SCE&G Final Calibration of the CE-QUAL-W2 Model For Lake Murray Prepared for SCE&G Prepared By Andy F. Sawyer and Richard J. Ruane, Reservoir Environmental Management, Inc Chattanooga, TN [email protected] 423-265-5820 Final Report December 2006 RESERVOIR ENVIRONMENTAL MANAGEMENT, INC. Chattanooga, Tennessee SCE&G Final Contents Acknowledgments .................................................................................................................. iv List of Acronyms......................................................................................................................v List of Figures......................................................................................................................... vi List of Tables ......................................................................................................................... xii Executive Summary...............................................................................................................14 1. Introduction......................................................................................................................16 2. Description of Lake Murray and Saluda Dam..............................................................18 3. Water Quality Characteristics of Lake Murray and Releases from Saluda Hydro ..........................................................................................................................21 Nutrients, Algae, and Water Clarity .............................................................................. 22 Inflow Stations........................................................................................................ 22 Upper End of Lake Murray, Including Embayments........................................ 33 The Lower End of Lake Murray, Including The Embayments........................ 33 Summary for TP in Lake Murray, Including The Embayments ...................... 34 Temperature, Dissolved Oxygen, and pH...................................................................... 38 Lake Data ............................................................................................................... 38 Tailwater Data........................................................................................................ 41 Limnological Considerations for Effects of Phosphorus on Lake Murray.................... 50 Summary of Water Quality Analyses ............................................................................ 54 4. Approach to Water Quality Management for Lake Murray.......................................56 CE-QUAL-W2............................................................................................................... 57 W2i and AGPM ............................................................................................................. 59 Modeling Plan................................................................................................................ 60 Objectives............................................................................................................... 60 Modeling Approach ............................................................................................... 60 5. W2 Model Inputs..............................................................................................................62 Bathymetry..................................................................................................................... 62 Inflows ........................................................................................................................... 69 Outflows......................................................................................................................... 75 Dam Releases ....................................................................................................... 75 McMeekin Steam Plant Cooling Water.............................................................. 76 Inflow Temperatures...................................................................................................... 78 Branch 1 - Saluda River Inflow into Lake Murray............................................. 79 Reservoir Environmental Management, Inc Jim Ruane 423-265-5820 [email protected] i SCE&G Final Tributary 1 – Bush River Inflow into Lake Murray............................................ 79 Branch 2 – Little Saluda River Inflow into Lake Murray .................................. 80 Tributary 2 – Clouds Creek Inflow into Little Saluda River Arm of Lake Murray ..................................................................................................................... 80 All Other Inflows into Lake Murray...................................................................... 80 Tributary 3 – Discharge from McMeekin Steam Plant into Saluda Hydro Unit 3 ............................................................................................................................... 81 Simulation of the Effects of the McMeekin Thermal Discharge ..................... 81 Inflow Dissolved Oxygen .............................................................................................. 86 Branch 1 - Saluda River inflow into Lake Murray............................................. 86 All Other Natural Inflows ...................................................................................... 86 Tributary 3 – Discharge from McMeekin Steam Plant into Saluda Hydro Unit 3 ............................................................................................................................... 86 Determination of Labile and Refractory Organic Matter and Nutrient Content of Organic Matter............................................................................................................... 90 Inflow Phosphorus and Organic Matter......................................................................... 93 Branch 1 - Saluda River Inflow into Lake Murray............................................. 94 Tributary 1 – Bush River Inflow into Lake Murray............................................ 94 Branch 2 – Little Saluda River Inflow into Lake Murray .................................. 95 Tributary 2 – Clouds Creek Inflow into Little Saluda River Arm of Lake Murray ..................................................................................................................... 95 All Other Natural Inflows into Lake Murray ....................................................... 96 Tributary 3 – Discharge from McMeekin Steam Plant into Saluda Hydro Unit 3 ............................................................................................................................... 96 Other Inflow Parameters.............................................................................................. 102 Inorganic Suspended Solids.............................................................................. 102 Nitrate and Ammonium....................................................................................... 102 Algae ..................................................................................................................... 102 Initial Conditions ......................................................................................................... 104 Meteorology................................................................................................................. 105 Wind Sheltering Coefficients....................................................................................... 106 Sediment Oxygen Demand .......................................................................................... 106 6. Model Calibration..........................................................................................................109 Headwater Calibration ................................................................................................. 114 Temperature Calibration .............................................................................................. 114 Water Quality Calibration............................................................................................ 128 Phosphorus and Nitrate ..................................................................................... 128 Reservoir Environmental Management, Inc Jim Ruane 423-265-5820 [email protected] ii SCE&G Final Algae ..................................................................................................................... 138 TKN and TOC ...................................................................................................... 142 Dissolved Oxygen ............................................................................................... 142 Alkalinity and pH.................................................................................................. 144 Summary of Calibration............................................................................................... 163 7. Applications for the Model............................................................................................164 Reduced Phosphorus in the Inflows............................................................................. 164 Estimated Future Concentrations of Phosphorus for Inflows....................... 164 Estimated Sediment Oxygen Demand for Lower Phosphorus in Inflows ................... 167 Results of Model Simulations...................................................................................... 168 Case for Reduced Phosphorus in the