Prepared for San Diego Gas & Electric Company 101 Ash Street, HQ13 San Diego, California 92101 Water Resources Availability Study Non-Groundwater Sources Sunrise Powerlink Environmentally Superior Southern Route Prepared by Geosyntec Consultants 10875 Rancho Bernardo Road, Suite 200 San Diego, California 92127 Geosyntec Project Number: SC0522 23 April 2010 Sunrise Powerlink Water Resources Availability Study Non-Groundwater Sources Table of Contents Page EXECUTIVE SUMMARY ....................................................................................................................... 1 1. INTRODUCTION ........................................................................................................................... 1 1.1 Objectives ..................................................................................................................... 1 1.2 Water Sources Evaluated .............................................................................................. 1 2. RECLAIMED WATER .................................................................................................................. 3 2.1 Regulatory Compliance for Use of Reclaimed Water .................................................. 4 2.1.1 Regional Water Quality Control Board – Region 9 – San Diego Basin ............................................................................................................ 4 2.1.2 Regional Water Quality Control Board – Region 7 – Colorado River Basin ............................................................................................................ 5 2.1.3 San Diego County, Department of Environmental Health .......................... 5 2.2 City of San Diego – Water Department ........................................................................ 6 2.2.1 Availability .................................................................................................. 6 2.2.2 Usage Restrictions ....................................................................................... 7 2.3 Padre Dam Municipal Water District (PDMWD) ........................................................ 8 2.3.1 Availability .................................................................................................. 8 2.3.2 Usage Restrictions ....................................................................................... 9 2.4 Infeasible Reclaimed Water Providers Contacted ........................................................ 9 2.4.1 Tribal Water Treatment Systems ................................................................. 9 2.4.2 City of Poway ............................................................................................ 10 2.4.3 Helix Water District .................................................................................. 10 2.4.4 Seeley County Water District .................................................................... 10 2.4.5 City of El Centro ....................................................................................... 11 2.4.6 Imperial Irrigation District ........................................................................ 11 2.4.7 Otay Water District.................................................................................... 11 3. POTABLE WATER ...................................................................................................................... 13 3.1 City of San Diego – Water Department ...................................................................... 13 3.1.1 Availability ................................................................................................ 13 3.1.2 Usage Restrictions ..................................................................................... 14 3.2 City of Poway ............................................................................................................. 14 3.2.1 Availability ................................................................................................ 14 3.2.2 Usage Restrictions ..................................................................................... 14 3.3 Helix Water District ................................................................................................... 15 3.3.1 Availability ................................................................................................ 15 3.3.2 Usage Restrictions ..................................................................................... 15 3.4 Imperial Irrigation District.......................................................................................... 15 3.4.1 Availability ................................................................................................ 15 3.5 Padre Dam Municipal Water District ......................................................................... 15 3.5.1 Availability ................................................................................................ 16 3.5.2 Usage Restrictions ..................................................................................... 16 3.6 Lakeside Water District .............................................................................................. 16 Sunrise Powerlink Water Resources Availability Study Non-Groundwater Sources 3.6.1 Availability ................................................................................................ 16 3.6.2 Usage Restrictions ..................................................................................... 17 3.7 Otay Water District ..................................................................................................... 17 3.7.1 Availability ................................................................................................ 17 3.7.2 Usage Restrictions ..................................................................................... 17 3.8 Seeley County Water District ..................................................................................... 18 3.8.1 Availability ................................................................................................ 18 3.8.2 Usage Restrictions ..................................................................................... 18 3.9 City of El Centro ........................................................................................................ 18 4. SURFACE WATER ...................................................................................................................... 19 4.1 Imperial Irrigation District.......................................................................................... 19 4.1.1 Availability ................................................................................................ 19 4.1.2 Usage Restrictions ..................................................................................... 20 4.2 City of San Diego – Water Department Reservoirs .................................................... 20 4.2.1 San Vicente Reservoir ............................................................................... 21 4.2.2 El Capitan Reservoir.................................................................................. 21 4.2.3 Barrett Lake ............................................................................................... 22 4.2.4 Lake Morena .............................................................................................. 22 4.3 Sweetwater Authority ................................................................................................. 23 4.3.1 Loveland Reservoir ................................................................................... 23 5. INFILTRATED WATER FROM ROCK-FILL ........................................................................ 24 6. CONCLUSION .............................................................................................................................. 25 7. LIMITATIONS ............................................................................................................................. 26 8. REFERENCES .............................................................................................................................. 27 Sunrise Powerlink Water Resources Availability Study Non-Groundwater Sources — List of Tables — Table ES-1 Summary of Feasible Water Resources Table 1 Summary of Reclaimed Water Sources Evaluated Table 2 Summary of Potable Water Sources Evaluated Table 3 Summary of Surface Water Sources Evaluated — List of Figures — Figure ES-1 Conceptual Estimated Availability of Water Figure 1 Sunrise Powerlink – Final Environmentally Superior Southern Route Figure 2 Feasible Water Sources Figure 3 Water District Boundaries – West Figure 4 RWQCB Region 9 Hydrologic Sub-Areas Figure 5 RWQCB Region 7 Hydrologic Sub-Areas — List of Appendices — Appendix A RWQCB – Region 9 Conditional Waiver No. 7 – Temporary Discharges of Reclaimed Water to Land Appendix B City of San Diego Reclaimed Water – Detailed Acquisition Instructions Appendix C City of San Diego – Rules and Regulations for Recycled Water Use and Distribution Appendix D City of San Diego - Reclaimed Water Training Guide Appendix E Padre Dam - “Rules and Regulations” section of RWQCB Order No. 97-49 Sunrise Powerlink Water Resources Availability Study Non-Groundwater Sources EXECUTIVE SUMMARY Project construction is expected to require an estimated average of 300,000 gallons of water per day for construction, which is less than the estimated average daily water use of a typical golf course in the southwestern United States.