatives. Furthermore, a reviewer of the recreation study for
the National Research Council told us that the recreation analysis
reflected current professional practices and was well done.
INTRODUCTION
------------------------------------------------------- Appendix VII:1
Recreation is an important use of the Colorado River below the Glen
Canyon Dam. The 15-mile segment of the river below the dam--located
within the Glen Canyon National Recreational Area--is the last
remaining riverine section of the 189-mile, river-carved channel that
once was Glen Canyon. A variety of recreationists use this portion
of the river, including anglers, boaters, day-rafters, campers, and
hikers. Downstream from Glen Canyon, the Colorado River runs through
Marble Canyon and Grand Canyon. This segment of the river is the
longest stretch of river (278 miles) for recreational use that is
entirely located within a national park. A large number of rapids,
as well as the river's isolation within the Grand Canyon, enhance
recreational activities along this portion of the river. After
passing through the Grand Canyon, the Colorado River is impounded by
the Hoover Dam and forms the largest reservoir in the Western United
States--Lake Mead. According to Reclamation, about 100,000 boaters
annually use this stretch of the Colorado River and Lake Mead for
scenic boating, camping, fishing, and water-skiing.
EFFECTS OF PRE- AND POSTDAM
CONDITIONS ON RECREATION
------------------------------------------------------- Appendix VII:2
The Glen Canyon trout fishery has flourished since the construction
of the dam. Water flows from the dam are colder, carry less silt,
and are more stable on an annual basis than before the dam was
constructed. According to the Department of the Interior, following
the completion of the Glen Canyon Dam, the first 15 miles of flat
water between the dam and Lees Ferry, once stocked with trout, became
an excellent coldwater fishery. This section of the river is also
used for half-day commercial raft trips, which, depending upon the
flow level, depart either from a dock near the Glen Canyon Dam and
float down to Lees Ferry or from Lees Ferry and motor part way
upstream before floating back downstream.\1
Before the early 1960s, and before the dam was completed, few
visitors entered the canyon or ran the river. However, Reclamation's
EIS indicates that white-water boating in the Grand Canyon is a major
industry today, with 15,000 to 20,000 commercial and private boaters
annually, paralleling an increasing trend nationwide in white-water
boating. In order to help minimize impacts by recreationists, the
National Park Service established a ceiling on the number of user
days allowed each year along with stricter river-use regulations.
Before the dam, riverflows were highly variable and ranged from low
flows (frequently less than 3,000 cubic feet per second) to peak
flows (occasionally in excess of 100,000 cfs) in spring and early
summer. Now, riverflows are within a much narrower range--generally
from 3,000 cfs to 31,500 cfs (20,000 cfs under the interim operating
criteria)--and show less seasonal variation, reducing the high- and
low-water risks associated with recreating on the river.
Before the construction of the Glen Canyon Dam, spring runoff carried
sediment down the Colorado River to Lake Mead. After construction of
the dam, sediment from side canyons and beaches continued to be
transported down the river, but in smaller quantities. Over the
years, these sediment deposits have built up to form broad mud flats
at the upper end of Lake Mead. When the water level in Lake Mead
falls below 1,180 feet, boat navigation is difficult because the
river is too shallow at low flows and the channel changes with water
fluctuations.
--------------------
\1 High discharges associated with flood flows preclude rafting trips
from departing near the dam. The probability that such flows will
occur is diminished by several features of the action alternatives
described in Reclamation's EIS.
ISSUE
------------------------------------------------------- Appendix VII:3
The major issue addressed by Reclamation in its EIS analysis of
recreation was how do dam operations affect recreation in the study
area? Specifically, Reclamation's assessment focused on how changes
in the dam's operations would affect angling, day-rafting, and
white-water boating along the Colorado River in the Glen and Grand
canyons, as well as the recreationists using lakes Powell and Mead.
INDICATORS
------------------------------------------------------- Appendix VII:4
Reclamation evaluated the impact of alternative flow regimes on a
series of indicator activities. The indicators are:
-- Fishing trip attributes, safety, and access.
-- Day-rafting trip attributes and access.
-- White-water boating trip attributes, camping beaches, safety,
and wilderness values.
-- Lake activities and facilities.
-- Net economic value of recreation.
EFFECTS OF FLOW ALTERNATIVES ON
RECREATION
------------------------------------------------------- Appendix VII:5
According to Reclamation's EIS, fishing in the Glen Canyon occurs
mostly from boats, but some anglers wade in the area around Lees
Ferry. The magnitude and rate of change in the river's stage
increases the danger for anglers wading in the Glen Canyon reach.
Therefore, fishing safety would improve under the Moderate, Modified
Low and the Interim Low Fluctuating Flow alternatives, because
fluctuations are reduced and the rate at which the river's stage
rises is constrained. Upstream fishing access by boat under the
Maximum Powerplant Capacity alternative is the same as under the
No-Action alternative. Increased minimum flows under the High
Fluctuating Flow alternative would result in a negligible increase in
the ease of upstream access by anglers. Because damage to boats and
motors is more likely during the low-flow periods that typically
occur in the morning before peak power generation occurs, increased
minimums and changes in the magnitude of upramp and downramp rates
(that is, changes in cfs per hour) would greatly improve upstream
access under all other alternatives.
Reclamation's EIS states that the flood control measures included in
the restricted fluctuating and steady flow alternatives would reduce
the probability of flood events and the corresponding need to launch
from Lees Ferry, thus improving the quality of the day-rafting
experience in Glen Canyon. In addition, the risk of white-water
boating accidents would be highest under the No-Action and Maximum
Powerplant Capacity alternatives, slightly lower under the High
Fluctuating Flow alternative, and lower under the remaining
restricted fluctuating flow alternatives. All steady flow
alternatives would decrease the risk of white-water boating accidents
over the No-Action alternative.
According to the EIS, wilderness characteristics would improve as
variations in riverflow are reduced. To the extent that habitat
maintenance and beach/habitat-building flows maintain beaches and
reduce the rate of vegetative encroachment, the alternatives with
these flows would further enhance wilderness values.
In the short term, the greatest increase in available beach area
would occur under the steady flow alternatives. In the long term,
low steady flows would remove all of the system's natural variation.
The absence of natural system cycles is likely to encourage
vegetative growth and result in a net loss of camping beach area.
The available beach area would be slightly increased under the
Moderate, Modified Low, and Interim Low Fluctuating Flow alternatives
in the short term. In the long term, habitat maintenance flows
(included in the Moderate and Modified Low Fluctuating and Seasonally
Adjusted Steady Flow alternatives) would help maintain the number of
beaches and their camping areas.
Because riverflows and the magnitude and frequency of fluctuations
differ under each alternative, the net economic value of recreation
would also differ. The majority of recreational benefits are derived
from commercial white-water rafting, which in general is positively
related to average daily flows and negatively related to
fluctuations. Those alternatives that increase average summer flows
or eliminate daily fluctuations in excess of 10,000 cfs tend to
increase recreational benefits.
RECLAMATION'S METHODOLOGY FOR
MAKING IMPACT ASSESSMENTS
------------------------------------------------------- Appendix VII:6
In assessing the effects on recreation of the different operating
regimes for the Glen Canyon Dam, the final EIS gives numerical values
where possible; otherwise, it gives qualitative assessments that are
based on physical, biological, and economic research. There are
three distinct and independent components to the recreational
material presented in the EIS. The first is a quantitative
assessment of the net economic value of river-based recreation
associated with the different flow alternatives. The second
component is a qualitative assessment performed by resource managers
using the results of scientific studies of the impact of flow
alternatives on individual resources. The third recreation component
involves an analysis of the regional economic impacts of recreation.
Regional economic impact refers to expenditures and their importance
to the local economy in the study area. The first two components are
based on a study of visitors' preferences conducted by Bishop et al
(1987). This appendix will address only the specifics of the first
component--the economic benefits associated with recreation.
RECLAMATION'S RECREATION IMPACT
METHODOLOGY IS GENERALLY
REASONABLE
------------------------------------------------------- Appendix VII:7
We found that the methodology that Reclamation used to estimate the
economic impact of alternative flows on recreation activities is
generally reasonable. For example, to obtain information from river
recreationists, the researchers used a two-stage research design.
They conducted two sets of surveys to obtain information from
white-water boaters, anglers, and day-rafters. In addition, the
researchers analyzed the survey data using a "logit" regression model
to determine the amount of money that recreationists would be willing
to pay to experience recreational activities under different flow
regimes. Also, they used a national economic perspective in the
analysis to estimate the recreation benefits accruing to the national
economy.
To design and conduct the recreation study, Reclamation contracted
with a private consulting firm, HBRS, Inc. (now Hagler Bailly
Consulting; hereinafter, the contractor or researchers). The
contractor completed an initial study in 1987 and an updated study in
1993.\2 The updated study was used as the basis for the recreation
benefits cited in the final EIS.
--------------------
\2 Glen Canyon Dam Releases and Downstream Recreation: An Analysis
of User Preferences and Economic Values, 1987; and Analysis of the
Impact of GCDEIS Alternatives on Recreational Benefits Downstream
From Glen Canyon, Madison, Wisconsin: HBRS, Inc., 1993.
A TWO-STAGE RESEARCH DESIGN
WAS USED TO OBTAIN SURVEY
DATA
----------------------------------------------------- Appendix VII:7.1
The contractor used a two-stage research design to determine the
potential impact of alternative flows at the Glen Canyon Dam on three
groups of recreationists--white-water boaters, day-rafters, and
anglers. Because riverflows during the period the research was
carried out were predominately high and steady, there was no way to
ensure that a representative sample drawn from the three groups would
include recreationists who had experienced the full range of flows
being evaluated. Therefore, the contractor asked the respondents to
evaluate their actual trips as well as written descriptions
(scenarios) of recreational experiences under a variety of flow
levels that they may not have experienced.
During the first stage, the contractor surveyed each recreational
group to identify the important characteristics (or attributes) of
the recreational experience on the Colorado River and what effect, if
any, riverflows would have on these experiences. The contractor also
administered these attribute surveys to commercial white-water
boating guides and private trip leaders to get a more informed view
of how riverflows affect the experiences of boaters on the river.
White-water boating participants in the attribute survey were
selected from the National Park Service's records of trip launches
for the 1982 and 1984 seasons. For anglers, the contractor attempted
to survey anglers at Lees Ferry during selected days in November and
December 1984. The researchers chose day-rafters from a
concessionaire's list of individuals who took a Glen Canyon raft trip
during the months of April through October 1985.
The contractor applied what had been learned from the attribute
surveys to the design of the scenarios for the contingent valuation
survey.\3 A contingent valuation survey attempts to measure the
willingness of a group of people to pay for hypothetical projects or
programs. The contractor used questionnaires to ask individuals
about their dollar valuation of a series of specific hypothetical
changes in Colorado River flows. Because the valuation is contingent
on the specific hypothetical change identified, these values are
called "contingent values" and the method of obtaining data is termed
the "contingent valuation method," or CVM.\4
The scenarios described white-water trips and angling trips at
various flow levels in terms of identified flow-sensitive
attributes.\5 The scenarios also distinguished between constant and
fluctuating flows. A fluctuating flow primarily occurs when the dam
is being operated for peak power production. Fluctuations in excess
of 10,000 cfs within a 24-hour period constituted a fluctuating flow
for the recreation study's purposes. The 10,000-cfs threshold was
based on the results of the attribute surveys.
In the second stage, the contractor used the scenarios as the basis
of the contingent valuation survey. Along with the actual trip
experience and its total cost, the contractor used these hypothetical
descriptions to quantify the effects of different flow regimes on the
recreational experience. Specifically, the contractor described the
change in the recreational experience and asked those surveyed
whether they would still take such a trip if their expenses were to
increase by a certain randomly assigned dollar amount over their
trip's actual cost. The respondents were limited to "yes" and "no"
answers. The researchers also provided the respondents with
riverflow information corresponding to the date of their actual trip
in order to gain information about the trip and establish a context
for the responses to the scenarios. In addition to this information,
the researchers asked the recreationists about the characteristics of
their actual trip and reasons for taking the trip. Also included
were questions about the respondent's income level and indicators of
how well the respondents understood the survey and thought the
results would affect the cost of future recreation.
A 1987 review by the National Research Council stated that the use of
the contingent valuation technique to address the public's
willingness to pay for angling and rafting opportunities through the
Grand Canyon was "a bold application of this promising method. The
researchers, who are well known for their development of the
technique, have ably and creatively analyzed the satisfaction of
recent recreationists."\6
--------------------
\3 Another approach for measuring recreation impacts is the travel
cost method. This method uses travel and related costs that are
incurred during a recreational activity to approximate the market
price for a recreation trip.
\4 In our review of the contingent valuation survey, we relied on
Dillman's total design method as well as on economic reasoning in
assessing the reasonableness of Reclamation's application of the CVM
approach. Dillman's method is an accepted standard in survey
research for achieving the maximum quality and quantity of responses
to mail questionnaires. By achieving the maximum quality of
responses, for example, researchers can have greater confidence in
the validity of the work; that is, they can be more sure of measuring
what they intend to measure. By achieving the maximum quantity of
responses, researchers can have greater confidence in the reliability
of their work that repeated investigations will produce similar
results. A more detailed discussion of the CVM approach is presented
in app. VI of this report; the total design method is described in
Dillman, Don A., Mail and Telephone Surveys: The Total Design
Method, John Wiley & Sons, New York, 1978.
\5 Because the attribute survey found day-rafters insensitive to
flows, no scenarios were presented to this sample group.
\6 River and Dam Management: A Review of the Bureau of Reclamation's
Glen Canyon Environmental Studies, National Academy Press, Washington
D.C., 1987, p. 63.
ECONOMIC ESTIMATES DEVELOPED
USING FEDERAL PRINCIPLES AND
GUIDELINES
----------------------------------------------------- Appendix VII:7.2
We found that the contractor followed federal principles and
guidelines for water resources planning where applicable in
developing estimates of the recreation benefits. For example,
federal principles and guidelines state that the federal objective of
water and related land resources planning is to contribute to
national economic development (consistent with protecting the
environment).\7 In addition, the guidelines state that the benefits
arising from recreational opportunities created by a project are
measured in terms of willingness to pay. The contractor defined
recreational benefits in terms of consumers' willingness to pay and
calculated the net economic benefit, or "surplus value," associated
with the recreational experiences under different flow conditions.
Surplus value is the value that the recreationists placed on their
recreational experience over and above what they actually paid for
the recreational experience. Expenditures, such as the price of a
Grand Canyon white-water boat trip, were excluded from the net
economic benefit calculations because the expenditures represent a
transfer payment to the local economy. Transfer payments simply
redistribute income from one group in society to another, and
therefore they do not reflect an economic benefit to the national
economy.
Nonetheless, expenditures are important because they support local
businesses and provide employment for local residents. For this
reason, recreational expenditures were the focus of a separate
analysis of regional economic activity that Reclamation performed.
--------------------
\7 Economic and Environmental Principles and Guidelines for Water and
Related Land Resources Implementation Studies, U.S. Water Resources
Council, Mar. 10, 1983.
ECONOMIC BENEFITS WERE
ESTIMATED USING ECONOMETRIC
MODEL
----------------------------------------------------- Appendix VII:7.3
The contractor used a now standard econometric approach to evaluate
the contingent valuation response data. For example, surplus values
were estimated using a "logit" model, that was based on the "yes" and
"no" answers to the survey's valuation question. Using the logit
model, the contractor estimated the probability that a respondent
would be willing to pay a specific dollar amount (termed "offer
amount") above his/her actual trip cost to recreate under the various
flow regimes. This probability was assumed to be a function of
several independent variables, including the offer amount, the amount
the recreationist spent to take an actual trip, and the number of
days spent on the river.
To update the estimated values obtained during the 1985 survey, the
contractor used the 1985 model with the hydrologic conditions for
1991 to generate surplus values for various alternatives by month and
by recreational activity. The contractor then multiplied the surplus
values by the observed 1991 monthly participation rates for each
activity. The resulting estimates were then inflated to 1991
dollars. In addition, because the initial recreation study was
completed before Reclamation developed the alternative flow regimes
in the EIS, the contractor extrapolated from the flow regimes used in
the contingent valuation survey to the EIS flow regimes using a
combination of historical data on the dam's operations and
projections of future hydrologic conditions over a 20-year planning
period. The 20th year was repeated for 30 years to complete the
50-year analysis period. The Colorado River Simulation System model
was used to develop the future hydrologic projections, which were
identical to those used in the power analysis.
To determine the present value of future recreation benefits over the
50-year analysis period, the contractor discounted future annual
benefits using the federal discount rate of 8.5 percent.\8
The present value was "levelized" over the 50-year analysis period to
determine equivalent annual benefits. Table VII.1 shows the
estimated net economic benefits for recreation associated with the
nine alternatives discussed in the final EIS. The table reflects the
net benefits associated with white-water boating and angling
activities. The number of white-water boating and angler trips were
held constant at 1991 levels over the 50-year analysis period. The
researchers found that day-rafters are not sensitive to river stage
and fluctuations; thus, the economic impact of changes in the dam's
operations on day-rafters was estimated to be zero.
Table VII.1
Economic Benefits Associated With
Recreation Activities, Relative to the
No-Action Alternative (1991 Nominal
Dollars in Millions)
Present value
of net
benefits over
50-year Equivalent
analysis annual net
EIS alternatives period benefits
-------------------------------------- -------------- --------------
No Action $0 $0
Maximum Powerplant Capacity $0 $0
High Fluctuating Flow $0 $0
Moderate Fluctuating Flow $4.6 $0.4
Modified Low Fluctuating Flow $43.3 $3.7
Interim Low Fluctuating Flow $45.6 $3.9
Existing Monthly Volume Steady Flow $45.6 $3.9
Seasonally Adjusted Steady Flow $55.0 $4.8
Year-Round Steady Flow $23.5 $2.9
----------------------------------------------------------------------
Source: Bureau of Reclamation.
--------------------
\8 The net recreation benefits in each year in the analysis period
were inflated by the projected gross national product price deflator
for that year. The same deflator and discount rate were also used in
the hydropower analysis.
SHORTCOMINGS IN RECREATION
ANALYSIS SUGGEST ECONOMIC
IMPACTS COULD BE OVER- OR
UNDERSTATED
------------------------------------------------------- Appendix VII:8
Although the recreation methodology is generally reasonable, we found
limitations in the analysis. For example, because the initial
recreation study was completed in 1985 and some recreational
conditions have changed since then, some of the study's data may not
reflect more recent trends in the recreational activities below the
dam. Also, the researchers gathered the survey data during an
unusually high-water year, limiting the ability to capture
representative recreational experiences, and they did not adequately
pretest some of the survey instruments to minimize bias and confusion
on the part of the participants. In addition, the contractor did not
include Grand Canyon anglers in the survey. Finally, some of the
econometric results are inconsistent with expectations based on
conventional economic reasoning. These limitations indicate that the
estimated recreation benefits could be over- or understated. Because
of the time and expense that would be required to recompute the
results with revised methodology and data, we did not determine the
net effect of the limitations on the estimated economic impacts.
RECREATION CONDITIONS MAY
HAVE CHANGED SINCE THE
SURVEY
----------------------------------------------------- Appendix VII:8.1
We found that some of the data used to develop the economic benefits
may be dated because of changes in the recreation environment since
recreationists were surveyed in 1985. The contractor used 1985
surplus values and number of trips taken in 1991 to derive recreation
benefits for alternative flows. However, because the estimated
benefits were derived using 1985 surplus values, they may not account
for more recent changes in recreational activities that could affect
value.\9
The years 1985 and 1991 combined for use in the model were different
in terms of the number of recreational trips taken, especially for
anglers. For example, according to study statistics, the actual
number of fishing trips at Lees Ferry more than doubled between 1985
and 1991, from 6,064 to 12,902. In addition, the fishing regulations
changed during this period, strictly limiting anglers to artificial
lures and imposing new restrictions on the size and number of fish
caught. Because of the substantial change in the number of fishing
trips taken and a change in fishing regulations, it may not be
reasonable to assume that the value per fishing trip, relative to
other goods and services, would have remained unchanged between 1985
and 1991.
--------------------
\9 Surplus values were adjusted for inflation between 1985 and 1991.
SURVEY DATA BASED ON A YEAR
WITH UNUSUALLY HIGH WATER
----------------------------------------------------- Appendix VII:8.2
The researchers were not able to capture representative recreational
experiences because of the river conditions present during the
recreation study. The sample year--1985--used to develop the
statistical relationship between flow rates and surplus values was an
atypical year for the Colorado River, characterized by relatively
high, constant flows and poor fishing. To address this data issue,
the contractor used hypothetical scenarios (developed using the
attribute survey information) to determine the effect of different
flow regimes on recreational experiences. However, two potential
problems with the use of the high-water year and scenario data are
(1) the estimated surplus values depend heavily on the ability of the
respondents to meaningfully interpret the scenarios using their
high-water experience and (2) the surplus values generated from
scenario data may differ from those based on actual experiences.
Ideally, the respondents should be asked about their willingness to
pay for alternative flow regimes that they have actually experienced.
At the time of the recreation survey in 1985, however, there had been
already 2 consecutive years of high-water flows. In addition,
according to Reclamation, it was not feasible to adjust the Glen
Canyon Dam's operations to create alternative flow conditions for the
recreation study. Therefore, the contractor constructed hypothetical
scenarios to simulate recreational experiences under different flow
conditions. The contractor then asked the recreationists to compare
their actual trip experiences with the hypothetical trip experiences.
However, because 1985 and the preceding years were unusually
high-water years characterized by constant flows, some recreationists
may not have experienced a variety of flow conditions. For example,
the researchers could not make inferences about the influence of
fluctuating flows on white-water boaters using information from
actual trips because only 12 percent of the respondents experienced
these fluctuations. Similarly, because there was little variation in
the actual trip experiences for anglers, the researchers were unable
to make a direct link between the actual trip's surplus value and the
flow levels experienced by the respondent. This condition is
attributable to all anglers having experienced such small variation
in flow conditions that substantially all of the respondents compared
the scenarios with essentially the same limited actual flow
experiences. Consequently, there was no way to determine whether
recreationists who experienced other types of flows would have valued
the scenarios differently. For example, a recreationist who had
experienced low, fluctuating flows might value a medium flow more
than a recreationist who experienced only a high constant flow.
SOME QUESTIONNAIRES WERE NOT
ADEQUATELY PRETESTED
----------------------------------------------------- Appendix VII:8.3
Although the researchers used Dillman's total design method for the
implementation of the surveys and tested proposed questions to
determine which wording options offered the highest response rates,
they did not adequately pretest some survey instruments to detect
defects in wording, construction, presentation, or other
inadequacies. As a result, we cannot be completely confident that
the surveys actually measured what they were intending to measure.
Reclamation's contractor used mail questionnaires to gather data on
recreational attributes and contingent values. We found that the
contractor generally followed Dillman's total design method in the
design and implementation of these questionnaires. For example, the
contractor met Dillman's standards for questionnaire design and
mailing procedures, which helped to obtain response rates between 70
and 93 percent. These response rates allow the researchers to have
greater confidence that they do not have a biased picture of the
sample caused by differences between the respondents and
nonrespondents.
However, we also found that the contractor did not follow Dillman's
pretesting standards. For example, the attribute survey for anglers
and the questionnaire used for white-water guides were pretested in
person, while other questionnaires were pretested through the mail.
According to Dillman, mail pretesting is "destined to be of very
limited value." Only by having respondents fill out the draft in the
presence of the researchers can they discover such information as:
Is each question measuring what it is intended to measure? Are all
the words understood? Are the questions interpreted similarly by all
respondents? Is any part of the questionnaire biased? Because such
pretesting was not done, neither we nor the contractor can be
confident about the validity of the questions or the instruments as a
whole.
An example of problems that may have resulted from inadequate
pretesting can be seen in the interpretation of the water levels
experienced by anglers. In the in-person interviews performed for
the angler attribute questionnaire, the researchers found problems
with the responses to questions that dealt with water levels
experienced by the anglers. The authors of the recreation study
noted that for the 2 years before the attribute survey, steady high
water was the rule. However, some respondents who had fished at Lees
Ferry only during 1984 and 1985 answered that they had experienced
low, medium, or fluctuating flows. The authors conclude that some
anglers may have answered the water-level experience question
incorrectly. These responses are evidence of possible problems in
the validity of the measures used. We do not know the extent of
misunderstanding between the respondents and the contractor, but this
example suggests that there was some. Adequate pretesting may have
detected and corrected this misunderstanding.
GRAND CANYON ANGLERS WERE
EXCLUDED FROM SURVEY
----------------------------------------------------- Appendix VII:8.4
The contractor assumed that fishing in locations other than Lees
Ferry was an incidental activity and therefore did not include these
anglers in the survey. As a result, the data for anglers are based
solely on the recreational experiences of anglers at Lees Ferry. To
the extent that other anglers who fish downstream in the Colorado
River or its tributaries have surplus values that are different from
the Lees Ferry anglers (but also positive), the estimated benefits
may understate the total benefits to anglers resulting from
alternative flow regimes.
The researchers defined the angling population to include those who
access the river from Lees Ferry in Glen Canyon, which had the effect
of excluding anglers in the Grand Canyon. According to the
researchers and recreation subteam members, the Grand Canyon anglers
were not included in the study for a variety of reasons. For
example, they were thought to represent only a small percentage of
fishing activity; they might be difficult to sample; and fishing
itself was not considered to be the focus of a Grand Canyon
recreational experience. Although little information exists on the
extent of angling in the Grand Canyon or the characteristics of these
anglers, the EIS makes reference to 15 sites in the Grand Canyon that
are managed for anglers who want to catch "fish that are naturally
reproduced in the wild." In addition, the National Park Service and
Arizona Game and Fish Department officials we contacted indicated
that some anglers fish in the vicinity of Marble Canyon to avoid the
restrictions on natural bait enforced at Lees Ferry, and other
anglers hike down into Phantom Ranch to fish in Bright Angel Creek.
The difficulty or expense of reaching or staying at a location other
than Lees Ferry, a preference for "wild" rather than hatchery fish,
and reasons for going to the river other than fishing could mean that
these groups of anglers have different opinions of the values of
flows than those who were sampled.
SURVEY DATA DO NOT PRECISELY
CORRESPOND TO EIS FLOW
ALTERNATIVES
----------------------------------------------------- Appendix VII:8.5
Because the researchers designed and conducted the recreation
contingent valuation survey well before the EIS operating regimes
were proposed for the Glen Canyon Dam, the flow regimes used in the
survey scenarios do not precisely correspond to the flow alternatives
identified in the final EIS. As a result, there is some uncertainty
as to whether the survey data reflect the same environmental changes
proposed in the EIS alternatives.
An unusual aspect of the recreational modeling effort is that it is
composed of two separate segments of work, several years apart,
occurring within the framework of the Glen Canyon Environmental
Studies. Reclamation's contractor began the initial study of
recreational values in 1984, and the results were published in 1987.
The 1987 study, however, predated the development of the preferred
alternative.
In order to allocate the estimated recreation benefits to the
alternative flow regimes in the EIS, the contractor converted the EIS
alternatives into the same terms as those used in the original
survey. This was done by translating the EIS alternatives into
average flow terms and identifying fluctuations in flow using a
mixture of theoretical data and data from the dam's actual
operations. However, the recreation survey was based on broad
groupings of flows, while the EIS flow alternatives are much more
detailed in their characteristics. As a result of this sequencing,
it is not clear that the aggregate recreational values captured in
the 1987 study reflect the same environmental changes proposed in the
EIS alternatives. The recreation analysis may not have captured the
nuances that distinguish the individual EIS flow alternatives. For
example, the scenarios used in the 1987 study used average flow
figures (such as 13,000 cfs) to ask individuals about their dollar
valuation of a hypothetical change in riverflows, while the EIS
describes complex alternatives stated both in terms of minimum and
maximum flows (for example, 1,000 cfs to 31,500 cfs) as well as the
rate of change in flows per hour (that is, ramping up or down).
Although ramping can affect the recreational experience, by using
these averages, the recreation analysis was not able to assess the
impact of ramping on recreational activities. For example, rapid
changes in the upramp rate of the dam's operations can put wading
anglers at risk of inundation, as well as affect the "naturalness" of
a wilderness boating experience. Similarly, rapid changes in the
downramp rate of the dam's operations can strand anglers in boats, as
well as fish in backwaters.
A Reclamation official and the contract researchers acknowledge that
there is no systematic linkage between the scenarios used in the
contingent valuation surveys and the flow regimes in the final EIS.
A Reclamation official told us that translating the EIS alternatives
into the same terms used in the 1985 scenarios involved a great
simplification. For example, the scenarios were based on a
dichotomous approach: a single mean monthly flow rate and the
presence or absence of fluctuations. If the flow levels varied by
more than 10,000 cfs, they were considered fluctuating. If the flow
levels varied by less than or were equal to 10,000 cfs, they were
considered steady. By contrast, the EIS alternatives involve complex
variables, including flow ranges and rates that change hourly. As a
result of this simplification, the recreation model cannot
distinguish between several alternatives. That is, the model
predicted the same economic benefits for the No-Action, Maximum
Powerplant Capacity, and High Fluctuating Flows, as well as for the
Interim Low Fluctuating Flow and the Existing Monthly Volume Steady
Flow.
SOME ECONOMETRIC RESULTS ARE
INCONSISTENT WITH
CONVENTIONAL ECONOMIC
REASONING
----------------------------------------------------- Appendix VII:8.6
Some of the econometric results indicate a positive and significant
relationship between surplus value and the expenditure variable,
which is inconsistent with conventional economic reasoning. For
example, in the analysis of white-water boaters' and anglers'
responses, the contractor found that the respondents' surplus values
increased with the amounts they spent to take their actual trips.
This result is inconsistent with conventional economic reasoning
because we would expect that the more an individual spends on a trip,
the lower would be his or her surplus value, all else being the same.
Because this result may be symptomatic of a technical problem, such
as a misspecification of the model, a measurement error, or an
insufficient sample size, it suggests that the results lack
precision.\10
Some members of the contract research team acknowledged this
inconsistency between the results of the model and conventional
economic reasoning. One of the contractor's researchers told us that
the positive relationship between surplus value and expenditure may
be attributable to an omitted price variable. In his opinion,
however, this omission does not affect the validity of the results
incorporated into the EIS.
--------------------
\10 Researchers were unable to calculate a standard error because the
appropriate statistical techniques were not available at the time of
the study. However, a Reclamation official told us that the
estimates are subject to an error of about plus or minus 20 percent.
THE EIS TEAM USED ESTIMATED
RECREATION BENEFITS ONLY TO AID
DECISION-MAKING
------------------------------------------------------- Appendix VII:9
Reclamation and National Park Service officials involved in the EIS
process told us they were generally aware of the limitations of the
recreation analysis but believe that addressing the limitations would
not change the basic conclusions of the EIS, the choice of the
preferred alternative, or the ranking of alternatives. No such
changes would occur because the study results were used more as an
adjunct in developing a preferred alternative, rather than a focal
point.
A Reclamation official involved in the selection of the preferred
alternative told us that the first criterion applied to the nine
proposed alternatives was how the sediment balance in the canyon
would be affected. Alternatives that negatively affected the amount
and location of sediment were eliminated, leaving only three
alternatives, none of which posed a safety threat to recreationists
except at very low flows. Since two of the three remaining
alternatives were identical except for a habitat maintenance flow,
the EIS team had to choose between only two alternatives. In
choosing between these two alternatives, the EIS team weighed the
power costs associated with each, the recreational benefits, and
unquantified ecological concerns, such as benefits to the aquatic
food base. According to this official, the EIS team selected the
Modified Low Fluctuating Flow as the preferred alternative because
the loss of power revenues was roughly offset by the gains to the
other resources.
National Park Service and Reclamation officials told us that
Reclamation considered revising the recreation economic study after
the EIS alternatives were developed to get better data on how
respondents valued a wide variety of actual flow conditions and on
anglers' participation in the Lees Ferry fishery. In particular, a
researcher raised the prospect of further investigating anglers'
values to overcome the limitations of the original study. However,
Reclamation decided not to spend additional resources on revising the
recreational analysis in order to further study areas that were
deemed more critical. A National Park Service representative told us
that because most of the unanswered questions were in the areas of
sediment, vegetation, and endangered fish, funds were directed to
these "higher-priority data gaps."
RECREATION RESULTS CAN BE
USEFUL DESPITE LIMITATIONS
------------------------------------------------------ Appendix VII:10
Because there is inherent uncertainty associated with projecting
future impacts, the actual economic impacts on recreation may differ
from those estimated. The limitations we have identified suggest
that the estimated impacts could be over- or understated.
Nonetheless, despite these limitations, we believe that the estimated
impacts can be useful for generally assessing the impacts that may be
associated with moving from a No-Action alternative to a restricted
fluctuating or steady flow alternative. Moreover, a reviewer of the
recreation study for the National Research Council indicated to us
that the recreation modeling was conducted using current professional
practices and was a state-of-the-art effort given the budget and time
constraints. In addition, this reviewer indicated that the work on
the economics of recreational use was well done and a good use of
taxpayer money given the many other demands on the Glen Canyon
Environmental Studies budget.
RECLAMATION'S AND THE NATIONAL
PARK SERVICE'S RESPONSE TO THE
RECREATION ISSUES RAISED
------------------------------------------------------ Appendix VII:11
We discussed our findings with a National Park Service and a
Reclamation official who, as EIS team members, were responsible for
incorporating recreation and the economics of recreational use into
the EIS. These officials, a resource management specialist with the
National Park Service and an economist with the Bureau of
Reclamation, generally agreed with our statements concerning the
strengths and weaknesses of the recreation analysis. Reclamation's
economist acknowledged that recreational conditions may have changed
since the study's survey was implemented in 1985. Both officials
said that the methodology was reasonable and appropriate and the data
were the best available at the time of the study. For these reasons,
they told us that neither the ranking of alternatives nor the choice
of a preferred alternative would change, even if the issues we
identified as shortcomings were resolved.
SCOPE AND METHODOLOGY
------------------------------------------------------ Appendix VII:12
To gain an understanding of general recreational issues we reviewed
studies on recreation use in the Glen and Grand canyons. To assess
the reasonableness of the recreation methodology, assumptions, and
results, we reviewed the documents that describe Reclamation's
methodology, assumptions and data, and literature on the contingent
valuation method, and we used standard economic principles. Our
assessment was limited to a review of the general analytical
framework and an assessment of the reasonableness of key assumptions
and data. We did not validate data inputs.
The documents we reviewed include the following:
Analysis of the Impact of GCDEIS Alternatives on Recreational
Benefits Downstream From Glen Canyon (draft report). Madison,
Wisconsin: HBRS, Inc., 1993.
Bishop, R., C. Brown, M. Welsh, and K.J. Boyle. "Grand Canyon
Recreation and Glen Canyon Dam Operations: An Economic Evaluation,
W-133," Benefits and Costs in Natural Resource Planning: Interim
Report 2. Edited by Kevin J. Boyle and Trish Heekin. Orono, Maine:
Department of Agricultural and Resource Economics, University of
Maine, 1989.
Bishop, R., K. Boyle, M. Welsh, R. Baumgartner, and P. Rathbun.
Glen Canyon Dam Releases and Downstream Recreation. Glen Canyon
Environmental Studies Technical Report. Salt Lake City, Utah:
Bureau of Reclamation, 1987.
Boyle, K., M. Welsh, and R. Bishop. "The Role of Question Order
and Respondent Experience in Contingent-Valuation Studies," Journal
of Environmental Economics and Management, pp. 80-99, 1993.
Boyle, K., M. Welsh, R. Bishop, and R. Baumgartner. "Analyzing
the Effects of Glen Canyon Dam Releases on Colorado River Recreation
Using Scenarios of Unexperienced Flow Conditions, W-133," Benefits
and Costs in Natural Resource Planning: Interim Report. Compiled by
John B. Loomis. Davis, California: Department of Agricultural and
Resource Economics, University of California, 1988.
Chestnut, L., R. Raucher, and R. Rowe. A Review of the Economic
Studies Conducted in Phase I of the Glen Canyon Environmental
Studies. Report to Mr. Dave Wegner, Bureau of Reclamation - Upper
Colorado Region, Flagstaff, Arizona. Economic Studies for the Glen
Canyon Environmental Studies, Phase II. RCG/Hagler, Bailly, Inc.,
1991.
Cummings, R.G., D.S. Brookshire, and W.D. Schulze. Valuing
Environmental Goods: An Assessment of the Contingent Valuation
Method. Rowman & Littlefield Publishers, 1986.
Diamond, P.A., J. Hausman. "Contingent Valuation: Is Some Number
Better than No Number?" Journal of Economic Perspectives, Vol. 8,
No. 4, pp. 45-64, 1994.
Economic and Environmental Principles and Guidelines for Water and
Related Land Resources Implementation Studies, U.S. Water Resources
Council, Mar. 10, 1983.
Final Report: Hualapai Recreation Studies. SWCA, Inc.
Environmental Consultants. Feb. 1995.
Final 1993 Annual Report: Hualapai Recreation Studies. SWCA, Inc.,
Jan. 1994.
Glen Canyon Environmental Studies Final Report. Salt Lake City,
Utah: Bureau of Reclamation, U.S. Department of the Interior, 1988.
Hanemann, W. M. "Valuing the Environment Through Contingent
Valuation," Journal of Economic Perspectives, Vol. 8, No. 4, pp.
19-43, 1994.
HBRS, Inc. Glen Canyon Dam Releases and Downstream Recreation: An
Analysis of User Preferences and Economic Values, 1987.
Jalbert, L. The Influence of Discharge on Recreational Values
Including Crowding and Congestion and Safety in Grand Canyon National
Park. Grand Canyon National Park Division of Resources Management,
1992.
Jalbert, L. Monitoring Visitor Distribution and Use Patterns Along
the Colorado River Corridor: River Contact Survey and Attraction
Site Monitoring (status report). Grand Canyon National Park Division
of Resources Management and Planning, 1991.
Kearsley, L. Monitoring the Effects of Glen Canyon Dam Interim Flows
on Campsite Size Along the Colorado River in Grand Canyon National
Park (final report). Grand Canyon National Park Division of
Resources Management, National Park Service, 1995.
Kearsley, L., J. Schmidt, and K. Warren. "Effects of Glen Canyon
Dam on Colorado River Sand Deposits Used as Campsites in Grand Canyon
National Park, USA," Regulated Rivers: Research and Management, Vol.
9, pp. 137-149, 1994.
Kearsley, L., and K. Warren. River Campsites in Grand Canyon
National Park: Inventory and Effects of Discharge on Campsite Size
and Availability (final report). Grand Canyon National Park Division
of Resource Management, National Park Service, 1993.
Operation of Glen Canyon Dam Final Environmental Impact Statement.
Bureau of Reclamation, U.S. Department of the Interior, 1995.
Operation of Glen Canyon Dam Draft Environmental Impact Statement:
Public Comments Analysis Report. Prepared by the Bear West
Consulting Team for the Bureau of Reclamation, 1994.
Portney, P.R. "The Contingent Valuation Debate: Why Economists
Should Care," Journal of Economic Perspectives, Vol. 8, No. 4, pp.
3-17, 1994.
Reger, S., K. Tinning, and L. Piest. Colorado River Lee's Ferry
Fish Management Report, 1985-1988. Phoenix, Arizona: Arizona Game
and Fish Department, 1989.
Richards, M., and D.B. Wood. "The Economic Value of Sportfishing at
Lees Ferry, Arizona," Riparian Ecosystems and Their Management:
Reconciling Conflicting Uses. Proceedings of the First North
American Riparian Conference. Apr. 16-18, 1985. Tucson, Arizona.
U.S.D.A. Forest Service General Technical Report RM 120. Ft.
Collins, Colorado: Rocky Mountain Forest and Range Experiment
Station.
River Resource Management in the Grand Canyon, Committee to Review
the Glen Canyon Environmental Studies, National Research Council,
Washington, D.C.: National Academy Press, 1996.
River and Dam Management: A Review of the Bureau of Reclamation's
Glen Canyon Environmental Studies, Committee to Review the Glen
Canyon Environmental Studies, National Research Council. Washington,
D.C.: National Academy Press, 1987.
Schulze, W., R. d'Arge, and D. Brookshire. "Valuing Environmental
Commodities: Some Recent Experiments," Land Economics, Vol. 57, No.
2, pp. 151-172, 1981.
Shelby, B., T.C. Brown, and R. Baumgartner. "Effects of
Streamflows on River Trips on the Colorado River in Grand Canyon,
Arizona," Rivers, Vol. 3, No. 3, pp. 191-201, 1992.
Stevens, L., K. Buck, B. Brown, and N. Kline. Dam and Geomorphic
Influences on Colorado River Waterbird Distribution, Grand Canyon,
Arizona, USA, 1995 (unpublished original research).
We also interviewed researchers, members of the EIS and recreation
teams, including Reclamation officials and their contractors, as well
as representatives from the National Park Service and the Arizona
Game and Fish Department. In addition, we spoke to academic experts
in economics and members of the National Academy of Sciences Glen
Canyon Dam EIS review team. A list of the researchers, officials,
and experts follows.
Richard Bishop, Professor, University of Wisconsin
Kevin Boyle, Associate Professor, University of Maine
Curtis Brown, Social Psychologist, Bureau of Reclamation
Bonnie Colby, Associate Professor of Agricultural and Resource
Economics, University of Arizona, Tucson
Galen Collins, Assistant Dean of Hotel and Restaurant Management,
Northern Arizona University
Diane Dupont, Associate Professor of Economics, Brock University -
Ontario, Canada
Marshall Flug, Water Resources Engineer and Research Hydrologist,
National Biological Service and Colorado State University
Rusty Gattis, Acting Superintendent, Glen Canyon Dam, Bureau of
Reclamation
Terry Gunn, Owner, Lees Ferry Angler's Guides and Fly Shop
W. Michael Hanemann, Professor of Agricultural and Resource
Economics, University of California, Berkeley
Martha Hahn, Idaho State Director, Bureau of Land Management
David Harpman, Natural Resource Economist, Bureau of Reclamation
Amis Holm, Environmental Planner III, SWCA, Inc. Environmental
Consultants
Brice Hoskins, Project Manager, SWCA, Inc. Environmental
Consultants
Charles Howe, Professor of Economics, University of Colorado
Linda Jalbert, Biological Technician, National Park Service
Lisa Kearsley, former National Park Service employee and researcher
Mark Law, Colorado River Subdistrict Ranger, National Park Service
Jerry Mitchell, Chief, Cultural Resource Management, National Park
Service
Mike O'Donnell, Supervisory Natural Resource Specialist, Bureau of
Land Management
Timothy Randle, Hydraulic Engineer, Bureau of Reclamation
Larry Riley, Supervisor, Arizona Game and Fish Department
Michael Welsh, Senior Associate, Hagler Bailly Consulting
SEDIMENT
======================================================== Appendix VIII
Sediment is unconsolidated material that comes from the weathering of
rock and is transported and deposited by water or wind. It is seen
as a key indicator resource for the Grand Canyon ecosystem because
nearly all of the canyon's resources are strongly linked to sediment.
For example, sediment is critical for stabilizing archeological sites
and camping beaches, for developing and maintaining backwater fish
habitats, for transporting nutrients, and for supporting the
vegetation that provides wildlife habitat. The amount of sediment
transported through the Glen and the Grand canyons depends to a large
degree on the volume of water released by the Glen Canyon Dam.
According to the EIS team members and sediment researchers that we
interviewed, the data used in the preparation of the sediment section
of the Glen Canyon Dam's EIS were the latest and best scientific
information available at the time. Furthermore, they told us that
the EIS is as good a document as can be done for reviewing and
transferring technical information for use in public policy
decision-making. While some sediment study results were based on
data that were preliminary, draft, and/or unpublished at the time of
the draft and final EIS, the researchers told us that no new or
additional information has subsequently been obtained that would
alter the information or conclusions presented in the final EIS.
Also, for the most part, these researchers agree that the modeling
tools used in the sediment impact determinations, while fairly crude
in some respects, were the best available at the time and that their
use resulted in appropriate conclusions.
DESCRIPTION OF THE RESOURCE
------------------------------------------------------ Appendix VIII:1
Sediment currently entering the Colorado River comes from tributaries
downstream from the Glen Canyon Dam, primarily the Little Colorado
and Paria rivers. Through several complex processes, the sediment in
the river is transported, deposited, and then eroded for further
transport. The quantity of the sediment in motion at a given time
and its location depend on the amount and particle size of the
sediment available, the dimensions and slope of the channel, and the
magnitude of the water's flow. Four general classes of sediment, by
size, are found in the Glen and Grand canyons:
-- silts and clays (finer than 0.062 millimeter),
-- sand (0.062 to 2 millimeters),
-- gravels and cobbles (2 to 256 millimeters), and
-- boulders (greater than 256 millimeters).
The transport and deposition of sediment vary with the size of the
particles. Silts and clays are easily transported and generally pass
through the system in a relatively short time, although some may be
deposited in the low-water-velocity areas on sandbars and in
backwaters. Silt and clay-sized particles provide important
nutrients for vegetation, and clay also provides cohesion. The most
abundant class of sediment found along the river is sand. Many
sandbars, frequently called "beaches," are used as campsites by
boaters and rafters and are also important sites for riparian
vegetation and wildlife habitats. Some sandbars also contain
important cultural resource sites for Native American tribes. Gravel
and cobblestones cover the bottom of some streambeds. Some fish
species use shallow gravel beds for spawning. The larger boulders
fall from the canyon walls or reach the river during flash floods in
steep tributary canyons. Boulders create and modify most of the
major river rapids and are an important factor in the creation of
sandbars.
The river's capacity to transport sediment increases exponentially
with the amount of water flowing in the river. The greater the
river's flow, the greater the velocity and the greater the
turbulence. The turbulence of flowing water is the uplifting force
that causes sediment particles to be carried in suspension or roll
along the streambed. Because sediment particles weigh more than
water, they tend to settle to the bottom of the river channel. Small
clay and silt particles can be carried in suspension by nearly all
dam releases. Riverflows often are large enough to carry sand grains
in suspension. The grains may be temporarily deposited in areas
where the velocity of the water is insufficient to move them. Larger
flows and velocities are needed to move gravel and cobbles, whereas
the largest boulders may remain in place in the river channel for
decades.
EFFECTS OF PRE- AND POSTDAM
CONDITIONS ON SEDIMENT
------------------------------------------------------ Appendix VIII:2
The Colorado River historically carried large quantities of sediment
from the states in the Upper Colorado River Basin. The Glen Canyon
Dam has caused three major changes to the sediment resources in the
canyon. First, the supply of sediment has been reduced. The
construction of the Glen Canyon Dam caused virtually all of the high
concentration of sediment from the upper basin to be trapped by the
dam and deposited in Lake Powell. Second, by controlling the annual
historical peak flows that had a tremendous capacity to transport
sediment, the dam has reduced the capacity of the river to transport
sand and other sediment. Third, the height of the annual deposition
of sediment, which is responsible for the size of sandbars, has been
reduced because the dam now controls flood flows.
ISSUE
------------------------------------------------------ Appendix VIII:3
As defined in the final EIS, the issue of concern for sediment
resources is how the dam's operations affect sediment throughout the
Glen and the Grand canyons.
INDICATORS
------------------------------------------------------ Appendix VIII:4
The indicators for the sediment resource listed in the final EIS are
-- the probability of net gain in riverbed sand;
-- the active width and height of sandbars;
-- the erosion of high terraces (high sediment deposits having a
relatively flat surface and steep slope facing the river);
-- the constriction of debris fans (sloping masses of boulders,
cobbles, gravel, sand, silt, and clay formed by debris flows at
the mouth of a tributary) and rapids; and
-- the elevation of lake deltas (sediment deposits formed where the
Colorado River and other streams enter Lake Powell or Lake
Mead).
METHODOLOGY USED TO MAKE IMPACT
DETERMINATIONS
------------------------------------------------------ Appendix VIII:5
The EIS sediment team used a combination of historical riverflow and
sediment discharge data, established computer modeling techniques,
preliminary research results, and professional judgment to determine
the potential impacts of the nine flow alternatives on the various
types of sediment (especially riverbed sand). The long-term impacts
on riverbed sand were estimated using empirical data and computer
modeling, while the potential impacts on sandbars, high terraces,
debris fans, and lake deltas were developed using preliminary
research results, modeling, and professional judgment.
The sediment team was comprised of two individuals, a civil engineer
with Reclamation and a hydrologist with the U.S. Geological Survey.
In order to obtain the most recent scientific information, they
obtained the preliminary results of the Glen Canyon Environmental
Studies phase II research and attended the meetings of the phase II
sediment researchers. The sediment team also attended a special
session at an American Geophysical Union symposium to discuss the
latest research on backwaters and also participated in several raft
trips down the canyon with researchers in order to personally observe
the sedimentation processes.
Other researchers involved in the sediment impact determinations
included U.S. Geological Survey and National Park Service officials
experienced in the sediment resource area. In addition, researchers
from Utah State University, the University of Tucson, and the
University of Northern Arizona were also active in various projects.
All of the researchers were experienced in sedimentation data
collection and analysis.
The data used in drafting the sediment section of the EIS were
obtained from measurements and observations at selected canyon sites
under various conditions, including during floods, historic
powerplant operations and operations under the interim operating
criteria, and also under specially designed research flows. The data
collected underwent several different reviews.
The data obtained by the U.S. Geological Survey and used in the
final EIS received additional reviews. Within the Geological Survey,
each report was reviewed by at least two other researchers, plus an
additional review at the regional level. External review was
provided by the editors of outside publications or other
professionals when the work was published in a U.S. Geological
Survey professional paper.
In addition, the National Academy of Sciences, through its National
Research Council, reviewed the preliminary draft EIS and provided
official comments. The draft EIS was also made available for public
review and comment. Over 470 public comments were received that
related to sediment. The public comments reflected many differing
and even contradictory views and opinions. For example, some
commentors suggested that the dam's historical operations have
damaged the beaches and increased erosion. Other commentors said
that without the dam, there would be fewer beaches or that the
increases in erosion are overstated. The effect of steady flows
versus fluctuating flows on beach erosion was also argued on both
sides. Some believed that steady flows would preserve beaches, while
others said that they would destroy beaches. Other commentors
expressed the belief that controlling fluctuation within certain
parameters can control erosion, while others said that as long as
there is a flow of any kind, erosion will occur.
The EIS team needed detailed analyses of the projected flow patterns
for the various alternatives to evaluate different impacts. To
develop these technical analyses, the EIS team used the Colorado
River Simulation System (CRSS), a package of computer programs and
databases designed to assist water resource managers in long-range
planning and operations studies. The development of CRSS took place
over a 10-year period and stemmed from the need for a comprehensive
model of the Colorado River Basin that would incorporate all areas of
interest, including legislative requirements. According to
Reclamation and other experts, today, CRSS is the most comprehensive
and detailed simulation of the Colorado River system that exists.
The CRSS database contains reconstructed natural flow data for the
Colorado River between 1906 and 1990. The CRSS model can simulate
the Colorado River's operations and the effects of changes to the
Glen Canyon Dam's operations for the entire river basin. The
modeling process begins with the assumption that previous natural
flows in the river are indicative of future activity. Thus, the
model uses the historical data to project future water availability.
The CRSS can address many of the "what if" questions stemming from
proposed changes in the Colorado River's operations, from proposed
Colorado River basin development or from changes to present water use
throughout the basin. The model's long-term estimates are widely
accepted by water resource managers. The short-term estimates,
between 5 and 10 years, are considered to be somewhat less precise.
The model produces data on a monthly basis, whereas the EIS team
needed hourly projections in order to make their analyses for the
fluctuating flow alternatives. The steady flow alternatives did not
require this analysis because they provide for essentially steady
monthly flows. To make the necessary adjustments for analyzing the
fluctuating flows, a peak-shaving model was used to calculate the
hourly distributions from the CRSS-projected monthly release volumes.
(Peak shaving is the concept whereby hydroelectric powerplants are
used to serve (shave) the highest electric load (peak) during a
24-hour period.) These hourly distributions were produced for the
No-Action and Maximum Powerplant Capacity alternatives and for each
of the restricted fluctuating flow alternatives.
The combined outputs of the CRSS model and the peak-shaving model
were then used in the development of a sand-mass balance model. This
model used 85 different hydrological scenarios (for 50 years each) to
estimate the changes in riverbed sand due to differing flow
alternatives from the Glen Canyon Dam. Using regression analysis,
the sediment team calculated a sand-load discharge rating curve using
the water flow rate as the independent variable and total sand load
as the dependent variable. This curve shows the amount of sediment
transported for any given discharge rate. The sand-load discharge
rating curves were used as input into the 85 water release scenarios
to determine the probability that a given flow alternative would
result in higher amounts of sand in the riverbed over 20- and 50-year
periods. EIS team members stated that the resulting numbers were
reasonably accurate indicators of the relative differences between
the nine flow alternatives considered in the EIS.
EFFECTS OF FLOW ALTERNATIVES ON
SEDIMENT
------------------------------------------------------ Appendix VIII:6
According to the final EIS, the type of water release pattern
selected for the dam's operations will greatly affect sediment. The
analysis of the impacts on sediment was limited to the Colorado River
corridor from Glen Canyon Dam to Lake Mead and the deltas in Lake
Powell and Lake Mead. The direct impacts on sediment will vary with
the level and pattern of riverflow. The direct impacts include
changes in riverbed sand storage, aggradation (the process of filling
and raising the level of a streambed, flood plain, or sandbar by the
deposition of sediment) and degradation (the process wherein the
elevation of streambeds, flood plains, and sandbars is lowered by
erosion) of sandbars, and changes in the capacity to move large
boulders from rapids. Future levels of riverbed sand will vary
depending on the amount of riverbed sand available and the water
volume and release patterns of the alternative implemented.
On the basis of the results of computer models and the most recent
scientific research, the EIS sediment team determined what the
potential impacts of the various alternatives would be:
-- The No-Action, Maximum Powerplant Capacity, and High Fluctuating
Flow alternatives all had excessive sand transport capacity,
which jeopardized the long-term storage of sediment.
-- The Interim Low Fluctuating Flow, Existing Monthly Volume, and
Year-Round Steady Flow alternatives all maximized long-term sand
storage but provide limited ability to build sandbars. These
alternatives would result in vegetation encroachment on sandbars
and net erosion of sandbars above the normal river stage.
-- The Seasonally Adjusted Steady Flow, the Moderate Fluctuating
Flow, and the Modified Low Fluctuating Flow alternatives all
provided long-term sand storage and system dynamics.
On the basis of this analysis, the sediment team focused on the
Seasonally Adjusted Steady Flow, the Moderate Fluctuating Flow, and
the Modified Low Fluctuating Flow alternatives as the ones that would
provide preferable potential impacts on sediment.
ASSESSMENT OF IMPACT
DETERMINATIONS
------------------------------------------------------ Appendix VIII:7
The EIS team members and sediment researchers whom we contacted
provided us with comments on a variety of subjects, including the
sand-mass balance model, the quality of the data used, the accuracy
of the EIS in reflecting the research data, and whether other
evidence existed that would change the impact determinations in the
EIS. Generally, they agreed that the sand-mass balance model was the
best modeling tool available at the time, although two researchers
told us that more refined models are currently being developed by
U.S. Geological Survey researchers. However, according to two
Geological Survey researchers, none of the preliminary results from
these newer models contradict the conclusions reached from the
sand-mass balance model.
The researchers we spoke to generally complimented the way
Reclamation interpreted and used their work in the impact
determination process and said that the quality of the data used was
the best available at the time. A limitation on the use of the more
recent research results was that the data were preliminary (in draft
form or unpublished) and the newer models were too complex to
simulate multiple years of dam operations. In some cases, definitive
information on the impacts of a specific flow alternative was not
available. Therefore, the team had to extrapolate from the existing
data using their professional judgment to estimate the potential
impact of the alternative. However, they always verified the
reasonableness of their conclusions and extrapolations with the
researchers involved.
The officials we contacted also agreed with Reclamation's selection
of a preferred alternative and could find no evidence to change the
outcomes of the impact determinations for the sediment resource.
Specific comments made by some of those with whom we spoke included
the following:
-- Some commentors described the sand-mass balance model as
simplistic or fairly crude. However, they agreed that it was
the best and only tool available at the time. Also, they agreed
that the impact determinations reached as a result of the model
were correct. The leader of the sediment team agreed that the
sand-mass balance model is simplistic, but he believed it
produced reliable results for general, long-term information
needs. He did not think that any other model now available
would have been better. In fact, he stressed that the models
available today cannot handle the amount and types of data that
were required for the EIS process.
-- Some commentors believed that the sediment information in the
EIS was somewhat out of date in that it reflected the scientific
data of 1992-93. However, there was a general belief that the
EIS team did an excellent job of using the latest sediment
research. While more is known about the sedimentation processes
in the canyon today than was known when the EIS was written, the
EIS does contain the best information available at the time.
Also, they told us that even if the newer data had been
available, the same decisions would have been reached. The
discontinuity between the research and the administrative time
frames was a limitation on the EIS process, but they said that
the only impact would have been changes in some of the
statements made in the EIS. For example, they said that the
reasons for the selection of the preferred alternative would
have been more clearly supported.
-- Most of the researchers we contacted believed that their work
was properly used and interpreted in the EIS. With only a few
exceptions, discussions and communication between the EIS team
and the researchers were frequent and thorough enough to ensure
that the work was properly integrated into the EIS.
Consequently, the researchers believe that the sediment team
came up with the right conclusions. We found no examples that
would contradict or change the impact determinations in the EIS
or the selection of a preferred alternative. According to one
researcher, the sediment team examined all of the existing
professional papers and "followed up every lead, public or
private, for additional work."
The sediment team leader's overall position, taking into
consideration the various perspectives and opinions expressed, was
that
-- the process used in making the impact determinations for
sediment was reasonable,
-- the methodologies employed in this process were appropriate, and
-- the data used were the best available.
SCOPE AND METHODOLOGY
------------------------------------------------------ Appendix VIII:8
To determine the process used in developing the impacts on the
sediment resource, we identified and reviewed the following
documents: the draft and final Glen Canyon Dam environmental impact
statements and associated appendixes, the public comments on the
draft and final environmental impact statements, and Reclamation's
responses to the comments on the draft. We obtained and reviewed
copies of the minutes from the EIS team meetings and summaries of the
cooperating agencies' meetings. We also reviewed the Colorado River
Simulation System Overview, the Final Analysis Report on Scoping
Comments, the Glen Canyon Dam EIS Preliminary Alternatives Report,
and the newsletters issued by the Colorado River Studies Office from
June 1990 to February 1995. We also obtained and studied the Glen
Canyon Dam: Beach/Habitat-Building Test Flow, Final Environmental
Assessment and Finding of No Significant Impact, issued in February
1996.
In addition, we reviewed the paper entitled "Sediment Transport in
the Colorado River Basin" by Edmund D. Andrews. This paper was
published in Colorado River Ecology and Dam Management by the
National Academy of Sciences. This book contains various papers
presented in a 1990 symposium on the Grand Canyon.
We also reviewed Reclamation's paper entitled "Assessment of Changes
to the Glen Canyon Dam Environmental Impact Statement Preferred
Alternative From Draft to Final EIS." This paper explained the
background and scientific basis for the changes to the preferred
alternative between the draft and the final EIS.
To assess the procedures followed and obtain views on the quality of
data used in developing the impact determinations, we interviewed the
members of the sediment resource team and reviewers of the sediment
section of the draft EIS. We also identified and interviewed several
key Glen Canyon Environmental Studies principal investigators on
sediment issues.
Finally, we asked a member of the sediment team to review our
description of the impact determination process for factual accuracy.
He agreed that our description was generally accurate but made some
suggestions for changes. We have incorporated these changes into our
description of the process. We also presented him with our summary
of the resource process in order to provide him with an opportunity
to comment on and respond to the various issues raised through our
audit work.
KEY STUDIES IDENTIFIED
---------------------------------------------------- Appendix VIII:8.1
Beaus, S.S., and C.C. Avery (editors). The Influence of Variable
Discharge Regimes on Colorado River Sand Bars Below Glen Canyon Dam.
Flagstaff, Arizona: Northern Arizona University, 1992.
Budhu, M. "Mechanisms of Erosion and a Model to Predict
Seepage-Driven Erosion due to Transient Flow," in The Influence of
Variable Discharge Regimes on Colorado River Sand Bars Below Glen
Canyon Dam, S.S. Beaus and C.C. Avery, editors. Flagstaff,
Arizona: Northern Arizona University, 1992.
Ferrari, R.L. 1986 Lake Powell Survey. Bureau of Reclamation,
Report no. REC-ERC-88-6, 1988.
Hereford, R., H.C. Fairley, K.S. Thompson, and J.R. Balsom.
Surficial Geology, Geomorphology, and Erosion of Archeological Sites
Along the Colorado River, Eastern Grand Canyon, Grand Canyon National
Park, Arizona. U.S. Geological Survey Open-File Report 93-517,
1993.
Leopold, L.B. "The Rapids and the Pools--Grand Canyon." U.S.
Geological Survey Professional Paper 669-D, 1969.
Pemberton, E.L. "Sediment Data Collection and Analysis for Five
Stations on the Colorado River from Lees Ferry to Diamond Creek,"
Glen Canyon Environmental Studies Technical Report. Salt Lake City,
Utah: Bureau of Reclamation, 1987.
Randle, T.J., and E.L. Pemberton. "Results and Analysis of STARS
Modeling Efforts of the Colorado River in Grand Canyon," Glen Canyon
Environmental Studies Technical Report. Salt Lake City, Utah:
Bureau of Reclamation, 1987.
Randle, T.J., R.I. Strand, and A. Streifel. "Engineering and
Environmental Considerations of Grand Canyon Sediment Management,"
Engineering Solutions to Environmental Challenges: Thirteenth Annual
USCOLD Lecture, Chattanooga, Tennessee. Denver, Colorado: U.S.
Committee on Large Dams, 1993.
Schmidt, J.C. "Temporal and Spatial Changes in Sediment Storage in
Grand Canyon," The Influence of Variable Discharge Regimes on
Colorado River Sand Bars Below Glen Canyon Dam, S.S. Beaus and C.C.
Avery, editors. Flagstaff, Arizona: Northern Arizona University,
1992.
Schmidt, J.C., and J.B. Graf. "Aggradation and Degradation of
Alluvial Sand Deposits, 1965 to 1986, Colorado River, Grand Canyon
National Park, Arizona." U.S. Geological Survey Professional Paper
1493, 1990.
Smillie, G.M., W.L. Jackson, and D. Tucker. "Colorado River Sand
Budget: Lees Ferry to Little Colorado River." National Park Service
Technical Report NPS/NRWRD/NRTR-92/12. Fort Collins, Colorado:
National Park Service, 1993.
Webb, R.H., P.T. Pringle, and G.R. Rink. "Debris Flows From
Tributaries of the Colorado River, Grand Canyon National Park,
Arizona." U.S. Geological Survey Professional Paper 1492, 1989.
OFFICIALS INTERVIEWED
---------------------------------------------------- Appendix VIII:8.2
We interviewed the following individuals about the sediment impact
determination.
Edmund (Ned) Andrews, U.S. Geological Survey, Boulder, Colorado
Julia Graf, U.S. Geological Survey, Tucson, Arizona
Bill Jackson, National Park Service, Ft. Collins, Colorado
Dick Marzolf, U.S. Geological Survey, Boulder, Colorado
Margaret Matter, Western Area Power Administration, Denver,
Colorado
Timothy Randle, Bureau of Reclamation, Denver, Colorado
Spreck Rosekrans, Environmental Defense Fund
Jack Schmidt, Utah State University
James Smith, U.S. Geological Survey, Boulder, Colorado
Robert Webb, U.S. Geological Survey, Tucson, Arizona
James Wilson, U.S. Geological Survey, Cheyenne, Wyoming
VEGETATION AND WILDLIFE/HABITAT
========================================================== Appendix IX
The resources downstream from Glen Canyon Dam through the Grand
Canyon are interrelated, or linked, since virtually all of them are
associated with or are dependent on water and sediment. This link is
true for vegetation and wildlife and their habitat. The complex
Grand Canyon ecosystem contains a variety of native and nonnative
plants and animal communities that began developing before the
construction of the dam. However, since the dam was completed, the
ecosystem immediately surrounding the Colorado River has been
significantly influenced by the operations of the dam.
We have combined our analysis of the vegetation and the
wildlife/habitat impact determinations in this appendix because (1)
with the exception of the abundance of aquatic food base for
wintering waterfowl, similar indicators were studied in making the
impact determinations for these resources; (2) the riparian
vegetation that developed along the Colorado River corridor plays an
important role as habitat to support the diversity of wildlife within
the Glen and the Grand canyons; and (3) the same EIS team member was
responsible for the impact determinations for both resources.
There has been little controversy surrounding the results of the
impact determinations as presented in the final EIS for the
vegetation and wildlife/habitat resources. Generally, the team
leader and other experts we interviewed believed that the processes
used in making the impact determinations were reasonable, the
methodologies employed in these processes were appropriate, and the
data used were the best available.
DESCRIPTION OF THE RESOURCE
-------------------------------------------------------- Appendix IX:1
The plant communities surrounding the Grand Canyon reflect the
influences of desert conditions. These plants include barrel cactus,
brittle bush, creosote bush, ocotilla, and cholla cactus. The
Colorado River and the operations of the Glen Canyon Dam have little
effect on these plants. However, the dam's operations, which
modified the natural hydrology within the Colorado River corridor, do
affect a narrow band of vegetation known as the riparian (near water)
zone. The availability of water in the riparian zone supports plants
that could not otherwise survive in a desert climate, and the types
and abundance of vegetation that exists reflect the water regime that
supports it. Among the plants found in areas of the riparian zone
are netleaf hackberry, honey mesquite, catclaw acacia, seep-willow,
arrowweed, desert broom, coyote willow, and tamarisk.
The riparian zone is the focus of both the vegetation and the
wildlife/habitat studies for the EIS. The thick growth and variety
of plant species as well as the several thousand species of
invertebrates found there make the riparian zone some of the most
important wildlife habitat in the Grand Canyon region. For example,
riparian plants provide cover and food for 26 species of mammals.
Also, of the 303 species of birds that have been documented in the
Grand Canyon region, 250 species use the riparian zone within the
Colorado River corridor. Over half of the bird species nesting along
the river corridor nest in riparian vegetation. Furthermore, 27
species of reptiles and amphibians are supported by the resources
found in the riparian zone. In some Colorado River corridor
locations, lizard population densities are higher than anywhere else
in the Southwest.
Also, during peak winter months, 19 species of wintering waterfowl
have been found along the river corridor between Lees Ferry and Soap
Creek. These waterfowl cannot be directly linked to riparian
vegetation, but they are attracted to and use the clear, open, cold
water of the Colorado River that resulted after the dam was
constructed and that supports the abundant algae that are important
to the aquatic food chain. Although survey data are not available,
the EIS states that before the construction of the dam, the turbid
river water was probably not very attractive to wintering waterfowl.
EFFECTS OF PRE- AND POSTDAM
CONDITIONS ON VEGETATION AND
WILDLIFE/HABITAT
-------------------------------------------------------- Appendix IX:2
Because of the dynamic interaction between riparian vegetation and
water availability, the construction of the dam and any changes in
its operations that change specific water release patterns would be
expected to affect the abundance and distribution of plants. Before
the Glen Canyon Dam was constructed, seasonally high riverflows
carried large sediment deposits through the Glen and the Grand
canyons and scoured away or buried most vegetation from the river
corridor below the 100,000 to 125,000 cubic feet per second river
stage elevation. Annual floodflows prevented the establishment of
marsh plants (cattails and similar aquatic plants) along the river
corridor. Before the dam, the only riparian vegetation present along
the river was woody plants (trees and shrubs) that developed in what
became known as the old high-water zone. Plants that can withstand
the conditions created by periodic flooding characterize the old
high-water zone--netleaf hackberry, honey mesquite, and catclaw
acacia.
After the dam began operations and controlled annual spring flooding,
additional vegetation began to develop near the river below the old
high-water zone. This vegetation developed rapidly in what has
become known as the new high-water zone. Within this new high-water
zone are found both woody plants and emergent marsh plants (cattails
and similar aquatic plants). Common woody plants found in the new
high-water zone include both native and nonnative species such as the
seep-willow, arrowweed, desert broom, coyote willow, and tamarisk.
Tamarisk is a nonnative tree that has become the dominant woody plant
in the new high-water zone. Besides cattails, emergent marsh plants
found in the new high-water zone include bulrushes and giant reed.
This new high-water zone provides over 1,000 acres of additional
habitat for wildlife. Figure IX.1 illustrates the relative positions
of the predam and postdam riparian zones in the Grand Canyon.
Figure IX.1: Grand Canyon
Riparian Zone, Predam (Before
1963) and Postdam (After 1963)
(See figure in printed
edition.)
Source: Bureau of Reclamation.
ISSUE
-------------------------------------------------------- Appendix IX:3
As developed in the final EIS, the issue of concern is how the dam's
operations affect vegetation and wildlife and their habitat
throughout the Glen and the Grand canyons.
INDICATORS
-------------------------------------------------------- Appendix IX:4
Two plant groups found in the Colorado River corridor--woody plants
and emergent marsh plants--were selected by the EIS team for detailed
evaluation and to serve as indicators of riparian vegetation. The
impact determination for vegetation was generally limited to the
Colorado River corridor that extends between the Glen Canyon Dam and
Separation Canyon. Because of the variety of plants growing in the
riparian zone and their differing water requirements, EIS team
members concluded that a comprehensive evaluation of the effects of
all of the dam's operating alternatives on all plants was beyond the
scope of the EIS.
Although very little information on wildlife population exists for
either the predam or postdam habitats found along the river corridor,
it was assumed that almost all wildlife concerns could be addressed
by considering the effects of the operating alternatives on riparian
vegetation because it serves as habitat for many wildlife species
that inhabit the river corridor. Thus, rather than make specific
analyses of impacts on individual wildlife species, the EIS team
assumed that almost all wildlife concerns could be addressed by
considering the effects of each of the dam's alternative operating
procedures on riparian vegetation. However, wintering waterfowl do
not depend on riparian vegetation within the Colorado River corridor
below the Glen Canyon Dam. Therefore, the EIS team used the
abundance of the aquatic food base, mainly Cladophora, as an
indicator for wintering waterfowl.
METHODOLOGY USED TO MAKE IMPACT
DETERMINATION
-------------------------------------------------------- Appendix IX:5
Reclamation designated a lead position for each resource and assigned
that person the overall responsibility for developing the general
impact determinations. For example, a riparian specialist was
assigned for both the vegetation and wildlife/habitat resources. The
riparian specialist developed his sections of the EIS through an
iterative process of report drafting, formal and informal
presentations to and review by the entire EIS team, and discussions
with and input from key researchers and colleagues. In this process,
it was important that the work of resource specialists responsible
for other resource impact determinations be considered in the
vegetation and wildlife/habitat analyses. For example, sediment is
critical for supporting the riparian vegetation that provides
wildlife habitat. Therefore, the impact determinations for the
sediment resource are directly linked to the vegetation and wildlife
and habitat resources and were used in the vegetation analyses. (See
app. VIII for a discussion of the impact determinations for
sediment.)
The riparian specialist prepared the vegetation and wildlife/habitat
sections of the draft EIS and was responsible for any revisions to
the EIS that were based on the 170 public comments received on these
sections of the draft EIS (123 on vegetation and 47 on wildlife and
habitat). In the preparation of material for the EIS impact
determinations, he relied extensively on the research work of other
scientists that was specific to the canyon's resources. For example,
an ecologist, who is considered a leading authority on vegetation in
the Grand Canyon region, was a major contributor of science-based
information on the vegetation and wildlife and habitat resources of
the canyon area. Key documented research considered by the riparian
specialist in his analyses of impacts on vegetation and
wildlife/habitat can be found in the scope and methodology section of
this appendix.
The ecologist was also one of the peer reviewers of the impact
determinations prepared by the riparian specialist. Others who
reviewed the riparian specialist's work were a zoologist, who has
done extensive fieldwork in the Glen Canyon, and a senior Glen Canyon
Environmental Studies scientist affiliated with Arizona State
University.
EFFECTS OF FLOW ALTERNATIVES ON
THE RESOURCES
-------------------------------------------------------- Appendix IX:6
SUMMARY OF IMPACTS ON
VEGETATION
------------------------------------------------------ Appendix IX:6.1
According to the final EIS, in the short-term period of analysis,
which was considered in the EIS to be between 5 and 20 years, the
alternative operations of the Glen Canyon Dam would affect riparian
vegetation within the river corridor in several different ways.
While some plants do well in drier conditions, others require wetter
conditions to survive. Some plants would likely decline as others
adjusted to new water regimes. The reduced frequency of major,
uncontrolled flood releases would result in an unknown, but assumed
equal, decline in the area of coverage of riparian vegetation in the
old high-water zone under all alternatives. Some plant species found
in the old high-water zone would expand into the new high-water zone.
The Maximum Powerplant Capacity alternative would result in reduced
areas of riparian vegetation in the new high-water zone because of
the higher maximum flows permitted under this alternative. Under the
No-Action alternative, woody plants within the new high-water zone
would be maintained within stage boundaries equivalent to flows
between about 22,000 cfs and 40,500 cfs. Periodic flooding that is
similar to existing conditions would maintain emergent marsh
vegetation at sites that are currently occupied at elevations between
flows ranging from 10,000 cfs to 20,000 cfs.
Under alternatives with lower maximum flows--the restricted
fluctuating and steady flow alternatives--new areas of sediment would
be exposed, and these areas would be available for plant growth.
These flow alternatives would all permit riparian vegetation to
expand into sites created by the reduced maximum flows. Woody
plants, such as coyote willow and arrowweed, found in the new
high-water zone would continue to increase. Some new establishment
of emergent marsh plants would occur at suitable sites; however,
existing areas of emergent marsh plants that lose their water supply
would become dominated by woody plants and eventually disappear.
The habitat maintenance flows included under the Moderate and
Modified Low Fluctuating Flow alternatives and the Seasonally
Adjusted Steady Flow alternative are assumed to affect the area
available for vegetation, but the magnitude of the effect is unknown.
Beach/habitat-building flows that restructure sediment deposits would
disturb plants and interrupt succession in the riparian community.
As a result of these flows, some woody vegetation would be buried and
lost as sand is deposited on higher elevations, and patches of
emergent marsh plants would be lost through scouring or burial. Both
woody plants and emergent marsh vegetation would develop in the years
following beach/habitat-building flows that would induce periodic
changes in the combination of vegetation and open, bare areas.
In the long-term period of analyses (20 to 50 years), the differences
among the alternatives would continue to develop. Because at least
one major flood event is assumed to occur in the long term under the
No-Action and Maximum Powerplant Capacity alternatives, riparian
vegetation would decrease. However, woody and emergent marsh plants
would recover after the flooding to a level comparable to baseline or
no-action conditions. Also in the long term, riparian vegetation
that is supported by Lake Mead would increase by an unknown but
assumed equal amount under all alternatives.
The restricted fluctuating and steady flow alternatives include
measures to reduce the frequency of floods that would support
increases in the coverage of woody plants at the end of the long-term
period of analysis. Over the long term, habitat maintenance and
beach/habitat-building flows would maintain woody and emergent marsh
plants that developed during the short term. The dryer conditions
created in the upper elevations of the new high-water zone would
shift species composition from tamarisk and willow to mesquite and
other plants. Tamarisk, willow, and other plants would favor the
wetter sites at lower elevations.
SUMMARY OF IMPACTS ON
WILDLIFE/HABITAT
------------------------------------------------------ Appendix IX:6.2
According to the final EIS, wildlife and habitat would be affected in
ways similar to riparian vegetation under the operating alternatives,
i.e., those dam-operating alternatives that tend to increase riparian
vegetation would result in increased wildlife habitat. In the short
term, woody plant coverage, and therefore riparian habitat, would
increase under most alternatives. Emergent marsh plants would either
remain similar in coverage to the no- action condition or decrease.
The No-Action alternative would maintain the existing riparian
vegetation area, while the Maximum Powerplant Capacity alternative
would create conditions leading to a decline in habitat area. The
remaining alternatives would permit woody riparian vegetation to
expand. It is assumed that as the area of woody riparian vegetation
increases, so too will the size of the area of wildlife habitat that
would provide valuable food resources and shelter. Habitat
maintenance and beach/habitat-building flows would move and deposit
sediment that would bury some vegetation, thus temporarily reducing
its value as habitat. Vegetation that is not buried or that grows up
through new sediment deposits would be unusable to area wildlife
during the period of inundation.
Generally, individual animals would not be directly affected by the
daily operations of the Glen Canyon Dam because animals are mobile
and would move as required by the daily fluctuations in water
releases. Birds using the riparian zone as a travel lane through the
Grand Canyon would not be directly affected by any of the
alternatives. However, species that nest in riparian vegetation
would be indirectly affected by changes in area coverage of plants.
Wintering waterfowl would be affected by changes in minimum
discharge. The No-Action and Maximum Powerplant Capacity
alternatives have a minimum discharge of 1,000 cfs. The remaining
alternatives increase minimums from 3,000 cfs to 11,400 cfs.
Increased minimum discharges, as well as brief high release periods
during habitat maintenance and beach/habitat-building flows, are
assumed to benefit the aquatic food base and ultimately wintering
waterfowl.
ASSESSMENT OF IMPACT
DETERMINATIONS
-------------------------------------------------------- Appendix IX:7
EIS team members and researchers we contacted were generally
complimentary of the process used in making the impact determinations
of the dam's various operating procedures on the vegetation and the
wildlife/habitat resources. Also, scientists we interviewed believed
that the data used in the analyses were the best and most current
available at the time and that the research used in the analyses was
properly interpreted. While some scientists believe that some data
may have been incomplete at the time the EIS segments were prepared,
subsequent research only served to confirm and refine the analyses
presented in the final EIS. Therefore, according to one official,
there was little controversy associated with these resources and the
presentation of impact determinations in the EIS. This opinion seems
to be supported by the relatively low number of comments received on
the draft EIS in connection with these resources.
Also, many people we talked to were supportive of the preferred
alternative selected by Reclamation. There were, however, some
concerns expressed. For example, one researcher believed that to
further improve the aquatic food base, the Seasonally Adjusted Steady
Flow may be a more advantageous operating regime. However, the
riparian specialist disagreed with the researchers who favored the
Seasonally Adjusted Steady Flow because he believes that the
preferred alternative provides for higher water levels during the
summer months, which would be more beneficial to plants that are
important as an aquatic food base. Overall, he believes that the
preferred alternative was the proper choice and that it would create
conditions that permit the recovery of downstream resources to
acceptable management levels while maintaining some hydropower
capability. Overall, the riparian specialist believed that the
results of the impact determinations for the vegetation and
wildlife/habitat resources were reasonable. The riparian specialist
thought that the methodology used in making the impact determinations
was appropriate and properly implemented and the data used were the
best available.
SCOPE AND METHODOLOGY
-------------------------------------------------------- Appendix IX:8
Our analyses of the impact determinations on the vegetation and
wildlife/habitat resources were based on an evaluation of scientific
studies used by the riparian specialist in his assessments, the study
review process used, the impact determinations themselves, and
extensive interviews with officials involved in the process. In
addition, we provided the riparian specialist with our description of
the processes followed in making the impact determinations for his
review and comment. He agreed that our description accurately
presented the facts.
KEY STUDIES IDENTIFIED
------------------------------------------------------ Appendix IX:8.1
We reviewed the following studies and research materials that
Reclamation officials said were instrumental in making EIS decisions:
-- Anderson, L.S., and G.A. Ruffner. "Effects of Post-Glen Canyon
Flow Regime on the Old High Water Line Plant Community Along the
Colorado River in Grand Canyon," Glen Canyon Environmental
Studies Technical Report. Salt Lake City, Utah: Bureau of
Reclamation, 1987.
-- Carothers, S.W., and B.T. Brown. "The Colorado River Through
Grand Canyon: Natural History and Human Change." Tucson,
Arizona: University of Arizona Press, 1991.
-- Pucherelli, M.J. "Evaluation of Riparian Vegetation Trends in
the Grand Canyon Using Multitemporal Remote Sensing Techniques,"
pp. 172-181. Anchorage, Alaska: American Society of
Photogrammetry and Remote Sensing Technical Papers, 1986.
-- Stevens, L.E., and T. J. Ayers. "The Impacts of Glen Canyon
Dam on Riparian Vegetation and Soil Stability in the Colorado
River Corridor, Grand Canyon, Arizona," Draft Annual Report.
National Park Service Cooperative Studies Unit. Northern
Arizona University, Flagstaff, Arizona. 1991.
-- Stevens, L.E., J.C. Schmidt, and B.T. Brown. "Geomorphic
Control of Vegetation Establishment and Marsh Development Along
the Colorado River in Grand Canyon, Arizona," in AGU 1991 Fall
Meeting Program and Abstracts. American Geophysical Union EOS
Transactions, supp. to vol. 72, No. 44, p. 223, 1991.
-- Stevens, L.E., and G.L. Waring. "Effects of Post-Dam Flooding
on Riparian Substrates, Vegetation, and Invertebrate Populations
in the Colorado River Corridor in Grand Canyon, Arizona," Glen
Canyon Environmental Studies Technical Report. Salt Lake City,
Utah: Bureau of Reclamation, 1986.
In addition to the above studies, which directly addressed vegetation
resources, we examined the following other relevant documents in the
wildlife and habitat resource area:
-- Threatened Native Wildlife in Arizona. Phoenix, Arizona:
Arizona Game and Fish Department, 1988.
-- Brown, B.T. "Monitoring Bird Population Densities Along the
Colorado River in Grand Canyon," Glen Canyon Environmental
Studies Technical Report. Salt Lake City, Utah: Bureau of
Reclamation, 1987.
-- _____. Abundance, Distribution, and Ecology of Nesting
Peregrine Falcons in Grand Canyon National Park, Arizona. Final
report submitted to Grand Canyon National Park, Grand Canyon,
Arizona, 1991b.
-- _____. Nesting Chronology, Density, and Habitat Use of
Black-Chinned Hummingbirds Along the Colorado River, Arizona,
1991c.
-- Brown, B.T., R. Mesta, L.E. Stevens, and J. Weisheit.
"Changes in Winter Distribution of Bald Eagles Along the
Colorado River in Grand Canyon, Arizona," Journal of Raptor
Research, vol. 23, No. 3, pp. 110-113, 1989.
-- Brown, B.T., G.S. Mills, R.L. Glinski, and S.W. Hoffman.
"Density of Nesting Peregrine Falcons in Grand Canyon National
Park, Arizona," Southwestern Naturalist, Vol. 37, No. 2, pp.
188-193, 1992.
-- Jakle, M.D., and T.A. Gatz. "Herpetofaunal Use of Four
Habitats of the Middle Gila River Drainage, Arizona," Riparian
Ecosystems and Their Management: Reconciling Conflicting Uses,
R.R. Johnson et al. (technical coordinators). Forest Service
General Technical Report RM-120, pp. 355-358, 1985.
-- Jones, K.B., and P.C. Glinski. "Microhabits of Lizards in a
Southwestern Riparian Community," Riparian Ecosystems and Their
Management: Reconciling Conflicting Uses, R.R. Johnson et al.
(technical coordinators). Forest Service General Technical
Report RM-120, pp. 342-346, 1985.
-- Warren, P.L., and C.R. Schwalbe. "Lizards Along the Colorado
River in Grand Canyon National Park: Possible Effects of
Fluctuating River Flows," Glen Canyon Environmental Studies
Technical Report. Salt Lake City, Utah: Bureau of Reclamation,
1988.
-- Wilson, M.F., and S.W. Carothers. "Avifauna of Habitat Islands
in the Grand Canyon," Southwestern Naturalist, Vol. 24, No. 4,
pp. 563-576, 1979.
OFFICIALS INTERVIEWED
------------------------------------------------------ Appendix IX:8.2
In addition to the riparian specialist, we interviewed 11 other EIS
team members and researchers from the government, private, and
academic sectors. A listing of the officials we contacted and the
organizations they represent follows.
Michael Armbruster, Bureau of Reclamation, Denver, Colorado
Steven W. Carothers, SWCA Inc., Flagstaff, Arizona
Byran Brown, SWCA Inc., Salt Lake City, Utah
Duncan Patten, Arizona State University (Retired), Tempe, Arizona
Larry Stevens, Glen Canyon Environmental Studies, Flagstaff,
Arizona
Dean W. Blinn, Northern Arizona University, Flagstaff, Arizona
Tina Ayers, Northern Arizona University, Flagstaff, Arizona
Michael Pucherelli, Bureau of Reclamation, Denver, Colorado
Susan Anderson, The Nature Conservancy, Tucson, Arizona
William Leibfried, SWCA Inc., Flagstaff, Arizona
David Wegner, Glen Canyon Environmental Studies, Flagstaff, Arizona
Mark Sogge, National Biological Service, Flagstaff, Arizona
WATER
=========================================================== Appendix X
The construction of the Glen Canyon Dam altered the historical flow
pattern of the Colorado River and the characteristics of the water
being discharged downstream. While different water flow alternatives
would alter the pattern of water that is released from the dam,
existing statutes, compacts, a treaty, and operating criteria guide
the allocation of water to the seven basin states.\1
Currently, these laws, known collectively as the "Law of the River,"
establish minimum annual releases of water from the Glen Canyon Dam.
The area of potential impact for the resource water includes the
Colorado River downstream from the Glen Canyon Dam, Lakes Powell and
Mead, and the upper and lower basin states. These impacts include
annual streamflows, reservoir storage, water allocation deliveries,
upper basin state yield determinations, and water quality. The EIS
team used computer modeling studies to project the dam's operations
for 50 years to estimate the long-term impacts and for 20 years to
estimate the short-term impacts.
The EIS team found that the impacts on water issues of the dam's
various flow alternatives are essentially the same as under the
No-Action alternative, except for the volume of monthly water
releases and floodflow frequency. The annual streamflows, reservoir
storage, water allocation deliveries, upper basin yield
determinations, and water quality are only slightly affected by the
alternatives.
The EIS team members and researchers we spoke with were confident
that the computer modeling tools and the data used in the analyses
were the best available at the time. Also, while some researchers
believed that the maximum flow parameters under the preferred
alternative should be increased, there was general acceptance of the
selection of the Modified Low Fluctuating Flow as the preferred
alternative.
--------------------
\1 The basin states consist of the upper basin--which covers parts of
Arizona, Colorado, New Mexico, Utah, and Wyoming; and the lower
basin--which covers parts of Arizona, California, Nevada, New Mexico,
and Utah.
DESCRIPTION OF THE RESOURCE
--------------------------------------------------------- Appendix X:1
Most of the Colorado River water flowing into Lake Powell and
ultimately released into the Glen and the Grand canyons originates in
the Rocky Mountains. Runoff from spring snowmelt in the Rockies is
high during April through July, when the flow in the Colorado River
above Lake Powell reaches its annual maximum, then recedes for the
remainder of the year. During the summer and fall, thunderstorms
cause flooding in the tributaries originating on the Colorado
Plateau, producing additional peaks in the river, but they are
usually smaller than the snowmelt peaks and of much shorter duration.
Since the Glen Canyon Dam was completed in 1963, flows immediately
below the dam have consisted almost entirely of water released from
Lake Powell.
For purposes of the resources addressed in the EIS, water was
described in terms of streamflows, floodflows, reservoir storage,
annual water allocation deliveries, upper basin state yield
determinations, and water quality:
-- The annual streamflows are determined by the Law of the River,
which currently requires a minimum annual release of 8.23
million acre-feet of water from the Glen Canyon Dam.
-- Floodflows are defined as releases in excess of the powerplant
capacity of 33,200 cubic feet per second (cfs).
-- The reservoir storage in Lakes Powell and Mead depends on annual
and monthly reservoir inflow and release volumes. Storage
levels affect shore line resources and recreation on the lake.
Furthermore, the upper basin states use storage in Lake Powell
to meet their water delivery requirements to the lower basin
states.
-- The water allocation deliveries are the deliveries of Colorado
River water to entities in the seven basin states and Mexico in
accordance with the Law of the River. In recent years, the
demand for water by the lower basin states has approached their
entitlement of 7.5 million acre-feet.
-- The upper basin state yield determination is the legal maximum
volume of water available for annual use by the upper basin
states.
-- The Glen Canyon Dam altered downstream water quality by changing
the water's temperature and clarity.
EFFECTS OF PRE- AND POSTDAM
CONDITIONS ON WATER
--------------------------------------------------------- Appendix X:2
Before construction of the Glen Canyon Dam, the Colorado River was
sediment-laden, and its flows fluctuated dramatically during
different seasons of the year. Flows of greater than 80,000 cfs were
common during the spring. In contrast, flows of less than 3,000 cfs
were typical throughout the late summer, fall, and winter. The water
temperatures ranged from near freezing in the winter to more than 80
degrees Fahrenheit in the summer.
The construction of the Glen Canyon Dam altered the natural dynamics
of the Colorado River. The dam replaced seasonal flow variations
with daily fluctuations and greatly reduced the amount of sediment in
the river. Lake Powell now accumulates the sediment that would have
traveled the Colorado River before the dam's construction. In
addition, the water released from the dam to produce hydropower is
withdrawn from the cold depths of Lake Powell, 230 feet below the
surface when the reservoir is full. As a result of this water
withdrawal process, the water temperature downstream of the dam is
nearly a constant, year-round 46 degrees Fahrenheit.
The quality of the water has also been affected. Most of the
nutrients carried by the river are associated with or attached to
sediments, and sediments are now trapped by the dam. Variations in
the levels of salinity in the water have also been reduced.
ISSUE
--------------------------------------------------------- Appendix X:3
As defined in the final EIS, the issue of concern for water resources
is how the dam's operations affect the amount and quality of water
available from Lake Powell at specific times.
INDICATORS
--------------------------------------------------------- Appendix X:4
The indicators for water resources listed in the final EIS are the
-- acre-feet of streamflows,
-- frequency and volume of floodflows,
-- reservoir storage in Lakes Powell and Mead,
-- acre-feet of annual water allocation deliveries (deliveries of
Colorado River water to entities in the seven basin states and
Mexico),
-- acre-feet of upper basin state yield determination (hydrologic
assessment of the total water depletion that can ultimately be
allowed in the upper basin), and
-- chemical, physical, and biological characteristics of water
quality.
METHODOLOGY USED TO MAKE IMPACT
DETERMINATIONS
--------------------------------------------------------- Appendix X:5
Reclamation established a water resource team to make the impact
determinations for the EIS. The team consisted of two hydraulic
engineers from Reclamation; one was a water resource and an
environmental specialist, and the other was a water quality
specialist.
The water resource specialist was assigned the responsibility for the
hydrology impact assessment and provided information on the Colorado
River's operations. He wrote the background sections for the water
resource area and helped write the technical descriptions of the
various alternatives presented in the EIS. The water quality
specialist was responsible for water quality issues in the EIS.
The team used the Colorado River Simulation System (CRSS) to analyze
the impacts of the nine flow alternatives on the annual and monthly
streamflows, floodflows and other spills, water storage, water
allocation deliveries, and upper basin yield determinations for the
EIS. CRSS, a package of computer programs and databases, is widely
regarded as the most comprehensive and detailed simulation system of
the Colorado River. CRSS is designed to assist water resource
managers in performing long-range planning and operation studies.
The CRSS database contains reconstructed natural flow data from the
U.S. Geological Survey for the Colorado River during 1906 through
1990. The CRSS model can simulate the operations of the Colorado
River, including the effects of changes to the operation of the Glen
Canyon Dam. The modeling process begins with the assumption that the
previous natural flows in the river are indicative of future
activity. Thus, the model uses historical data to project water
availability in the future. The CRSS can address many of the "what
if" questions stemming from proposed changes in the Colorado River's
operations, from proposed development in the Colorado River Basin, or
from changes to present water use throughout the basin. The model's
estimates are widely accepted by water resource managers.
CRSS produces data on a monthly basis; therefore, a peak-shaving
model was used to predict hourly distribution from the CRSS-projected
monthly release volumes. (Peak shaving is the concept whereby
hydroelectric powerplants are used to serve (shave) the highest
electric load (peak) during a 24-hour period.) These hourly
distributions were produced for the No-Action and the Maximum
Powerplant Capacity Flow alternatives and for each of the restricted
fluctuating flow alternatives. The hourly projections were needed to
develop and analyze the effects of fluctuating flows on sediment and
other resources. The steady flow alternatives did not require this
analysis because flows from hour to hour would be essentially steady.
The water resource specialist developed the technical analyses of the
alternatives using the CRSS model. The technical development of the
alternatives was an iterative process, whereby the team presented the
results of the modeling program at the EIS team meetings; the EIS
team would then analyze and discuss the information to determine what
additional adjustments to the alternatives were needed. Using the
CRSS program, the water resource specialist calculated various
parameters for each alternative, including annual releases, monthly
releases, reservoir storage, water allocation yield, and floodflows.
The EIS team members then prepared impact analyses of each
alternative for the various resource areas. Their analyses were
based on the CRSS results, preliminary data from various research
projects, and their professional judgment. The results of the impact
analyses were presented and discussed at the EIS team meetings.
EFFECTS OF THE FLOW
ALTERNATIVES ON WATER
--------------------------------------------------------- Appendix X:6
According to the final EIS, the annual streamflows would differ only
slightly from the No-Action alternative under all alternatives and
are therefore not expected to affect the distribution of water among
the basin states. Under the restricted fluctuating and steady flow
alternatives, the measures included for reducing the frequency of
floods would reduce the frequency of unscheduled floodflows that are
greater than 45,000 cfs from an average of once in 40 years to once
in 100 years. Other spills would differ only slightly from the
No-Action alternative under all other alternatives.
Reservoir storage under all fluctuating flow alternatives would be
essentially the same as under the No-Action alternative. Water
allocation deliveries would be affected slightly under all
alternatives. However, if reserving more space in the reservoir is
used to reduce flood frequency, the amount of water available for use
by the upper basin states would be reduced. None of the alternatives
affect water quality under normal reservoir levels, which occur 95
percent of the time.
ASSESSMENT OF IMPACT
DETERMINATIONS
--------------------------------------------------------- Appendix X:7
The CRSS model is widely accepted as the best method available for
analyzing the effects of changes to the operations of the Glen Canyon
Dam. The officials and researchers we interviewed generally stated
that the CRSS model was the best method available at the time for
analyzing and describing the various alternatives. Some alternative
modeling programs did exist; however, EIS team members told us they
would not have produced significantly different results.
The EIS team members and researchers we spoke with generally support
the preferred alternative. Two reasons cited were that the
alternative (1) strikes a balance for the resources at Glen Canyon
Dam and (2) represents a reasonable compromise among the various
interest groups. However, two researchers believe that the preferred
alternative's operating parameters are still too conservative, even
after they were increased following public comment on the draft EIS.
They told us that higher maximum releases and higher fluctuating
flows are needed and that adaptive management will show that the
higher flows are acceptable. They stated that compromises made for
the benefit of environmental issues may have gone too far because
one-third of the hydropower capacity of the dam was lost.
In addition, none of the EIS team members or researchers we
interviewed provided any data or research that would change the
conclusions reached by the EIS team.
The team's water resource specialist provided us with his responses
to the issues and comments noted above. He agreed with the comments,
especially noting that the preferred alternative was a reasonable
compromise and that adaptive management may lead to less restrictive
flows. He stated that
-- the process used in making the impact determinations for the
water resource was reasonable,
-- the methodologies employed in this process were appropriate, and
-- the data used were the best available.
SCOPE AND METHODOLOGY
--------------------------------------------------------- Appendix X:8
To determine the process used to develop the flow alternatives, we
identified and reviewed the following documents.
KEY STUDIES IDENTIFIED
------------------------------------------------------- Appendix X:8.1
Key documents we reviewed were the draft EIS and final EIS and
associated appendixes, the public comments on the draft EIS and final
EIS, and Reclamation's responses to the comments on the draft EIS.
We also obtained and reviewed copies of the minutes of the EIS team
meetings and summaries of the cooperating agencies' meetings. We
studied the Colorado River Simulation System Overview prepared by
Reclamation and the Glen Canyon Environmental Studies chapter
prepared by the Power Resources Committee. We also reviewed the
Final Analysis Report on Scoping Comments, the Glen Canyon Dam EIS
Preliminary Alternatives Report, and the newsletters issued by the
Colorado River Studies Office from June 1990 to February 1995. We
also obtained and studied the Glen Canyon Dam:
Beach/Habitat-Building Test Flow, Final Environmental Assessment and
Finding of No Significant Impact, issued in February 1996.
We also reviewed three papers presented at a 1990 symposium on the
Grand Canyon (published in Colorado River Ecology and Dam Management
by the National Academy of Sciences in 1991). These papers were
"Sediment Transport in the Colorado River Basin" by Edmund D.
Andrews, "Hydrology of Glen Canyon and the Grand Canyon" by David R.
Dawdy, and "Reservoir Operations" by Trevor C. Hughes.
Furthermore, we reviewed "Assessment of Changes to the Glen Canyon
Dam Environmental Impact Statement Preferred Alternative from Draft
to Final EIS," issued by Reclamation in October 1995. This paper
explained the background and scientific basis for the changes to the
preferred alternative between the draft and final EIS.
EIS team members stated that the documents generated using the CRSS
model were key to the development of the water resource area.
Appendix VIII of this report contains a list of those documents.
Another document that was identified as important to the process was
Hydrologic Determination 1988: Water Availability From Navajo
Reservoir and the Upper Colorado River Basin for Use in New Mexico.
Salt Lake City, Utah: Bureau of Reclamation, 1989.
OFFICIALS INTERVIEWED
------------------------------------------------------- Appendix X:8.2
To assess the procedures followed and obtain views on the quality of
the data used in developing the flow alternatives, we interviewed the
water resource team and the internal and external reviewers of the
work. Finally, we asked the EIS team's water resource specialist to
review our description of the impact determination process for
factual accuracy. He agreed that our description was generally
accurate but made some suggestions for changes. We have incorporated
these changes into our process description. A list of the officials
we interviewed follows.
Trevor Hughes, Utah State University/National Research Council
William Lewis Jr., University of Colorado-Boulder/National
Research Council
Margaret Matter, Western Area Power Administration, Denver,
Colorado
Randy Peterson, Bureau of Reclamation, Salt Lake City, Utah
Craig Phillips, Bureau of Reclamation, Denver, Colorado
Tim Randle, Bureau of Reclamation, Denver, Colorado
Spreck Rosekrans, Environmental Defense Fund
Thomas Slater, Bureau of Land Management, Salt Lake City, Utah
Leslie Stillwater, Bureau of Reclamation, Denver, Colorado
(See figure in printed edition.)Appendix XI
SUMMARY COMPARISON OF THE
ALTERNATIVES AND IMPACTS AS
PRESENTED IN THE GLEN CANYON DAM'S
FINAL ENVIRONMENTAL IMPACT
STATEMENT
=========================================================== Appendix X
(See figure in printed edition.)
(See figure in printed edition.)
(See figure in printed edition.)
(See figure in printed edition.)
(See figure in printed edition.)
(See figure in printed edition.)
(See figure in printed edition.)
Source: Bureau of Reclamation.
(See figure in printed edition.)Appendix XII
COMMENTS FROM THE DEPARTMENT OF
THE INTERIOR
=========================================================== Appendix X
(See figure in printed edition.)
GAO'S COMMENTS
--------------------------------------------------------- Appendix X:9
The following are GAO's comments on the Department of the Interior's
comments enclosed in a letter dated September 13, 1996.
1. We have revised the title of the report as suggested.
2. We have added the term "periodic" to our description of the
Modified Low Fluctuating Flow alternative.
3. We revised the text to clarify that the computational errors were
made during the third phase of the power analysis.
4. The year was changed to 1968.
5. We have deleted the sentence from the report.
6. See comment 3 above.
7. We deleted the word "load" from the report.
8. We revised the footnote to clarify that the energy and capacity
values referred to in the table are attributable to the Salt Lake
City Area/Integrated Projects in total, but the change in annual
economic costs are attributable solely to the Glen Canyon Dam's
operations.
MAJOR CONTRIBUTORS TO THIS REPORT
======================================================== Appendix XIII
RESOURCES, COMMUNITY, AND ECONOMIC
DEVELOPMENT DIVISION, WASHINGTON,
D.C.
Jonathan Bachman
Steve Brown
Jay R. Cherlow
Timothy J. Guinane
Barry T. Hill
Edward A. Niemi
Jim Yeager
DENVER, COLORADO
Sandra P. Davis
W. Stephen Lowrey
Craig D. Richards
William J. Temmler
Frank B. Waterous
Alan J. Wernz
OFFICE OF THE GENERAL COUNSEL
Martin J. Fitzgerald
Alan R. Kasdan
*** End of document. ***