Colorado River Ecology and Dam Management -- Copyright -- Contents -- Acknowledgments -- Committee Synopsis -- FINDINGS AND RECOMMENDATIONS -- Initiate Long-Term Research and Monitoring in the Grand Canyon -- Ensure that Dam Operations Are Flexible -- Seek Research Talent from the Academic Sector -- Include the USGS on the Federal Executive Management Committee -- Use an Ecosystem Approach to Grand Canyon Research -- Revisit 1987 NRC Recommendations on the GCES -- REFERENCES -- 1 The Law and Politics of the Operation of Glen Canyon Dam -- INTRODUCTION -- HISTORY OF RIVER DEVELOPMENT -- DIVIDING THE WATERS: THE ORIGINS OF THE LAW OF THE RIVER -- Structure of the Compact -- The Evolving Law of the River -- DISTRIBUTING FEDERAL LARGESSE -- THE NECESSITY FOR FURTHER ALLOCATIONS: SECURITY UNDERMINED BY CONFLICT -- ACCOMMODATION OF NEW VALUES -- Omitted Interests: Indians and Mexico -- Accommodating Emerging Values -- HOW SHALL THE COMPUTERS BE PROGRAMMED: MANAGING THE RIVER IN THE SHADOW OF THE LAW -- CONCLUSION -- REFERENCES -- 2 The Role of Science in Natural Resource Management: The Case for the Colorado River -- INTRODUCTION -- THE STRENGTH OF SCIENCE -- THE LIMITS OF SCIENCE -- MANAGEMENT CHOICES -- THE CASE FOR THE COLORADO RIVER -- THE LONG-TERM INTERACTION BETWEEN SCIENCE AND MANAGEMENT -- ECOSYSTEM SCIENCE -- OPPORTUNITY FOR MANAGEMENT -- LONG-TERM MONITORING AND SUSTAINED EXPERIMENTAL RESEARCH IN MANAGEMENT TERMS -- MANAGEMENT IN SCIENTIFIC TERMS -- THE PRESENT STATE OF AFFAIRS -- REFERENCES -- 3 Hydrology of Glen Canyon and the Grand Canyon -- INTRODUCTION-NATURAL FLOWS INTO LAKE POWELL -- EARLY UNDERSTANDING OF COLORADO RIVER FLOWS -- THE EARLY HEARINGS ON DEVELOPMENT OF THE LOWER COLORADO -- UNCERTAINTY IN AVERAGE STREAMFLOW -- EVAPORATION, BANK STORAGE, AND LAKE POWELL WATER BALANCE -- RECONSTITUTED, NATURAL INFLOWS TO LAKE POWELL.

GLEN CANYON AND THE RELEASE RULES -- RELATIONSHIP OF SEDIMENT TRANSPORT TO STREAM FLOW IN THE CANYON -- EFFECT OF OPERATION OF UPPER BASIN STATE RESERVOIRS ON GLEN CANYON AND THE GRAND CANYON -- TRAVEL TIMES THROUGH THE GRAND CANYON -- CONCLUSION -- REFERENCES -- 4 Sediment Transport in the Colorado River Basin -- INTRODUCTION -- HISTORICAL SAMPLING OF SEDIMENT CONCENTRATIONS -- SOURCE AREAS OF RUNOFF AND SEDIMENT -- EFFECTS OF RESERVOIR STORAGE ON SEDIMENT BALANCE IN SELECTED REACHES OF THE COLORADO RIVER -- GREEN RIVER DOWNSTREAM FROM FLAMING GORGE RESERVOIR -- COLORADO RIVER DOWNSTREAM FROM GLEN CANYON DAM -- CONCLUSION -- REFERENCES -- 5 Limnology of Lake Powell and the Chemistry of the Colorado River -- INTRODUCTION -- MORPHOMETRY AND HYDRODYNAMICS OF LAKE POWELL -- Glen Canyon Dam -- Physical Features of the Reservoir -- River Discharge and the Water Budget of Lake Powell -- Seasonal Stratification -- PARTICULATE AND DISSOLVED SOLIDS DYNAMICS -- Suspended Sediment -- Nitrogen, Phosphorus, and Silica -- Bioavailability of Particulate Phosphorus -- Salinity -- Heavy Metals and Other Pollutants -- LAKE POWELL FOOD WEB -- Phytoplankton -- Zooplankton -- Benthos -- Fishes -- Riparian Systems -- INFLUENCE OF LAKE POWELL ON ENVIRONMENTS DOWNSTREAM -- Lake Powell as a Heat and Materials Sink -- Stream Regulation and the Manifestation of Serial Discontinuity -- AN ECOSYSTEM APPROACH TO MANAGEMENT -- REFERENCES -- 6 Algal and Invertebrate Biota in the Colorado River: Comparison of Pre- and Post-Dam Conditions -- INTRODUCTION -- PREIMPOUNDMENT CONDITIONS -- Algal Communities -- Aquatic Invertebrates -- POSTIMPOUNDMENT CONDITIONS -- Algal Communities -- AQUATIC INVERTEBRATE COMMUNITIES -- Records of Intentional Stocking -- Zooplankton -- Macroinvertebrates -- The Amphipod Gammarus Lacustris -- Exotic and Unusual Species.

MODIFICATIONS IN BIOTA DUE TO REGULATED FLOWS -- Colorado River Studies Between Glen Canyon and Lake Mead -- STUDIES ON OTHER REGULATED RIVERS -- Plant Communities -- Invertebrate Communities -- RECOMMENDED RESEARCH -- REFERENCES -- 7 Native Fishes of the Grand Canyon Region: An Obituary? -- INTRODUCTION -- THE PRISTINE HABITAT -- UNIQUENESS OF THE FISH FAUNA -- HISTORIC REVIEW -- Early Records and Surveys -- EVIDENCES OF FAUNAL CHANGE -- NATIVE FISHES -- THE FISH COMMUNITY -- REASONS FOR DISAPPEARANCE OF THE FAUNA -- Nonbiological Changes -- Biological Changes -- DISCUSSION -- Management Considerations -- Politics of Conservation -- CONCLUSION -- ACKNOWLEDGMENTS -- APPENDIX I -- Accounts of Species -- Humpback Chub -- Bonytail -- Colorado Squawfish -- Speckled Dace -- Flannelmouth Sucker -- Bluehead Sucker -- Razorback Sucker -- REFERENCES -- 8 Historic Changes in Vegetation Along the Colorado River in the Grand Canyon -- INTRODUCTION AND OBJECTIVES -- Objectives -- HISTORY AND BACKGROUND OF BOTANICAL EXPLORATION ALONG THE COLORADO RIVER IN GRAND CANYON -- PHOTOGRAPHY AND THE BOTANICAL RECORD -- Recent Research and Plant Collections -- DISCUSSION -- PREDAM AND POSTDAM VEGETATIONAL COMMUNITIES -- CLASSIFICATION OF DESERTS AND PLANT COMMUNITIES -- THE COLORADO RIVER AS AN EXCEPTION TO RIPARIAN DESERTIFICATION -- EARLY STUDIES AND IMPORTANCE OF RIPARIAN LANDS AS AVIAN HABITAT -- IMPACTS OF FLOODING AND FIRE ON THE RIPARIAN ZONE -- WOODY RIPARIAN SPECIES OF THE RIPARIAN ZONE -- Nonnative Species -- Native Species -- HERBACEOUS RIPARIAN SPECIES -- FLORA AND CHECKLISTS -- FAUNA AND CHECKLISTS -- Amphibians and Reptiles (Herps) -- Birds -- Mammals -- THREATENED AND ENDANGERED (T & E), RARE, AND ENDEMIC SPECIES -- Riparian -- Endangered Species -- AQUATIC -- SUMMARY AND CONCLUSIONS -- ACKNOWLEDGMENTS -- REFERENCES -- APPENDIX A -- 9 Reservoir Operations.

INTRODUCTION -- ANNUAL OPERATION WITH MONTHLY TIME STEPS -- The USBR Reservoir Model -- Modes of Operation for CRSS -- Other Reservoir Models -- Who Operates the Dam? -- USBR Operating Plan -- SHORT-TERM OPERATION OF THE DAM -- WAPA MODELS OF INCREASED MINIMUM FLOWS -- GCES I Model -- OTHER RELATED WAPA REPORTS -- Report on Impact of Alternative Interim Flows -- Report on Cost of Research Flows -- GCES ECONOMIC TEAM PROGRESS TO DATE -- Ramping Rates -- Flows in the Grand Canyon Relative to Dam Releases -- Conclusions -- REFERENCES -- 10 A Brief History of the Glen Canyon Environmental Studies -- INTRODUCTION -- NATIONAL RESEACH COUNCIL INVOLVEMENT WITH THE GLEN CANYON ENVIRONMENTAL STUDIES -- APPLICATION OF SCIENCE AND RESEARCH TO MANAGEMENT -- GLEN CANYON ENVIRONMENTAL STUDIES-PHASE II -- ECOSYSTEM APPROACH AND INTEGRATION OF THE NAS PHASE I CRITIQUE -- DEVELOPMENT PROBLEMS FOR THE GLEN CANYON ENVIRONMENTAL STUDIES PROGRAM -- INTEGRATING THE GLEN CANYON ENVIRONMENTAL STUDIES PROGRAM WITH THE GLEN CANYON DAM ENVIRONMENTAL IMP... -- OPTIONS FOR THE FUTURE -- THE CHALLENGES THA LAY AHEAD -- SUMMARY AND CLOSURE -- 11 Glen Canyon Environmental Studies Research Program: Past, Present and Future -- BACKGROUND: GLEN CANYON ENVIRONMENTAL STUDIES I, 1982-1987 -- DEVELOPMENT OF GLEN CANYON ENVIRONMENTAL STUDIES II RESEARCH PROGRAM -- REVIEW OF GCES I BY THE NRC COMMITTEE -- INITIAL INTEGRATION PHASE OF GCES II -- DEVELOPMENT OF SHORT-TERM RESEARCH HYPOTHESES AND EXPERIMENTAL DESIGNS -- DEVELOPMENT OF CONTROLLED RESEARCH DISCHARGES FROM GLEN CANYON DAM -- DEVELOPMENT OF LONG-TERM RESEARCH AND MONITORING NEEDS -- EXPANSION OF THE SHORT-TERM RESEARCH PROGRAM -- LONG-TERM MONITORING -- CONCLUSIONS -- REFERENCES -- 12 Closing Remarks -- APPENDIXES -- Appendix A Symposium Program -- APPENDIX B Biographical Sketches of Committee Members.

APPENDIX C Symposium Invitees -- APPENDIX D Glen Canyon Environmental Studies Technical Reports and Related Documents.