BURNT RIVER WATER TEMPERATURE STUDY STEERING COMMITTEE FINAL REPORT Prepared for the Burnt River Steering Committee by David Duncan and Associates Boise, Idaho April 2002 TABLE OF CONTENTS INTRODUCTION ............................................................................................................................ 1 Study Description ...................................................................................................................... 1 Study Area ................................................................................................................................. 1 OBJECTIVE 1: FACTORS CONTRIBUTING TO STREAM TEMPERATURES ...................... 2 Baseline Temperatures............................................................................................................... 2 Upper Watersheds .............................................................................................................. 2 Lower Watersheds .............................................................................................................. 2 How Does Heat Energy Enter and Leave a Stream? ................................................................. 3 Radiation.................................................................................................................................... 5 Atmospheric Radiation....................................................................................................... 7 Radiation from Riparian Vegetation and Topographic Features........................................ 7 Solar Radiation ................................................................................................................... 8 Water Radiation.................................................................................................................. 8 Evaporation................................................................................................................................8 Convection and Conduction ...................................................................................................... 9 Streambed Conduction .............................................................................................................. 9 Groundwater .............................................................................................................................. 9 Stream Characteristics Important to Temperature................................................................... 10 Elevation........................................................................................................................... 10 Aspect............................................................................................................................... 10 Topographic Features ....................................................................................................... 10 Flow.................................................................................................................................. 10 Channel Width and Depth ................................................................................................ 10 Vegetative Shade .............................................................................................................. 11 Reservoirs......................................................................................................................... 11 Summary.................................................................................................................................. 13 Processes that Involve the Transfer of Heat Energy......................................................... 13 Stream Characteristics Important to Temperature............................................................ 14 OBJECTIVE 2: TEMPERATURE MANAGEMENT ALTERNATIVES .................................... 15 Methodology............................................................................................................................ 15 Shade ....................................................................................................................................... 15 Site Capability .................................................................................................................. 15 Reclamation Findings....................................................................................................... 16 Irrigation Operations................................................................................................................ 17 Combining Shade Improvements with Irrigation Efficiency................................................... 17 OBJECTIVE 3: DEVELOP AND TEST A SURROGATE.......................................................... 18 Rationale for a Surrogate ......................................................................................................... 18 Temperature Surrogate ............................................................................................................ 18 Definition.......................................................................................................................... 19 Components...................................................................................................................... 19 i Process.............................................................................................................................. 19 Healthy Streams Surrogate ...................................................................................................... 20 Considerations .................................................................................................................. 20 Possible Additional Components ..................................................................................... 20 Conclusions ...................................................................................................................... 21 OBJECTIVE 4: 1010 PLAN.......................................................................................................... 22 Conservation Activities ........................................................................................................... 22 Implementation Problems........................................................................................................ 22 Process.............................................................................................................................. 22 Scientific Disagreements .................................................................................................. 23 Socioeconomic ................................................................................................................. 23 Use of Surrogates..................................................................................................................... 24 Feasibility ................................................................................................................................24 Measures of Progress............................................................................................................... 25 Burnt River 1010 Plan ............................................................................................................. 25 FUTURE RESEARCH ................................................................................................................... 26 Objective 1: Factors Contributing to Stream Temperatures ................................................... 26 Burnt River ....................................................................................................................... 26 General ............................................................................................................................. 26 Tools................................................................................................................................. 26 Objective 2: Temperature Management Alternatives............................................................. 27 Objective 3: Develop and Test a Surrogate ............................................................................ 27 BIBLIOGRAPHY............................................................................................................................28 NOTES.............................................................................................................................................31 FIGURES Figure 1. Location…………………………….......………………………..……......….Frontispiece Figure 2. Seven-day Average Maximum Daily Stream Temperatures at Upper Monitoring Sites. 2 Figure 3. Seven-day Average Maximum Daily Stream Temperatures at Lower Monitoring Sites. 3 Figure 4. Seven-day Average Mean Daily Stream Temperatures at Lower Monitoring Sites......... 3 Figure 5. Budget of Radiation from the Sun, the Atmosphere, and the Ground.............................. 4 Figure 6. Processes that Involve the Transfer of Heat Energy......................................................... 5 Figure 7. Energy Processes Occurring in the Lower Burnt River During One July Day................. 6 Figure 8. Long-wave Radiation in the Lower Burnt River During One July Day. .......................... 6 Figure 9. Vegetation Shade Angle. ................................................................................................ 11 Figure 10. Unity Reservoir Inflow and Outflow – 7-day Average Mean Daily Stream Temperatures ................................................................................................................................................