Review of the Draft Federal Long-Term Monitoring Plan for the Colorado River below Glen Canyon Dam (1994)

William Lewis (Chair) is Professor and Chair of the Department of Environmental, Population, and Organismic Biology at the University of Colorado, Boulder, and also serves as Director of the Center for Limnology at CU-Boulder. Professor Lewis received his Ph.D. degree in 1974 at Indiana University with emphasis on limnology, the study of inland waters. His research interests, as reflected by over 120 journal articles and books, include productivity and other metabolic aspects of aquatic ecosystems, aquatic food webs, composition of biotic communities, nutrient cycling, and the quality of inland waters. The geographic extent of Professor Lewis's work encompasses not only the montane and plains areas of Colorado, but also Latin America and southeast Asia, where he has conducted extensive studies of tropical aquatic systems. Professor Lewis has served on the National Academy of Sciences/National Research Council Committee on Irrigation-Induced Water Quality Problems and is currently Chair of the newly created NAS/NRC Wetlands Committee. He is also a member of the NRC's Water Science and Technology Board.

Garrick A. Bailey earned his B.A. in history from the University of Oklahoma, and his M.A. and Ph.D. in anthropology from the University of Oregon. He is a professor in the Department of Anthropology and is Director of the Indian Studies Program at the University of Tulsa. Dr. Bailey specializes in North American Indians, legal systems, cultural ecology, ethnohistoric methods, and social organization. He is a member of the American Anthropological Association, Plains Anthropological Society, American Ethnological Society, and the American Society of Ethnohistory.

Bonnie Colby is Associate Professor of Agricultural and Resource Economics at the University of Arizona Department of Agricultural Economics. Her undergraduate degree is from the University of California and Ph.D. from the University of Wisconsin. Her

research, teaching and consulting focus is on the economics of water resources management and policy. She has authored over 40 publications in this area, including a number of journal articles and a book, Water Marketing in Theory and Practice: Market Transfers, Water Values and Public Policy, 1987. In addition to her work on water reallocation, she specialized in research on water quality, valuation of water rights and environmental amenities, and natural resource management in developing tribal and rural economies. Dr. Colby served on the NRC's Committee on Western Water Management.

David Dawdy received his M.S. in statistics from Stanford University. His professional experience is with U.S. Geological Survey from 1951 to 1976 as a research hydraulic engineer; Adjunct Professor of Civil Engineering from 1969 to 1972 at Colorado State University, Ft. Collins; and Assistant District Chief for Programming, California District, Water Resources Division from 1972 to 1975. He has served on numerous advisory groups including NRC committees. From 1976 to 1980 he was Chief Hydrologist with Dames and Moore in Washington, D.C., and is currently a private consultant in surface water hydrology.

Robert C. Euler is a consulting anthropologist specializing in the applied anthropology, archeology, ethnology, and ethnohistory of the American Southwest and Great Basin. As such, he conducts research in cross-cultural resources management, social and economic impact assessments, Indian legal claims cases, and archaeological investigations, especially those related to environmental impacts. Dr. Euler is also Adjunct Professor of Anthropology at Arizona State University, Tempe. In addition, he serves as Tribal Anthropologist for the Yavapai-Prescott Indian Tribe. Dr. Euler earned his B.A. and M.A. in economics from Northern Arizona University, and his Ph.D. in anthropology from the University of New Mexico.

Ian Goodman earned his B.S. in civil engineering from Massachusetts Institute of Technology in 1977. Initially in his career, he performed research at MIT where he developed inputs to a policy-specific model of energy use for intercity goods movement. He began consulting in 1978 and was employed with several firms in the Boston area working on various aspects of utility regulation and economics. He is now the principal of his own consulting firm, The Goodman Group, where his work includes assessing electric and gas resource planning, demand forecasts, supply options, and environmental effects. Mr. Goodman also evaluates conservation potential and cost-effectiveness, program design, and utility demand-side management initiatives.

William Graf obtained his Ph.D. from the University of Wisconsin, Madison with a major in physical geography and a minor in water resources management. He specialized in fluvial geomorphology, hydrology, conservation policy and public land

management, and aerial photographic interpretation. He has served as Consulting Geomorphologist for the U.S. Army Corps of Engineers in a research and advisory role concerning the environmental impact assessment of flood control works, Salt and Gila Rivers in Arizona; and for Camp, Dresser, and McKee, Inc. for geomorphology and geology, and the state of Arizona for fluvial geomorphology. His research activities have emphasized fluvial geomorphology and the effects of human activities on streams; public land management, especially wilderness preservation, and rapids in canyon rivers; dynamics and recreation management; and the problems of heavy metal and radionuclide transport in river systems. Dr. Graf has published about 50 articles and book chapters on the impact of suburbanization on fluvial geomorphology; resources, the environment and the American experience; and the effect of dam closure on downstream rapids. His books include The Geomorphic Systems of North America, The Colorado River: Basin Stability and Management, Fluvial Processes and Dryland Rivers, Wilderness Preservation and the Sagebrush Rebellions, and Plutonium and the Rio Grande. Dr. Graf is a member of the NRC's Water Science and Technology Board.

Clark Hubbs received his Ph.D. in biology from Stanford University in 1951. He joined the faculty of The University of Texas at Austin in 1949, became Professor of Zoology in 1963 and the Clark Hubbs Regents Professor in 1989 and has been Regents Professor Emeritus since 1991. He served as Chairman of Biology 1974-76 and Chairman of Zoology 1978-85. He was concurrently Visiting Professor of Zoology at the University of Oklahoma 1973-86 and on the faculty of Texas A&M 1975-81. He has served as Curator of Ichthyology at the Texas Memorial Museum from 1975 to the present. He has received the Award of Excellence from the American Fisheries Society and the Lifetime Achievement Award from the American Society of Ichthyologists. He has published more than 250 papers on aquatic biology. His research interests include distribution and speciation of fishes; hybridization of freshwater fishes; environmental modification of freshwater fishes. Dr. Hubbs has a history of work with endangered fishes and now has a substantial program on predation of adults on their young.

Trevor C. Hughes acquired his Ph.D. in civil engineering from Utah State University. His professional experience includes teaching since 1972 at Utah State University in the Civil and Environmental Engineering Department; research experience as NDEA Fellow at Utah State; Associate Professor of Civil and Environmental Engineering, Utah Water Research Lab; and Research Scientist at International Institute of Applied Systems Analysis, Austria. Since 1971 he has conducted research projects on the management of salinity in the Colorado Basin; drought management analysis and policy design; regional planning of rural water supply systems; economic analysis of alternative water conservation concepts; river system operational models--Sevier River; and application and development of water demand function for domestic water systems at recreation developments.

Roderick F. Nash received an M.A. and Ph.D. in 1961 and 1964 from the University of Wisconsin. He specialized in American intellectual history under Professor Merle Curti. Before his appointment at University of California at Santa Barbara in 1966, he taught for two years at Dartmouth College. Dr. Nash published the first collection of documents relating to environmental history, The American Environment, 1968. His most significant recent work is The Rights of Nature: A History of Environmental Ethics, 1989. A national leader in the field of conservation, environmental management, and environmental education, Dr. Nash has a special interest in problems relating to wilderness and its preservation.

A. Dan Tarlock obtained his LL.B. from Stanford University. His professional experience includes private practice, San Francisco, 1966; professor in residence at a law firm in Nebraska, summers of 1977 to 1979; and consultant. He has been a Professor of Law at Chicago Kent College of Law since 1981. He has authored and co-authored many publications and articles concerning water resources management and environmental law and policy. Mr. Tarlock served as a member of an NRC Committee on Pest Management, is Vice Chair of the NRC's Water Science and Technology Board, and co-authored one of the basic casebooks in water law.

Duncan T. Patten, PhD

Chief Scientist

Glen Canyon Environmental Studies

May 1993

LONG-TERM MONITORING IN GLEN AND GRAND CANYON: RESPONSE TO OPERATIONS OF GLEN CANYON DAM

Grand Canyon is an internationally significant natural landscape feature. Ironically, the Colorado River, the physical feature responsible for carving Grand Canyon, is now the most heavily regulated large river in North America. The physical hydrology of Colorado stream flow, as with the associated sediment load and dissolved constituents transported by the river, have changed dramatically since closure of Glen Canyon Dam in 1963. Numerous studies, including those sponsored by the U.S. Bureau of Reclamation's Glen Canyon Environmental Studies since 1982, have documented these changes.

The Grand Canyon Protection Act of 1992 has directed the Secretary of the Interior to establish and implement long-term monitoring programs and activities that will ensure that Glen Canyon Dam is operated “… in such a manner as to protect, mitigate adverse impacts to, and improve the values for which Grand Canyon National Park and Glen Canyon National Recreation Area were established…”. In response to this directive, the Glen Canyon Dam EIS resource management agencies and interests have initiated the planning of a long-term monitoring program which would permit continued evaluation of the effect of Glen Canyon Dam operations, as described in the Record of Decision, on the riverine environment of Grand Canyon.

This document describes the long-term monitoring program. It does not project costs for any of the long-term monitoring program components. These would be determined on (1) availability of funds, (2) priorities assigned to the various monitoring components, and (3) costs proposed by those entities responding to the “Request for Proposals” which would be used to develop and select the detailed methodologies and procedures of this long-term monitoring program.

Long-term monitoring is used for a variety of purposes including, but not limited to, assessing (1) baseline conditions, (2) trends of attributes, (3) implementation of a decision, (4) effectiveness of a decision, (5) project impacts, (6) model efficacy, and (7) compliance to a set of standards. Many of these purposes are attributable to the evaluation of the impacts of Glen Canyon Dam operations.

Long-term monitoring would be designed to provide regular feedback for adaptive management. This permits mid-course adjustments in the operations of the dam to ensure achievement of the goals of the EIS and the management objectives of the resource management agencies and interests.

Long-term monitoring would also be used to determine variability over time and space of the resources being monitored. This needs to be done in conjunction with appropriate controls to evaluate the source of the variability. In addition, long-term monitoring would provide clues for identifying associations, understanding system behavior, and guiding future process-based research.

Long-term monitoring is the “repetition of measurements over time for the purpose of detecting change” (MacDonald et al 1991). These measurements, because they are made over a period of time, are different from an inventory, which is a measurement, or a number of measurements, made at a specific point in time. Inventories, or establishing baseline conditions, are often the first step in conducting a monitoring effort, but the measurement of possible change over time is the distinguishing attribute of a monitoring effort. Research, on the other hand, is used to test or understand the relationships between and among various attributes of the system. Inventory and monitoring information may be used in research. This document addresses only the long-term monitoring program which emphasizes measurement of those parameters, or attributes, that might change with time and whose change might be related to operations of Glen Canyon.

This proposed long-term monitoring program for the river corridor in Grand Canyon would not be considered equivalent to a long-term monitoring plan for all of Grand Canyon, or in fact for the whole river corridor ecosystem. Although the difference between the two objectives may seem to be semantic, it is critical to distinguish this program, whose intent is the monitoring of the effectiveness of the prescribed operations of Glen Canyon Dam in meeting the objectives of the EIS, the 1992 Grand Canyon Protection Act and the management objectives of the resource management agencies and interests, from a general ecosystem monitoring plan for the river corridor. Clearly, the two objectives are closely aligned because it is impossible to interpret change related to dam operations without understanding the broad range of ecological interactions. Nevertheless, the ultimate purpose of this program is to monitor ecological changes that are related to dam operations.

Grand Canyon is a unique environment. It is also a highly regulated system, both in terms of river flows and use. Its uniqueness demands careful stewardship. In the face of evolving scientific understanding about Grand Canyon's riverine ecosystem, it is not yet possible to identify only a few attributes that characterize the entire system. In light of this uncertainty, it would be irresponsible to restrict monitoring within the river corridor ecosystem to a very small number of attributes and assume that all other attributes are related to those measured.

This proposed program attempts to strike a balance between the extremes of (1) very restricted monitoring which recognizes the impacts of scientific study on the essence of what Grand Canyon means to most humans, and (2) full measurement of all ecosystem attributes predicated on a belief that an unmeasured parameter might be critical at a later time.

This proposed program emphasizes measurement of attributes deemed critical by the resource management agencies and interests (re: Draft EIS), and the scientific community which has studied the system for decades, for evaluating the effects of alternative operations of Glen Canyon Dam. The prediction and significance of the attribute response to dam operations is discussed in the monitoring program section for each attribute. Under the long-term monitoring program, responses of these attributes would be used in adaptive management decisions. These attributes are:

1. Quantity and quality of water from Lake Powell and in the Canyon.

   1. annual streamflows

   2. discharge rates and spill volume and frequency

   3. chemical, physical and biological characteristics of water in Lake Powell and the Colorado River from Glen Canyon Dam to Lake Mead

2. Sediment dynamics and sediment budget.

   1. stored riverbed sand

   2. sandbar topography

   3. elevated sandbar erosion

   4. dynamics of debris fans and rapids

3. Fish.

   1. aquatic food base

   2. reproduction, recruitment and growth of native fishes

   3. reproduction, recruitment and growth of non-native warmwater and coolwater fishes including trout

4. Vegetation.

   1. area of woody riparian plants and species composition

   2. area of emergent marsh plants and species composition

5. Wildlife and wildlife habitat.

   1. area and species composition of riparian habitat for associated vertebrates and invertebrates

   2. aquatic food base for wintering waterfowl

6. Endangered and other special status species, their habitat and food base.

   1. humpback chub

   2. razorback sucker

   3. bald eagle

   4. peregrine falcon

   5. southwestern willow flycatcher

   6. belted kingfisher

   7. Kanab ambersnail

   8. other federal and state species of concern

7. Cultural resources.

   1. archaeological sites directly, indirectly, or potentially affected

   2. Native American traditional cultural properties directly, indirectly, or potentially affected

8. Recreation.

   1. fishing trips and angler safety

   2. day rafting trips attributes and access

   3. white-water rafting trip attributes, camping beaches, safety, and wilderness values

   4. net economic value and regional economics

9. Powerplant supply of hydropower to network and customers at lowest costs.

   1. changes in power operations

   2. power marketing benefits lost or gained

10. Non-use valuation.

    1. Values placed on Glen and Grand Canyon riverine system by the public

This program also adopts a conservative approach of measuring attributes which reasonably might be affected by dam operations and for which no surrogate attributes exist. However, this program does not propose measurement of those attributes clearly unrelated to dam operations or which are adequately represented by other parameters. It also emphasizes use of data collected in Grand Canyon that are not field intensive. Wherever possible, monitoring should be conducted using non-invasive means.

To reduce the overall impact and cost of this program, data generated from other complementary long-term monitoring programs in the Grand Canyon region (e.g., Lake Powell long-term studies, and the Programmatic Agreement for Compliance with Section 106 of the National Historic Preservation Act) would be used when appropriate for evaluating the effects of the operations of Glen Canyon Dam. There are also background and input data collected from other sources (e.g., climatological and hydrological data) that are critical to interpretation of the long-term monitoring information. These types of data are discussed in the addenda.

Lastly, this program is designed to respond to the long-term missions, goals and management objectives of the resource management agencies and interests. Acceptance of changing conditions of each of the above attributes as it responds to the environment created by the prescribed dam operation is contingent upon these management objectives. A change in an attribute, determined through the long-term monitoring program, may represent a deviation from an acceptable condition (determined by management agencies and interests) that would trigger consideration of suggested changes in dam operations as described in the “Adaptive Management” section of chapter II. The long-term monitoring program would, therefore, use methodologies that offer appropriate information about the response of the critical attributes to enable an Adaptive Management Work Group to evaluate these changes in light of the overall management objectives for “the Canyon”.

The following statements represent an abbreviated version of the management objectives of each of the resource management agencies and interests. For many of these agencies and interests, these management objectives for specific attributes represent goals rather than existing baseline conditions at initiation of long-term monitoring or response conditions at some point after the effects of dam operations have occurred. Although not specifically stated below, they also recognize the importance of existing laws and statutes, for example, the Endangered Species Act, Trust responsibilities to Indian Tribes, and Cultural Acts. A more comprehensive statement for each interest is presented in chapter II of the DEIS.

The National Park Service, represented by Grand Canyon National Park and Glen Canyon National Recreation Area, has management objectives based upon both the ecosystem that existed prior to construction of Glen Canyon Dam and the ecosystem that has developed post-construction. Objectives are to attempt to maintain the essential dynamic elements and processes that existed pre-dam through restoration, maintenance and protection. The NPS is committed to managing the Colorado River ecosystem and its attendant cultural resources as a coherent whole that, to the extent possible, simulates the ecosystem that existed prior to the construction of the dam.

As manager of the Colorado River, the Bureau of Reclamation's management objectives are to strike a balance among water releases established under the “Law of the River” and the Annual Operating Plan for Glen Canyon Dam, the hydroelectric power requirements of Western Area Power Administration, and “protection” of the downstream ecosystem under the 1992 Grand Canyon Protection Act. The priorities given to each of these components under the EIS and long-term monitoring program are dependent on potential risk for change in Canyon resources or attributes of concern, and laws and regulations that direct the Bureau's operations.

The management objectives of the Fish and Wildlife Service in the Grand Canyon, as elsewhere, are to conserve, protect, and enhance fish and wildlife and their habitat for the continuing benefit of the public. In the Canyon emphasis is placed on threatened and endangered species, migratory birds, and native fish and sports fisheries.

Management objectives of Western Area Power Administration (Western) are the marketing and transmission of electricity generated at Federal water power projects.

The Bureau of Indian Affairs has no management role in the proposed action. However, it has management goals, among which is fostering of self-determination of Indian Tribes. Its goal is to assure that the interests of Indian Tribes are coordinated with other Federal agencies and to supply advice and assistance to Tribes when requested to do so.

Management objectives of the Hualapai Tribe are long-term sustainable and balanced multiple uses of its resources through natural integrated resource management. These resources include natural and cultural resources including sacred ceremonial and burial sites within the Canyon located outside the boundaries of the Reservation Lands.

The management objectives of other Indian Tribes with interest in Glen and Grand Canyons, but whose lands do not border the mainstem of the Colorado River, are the preservation of the natural and cultural resources of the Canyon to maintain their values to the tribes. This includes spiritual and ancestral stewardship and management responsibilities to the Grand Canyon and specific places contained therein.

The management objectives of the Arizona Game and Fish Department are to conserve, enhance and restore Arizona's wildlife and habitats, and to provide wildlife and safe watercraft recreation for the enjoyment, appreciation and use of the public.

The area to be monitored is primarily the Colorado River corridor between Glen Canyon Dam and Lake Mead reservoir. This area is about 255 miles long, as the headwaters of Lake Mead vary with reservoir elevation. Because the overwhelming effect on the ecosystem along the shores of Lake Mead reservoir comes from operations of the reservoir and Hoover Dam, the Grand Canyon monitoring program would end at Separation Canyon (RM 240), the generally accepted head of Lake Mead. However, the affects of fluctuations in Lake Mead and the influence of changes in the Colorado River below Separation Rapids resulting from dam operations might be considered as extensions of the geographical scope of the long-term monitoring program.

Delineation of the upstream boundary of Grand Canyon monitoring is also inexact. Water molecules and dissolved constituents may travel to Grand Canyon from any part of the Colorado River watershed, and sediment particles may be transported to Grand Canyon from much of southern Utah and northern Arizona. Geochemical transformations occur in Lake Powell reservoir that directly affect the chemical quality of water discharged into Grand Canyon.

Many of the relevant upstream data are already collected by the U.S. Geological Survey, National Oceanic and Atmospheric Administration, and the Bureau of Reclamation. Other information, such as from an expanded program of limnological monitoring of Lake Powell, are not available. Despite the linkages that exist between Grand Canyon and the entire upstream basin, the appropriate upstream limit for Grand Canyon monitoring, as related to effects of dam operations, is the forebay of Lake Powell, the intake point for water into the water release structures of the dam. Because of the critical role of reservoir-scale geochemical processes in determining the quality of water at the intake sites, the separate long-term monitoring effort of Lake Powell would continue as a valuable input to this program. The Lake Powell long-term monitoring program would not, however, be considered part of the Glen and Grand Canyon long-term monitoring program. Along this same line, ongoing studies in and along the shoreline of Lake Mead within normal pool fluctuation would not be considered part of the Glen and Grand Canyon long-term monitoring program.

The lateral extent of the monitoring effort is defined by the extent of processes and conditions influenced by dam discharges and river flows. The relevant discharge might be: (1) maximum powerplant discharge (31,500 cfs), (2) maximum regulated discharge and mean annual pre-dam peak flow (100,000 cfs), or (3) maximum pre-dam flood (220,000 -300,000 cfs). Because this proposed monitoring program is long-term in scope, the minimum discharge considered ought to be 100,000 cfs. However, the old high-water zone vegetation community begins at about this elevation and extends to higher levels and arroyo head cutting may extend above this level. Thus, it is prudent in some areas of the Canyon to include elevations above the stage associated with a discharge of 100,000 cfs.

Thirteen reaches, varying in length between 2 and 12 miles were established by GCES as Geographic Information System (GIS)-reaches, and detailed topographic data at a scale of 1:2400 is available for these reaches. The availability of detailed data for these reaches would lead to integrated resource perspectives in these areas and would necessarily focus data collection in these sites. These sites were selected because they represented reaches of the Colorado River in which there were ongoing studies or potentially important ecological conditions. However, the scientific basis for their selection was not necessarily for the long-term monitoring program because it was anticipated that the whole system would eventually be put into the GIS. As a consequence, additional sites may need to be selected to adequately represent each of the geomorphically distinctive reaches of Grand Canyon.

Information management is an integral part of data collection and long-term monitoring. It includes, characteristics of the data base, protocols for data collection and processing, protocols for data analysis and reporting, and the use of GIS and remote sensing. A discussion of information management is intended to give guidance to those who will manage the long-term monitoring program and its extensive data base and will be making adaptive management recommendations and decisions, and those who will prepare proposals and reports as part of their activities relative to this program. The success of the long-term monitoring program depends on the dependability, integrity and credibility of data generation and information management. For this reason, a discussion of information management and how it applies to the Grand Canyon Long-term Monitoring Program is presented in the addenda.

The water discharged from Glen Canyon Dam represents water from Lake Powell whose quality is a product of lake tributaries, level and mixing processes. A model explaining these relationships is being developed by a selective withdrawal study team and the Lake Powell study group. The model is not sufficiently developed to presently be used in long-term monitoring, although data for its development would continue to be gathered.

The quality of the discharge water may influence many of the aquatic biological processes within the Canyon. If these biological processes change, the cause for the change would be better interpreted if the quantity and quality of the discharge stream is known. Thus, the objectives of sampling in Lake Powell are to determine the quality of the water in the dam intake region in order to characterize dam discharges, and to determine whether the prescribed dam operations, especially if a selective withdrawal structure is used, affect the water in the forebay region of the dam as predicted by studies of the selective withdrawal study team. (This research, which includes collecting data on reservoir level and storage, and tributary inputs, is a parallel program to the long-term monitoring program, but it is essential for interpreting the affects of Lake Powell water chemistry and circulation on the below-dam aquatic ecosystem.)

Sampling stations in Lake Powell as part of the long-term monitoring program would be limited to the forebay above Glen Canyon Dam. Information from the long-term monitoring program of Lake Powell would be used to help interpret the findings in the forebay area. The forebay area is the direct input point to the below-dam ecosystem. At these stations physical, chemical and biological parameters would initially be measured monthly during studies of selective withdrawal and then quarterly in the water column at a sufficient number of locations to determine statistical variability. Physical parameters would be limited to temperature and light penetration. Chemical parameters would include pH, conductivity, nitrogen, phosphorus, dissolved oxygen and particulate organic matter. Biological parameters would include algae (especially blue greens and diatoms), zooplankton, total chlorophyll and chlorophyll a. Monitoring protocols would be developed to reduce the taxonomic and biomass studies of phyto- and zooplankton and replace these with chlorophyll a and other surrogate measurements.

Dam Discharges. Dam discharges create the physical conditions that control many of the downstream ecosystem processes, for example, sediment dynamics, habitat development, and biotic recruitment and survival. The objectives for monitoring the outputs of Glen Canyon Dam are to determine how closely dam discharge follows the prescribed operations of the dam and the extent of the variability in discharge, should it occur. These outputs, which also include discharges or spills above dam hydropower operations, would be measured both at the dam, based on power production, and at the U.S.G.S. gage just downstream. Outputs to be monitored include, hourly water discharge (both flow rate and volume) and ramping rates (changes in discharge over the hour). From the above data, information on maximum and minimum daily discharges and daily fluctuations, and frequency and volume of spills, can be determined and placed in a perspective of average conditions and variance.

Water and Sediment Transport. The transport of water and sediment through the Canyon are interconnected (e.g., sediment transport curves). Discharge rates and changes in river stage influence the amount of sediment transported and stored in the system; sediment being the primary substrate for many Canyon biological processes as well as camping beaches. The objectives for monitoring changes in water and sediment transport are to determine whether the flux of water and sediment through the Canyon is as at the level predicted by the EIS for the prescribed dam operations, and whether the flux varies as

expected within different reaches of the Canyon. Measurement objectives are: (1) continuously measure the flux of water through Grand Canyon (2) periodically measure flux of sediment through the Canyon, and (3) measure the differences in flux in different reaches. Measurements of flux not only permit comparison of measured differences in fluxes which can be compared with measured storage changes, but the fluxes themselves are critical determinants of biological processes.

Although a water flow and sediment routing model is being developed by the U.S. Geological Survey, it is not yet time to solely rely on this model to estimate fluxes; field measurements must be continued. Gaging stations do not exist at the end points of each geomorphologically distinct reach in Grand Canyon (whether using the classification of Schmidt and Graf, 1990; and others), and new gaging stations would not be established through the main channel to define each geomorphically distinct reach. The emphasis of long-term monitoring would be on maximizing the analysis of data collected at existing gages. Because most river managers have expressed greatest concern about impacts of dam operations on upstream reaches of Grand Canyon, and because those reaches have been shown to have the greatest potential for sediment storage deficit, it is important that gaging stations on the Colorado River at Lees Ferry, above the Little Colorado River, and upstream from Bright Angel Creek be maintained as sediment measurement stations as well as discharge stations. It is also critical to measure outflow from the system and therefore, of existing gaging stations, the station above Diamond Creek would be maintained. It is less critical to evaluate flux differences between miles 87-225, and the gage above National Canyon is considered the least important gage presently existing in Grand Canyon, although it continues to be useful for bed movement studies and sediment transport modelling. If one gage is removed in Grand Canyon, it should be the National Canyon gage although the economy of this decision over the long-term might be questionable.

If one gage were to be added in Grand Canyon, it should be located upstream from Nankoweap Creek (perhaps upstream from Buck Farm Canyon), so that fluxes could be measured through the distinctly different reaches of upper and lower Marble Canyon, reaches in which impacts from upramping waves are greatly attenuated. However, addition of a new gage in Grand Canyon would represent a significant increase in the impact of scientific activities on the Canyon, and the U.S. Geological Survey should explore alternative strategies to installation of permanent cableways for purposes of water and sediment gaging.

The ongoing water and sediment modeling effort, although primarily a research effort, would be included in the monitoring program because the modeling effort represents a long-term alternative to continued widespread gaging presence in Grand Canyon. Such modeling also holds out the hope for calculation of flux differences in short reaches of Grand Canyon. Other modeling efforts, although of possible use in long-term management of Grand Canyon, would not be considered part of a long-term monitoring program but rather long-term research. This is not to imply that development of these models would be discontinued as continued long-term research is essential to success of the long-term monitoring program.

Measurements of sediment fluxes would be the basis for computing annual reach-scale sediment budgets of Grand Canyon. The sediment budget approach to river management has been endorsed by geomorphology and sediment researchers (GCES Fort Collins, 1992). Because there are insufficient gages to compute sediment budgets for all

geomorphic reaches of Grand Canyon, such budgets would only be computed for the following reaches: Lees Ferry to Little Colorado River, Little Colorado River to Bright Angel Creek, and Bright Angel Creek to Diamond Creek.

Calculation of these budgets also necessitates measurement of sediment inflow from tributaries. The Geological Survey would continue to operate its stations on the Paria River at Lees Ferry and Little Colorado River near Cameron. Sediment from Moenkopi Wash, a major sediment contributor to the Little Colorado River, is not measured and consideration would be given to developing a measurement station on this wash. New sediment measurement stations would not be established on other tributaries to the mainstem because sediment input from these tributaries is inconsequential compared to inputs from the Paria and Little Colorado Rivers. This is not necessarily the case for water discharge data, and gages for these measurements on major tributaries might still be considered.

Water Chemistry. Chemistry of water in the mainstem of the Colorado influences most aquatic and riparian biological processes. Changes in water chemistry and temperature may alter physiological processes of aquatic biota potentially triggering changes in the aquatic trophic dynamics of the Canyon. Nutrient trapping by Glen Canyon Dam, changes in nutrient transport within Lake Powell resulting from changes in lake level, and in the mainstem resulting from water transport fluxes all influence the water chemistry of the mainstem below the dam. Thus, the objective of water chemistry monitoring is to determine the aquatic environment of the Canyon and evaluate this in terms of maintenance of those riverine ecosystem components deemed critical by the resource management agencies and interests; that is, fish, aquatic food base and riparian vegetation.

Evaluation of chemical and biological changes in the riverine ecosystem would be dependent, in part, on river discharge, water temperature and sediment data collected at the recommended gages on the mainstem and at the point of discharge from the dam (tailrace). Basic data on water temperature, conductivity and pH would be measured at these gages and the discharge point at the same time interval established for sampling discharge and/or sediment transport. Measurements of dissolved oxygen, particulate and dissolved organic matter, and nitrogen and phosphorus would be made seasonally.

Tributaries to the mainstem of the Colorado River in Glen and Grand Canyons are influenced by dam operations primarily at their confluence with the mainstem. With the exception of the influence of rising and falling river levels at the confluence, tributaries are an input to the mainstem. As such, the objective for collecting long-term monitoring information on changes in tributary characteristics is to evaluate possible causes of mainstem changes, that is, dam vs non-dam operational causes. Tributaries of the Colorado River are relatively pristine refugia for native fish, trout and other non-native fishes as well as riparian ecosystems. For this reason, they would be included in the long-term monitoring program where they would be considered as “control” for evaluating changes in selected attributes in the mainstem (e.g., aquatic biota), and as a source of attribute inputs.

Tributary inputs to the mainstem include hydrological, sediment and limnological attributes. Not all tributaries can be monitored thus emphasis would be limited to those with

major inputs, either abiotic or biotic. In addition to water and sediment discharges from the Paria and Little Colorado Rivers mentioned earlier, tributary discharges, water chemistry (see parameters above for mainstem) and biological attributes (see aquatic food base) would be monitored at the Paria and Little Colorado Rivers, and Kanab, Bright Angel, and Havasu Creeks. Measurements would be continuous for discharge rates, and seasonally for chemical and biological attributes and would be taken in conjunction with these measurements at the gages in the mainstem. Discharge rate monitoring would require maintenance, reinstallation, or installation of a gaging system in the above tributaries and the significance of the necessity for this invasive technology would be considered. Other selected tributaries, especially with perennial flows, would be sampled quarterly for comparison with primary tributary and mainstem data; measurements being limited to water chemistry and biological attributes.

Sediment in the Canyon is either in transport or in storage above or below the river surface. Sediment transport flux is monitored periodically at the gage sites in the Canyon. Stored sediment in the channel and eddies is the source and foundation of elevated sediment deposits. The prescribed dam operations in the Record of Decision would consider sediment accumulation in the riverine system, in the channel or eddies and as elevated deposits (e.g., beaches). Therefore, the objective of monitoring changes in stored sediment is to evaluate the sediment budget predictions of the EIS relative to the selected alternative. In order to determine the influence of dam operations on the integrity of these deposits, the measurement objective of the monitoring program is to determine the changes in sediment storage in different reaches of Grand Canyon. The accomplishment of this objective would permit measurement of temporal change in the status of critical bar and bank sediment deposits and in debris fan deposits, and to place that change within the context of measurements of all sediment storage change in Grand Canyon.

Selected campsite beaches would continue to be measured annually. Established survey techniques would be employed by trained surveyors. Measurement of short-term changes on bars, although of interest in determining sediment dynamics, are not the focus of the long-term monitoring program.

Measurement of bar changes throughout the Canyon would be made using air photo interpretation and video imaging analysis strategies. Such measurements permit wider ranging measurements using less invasive measurement strategies. Short-term repeat photography is not recommended as part of the long-term sediment monitoring program except perhaps at sensitive archaeological sites (see Cultural Resources section).

Many wildlife species, including fishes, depend on the aquatic food base for their survival. Fluctuations in aquatic food resulting from dam operations or other influences would invariably cause changes in some or all of the populations of native and non-native

fish species. The preferred alternative includes prediction of enhancement of the aquatic food base to ensure sufficient food for the endangered fish species and the economically valuable trout population. For this reason, the objective of the long-term monitoring program is to determine whether the biomass, habitat and composition of the aquatic food base is responding to dam operations as expected.

Aquatic food base monitoring would be seasonal and include the mainstem, and tributaries. Quantification of changes in species survival and productivity within categories or functional groups of lower trophic levels in the ecosystem may be used as gross indicators of change. Standing crop (biomass), dominance and habitat requirements of phyto-and zoobenthos, and phyto- and zooplankton would be measured seasonally at the dam, Lees Ferry, Little Colorado River and Diamond Creek and at least two wide-reach sites and two narrow-reach sites between the Little Colorado River and Diamond Creek. When appropriate, sampling protocol would be comparable with the protocols used during GCES II research to ensure compatibility of data.

The sampling protocol would sort the benthos into biotic categories. Numbers of organisms and ash-free dry mass would be determined for multiple samples numerous enough for each biotic category to assure statistical reliability. Complementing biotic sampling, the following abiotic parameters would be ascertained for comparison with abiotic data from gage sites: water temperature, dissolved oxygen, pH, and conductivity. Substratum, microhabitat conditions, turbidity, water velocity, stage, and depth would be recorded at each sampling site.

Fishes are an important part of the Colorado River ecosystem because of their intrinsic value if native, the trophic role of both native and non-native taxa, the important recreational value of non-native trouts, and because some native taxa are listed as endangered or candidates for listing under the Endangered Species Act. Fish populations depend on appropriate habitat and an adequate food base. Both of these factors may change as a result of dam operations. Habitat determination for many of the species is a result of the GCES research program. However, reproduction, recruitment and growth of various species in response to the aquatic environments created by dam operations would result in different demographic distributions of native and non-native species within the Canyon. Operations of the preferred alternative are predicted to enhance recruitment of native fish species through reduction of “flushing” of larval fish from tributaries into the mainstem for example, and trout through reduction in loss of spawning habitat (redds) and stranding of young. Loss of spawning habitat through armoring of normal redds areas may also be a consequence. In addition, dam operations are expected to enhance the food base to ensure growth and maintenance of the existing populations. The objective of this program, therefore, is to monitor the condition and population fluxes of native and non-native fish species to evaluate their response, as predicted, to dam operations.

Monitoring would include all native and non-native species. There would be a long-term data base existing for the status of adult fishes when the long-term monitoring program is initiated; information on pre-adult life stages would likely be less complete.

Sampling time-frames would differ for different taxa and life stages. Because information on some of the fish species is not complete, adults of long-lived taxa would be sampled annually. As information becomes more complete, sampling would be on a four-year cycle. Short-lived species and young-of-the-year of all taxa would be sampled twice annually during the period of larval fish presence (spring) and following the period of summer flooding. Sampling locations would correspond as closely as possible to those selected for monitoring of the aquatic food base, but would also include selected tributary sites (e.g., Paria, LCR, Bright Angel, Nankoweap, Havasu, and others to be determined). The assumption is that by the time long-term monitoring is initiated, sufficient understanding of many relationships among sampling sites and ecosystem parameters would have been established to allow use of sampling site data for assessing overall status, trends and changes of fish populations as well as the aquatic food base.

The sampling protocol for adults of long-lived species would be comparable with that used during GCES II research and interim flow monitoring to ensure compatibility of data. Monitoring in the Little Colorado River would be comparable with protocols developed during the GCES II humpback chub research program. Sampling protocols for short-lived species and young of others would be determined through evaluation of monitoring proposals but would produce data compatible with those generated through monitoring of other age classes.

Creel data, regular surveying of fishing guides, and other methods compatible with protocols developed by Arizona Game and Fish Department would be used for assessing trends in trout populations in the Lees Ferry reach, while protocols developed by Arizona Game and Fish and the Hualapai Wildlife Management Department to assess recreational fish populations would be used for lower reaches. Timing of those activities would be determined by the resource management agencies, but would not exceed an annual reporting schedule. Data collection and reporting from the two departments would be compatible.

Riparian vegetation along the Colorado River and its tributaries is important for streambank stability, wildlife habitat, campsite modification and aesthetic values. Riparian vegetation along the mainstem comprises three distinct communities, old high water zone (OHWZ), new high water zone (NHWZ), and near-shoreline wetlands (marshes). All of these communities are important ecosystem components; however, only the NHWZ and marshes would be impacted directly by dam operations. Maintenance of these vegetational communities for wildlife habitat is a predicted ecosystem response to the preferred alternative in the EIS. The National Park Service and the Hualapai Tribe consider the OHWZ important in maintaining relicts of the pre-dam ecosystem. The OHWZ may be maintained by periodic habitat maintenance flows through wetting of the substrate in the root zone downslope toward the river. These habitat maintenance flows are recommended for most of the alternatives with low or non-fluctuating discharge. The objective of this long-term program, therefore, is to monitor all three vegetation communities to determine the level of maintenance of these communities by the prescribed dam operations.

The National Park Service has established permanent quadrants along the mainstem and in selected perennial and ephemeral tributaries for the purpose of evaluating long-term responses of riparian and wetland communities to natural and anthropogenic influences (Stevens 1992). Equivalent quadrants have been established by the Hualapai Tribe in the riparian zone during interim flow monitoring. A statistically significant number of these quadrants, distributed throughout Schmidt and Graf's (1990) geomorphic reach designations between Glen Canyon Dam and Diamond Creek, and those below Diamond Creek on the Hualapai reservation, may be the appropriate sampling locations for riparian vegetation because they can be considered baseline information locations. Stage-to-discharge relationships would also have been developed for each by the time the long-term monitoring program begins. The geomorphic settings examined at each area would include marsh, NHWZ (which includes low bar, general beach, channel margin, debris fan) and OHWZ (see Stevens 1992 for stage elevations of these settings).

Because of different response rates to changes in river dynamics, sampling procedures (particularly timing) must differ in the different communities. Marshes and low bar settings would be sampled frequently (e.g., twice a year for the first five years and annually thereafter, except when there are unusual hydrological events, and then immediately after and again twice a year for three years). General-beach, channel-margin and debris-fan settings would be sampled annually, while OHWZ settings would be sampled infrequently (e.g., every five years).

Annual video- or photography of the Canyon would be used to map and quantify changes in cover of riparian vegetation in established (or expanded) GIS reaches. This would be linked with equivalent monitoring of sediment and bar changes.

Riparian vegetation near the mouths of the primary tributaries, but outside the influences of the mainstem, would be characterized and used as reference points for autogenic changes. Characterization would be limited to community structure and species composition and sampled about every five years after a baseline has been established. Tributary quadrants would be located in comparable settings as along the mainstem (i.e., channel margin, and debris flow terrace). Timing (i.e., time of year) of sampling along the tributaries would correspond with equivalent settings along the mainstem.

Habitat relations of most riparian fauna in the Canyon have not been well established. Determination of faunal responses to dam operations is extremely difficult and is dependent on known faunal responses to changing ambient conditions. Thus, to achieve the objective of monitoring the response of faunal assemblages to dam operations, it might be best to align these responses with sampling of riparian vegetation, recognizing that not all riparian fauna are associated with vegetation.

It is unlikely that a completed baseline of invertebrate assemblages will be available when long-term monitoring begins, although there presently exists a large database. Monitoring key taxa, when such are identified, may permit evaluation of responses to dam operations. An inventory of the invertebrate fauna would be established by the National Park Service and Hualapai Tribe as part of a general inventory program, but an extensive and intensive long-term monitoring program would even then disallow more than an estimate of invertebrate responses to variation in river discharges. Thus, as part of a long-term research program, it is essential to establish the invertebrate assemblages (e.g., selected taxa) that are associated with different riverine and shoreline vegetation communities. Long-term monitoring of these vegetation communities may in this way be used as a surrogate for estimating responses of invertebrates to operational changes.

The intensity of effort required for sampling terrestrial vertebrates (herpetofauna, mammals and birds), and the low potential for distinguishing between responses to non-dam changes and those caused by dam operations, limit usefulness of long-term population studies as indicators of change in the riverine ecosystem. In addition, baseline data to support a long-term monitoring program are minimal (except for avifauna), indicating the need for more inventory of terrestrial vertebrates by the National Park Service and the Hualapai Tribe. When inventory is complete and habitat relations of selected assemblages (especially herpetofauna and birds) are established, data from long-term monitoring of vegetation and other habitat components would indicate the probable status of many terrestrial vertebrate populations.

Avifaunal data are perhaps most extensive (see Brown 1989), and a substantial baseline may, in fact, be available if synthesized with the long-term monitoring program in mind. Avifaunal inventory and monitoring, if undertaken, would emphasize riparian-obligate species, resident non-obligate species, migrant species in a biogeographic/geomorphic/seasonal context, listed or special status taxa (e.g., bald eagle, peregrine falcon, southwestern willow flycatcher, belted kingfisher), and wintering and breeding waterfowl. Locations of birds and nests observed would be mapped on the GIS system within the Schmidt and Graf (1990) canyon reach designations. Intensive sampling would occur at the large sample sites (also to be used for herpetofauna and mammals, see below). Nest sites would be mapped and habitat described. [Annual survey of wintering bald eagles/trout population relationships at Nankoweap, representative of the impacts of aquatic responses on listed avian populations, would continue into the long-term monitoring using techniques compatible with those in Brown and Stevens (1991).]

Monitoring of vertebrates, if determined to be essential, would require large study sites where full descriptions of vegetation, soils and topography are available. Spot sampling elsewhere might also be required to expand the long-term monitoring data base. For herpetofauna and mammals, a seasonal sampling schedule is recommended. Establishment of a baseline is necessary for assessing population changes over time and the expense and effort to do this may be too great to include terrestrial vertebrates in the long-term monitoring program. This does not exclude the necessity of the National Park Service and

the Hualapai Tribe in initiating or continuing its inventory of these taxa, but not as part of the long-term monitoring program.

Information on the response of endangered and special status species to dam operation may be crucial to the species' recovery. In addition to their special status, these species are considered important because many were part of the pre-dam ecosystem. The objective of the long-term monitoring program is to track the populations of these species as they respond to changes in their habitat and food base caused by dam operations and other factors which are expected to enhance the chances of their survival and/or recovery. Of the list presented earlier in this document, humpback chub and razorback sucker would be monitored under the fish monitoring program, while the bald eagle, peregrine falcon, southwestern willow flycatcher, belted kingfisher and Kanab ambersnail would be monitored under the wildlife monitoring program.

Cultural resources include archaeological sites, traditional Indian cultural properties, and historical sites. All of these resources have the potential of being altered or lost through processes caused by dam operations as well as other factors, especially those within the discharge potential of the dam or along arroyos that may be influenced by loss of the sediment foundation. It is the objective of this long-term monitoring program to track the integrity of these resources over time and to determine possible mitigating measures when appropriate.

The long-term monitoring program for physical sites would adopt the Programmatic Agreement for Compliance with Section 106 of the National Historic Preservation Act between the National Park Service, Indian Tribes, Bureau of Reclamation, the Arizona State Historic Preservation Office and the Advisory Council on Historic Preservation, as the monitoring design under this long-term monitoring program. The important aspects of that agreement (from Balsom et al 1991) are presented here.

To effectively monitor impacts of dam operations on cultural sites, baseline information must be complete, with accurate maps, descriptions, and photographs of each site having potential of being impacted. The long-term monitoring program must be sensitive to the fragile nature of sites, the dynamic geomorphic conditions under which they persist, and the delicate situations relative to Indian Tribes and agency responsibilities for their protection and preservation.

The monitoring program must be designed to identify both the present condition of sites and actual changes resulting from dam operations and other factors. (Monitoring data would be used to guide mitigative measures to preserve sites in as pristine a condition as possible.)

Not all sites would be monitored. An extensive representation of sites with evidence of impact by mainstem discharges, including flooding, would be included, while a smaller representative sample of sites not presently impacted by river flows would also be monitored. If observations indicate that specific sites within the population of sites from which the sample was selected show evidence of impacts from dam operations, these sites would be added to those monitored under the long-term monitoring program. Sites to be monitored would be categorized into the following groups from which decisions on intensity of monitoring can be made: (1) direct impact, inundation or bank cutting within the site area in recent years; (2) indirect impact A, bank slumpage or slope steepening adjacent to the site, and B, evidence within the site of accelerated erosion exacerbated by the proximity to river eroded sediments; (3) potential impact A, buried in or located on old river alluvium and below the 300,000 cfs discharge zone, and B, located below the 300,000 cfs discharge zone and not situated in or on river alluvium.

Other impact categories dealing with arroyo cutting (from external causes not head cutting from the river), recreational use (unless evidence of changes in recreation resulting from dam operations), or sites located above the 300,000 cfs discharge zone are not included in this long-term monitoring program, but should be monitored under a continuing cultural site inventory and monitoring program of the National Park Service, the two efforts to be closely coordinated.

Representative samples of sites would be chosen, randomly and non-randomly, within the above categories to insure that sites in the greatest danger of impact are closely monitored and remedial actions taken when required. Sites that have no potential for external impacts would be identified and used as controls.

Schedule for monitoring cultural sites would be dependent on the baseline condition of the site. It is assumed that all sites will have been categorized and described, including geomorphological settings, prior to initiation of the long-term monitoring program. Sites that are directly impacted by river discharges (including loss of sediment foundation) would be monitored quarterly, while a sample of other sites (ca. 20%) would be visited annually. Selection of these latter sites would be based on sensitivity, tribal concerns and other factors determined by archaeologists, respective Indian Tribes and geologists. Sites which are not impacted by river discharges, but show impacts due to such factors as arroyo cutting, would be integrated with the long-term monitoring program. Annual aerial photo- or videographs would also be used to evaluate site changes, especially of those of sufficient size to allow remote sensing of change. This work would be coordinated with the sediment dynamics monitoring program. Sites with potential for rapid degradation would be monitored weekly through the use of oblique photography using hidden time-lapse cameras. If rapid loss is discovered, recovery archaeology and/or mitigation would immediately be initiated.

Monitoring of tribal values and concerns with dam operations and impacts would be an integral part of the long-term monitoring program. Tribal attitudes and values may change over time, both in response to passing years but also as a result of actual or perceived changes in the Canyon ecosystem or other influences or factors. The objective of this program is to monitor these values and attitudes on an ongoing basis and to structure them

to allow for quantitative analytical techniques and to determine possible changes in attitude or values in relation to dam operations.

Each affected Tribe should develop and implement a set of visitations on an annual basis. These visitations should include established sets of questions, determined by the Tribe and comparable over time, dealing with the Canyon resources. Questions and timing of visitations should be determined by each Tribe in cooperation with the organization responsible for the overall long-term monitoring program.

Recreational use of the Canyon is of economic and environmental importance. As a major use of the Canyon, recreation creates jobs and financial support within the region, but also is a significant component of impact analysis. The preferred alternative in the EIS has considered impacts on recreation and has attempted to enhance the recreational experience in the Canyon and increase safety. Also of importance are the possible impacts of recreation on Canyon resources. The objectives of the long-term monitoring program, therefore, are to determine whether recreation is enhanced and safety improved over impacts of the historic operation of the dam, and whether changes in recreational patterns resulting from the selected dam operational alternative have any effect on the Canyon.

To determine whether dam operations are affecting the pattern and amount of use in the Canyon, data on use and changes resulting from recreation would be compiled annually. Such data can be utilized to assess changes in use, but also may help determine causes of some changes in other resources (e.g., fish populations, and beach sizes or qualities, etc.). Recreation use data are available from or can be obtained through the National Park Service, Arizona Game and Fish Department, Native American tribes, and fishing guide, angler and boatman surveys, including the following: (1) Whitewater rafting, including commercial, private and tribal enterprises. Data would include user days, length of trip, put-in and takeout points, beaches used, and safety (accident) records. (2) Angler uses, including commercial and private use above Lees Ferry. Data would include angler user days, fish catch data, and safety (accident) records. (3) Miscellaneous uses, e.g., birdwatching, use of riparian habitats (both mainstem and tributaries) for hiking, sightseeing within the Canyon, etc. to be evaluated through National Park Service and Hualapai Tribe permitting records, Game and Fish surveys, and other means. Survey results would be summarized and evaluated annually.

Beach area data would be monitored using aerial video- or photography at the same discharge levels each year. Changes in beach camping area, above high discharge levels, can be determined through digitized video- or aerial photographs and validated on a sample basis through ground truthing coordinated with beach surveys under the sediment dynamics component of the long-term monitoring program.

To determine possible reasons for changes in recreational use, recreationist 's values and concerns would be monitored on a five year basis or following unusual events. This information would be gathered using surveys of appropriate user groups. Value evaluation is separate from values determined using non-use value methodologies. The former deals

directly with use and experiences in the Canyon while the latter are based on no direct contact with the Canyon.

Recreationists' values to be monitored using surveys that deal with the relative value of Canyon experiences include: (1) satisfaction with existing discharge levels, (2) perceptions of effects of dam operations, (3) attitudes about congestion at beaches or high level visitor sites, and (4) attitudes toward researcher/monitoring teams in the Canyon. Information gathered during the pre-long-term monitoring period would be used as the baseline for comparison and evaluation of change in these values and perceptions.

Hydropower supply is an integral part of the economy of the region. Changes in power operations resulting from changes in annual dam operations would affect the power supply and its costs. The objectives of this program are to determine the impact of changes in dam operations on hydropower outputs and the concomitant power marketing and economics of the region, a concern of those agencies tied to hydropower production.

Actual power generation would be monitored on an hourly basis as input to assessing the consequences of dam operations on power economics. Power generation is also a method for estimating water discharge rates and volumes.

Long-term monitoring would include the maintenance of a current data base for future power resource economic reviews to determine the consequences of the anticipated changes in Glen Canyon Dam operations. A periodic review of the electric power market would determine whether new information supports decisions based upon previous forecasts. The Power Resources Committee (PRC) Phase II effort would be used as the basis for the periodic review. For each review, current measured parameters can be compared to the risk and sensitivity analysis work completed in Phase II studies. If the current measures or assumptions fall within the range of assumptions made in Phase II, then the impacts can be determined from this information. Conclusion can then be made regarding the degree of influence changes in certain measured parameters (i.e., load growth, fuel escalation rates) would have on the economic and financial impacts.

A more detailed review would involve assessing the significance of changes in the value or financial benefits of power and recreational uses which might impact the economic and social benefits of changes in Glen Canyon Dam (GCD) operation. A detailed review would take place when a different operational alternative for GCD is proposed. The decision to go to this level of analysis, based in part on a recommendation of the Adaptive Management Working Group, would be made on a case-by-case basis.

In preparation for these reviews, a data base of revenues, rates, supplies, purchases and loads must be established through monitoring the following parameters: (1) annual revenue requirements of Western Area Power Administration (Western), (2) rate charges for

Western wholesale power, (3) regional power supply adequacy for Western Systems Coordinating Council (WSCC) annual reports (moving, 10-year projection), (4) historical regional power loads from WSCC, (5) annual evaluation of costs of power purchases and sales within and outside the region available from EIA, (6) updates of utility data already collected by the PRC.

Concomitant with evaluation of impacts on power revenues, should be an evaluation of impacts on the economics and revenues of other uses of Glen and Grand Canyon. These uses especially include recreational revenues, but changes in other regional revenue sources resulting from the selected dam operation would be considered.

The detailed review would follow procedures established by the PRC of Glen Canyon Environmental Studies to evaluate the economic impacts of various dam operation alternatives for the Glen Canyon EIS. If required, additional transmission related and short-term operational reviews may be necessary with any further changes at Glen Canyon Dam.

Evaluation of the non-use values of the Glen and Grand Canyon riverine system would also be part of the economic and financial component of the long-term monitoring program. It is possible that the public 's perception of the Canyon may change as a result of the future operations of Glen Canyon Dam; thus it is valuable to determine this perception through use of non-use economic methodologies.

(An extensive reference listing of ecological and environmental impact studies within Glen and Grand Canyons can be found in the EIS.)

Balsom, J., et al 1991. The Grand Canyon River corridor survey project: archaeological survey along the Colorado River between Glen Canyon Dam and Separation Canyon. Report on file, Grand Canon National Park and the Bureau of Reclamation, Flagstaff.

Brown, B.T. 1989. Ecology of riparian breeding birds along the Colorado River in Grand Canyon, Arizona. Coop. National Park Resources Stud. Unit Tech. Report No 25, NPS. Univ. of Arizona, Tucson.

Brown, B.T. and L. E. Stevens. 1991. Influences of fluctuating flows from Glen Canyon Dam and effects of human disturbance on wintering bald eagles along the Colorado River in Grand Canyon, Arizona. NPS Cooperative Parks Study Unit. Northern Arizona University, Flagstaff, AZ. (unpublished annual report).

MacDonald, L.H. 1991. Monitoring guidelines to evaluate effects of forestry activities on streams in the Pacific Northwest and Alaska. United States Environmental Protection Agency, Water Division. EPA/910/9-91-001.

Schmidt, J.C. and J.B. Graf. 1990. Aggradation and degradation of alluvial sand deposits, 1965-1986, Colorado River, Grand Canyon National Park, Arizona. U.S. Geol. Survey Prof. Paper 1493, Washington, D.C.

Stevens, L. E. 1992. Long-term monitoring of riparian biotic resources in the Colorado River corridor, Glen and Grand Canyons, Arizona. In, National Research Council, Long-term monitoring workshop.

Background and input attributes are those factors whose variation may be used to help explain changes in the mainstem Colorado River corridor ecosystem. They occur or are located above and/or below the dam, but are not those attributes along the mainstem corridor influenced by dam operations. Information on background and input attributes is important to archive for use by the long-term monitoring program on effects of dam operations, however, gathering of this information is not part of that program.

Although long-term monitoring of the Grand Canyon ecosystem may detect temporal change which might be associated with dam operations, other possible causative factors, such as climate, will exist. Thus, identification of external factors that may be regularly monitored for other purposes such as climatological data, and identification and monitoring of unregulated analogues to the Grand Canyon ecosystem could provide an opportunity to distinguish “natural” change from dam-related change.

Benchmark (unaffected) sites are locations that might be considered as control sites similar in geomorphology to the Grand Canyon that can be used to analyze differential influences of dam and non-dam variables. Unfortunately, there is insufficient scientific data on which to identify unregulated analogues to the Grand Canyon at this time. Candidate areas include Cataract Canyon and the Grand Canyon tributaries. The latter are only relevant for biological parameters. Research should be considered in Cataract Canyon to determine its possible analogue status as an “unregulated Grand Canyon”. At a later time, the National Park Service might propose a companion Cataract Canyon monitoring program as one basis for interpreting environmental change in Grand Canyon.

Some ecological monitoring of tributary conditions in Grand Canyon is included in this program, however, such efforts would be limited. Further research is necessary to determine the nature of appropriate comparisons between the “big river ecosystem” of the Colorado River and the “small river ecosystems” of the tributaries.

The external factors that would be used for differentiating between natural and dam caused changes are discussed below.

Regional Meteorology/Climate. Hydrology of the Glen Canyon/Grand Canyon region is a consequence of regional precipitation and temperature patterns. Tributaries, especially the Little Colorado River, Paria River and Kanab Creek, are all important in the dynamics of the river. As part of the background data base for long-term monitoring, and for interpreting different causes of change in the Colorado River ecosystem, it is essential to include climatological data from NOAA weather stations that influence major tributaries to the Colorado River above and below Glen Canyon Dam. The minimum set of climatological stations would include: Page, Jacob Lake, Kanab, Cameron, Supai, Pipe Springs NM and Peach Springs. Additional stations at the headwaters of the Little Colorado River, Kanab Creek and Paria River would also be considered. When necessary, data from stations at the headwaters of the San Juan, Green and Colorado Rivers would be archived.

Hydrometeorology. In addition to climatological data, it is essential to archive information on hydrometeorological changes. These include not only precipitation (part of climatological data), but snowpack and runoff in the major tributaries to Lake Powell and the Colorado River below Glen Canyon Dam. Hydrometeorological data are presently collected for some of the tributaries of Lake Powell. Snowpack measurements are also a regular part of the predictive models used by the Bureau of Reclamation in its forecasts for annual and monthly releases of water from Glen Canyon Dam. These data, however, would not only be used for predictive purposes but as part of the overall data set archived for the monitoring program.

Local Microclimate. There is a very limited set of local meteorological stations in the Grand Canyon, the primary one being at Phantom Ranch (Grand Canyon NP). Changes in the Colorado River riverine/riparian ecosystem may be a response to non-anthropogenic environmental changes as well as changes or influences from dam operations. As part of its inventory and monitoring program, NPS would need to upgrade and add to local climatological stations to give adequate coverage for interpreting local climatological influences. The Phantom Ranch station would be instrumented to measure solar radiation in addition to temperature and precipitation. Complete weather stations would be established at Lees Ferry. The Hualapai Tribe should add a complete weather station at Diamond Creek near the river as part of its long-term resource studies. Other stations within the Canyon, for example, Indian Gardens, would be upgraded to full climatological station status. Data from these stations then become part of the background archives for the long-term monitoring program. The importance of upgrading or adding climatological stations for data input into the long-term monitoring program cannot be over emphasized. There is such a critical need for this information, for example, the affects of solar insolation and canyon temperature on water temperature, that this effort would be considered as an integral part of the long-term monitoring program.

Essential to any long-term monitoring program is that it addresses management needs, specifically, it would be designed to ensure that management objectives are being met. It would also be designed to recognize the temporal characteristics of the system being monitored. In the case of the Grand Canyon, long-term monitoring in response to operations of Glen Canyon Dam would continue indefinitely, or as long as the dam is operable. Periodic review of the program is necessary to determine the intensity of the monitoring program. The potential longevity of this program would be recognized in the selection or establishment of institutions that can maintain continuity while carrying out monitoring activities. Because continuity in methodology and procedures is essential to ensure comparability of data, no monitoring activity should be based on the sole contributions of any one individual but would be aligned with an agency or long-term organization.

Monitoring activities must also recognize the spatial scale of the resources. The enormity of Grand Canyon requires that projects actually be a sample, and that an hierarchy of spatial scales (e.g., nesting or representative sample units) would be used. Selection of sample units or areas would also consider the sensitivity or fragility of the system, thus methodologies would leave as small a “foot print ” as possible. The type, frequency and location of measurements would, however, invariably follow from the objectives of the long-term monitoring program.

Lastly, the long-term monitoring program would be sufficiently flexible to permit initiation of “new” monitoring activities to respond to transient events such as floods or tributary sediment pulses, and to changes in direction which may result from changes in management goals.

Potential use and integrity of monitoring activities is dependent on their initial procedural design. Each proposed monitoring activity must be reviewed by other workers prior to implementation to ensure comparability of data, prevent overlapping efforts, and to encourage interaction and integration by using comparable spatial and temporal boundaries. Considerable resources would need to be devoted to careful documentation of procedures, quality assurance and quality control (QA/QC), definition of variability (i.e., defining uncertainty), etc. This would reduce the total amount of data which can be collected, but it is necessary to provide the documentation for future data use and interpretation.

All participants in the long-term monitoring program must be required as a condition of participation to have their data internally and externally reviewed and entered into a common data base system on a regular and timely basis. Field data must be carefully referenced to known, consistent locations (georeferenced). These reference points must be consistent among monitoring and research activities, and included as an integral part of the GIS data management system.

Effective monitoring activities must be based on a thorough knowledge of the physical and biological characteristics of the system. Because the baseline information may be limited for some areas and resources, and methodologies may not be fully tested, many activities would be initiated as “pilot projects” and the comparability of the data tested before being settled upon as a major part of the long-term monitoring program. Trade-off between minimum detectable effects and monitoring efforts and costs must furthermore be accepted as part of the evaluation procedures for selection of monitoring projects within the long-term monitoring program.

Each component of the long-term monitoring program must have an explicit, detailed protocol which spells out: (1) objectives, (2) experimental design, (3) procedures for data collection, QA/QC, data analysis, data storage, and reporting. This allows anyone to replicate measurements and to evaluate them in a consistent statistical manner. Where appropriate, each experimental design would be evaluated for statistical integrity. The protocol for each component would specify the level of knowledge and training required for those collecting field data, analyzing samples, entering data, and interpreting the data. There would be a comparable protocol for managing the data base.

Scientists collecting the data would be involved with data interpretation. Although the time frame of the long-term monitoring program extends well beyond the participation period of any one scientist, it is anticipated that those who collect the data would be familiar with the Grand Canyon and may use the data as part of ongoing research programs. This connection of data collection and interpretation would result in data being collected appropriately and efficiently.

Releasing and sharing data must be a requirement for every project. Those collecting original information, however, should be allowed a reasonable time for analysis and publication before releasing the data to the public. Trust must be established among data collectors and managers to ensure transfer and integration of information. Each monitoring project would prepare an annual report using a consistent and defined format, including reports from data base managers.

A general principle is that all data would be freely available. In some cases, however, such as archaeological-site data, data that Indian Tribes define as sensitive, or information on localized endangered species, a level of confidentiality may be necessary.

A centralized, integrated data base is necessary to avoid duplication of effort and facilitate exchanges of information among projects. This includes incorporation of information from past monitoring, inventories and research. Each file in the data base must be cross-referenced to files which document data-collection procedures, variability, and uncertainties. All data would be copied and stored in at least two locations to maximize security.

Certain kinds of data and collected information are unsuitable for storage in a traditional computerized data base. These include audio and video recordings, for example, as well as biological and geological specimens and copies of historical literature and photographs. This information and collections need to be archived following procedures appropriate to their unique characteristics, and cross-referenced to other information.

The resource management agencies and interests have established an Adaptive Management Working Group that would oversee the management and archiving of the long-term monitoring program and data (see chapter in EIS). This group would evaluate the findings of the long-term monitoring program. This evaluation may lead to recommendations for changes in dam operations to ensure compliance with the objectives of the 1992 Grand Canyon Protection Act.

Although no specific institution has been selected for the actual management of the long-term monitoring program or archiving of monitoring information, an organizational structure needs to be set in place prior to initiation of any phase of long-term monitoring of the effects of Glen Canyon Dam operations. It would need to absorb the ongoing program of the Glen Canyon Environmental Studies which has managed data collection efforts to date and has embarked on an information management program as well (Scientific Information Management system - SIM).

The use of Geographic Information Systems (GIS) for data storage is an important component of the data management process; however, not all data can be put into GIS format. GIS can be an important analytical tool for integrating and comparing spatially based data, but the applicability of this technique would depend upon the particular objectives of each monitoring project. Each project would specify which GIS data layers are required.

The validity of the existing GIS reaches in the Canyon would be tested for representativeness or designation as critical reaches. Usefulness of these reaches for the long-term monitoring program would be evaluated once the objectives and priorities for long-term monitoring are established. The use of satellite and remote sensing (e.g., aerial video- and photography) data would also be evaluated relative to the level of detail needed for each monitoring project (satellite data would probably be too coarse for use in monitoring in the Canyon).