Appendix D-1 Williamson County Regional Raw Water System Transmission and Operation Models by CDM Appendix D-1 Appendix D-1 Contents PART 1 MODELING REPORT Section 1 Project Objectives ................................................................................1-1 - 1-2 Section 2 The WCRRW System ......................................................................... 2-1 – 2-8 Section 3 Model Overview and Potential Uses............................................... 3-1 – 3-5 Section 4 Modeling Approach.......................................................................... 4-1 – 4-14 Section 5 Mathematical Formulations ............................................................ 5-1 – 5-21 Section 6 Model Validation ................................................................................ 6-1 – 6-6 Section 7 Analysis and Results .......................................................................... 7-1 – 7-7 Appendices ................................................................................................ A - B PART 2 INSTRUCTION GUIDE Section 1 Introduction .................................................................................................. 1-1 Section 2 Planning Simulation Model ........................................................... 2-1 – 2-24 Section 3 Operations Optimization Model ................................................... 3-1 – 3-27 PART 3 HYDROLOGIC REPORT Section 1 Introduction .................................................................................................. 1-1 Section 2 Hydrologic Methods Used ................................................................ 2-1 – 2-3 Section 3 Specifics on Data Sources and Procedures for Each Lake ......... 3-1 – 3-11 Section 4 Comparison of Flows ......................................................................... 4-1 – 4-5 Section 5 Lake Georgetown ......................................................................................... 5-1 Section 6 Lake Stillhouse Hollow .............................................................................. 6-1 Section 7 Lake Belton .................................................................................................... 7-1 Section 8 Conclusions ................................................................................................... 8-1 Section 9 References...................................................................................................... 9-1 Appendices ................................................................................................. A - F A i Table of Contents Appendix D-1 Appendix D-1 Contents PART 1 MODELING REPORT Section 1 Project Objectives ................................................................................................. 1-1 Section 2 The WCRRW System 2.1 Reservoirs .......................................................................................................... 2-1 2.2 Stillhouse Pump Station and WCRRW Pipeline .......................................... 2-2 2.3 Customer Water Demands ............................................................................. 2-7 Section 3 Model Overview and Potential Uses 3.1 Planning Simulation Model ............................................................................ 3-1 3.1.1 Brief Description of Planning Simulation Model ........................... 3-1 3.1.2 Potential uses of Planning Simulation Model ................................. 3-2 3.2 Operations Optimization Model .................................................................... 3-3 3.2.1 Brief Description of Operations Optimization Model ................... 3-3 3.2.2 Potential uses of Operations Optimization Model ......................... 3-5 Section 4 Modeling Approach 4.1 Planning Simulation Model ............................................................................ 4.1 4.1.1 Model Approach ................................................................................. 4-1 4.1.2 Model Modes ....................................................................................... 4-2 4.1.3 Scenario Input and Output ................................................................ 4-3 4.1.4 Operating Logic .................................................................................. 4-4 4.2 Operations Optimization Model .................................................................... 4-5 4.2.1 Model Approach ................................................................................. 4-5 4.2.2 Scenario Input and Output ................................................................ 4-7 4.2.2.1 Inputs ................................................................................... 4-7 4.2.2.2 Outputs ................................................................................ 4-8 4.2.3 Model Formulation ............................................................................. 4-9 4.2.4 Assumptions of Linearity ................................................................ 4-12 A i Table of Contents Appendix D-1 Table of Contents – Part 1 BRA WCRRW System Modeling Report Section 5 Mathematical Formulations 5.1 Mass Balance ..................................................................................................... 5-1 5.2 Hydrology ......................................................................................................... 5-3 5.3 Pump Station Calculations ............................................................................. 5-5 5.3.1 Physical Components ......................................................................... 5-6 5.3.2 Formulas............................................................................................... 5-6 5.3.3 Summary of Conditions and Restrictions ....................................... 5-8 5.3.3.1 Allowable Pump Configurations ..................................... 5-9 5.3.3.2 Pump Station Operating Strategies ................................ 5-11 5.3.3.3 Pipeline Pressure Rating .................................................. 5-11 5.4 Energy Cost Structure ................................................................................... 5-13 5.4.1 Energy Charges ................................................................................. 5-13 5.4.1.1 The Market Clearing Price for Energy (MCPE) ............ 5-14 5.4.1.2 Fixed Energy Charge ........................................................ 5-16 5.4.1.3 Day/Night Energy Charge ............................................. 5-17 5.4.2 Utility Charges .................................................................................. 5-17 5.4.2.1 Power Demand: Billing kW............................................. 5-18 5.4.2.2 Power Demand: 4 CP kW ................................................ 5-18 5.4.2.3 Power Factor ...................................................................... 5-18 5.5 Pump Operations ........................................................................................... 5-19 Section 6 Model Validation 6.1 Firm Yield Analysis ......................................................................................... 6-1 6.2 Comparison to FNI Model .............................................................................. 6-2 6.3 Comparison of Calculated Costs to Billing Records ................................... 6-4 Section 7 Analysis and Results 7.1 Minimum Trigger Levels ................................................................................ 7-1 7.1.1 Results .................................................................................................. 7-2 7.1.2 Conclusions .......................................................................................... 7-4 7.2 Total Energy Costs ........................................................................................... 7-5 7.2.1 Results .................................................................................................. 7-5 7.2.2 Conclusions .......................................................................................... 7-7 A ii Table of Contents Appendix D-1 Table of Contents – Part 1 BRA WCRRW System Modeling Report Appendices Appendix A Pipe Friction Factor, Pump Analysis for Williamson County, Regional Raw Water Line Appendix B Pump Curves Figures Figure 2-1 Schematic of Reservoir System ................................................................... 2-1 Figure 2-2 Lake Georgetown Elevation-Capacity Curve and Significant Reservoir Elevations ................................................................. 2-3 Figure 2-3 Lake Stillhouse Hollow Elevation-Capacity Curve and Significant Reservoir Elevations ................................................................. 2-4 Figure 2-4 Lake Belton Elevation-Capacity Curve and Significant Reservoir Elevations ................................................................. 2-5 Figure 2-5 Lake Granger Elevation-Capacity Curve and Significant Reservoir Elevations ................................................................. 2-6 Figure 5-1 Reservoir Mass Balance ............................................................................... 5-1 Figure 5-2 Cumulative Distribution of Annual Inflows ............................................ 5-4 Figure 5-3 Cumulative Distribution of Annual Net Evaporation............................. 5-4 Figure 5-4 Median Monthly Inflows ............................................................................. 5-5 Figure 5-5 Median Monthly Net Evaporation ............................................................