TIN/TDS Study - Phase 2B of the Santa Ana Watershed Wasteload Allocation Investigation Final Technical Memorandum Prepared for the TIN/TDS Task Force October 2002 Wildermuth WE Environmental, Inc. N/TDS Study Phase 2B Wasteload Allocation Investigation FINAL TECHNICAL MEMORANDUM Prepared for the N/TDS Task Force October 2002 Wildermuth Environmental, Inc. TABLE OF CONTENTS 1. INTRODUCTION .....................................................................................................................1-1 1.1 Summary of Prior Work............................................................................................................1-2 1.2 The Wasteload Allocation Approach........................................................................................1-4 1.3 Scope of Work ..........................................................................................................................1-5 1.4 Report Organization..................................................................................................................1-5 2. MODEL DESCRIPTION AND CALIBRATION ..............................................................................2-1 2.1 Model Origin and Uses .............................................................................................................2-1 2.2 Modeling Goals.........................................................................................................................2-1 2.3 Wasteload Allocation Model ....................................................................................................2-1 2.3.1 Model Organization ...................................................................................................................... 2-1 2.3.2 Rainfall Runoff Process ................................................................................................................ 2-1 2.3.3 Channel and Reservoir Routing ..................................................................................................... 2-3 2.3.4 Computational Time Step and Simulation Period......................................................................... 2-5 2.3.5 Description of Model Data............................................................................................................. 2-5 2.4 Calibration.................................................................................................................................2-8 2.4.1 Calibration Targets....................................................................................................................... 2-8 2.4.2 Surface Water Discharge Calibration........................................................................................... 2-8 2.4.3 TDS and TIN Calibration.............................................................................................................2-10 2.5 Limitation in the Use of the WLAM.......................................................................................2-10 3. BASELINE WASTELOAD ALLOCATION....................................................................................3-1 3.1 Objective of Baseline Wasteload Runs and Modeling Strategy ...............................................3-1 3.2 Planning Assumptions ..............................................................................................................3-1 3.2.1 Non-tributary Discharges ............................................................................................................. 3-1 3.2.2 Prado, San Antonio and Seven Oaks Reservoir Operations ........................................................ 3-1 3.2.3 Prado Wetlands Operations ......................................................................................................... 3-1 3.2.4 Lake Elsinore Discharge................................................................................................................ 3-2 3.2.5 Nitrogen Loss Rate in Streambed Recharge................................................................................... 3-2 3.2.6 Metrics Used to Evaluate the Baseline Wasteload Allocation ....................................................... 3-2 3.3 Results of Baseline Wasteload Allocation ................................................................................3-2 3.3.1 San Timoteo Reaches .................................................................................................................... 3-2 3.3.2Santa Ana River Reaches ............................................................................................................... 3-3 4. NEW WASTELOAD ALLOCATION FOR SAN TIMOTEO CREEK ...................................................4-1 4.1 San Timoteo Creek Simulations ...............................................................................................4-1 5. REFERENCES .......................................................................................................................5-1 PLATES Plate 1 – Drainage Area and Link-Node Network Plate 2 – Land Use Coverage 1993 i Wildermuth Environmental, Inc. TIN/TDS TASK FORCE PHASE 2B WASTELOAD ALLOCATION APPENDICES Appendix A – Tables Summarizing Results of Baseline Wasteload Allocation for 2001 Appendix B – Tables Summarizing Results of Baseline Wasteload Allocation for 2010, Recycling Plans per the 1995 Basin Plan (Baseline 2010A) Appendix C – Tables Summarizing Results of Baseline Wasteload Allocation for 2010, Recycling Plans per Recycling Agencies (Baseline 2010B) Appendix D – Comments and Responses Final ii Wildermuth Environmental, Inc. 10/8/2002 TIN/TDS TASK FORCE PHASE 2B WASTELOAD ALLOCATION LIST OF TABLES 2-1 Rainfall Monitoring Stations Used in the WLAM 2-2 USGS Surface Water Monitoring Stations Used in the WLAM 2-3 1993 Land Use Data Summarized Based on Anderson Landuse Code System 2-4 1993 Land Use Code Conversion 2-5 Land Use Data Summarized Based on WLAM Land Use Code System 2-6 Initial Estimates of Curve Numbers 2-7 TDS and TIN Range From Mountain Watersheds Non-Tributary Discharge and Other Discharges During Calibration Period 2-8 1994/95 through 1998/99 2-9 Calibration Stations 2-10 Flow Calibration Results Statistics 3-1 Recycled Water Production and Proposed Reuse by Surface Water Discharging Recycling Plants 3-2 Recycled Water Reuse in the 1995 Basin Plan 3-3 Alternative Wasteload Allocation Baselines for 2010 3-4 Metrics Evaluated for the Baseline Wasteload Allocation 3-5 TDS and TIN in Flow Below Prado, Year 2001 Baseline 3-6 TDS and TIN in Flow at Mission Boulevard, Year 2001 Baseline 3-7 TDS and TIN in Streambed Percolation in Santa Ana River Reach 3, Year 2001 Baseline 3-8 TDS and TIN in Streambed Percolation in Santa Ana River Reach 4, Year 2001 Baseline 3-9 TDS and TIN in Streambed Percolation in San Timoteo Cr Reach 3, Year 2001 Baseline 3-10 TDS and TIN in Streambed Percolation in San Timoteo Cr Reach 2, Year 2001 Baseline 3-11 TDS and TIN in Flow below Prado, Year 2010 Baseline A 3-12 TDS and TIN in Flow below Prado, Year 2010 Baseline B 3-13 TDS and TIN in Flow at Mission Boulevard, Year 2010 Baseline A 3-14 TDS and TIN in Flow at Mission Boulevard, Year 2010 Baseline B 3-15 TDS and TIN in Streambed Percolation in Santa Ana River Reach 3, Year 2010 Baseline A Final iii Wildermuth Environmental, Inc. 10/8/2002 TIN/TDS TASK FORCE PHASE 2B WASTELOAD ALLOCATION LIST OF TABLES 3-16 TDS and TIN in Streambed Percolation in Santa Ana River Reach 3, Year 2010 Baseline B 3-17 TDS and TIN in Streambed Percolation in Santa Ana River Reach 4, Year 2010 Baseline A 3-18 TDS and TIN in Streambed Percolation in Santa Ana River Reach 4, Year 2010 Baseline B TDS and TIN in Streambed Percolation in San Timoteo Cr Reaches 3 and 4, 3-19 Year 2010 Baseline A TDS and TIN in Streambed Percolation in San Timoteo Cr Reaches 3 and 4, 3-20 Year 2010 Baseline B 3-21 TDS and TIN in Streambed Percolation in San Timoteo Cr Reach 2, Year 2010 Baseline A 3-22 TDS and TIN in Streambed Percolation in San Timoteo Cr Reach 2, Year 2010 Baseline B Estimated Metrics and Corresponding TDS and TIN Objectives for Management Zones Impacted 3-23 by Streambed Recharge Final iv Wildermuth Environmental, Inc. 10/8/2002 TIN/TDS TASK FORCE PHASE 2B WASTELOAD ALLOCATION LIST OF FIGURES 2-1 Link-Node Descretization Example for WLAM 2-2 Rainfall Monitoring Stations Used in the WLAM 2-3 USGS Surface Water Monitoring Stations Used in the WLAM 2-4 SCS Hydrologic Soil Types 2-5 Map Showing Locations of NPDES Stormwater Quality Monitoring Stations 2-6 Estimated Total Dissolved Solid Concentration in Urban Runoff 2-7 Estimated Total Inorganic Nitrogen Concentration in Urban Runoff 2-8 Estimated Total Dissolved Solid Concentration in Mountain Runoff 2-9 Estimated Total Inorganic Nitrogen Concentration in Mountain Runoff 2-10 Comparison of Computed and Historical Discharge Data, San Timoteo Creek near Loma Linda 2-11 Comparison of Computed and Historical Discharge Data, Santa Ana River at E Street 2-12 Comparison of Computed and Historical Discharge Data, Lytle Creek at Colton 2-13 Comparison of Computed and Historical Discharge Data, Santa Ana River at MWD Crossing 2-14 Comparison of Computed and Historical Discharge Data, Temescal Creek above Main Street 2-15 Comparison of Computed and Historical Discharge Data, Chino Creek at Schaefer Avenue 2-16 Comparison of Computed and Historical Discharge Data, Cucamonga Creek near Mira Loma Comparison of Computed and Historical Discharge Data, 2-17 Santa Ana River below Prado Dam, Total Hydrograph Comparison of Computed and Historical Discharge