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HomeMy WebLinkAbout13 ADOPTION OF 2025 URBAN WATER MANAGEMENT PLANDocusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 MEETING DATE TO: FROM: SUBJECT: SUMMARY: Agenda Item 13 AGENDA REPORT Reviewed: City Manager a`L� Finance Director JUNE 16, 2026 ALDO E. SCHINDLER, CITY MANAGER MICHAEL GRISSO, DIRECTOR OF PUBLIC WORKS ADOPTION OF 2025 URBAN WATER MANAGEMENT PLAN California Water Code requires Urban Water Management Plans be prepared by urban water suppliers every five years. This plan supports the City's long-term water resource planning to ensure that adequate supplies are available to meet existing and future water demands. RECOMMENDATION: Recommend the City Council: 1. Conduct a public hearing for the 2025 Urban Water Management Plan; and 2. Adopt Resolution No. 26-34 approving the 2025 Urban Water Management Plan. FISCAL IMPACT: Sufficient funds were appropriated in the 2025-26 Water Enterprise Operating Budget to complete the 2025 Urban Water Management Plan. There are no additional fiscal impacts associated with plan adoption. CORRELATION TO THE STRATEGIC PLAN: This effort contributes to the fulfillment of the City's Strategic Plan Goal D: Strong Community and Regional Relationships. Specifically, the action implements Strategy 2, which, among other things, is to enhance collaboration efforts with agencies within and outside Tustin on issues of mutual interest and concern. BACKGROUND AND DISCUSSION: On June 1, 2021, the City Council adopted Resolution No. 21-36 approving the City's 2020 Urban Water Management Plan (UWMP). Every five years, the California Urban Water Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 City Council Agenda Report 2025 Urban Water Management Plan June 16, 2026 Page 2 Management Planning Act requires all urban water suppliers that provide water to more than 3000 service connections or produce more than 3000 acre-feet of water annually, to update their UWMP and conduct a public hearing of said plan. The City provides water service to a population of 65,143 throughout its 8.4 square mile service area and receives water from two main sources; the Orange County Groundwater Basin, which is managed by the Orange County Water District, and imported water from the Municipal Water District of Orange County via the East Orange County Water District. The UWMP provides a long-term assessment of water supply reliability and identifies strategies to meet projected water demands under normal, single dry -year, and multiple dry -year conditions. The City's UWMP evaluates water supplies obtained through regional wholesalers, local groundwater resources, and other available water sources. The plan also documents water conservation programs, demand management strategies, and includes a Water Shortage Contingency Plan as a required component of the Plan. The 2025 UWMP has been prepared in compliance with the California Urban Water Management Planning Act. The UWMP, along with the City's Water Master Plan and other planning documents, will support and guide the City's water management efforts through planning year 2030, at which time the plan will require its next update. The attached 2025 UWMP was made available for public review prior to the public hearing in accordance with State law and is recommended for City Council adoption. Michael Grisso Director of Public Works Attachments: 1. 2025 Urban Water Management Plan 2. Resolution 26-34 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 ATTACHMENT 1 2025 Urban Water Management Plan F e000, I r4MW. Y MADDAUS a j tp j1W in collaboration with S iM th and WATER ..ANAGEMENT INC. Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 Remembering what connects us. 2025 Urban Water Management Plan May 2026 / FINAL DRAFT Prepared By: Carollo Engineers, Inc. 707 Wilshire Boulevard, Suite 3920 Los Angeles, California 90017 Phone: 213.489.1587 https://www.carollo.com In collaboration with: Prepared For: City of Tustin 300 Centennial Way Tustin, California 92780 Phone: 714.573.3350 https://www.tustinca.org MADDAUS WATER MANAGEMENT Smith Making a Difference in the World of WaterTM listen. think. deliver. Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Contents EXECUTIVE SUMMARY ES.1 Introduction and UWMP Overview ES-1 ES.2 UWMP Preparation ES-1 ES.3 System Description ES-1 ESA Water Use Characterization ES-2 ES.4.1 Water Use in the Last Five Years ES-2 ES.4.2 Projected Water Use ES-2 ES.S Conservation Target Compliance ES-2 ES.6 Water Supply Characterization ES-2 ES.7 Water Service Reliability and Drought Risk Assessment ES-3 ES.8 Water Shortage Contingency Planning ES-3 ES.9 Demand Management Measures ES-3 ES.10 Plan Adoption, Submittal, and Implementation ES-4 CHAPTER 1 INTRODUCTION AND UWMP OVERVIEW 1.1 Overview of UWMP Requirements 1-1 1.2 UWMP Organization 1-2 CHAPTER 2 UWMP PREPARATION 2.1 Individual Planning and Compliance 2-1 2.2 Coordination and Outreach 2-2 2.2.1 Integration with Other Planning Efforts 2-2 2.2.2 Wholesale and Retail Coordination 2-4 2.2.3 Public Participation 2-4 CHAPTER 3 SYSTEM DESCRIPTION 3.1 Agency Overview 3-1 3.1.1 Formation and Purpose 3-1 3.1.2 City Council 3-1 3.1.3 Relationship to MWDOC 3-2 3.2 Water Service Area and Facilities 3-2 3.2.1 Water Service Area 3-2 3.2.2 Water Facilities 3-5 3.3 Climate 3-5 3.4 Population, Demographics, and Socioeconomics 3-6 3.4.1 Service Area Population 3-6 3.4.2 Demographics and Socioeconomics 3-6 3.4.3 Demographic Projection Methodology 3-6 CITY OF TUSTIN pw://Carollo/CAIMWDOC/204447-000000/03 Reports and Studies/02 Deliverables/Grp2_Tustin UWMP/ _Cover _TOC_Abbrevs_ AppxCovers.docx Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 3.5 Land Uses 3.5.1 Current Land Uses 3.5.2 Projected Land Uses CHAPTER 4 WATER USE CHARACTERIZATION 4.1 Water Use in the Last Five Years 4.2 Projected Water Use 4.2.1 Water Use Projections for 2026-2030 4.2.2 Water Use Projections for 2030-2050 4.3 Water Demand Projection Methodology 4.3.1 Econometric Approach, Data Acquisition, and Model Development 4.3.2 Forecasted Demands 4.4 Water Loss CHAPTER 5 CONSERVATION TARGET COMPLIANCE 5.1 Reporting Requirements CHAPTER 6 WATER SUPPLY CHARACTERIZATION 3-7 3-7 3-8 4-4 4-5 4-5 4-5 4-7 4-8 4-10 4-11 5-1 6.1 Water Supply Overview 6-1 6.2 Imported Water 6-5 6.2.1 Metropolitan Water District of Southern California 6-5 6.2.2 Colorado River Aqueduct 6-8 6.2.3 State Water Project 6-11 6.2.4 Storage, Transfers, and Conveyance Programs 6-14 6.2.5 Potential Future Water Projects 6-16 6.2.6 Supply Reliability Within MET 6-17 6.3 Local Groundwater 6-22 6.3.1 Orange County Groundwater Basin 6-22 6.3.2 Planned Future Groundwater Sources 6-30 6.4 Surface Water 6-30 6.4.1 Existing Surface Water Sources 6-30 6.4.2 Planned Future Surface Water Sources 6-31 6.5 Stormwater 6-31 6.5.1 Existing Stormwater Sources 6-31 6.5.2 Planned Future Stormwater Sources 6-31 6.6 Wastewater and Recycled Water 6-31 6.6.1 Agency Coordination 6-31 6.6.2 Wastewater 6-33 6.6.3 Current Recycled Water Uses 6-34 6.6.4 Projected Recycled Water Uses 6-34 6.6.5 Potential Recycled Water Uses 6-34 6.6.6 Optimization Plan 6-34 CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 6.7 Desalination Opportunities 6-35 6.7.1 Ocean Water Desalination 6-35 6.7.2 Groundwater Desalination 6-35 6.8 Water Exchanges and Transfers 6-35 6.8.1 Existing Exchanges and Transfers 6-35 6.8.2 Planned and Potential Exchanges and Transfers 6-36 6.9 Future Water Projects 6-36 6.10 Energy Intensity 6-36 6.10.1 Water Supply Energy Intensity 6-37 6.10.2 Wastewater and Recycled Water Energy Intensity 6-39 6.10.3 Key Findings and Next Steps 6-39 CHAPTER 7 WATER SERVICE RELIABILITY AND DROUGHT RISK ASSESSMENT 7.1 Water Service Reliability Overview 7-1 7.2 Factors Affecting Water Supply Reliability 7-2 7.2.1 Climate Change and the Environment 7-2 7.2.2 Regulatory and Legal 7-3 7.2.3 Water Quality 7-4 7.2.4 Locally Applicable Criteria 7-7 7.3 Water Service Reliability Assessment 7-8 7.3.1 Normal Year Reliability 7-8 7.3.2 Single Dry Year Reliability 7-8 7.3.3 Multiple Dry Years Reliability 7-9 7.4 Management Tools and Options 7-10 7.5 Drought Risk Assessment 7-11 7.5.1 Methodology 7-12 7.5.2 Total Water Supply and Use Comparison 7-13 7.5.3 Water Source Reliability 7-14 CHAPTER 8 WATER SHORTAGE CONTINGENCY PLANNING 8.1 Background 8-1 8.2 Overview of the Water Shortage Contingency Plan 8-1 8.3 Summary of Water Shortage Response Strategy and Required DWR Tables 8-2 CHAPTER 9 DEMAND MANAGEMENT MEASURES 9.1 City of Tustin Demand Management Measures 9-2 9.1.1 Operations Practices 9-3 9.1.2 Public Education and Outreach 9-6 9.1.3 Residential Indoor Rebate Programs 9-7 9.1.4 CII Programs 9-8 9.1.5 Landscape Programs 9-9 9.2 City of Tustin DMM Implementation (2020-2025) 9-10 CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 9.3 MWDOC Demand Management Implementation Assistance Programs 9-10 9.3.1 State Water Conservation Compliance Assistance 9-11 9.3.2 Regional Rebate Programs and Local Program Assistance 9-12 9.3.3 Research and Evaluation 9-12 9.4 Urban Water Use Objective and CII Performance Measure Compliance 9-13 9.4.1 UWUO Components 9-13 9.4.2 CII Performance Measures 9-14 CHAPTER 10 PLAN ADOPTION, SUBMITTAL, AND IMPLEMENTATION 10.1 Overview 10-1 10.2 Agency Coordination 10-2 10.3 Public Participation 10-3 10.4 UWMP Submittal 10-3 10.5 Amending the Adopted UWMP or WSCP 10-3 CHAPTER 11 REFERENCES Appendices APPENDIX A UWMP WATER CODE CHECKLIST APPENDIX B DEPARTMENT OF WATER RESOURCES (DWR) STANDARDIZED TABLES APPENDIX C REDUCED DELTA RELIANCE APPENDIX D AWWA WATER LOSS AUDITS APPENDIX E 2022 BASIN 8-1 ALTERNATIVE UPDATE APPENDIX F WATER SHORTAGE CONTINGENCY PLAN APPENDIX G WATER USE EFFICIENCY IMPLEMENTATION REPORT APPENDIX H 2O25 ORANGE COUNTY WATER DEMAND MODEL TECHNICAL MEMORANDUM APPENDIX I NOTIFICATION OF PUBLIC AND SERVICE AREA PROVIDERS APPENDIX J ADOPTED UWMP RESOLUTIONS Tables Table 2.1 Submittal Table 2-1 Retail: Public Water Systems 2-1 Table 2.2 Submittal Table 2-2: Plan Identification 2-2 Table 2.3 Submittal Table 2-3: Supplier Identification 2-2 Table 2.4 Submittal Table 2-4 Retail: Water Supplier Information Exchange 2-4 Table 3.1 Submittal Table 3-1 Retail: Population - Current and Projected 3-6 Table 3.2 City of Tustin Service Area Dwelling Units by Type 3-6 Table 4.1 Submittal Table 4-1 Retail: Total Uses for Potable and Non -Potable Water — Actual 4-4 Table 4.2 City of Tustin's Service Area Total Potable Demand for 2026-2030 4-5 Table 4.3 Submittal Table 4-2 Retail: Total Uses of Potable, and Non -Potable Water - Projected 4-6 CITY OF TUSTIN iv Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Table 4.4 Submittal Table 4-3 Retail: Inclusion in Water Use Projections 4-6 Table 4.5 Optional Submittal Table 4-4 Retail: Passive Water Savings Projections 4-7 Table 4.6 Summary of Demand Sectors 4-8 Table 4.7 Summary of Historical Data Collected for Model Development 4-9 Table 4.8 Future Model Parameters 4-11 Table 4.9 Submittal Table 4-5 Retail: Water Loss Audit Reporting 4-12 Table 4.10 Submittal Table 4-6 Retail: Progress Towards 2028 Water Loss Standard 4-13 Table 5.1 Submittal Table 5-1 Retail: SB X7-7 2020 Target Progress 5-2 Table 6.1 Water Supplies - 2025 Actual 6-2 Table 6.2 Water Supplies - Projected 6-4 Table 6.3 MET SWP Program Capabilities 6-12 Table 6.4 MET's Projected Supply Capability and Demands Through 2050 for a Normal Year 6-18 Table 6.5 MET's Projected Supply Capability and Demands Through 2050 for a Single Dry Year 6-19 Table 6.6 MET's Projected Supply Capability and Demands Through 2050 for a Drought (5 Consecutive Water Years) 6-20 Table 6.7 MET's Water Use, Supply, and DRA for 2026-2030 6-21 Table 6.8 Groundwater Pumped in the Past 5 Years Within the City's Service Area (AF) 6-22 Table 6.9 Management Actions Based on Changes in Groundwater Storage 6-27 Table 6.10 Wastewater Collected within the City's Service Area in 2025 6-33 Table 6.11 Energy Efficiency 6-38 Table 7.1 Optional Submittal Table 7-1 Retail: Basis of Water Year Data (Reliability Assessment) 7-2 Table 7.2 Submittal Table 7-2 Retail: Normal Year Supply and Use Comparison 7-8 Table 7.3 Submittal Table 7-3 Retail: Single Dry Year Supply and Demand Comparison Water Code Section 10635(a) 7-9 Table 7.4 Submittal Table 7-4 Retail: Multiple Dry Years Supply and Demand Comparison 7-10 Table 7.5 Submittal Table 7-5 Retail: Five -Year Drought Risk Assessment 7-14 Table 8.1 Cross -Reference for Standard vs Supplier Shortage Levels 8-4 Table 8.2 Supply Augmentation and Other Actions 8-4 Table 8.3 Demand Reduction Actions 8-5 Table 9.1 DMM Implementation Responsibility and Regional Programs in Orange County 9-2 Table 9.2 City Water Use Efficiency Program Participation 9-10 Table 9.3 MWDOC Programs to Help OC Retail Agencies Meet their Urban Water Use Objectives 9-13 Table 9.4 City CII BMP and Water Efficiency Programs and Incentives 9-15 Table 10.1 External Coordination and Outreach 10-1 Table 10.2 Submittal Table 10-1 Retail: Notification to Cities and Counties 10-2 CITY OF TUSTIN v Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Figures Figure 3.1 Regional Location of City of Tustin and Other MWDOC Member Agencies 3-3 Figure 3.2 City of Tustin Water Service Area 3-4 Figure 4.1 Historical Water Use and Population in Orange County 4-2 Figure 4.2 Projected Water Use Across All Orange County Water Agencies 4-3 Figure 4.3 Econometric Demand Forecast Development Process 4-10 Figure 6.1 City's Projected Water Supply 6-3 Figure 6.2 Major Aqueducts That Supply Imported Water to Southern California (MET, 2025) 6-6 Figure 6.3 MET Feeders and Transmission Mains That Serve Orange County 6-7 Figure 6.4 Map of the OC Basin (OCWD, 2022 (Basin 8-1 Alternative 2022 Update)) 6-24 Figure 6.5 Basin 8-1 Management Areas (OCWD, 2023) 6-25 Figure 6.6 MWDOC Imported Water Sales for Groundwater Replenishment 6-30 Figure 8.1 Purpose and Relationships of the UWMP, WSCP, and Water Shortage Response Ordinance 8-2 CITY OF TUSTIN vl Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Abbreviations AB Assembly Bill ACS US Census American Community Survey ADU accessory dwelling units AF acre-feet AFY acre-feet per year AVEK Antelope Valley -East Kern Water Agency AWWA American Water Works Association BEA Basin Equity Assessment BiOps Biological Opinions BMP best management practice BPP Basin Production Percentage BSA Boy Scouts of America Business Plan Water Loss Control Shared Services Business Plan CAMP4W Climate Adaptation Master Plan for Water CDR Center for Demographic Research at California State University, Fullerton CEE Consortium for Energy Efficiency cfs cubic feet per second CII Commercial, Industrial, and Institutional CIP Capital Improvement Program City City of Tustin Conservation Framework "Making California a Conservation Way of Life" Framework CPTP Coastal Pumping Transfer Program CRA Colorado River Aqueduct CRSSq Colorado River Simulation System CUP conjunctive use program CUWCC California Urban Water Conservation Council CVP Central Valley Project CWC California Water Code CY Calendar Year DCP Drought Contingency Plan / Delta Conveyance Project DCR Delivery Capability Report DDW Division of Drinking Water Delta Sacramento -San Joaquin Delta DIM dedicated irrigation meter DMM Demand Management Measure DOF State Department of Finance DRA Drought Risk Assessment CITY OF TUSTIN vii Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO DVL Diamond Valley Lake DWR California Department of Water Resources EIR Environmental Impact Report EO Executive Order EOCWD East Orange County Water District EPA US Environmental Protection Agency ESA Endangered Species Act FIRO Forecast Informed Reservoir Operations FMD flow monitoring devices FY fiscal year GAC granular activated carbon GAP Green Acres Project GDP gross domestic product GHG greenhouse gas GIS geographic information system GPCD gallons per capita per day gpf gallons per flush GRP Groundwater Resilience Plan / Groundwater Reliability Plan GSA Groundwater Sustainability Agency GSP Groundwater Sustainability Plan GSWC Golden State Water Company GWRS Groundwater Replenishment System HCF hundred cubic feet HDI hot -dry index HECW high efficiency clothes washer HET high efficiency toilet HRL Healthy Rivers and Landscapes ICS Intentionally Created Surplus IPR indirect potable reuse IRP Integrated Water Resources Plan IRWD Irvine Ranch Water District ITP Incidental Take Permit IWCM Interim Water Control Manual IX ion exchange JADU Junior ADU kWh kilowatt hour LAM landscape area measurements LODES Longitudinal Employer -Household Dynamics CITY OF TUSTIN vill Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO LRP Local Resources Program LVL Leo J. Vander Lans Advanced Water Treatment Facility M&I municipal and industrial MAF million acre-feet MCL maximum contaminant level MET Metropolitan Water District of Southern California MF microfiltration MG million gallons mg/L milligrams per liter mgd million gallons per day MSL mean sea level MUM mixed -use CII meters MWDOC Municipal Water District of Orange County ND non -detect NDMA N-nitrosodimethylamine ng/L nanograms per liter NPDES National Pollutant Discharge Elimination System OC Basin Orange County Groundwater Basin OC San Orange County Sanitation District OCWD Orange County Water District PFAS per- and polyfluoroalkyl substances PFOA Perfluorooctanoic Acid PFOS Perfluorooctane Sulfonate PPCP pharmaceuticals and personal care products ppt parts per trillion PRISM Parameter Elevation Regressions on Independent Slopes Model QSA Quantification Settlement Agreement QWEL Qualified Water Efficient Landscaper R&I retail and municipal RA Replenishment Assessment R-GPCD Residential Gallons Per Capita Per Day RHNA Regional Housing Needs Assessment RO reverse osmosis RUWMP Regional Urban Water Management Plan SARCCUP Santa Ana River Conservation and Conjunctive Use Program SIB Senate Bill SBVMWD San Bernardino Valley Municipal Water District SCAB South Coast Air Basin SCAG Southern California Association of Governments CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO SDCWA San Diego County Water Authority SGMA Sustainable Groundwater Management Act SNWA Southern Nevada Water Authority State State of California STEM science, technology, engineering, and mathematics Supplier urban water supplier SWP State Water Project SWRCB State Water Resources Control Board TAF thousand acre-feet TAP Technical Assistance Program TAZ traffic analysis zones TDS total dissolved solids TM technical memorandum USACE US Army Corps of Engineers USBR United States Bureau of Reclamation USGS United States Geological Survey UV ultraviolet UWMP Urban Water Management Plan UWMP Act or Act UWMP Act of 1983 UWUO Urban Water Use Objective Water Code California Water Code WCM Water Control Manual WEEA Water Energy Education Alliance WR P1 Delta Stewardship Council's Delta Plan Policy WR P1 WRD Water Replenishment District WSAP Water Supply Allocation Plan WSCP Water Shortage Contingency Plan WSIP Water Savings Incentive Program WUE Water Use Efficiency CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO EXECUTIVE SUMMARY ES.1 Introduction and UWMP Overview The City of Tustin (City) prepared this 2025 Urban Water Management Plan (UWMP) to submit to the California Department of Water Resources (DWR) to satisfy the UWMP Act of 1983 (UWMP Act or Act) and subsequent California Water Code (Water Code) requirements. UWMPs are comprehensive documents that present an evaluation of a water supplier's reliability over a long-term (20-25 year) horizon. This 2025 UWMP provides an assessment of the present and future water supply sources and demands within the City's service area. It presents an update to the 2020 UWMP on the City's water resource needs, water use efficiency programs, water reliability assessment, and strategies to mitigate water shortage conditions. It also presents the City's updated 2025 Water Shortage Contingency Plan (WSCP), designed to prepare for and respond to water shortages. This 2025 UWMP contains all elements required by the UWMP Act. ES.2 UWMP Preparation The City coordinated the preparation of this 2025 UWMP with other key entities, the Municipal Water District of Orange County (MWDOC), the regional wholesaler of imported water for Orange County, and the Orange County Water District (OCWD), Orange County Groundwater Basin (OC Basin) manager and provider of recycled water in north Orange County. The City also coordinated with the East Orange County Water District (EOCWD) for the purchase of imported water. In addition, the City also coordinated with other entities that provided valuable, regionally consistent data for the analyses prepared in this UWMP, including population projections from the Center for Demographic Research (CDR) at California State University, Fullerton, and the Orange County Water Demand Projection Model Technical Memorandum (TM). ES.3 System Description The City was incorporated in 1927 and is governed by a Council -Manager form of government. The City lies in central east Orange County and is bounded by the City of Orange to the north, the City of Santa Ana to the west, the City of Irvine to the south, and unincorporated areas of Orange County to the east. The City's water service area covers 8.4 square miles and includes most of the incorporated area of the City and also the unincorporated county areas north of the City. The City operates nine wells, six reservoirs with a combined storage capacity of approximately 13.83 million gallons (MG) and manages a 183-mile water mains system with 14,419 service connections. CITY OF TUSTIN ES-1 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO ESA Water Use Characterization ES.4.1 Water Use in the Last Five Years Total water use within the City's service area has fluctuated over the past five years (fiscal year [FY] 2021-25), with an annual average of approximately 10,343 acre-feet (AF). FY 2020-21 through FY 2021-22 saw the highest water use over the last five years due to region -wide drought conditions. FY2022-23 proved to be one of the wettest years on record in the State and the City saw a general decrease in water demand following this wet year, as precipitation offsets landscape irrigation demands. These year-to-year fluctuations in precipitation will continue to influence the City's annual demands. In general, the City saw a decrease in demand of 8.6 percent over the 5-year reporting period. ES.4.2 Projected Water Use The water use projection for this UWMP is based on the 2025 Orange County Water Demand Projection Model Technical Memorandum (TM). This demand projection represents the City's total water demand and considers factors such as weather, water price, regional economic conditions, and housing density through a regression, or econometric, model. Over the next 25 years, the City's total water demands are projected to decrease by 5.7 percent from 10,304 AF in 2025 to approximately 9,717 AF by 2050. The Orange County Groundwater Basin is expected to continue meeting a notable share of total water demand between 2025 and 2050 (with a Basin Pumping Percentage [BPP] of 85 percent forecasted through 2050). ES.S Conservation Target Compliance The City participated in the Orange County 20x2020 Regional Alliance along with all other Orange County water agencies. The alliance was created by MWDOC in collaboration with all its retail member agencies as well as the Cities of Anaheim, Fullerton, and Santa Ana, to assist Orange County retail agencies in complying with the requirements of the Water Conservation Act of 2009, also known as SBx7-7 (Senate Bill 7 as part of the Seventh Extraordinary Session). Signed into law on February 3, 2010, it required the State of California to reduce urban water use by 20 percent by 2020. Retail water suppliers are required to comply with SBx7-7 individually or as a region in collaboration with other retail water suppliers, to be eligible for water -related state grants and loans. Orange County, as a region, achieved its 2020 target water use of 159 gallons per capita per day (GPCD) prior to 2020, indicative of the collective efforts in reducing water use in the region. All Orange County water retailers, achieved individual compliance prior to 2020. By 2020, the City achieved a per capita per day water use of 95 GPCD (compared to its 151 GPCD target) and continues to implement water use efficiency measures. ES.6 Water Supply Characterization The City's main source of water supply is groundwater from the OC Basin. Imported water makes up the rest of the City's water supply portfolio. In FY 2024-25, the City relied on approximately 68 percent groundwater and 32 percent imported water. It is projected that by 2030, the City's water portfolio will shift to approximately 85 percent groundwater and 15 percent imported water as per -and polyfluoroalkyl substances (PFAS) treatment facilities are completed. CITY OF TUSTIN ES-2 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO ES.7 Water Service Reliability and Drought Risk Assessment Every urban water supplier is required to assess the reliability of their water service to its customers under a normal year, a single dry year, and multiple dry years. The water service reliability assessment compares projected supply to projected demand for three long-term hydrological conditions. The City's water sources are local groundwater from the OC Basin and imported water purchased from MWDOC/MET. The OC Basin manager, OCWD, has developed programs and projects to improve groundwater recharge and augment groundwater through recycled water, conjunctive use, and water transfers. OCWD assesses groundwater conditions and sets its BPP, which determines how much water will be pumped from the basin year, and the Basin Equity Assessment (BEA), which is a surcharge for exceeding the BPP. The BPP is set at 85 percent and is forecasted to remain so through 2050. MET, the Southern California regional wholesaler of imported water, has also invested in numerous programs and projects to augment its direct deliveries of imported water, such as water transfers, groundwater banking, and use of its reservoir storage. MET's 2025 UWMP demonstrates that MET will be able to meet its projected water demands for its entire service area for the next 25 years under normal, dry, and five consecutive dry year conditions. Overall, the City's service area is projected to meet full -service demands from 2026 through 2050 under normal years, single dry year, and five consecutive dry year conditions. ES.8 Water Shortage Contingency Planning The Water Shortage Contingency Plan (WSCP) is a standalone document adopted by the City serving as the guidance document used to prepare for and respond to water shortages and service disruptions of the City's water supplies through proactive mitigation measures. A water shortage, when water supply available is insufficient to meet the normally expected customer water use at a given point in time, may occur due to a number of reasons, such as water supply quality changes, climate change, drought, and catastrophic events (e.g., earthquake). The City's WSCP provides a water supply availability assessment and structured steps designed to respond to actual conditions. This level of detailed planning and preparation will help maintain reliable supplies and reduce the impacts of supply interruptions. The WSCP contains the processes and procedures that will be deployed when shortage conditions arise so that the City's governing body and its staff can easily identify and efficiently implement pre -determined steps to mitigate a water shortage to the level appropriate to the degree of water shortfall anticipated. ES.9 Demand Management Measures The City has demonstrated its commitment to water use efficiency through multi -faceted and holistic water use efficiency programs. The City's water use efficiency implementation can be described broadly under five categories: Operations Practices (e.g., conservation pricing, water waste prevention, water loss control, and metering with commodity rates), Education and Outreach (e.g., public outreach programs, K-12 school programs, Water Awareness Poster Contest, Qualified Water Efficiency Landscaper Training Program), Residential Indoor Program (e.g. various rebates), Commercial, Industrial, and Institutional Program (e.g., rebates, Water Savings Incentive Program, On -site Retrofit Program), and Landscape Programs (e.g., turf replacement, spray -to -drip irrigation rebate, residential landscape design assistance). CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO ES.10 Plan Adoption, Submittal, and Implementation The Water Code requires both the UWMP and the WSCP to be adopted by the Supplier's governing body. Before the adoption of the UWMP, the City notified the public and the cities and counties within its service area that MWDOC was in the process of preparing an UWMP and WSCP per the Water Code. The City circulated the final draft of the UWMP and WSCP to facilitate public review and held a public hearing to receive input from the public on the UWMP and WSCP. Upon completion of the public hearing, the City moved to adopt both the UWMP and WSCP. Post adoption, the City submitted the UWMP to DWR and other key agencies and made the document available for public review within 30 days after filing with DWR. The UWMP serves as a legal and technical water management foundation for the City and can be referenced as needed, until its next required update cycle in 2030. With approval from DWR, the City shall implement this plan into its public resources, providing City staff, the public, and elected officials with an understanding of past, current, and future water conditions and management. Furthermore, the WSCP serves as a strategic planning document designed to prepare for and respond to water shortages and service disruptions of the City's water supplies. CITY OF TUSTIN ES-4 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO CHAPTER 1 INTRODUCTION AND UWMP OVERVIEW The City of Tustin (City) prepared this 2025 Urban Water Management Plan (UWMP) to submit to the California Department of Water Resources (DWR) to satisfy the UWMP Act of 1983 (UWMP Act or Act) and subsequent California Water Code (Water Code) requirements. The City is a retail water supplier that provides water to its residents and other customers using the imported potable water supply from the Municipal Water District of Orange County (MWDOC), obtained through East Orange County Water District (EOCWD), and local groundwater from the Orange County Groundwater Basin (OC Basin), which is managed by the Orange County Water District (OCWD). The City, as one of MWDOC's 27 member agencies, prepared this 2025 UWMP in collaboration with MWDOC, EOCWD, Metropolitan Water District of Southern California (MET), OCWD, and other key agencies. UWMPs are comprehensive documents that present an evaluation of a water supplier's reliability over a long-term (20- to 25-year) horizon. In response to the changing climatic conditions since the 2020 UWMP, MWDOC has been assisting its member agencies and surrounding communities to manage both their water supplies and demands. The water loss audit program, water conservation measures, public outreach and education on conservation and efforts for increased self-reliance to reduce dependency on imported water from the Sacramento -San Joaquin Delta (the "Delta") are some of the water management actions that the City has taken to maintain the reliability of water supply for its service area. This UWMP provides an assessment of the present and future water supply sources and demands within the City's service area. It presents an update to the 2020 UWMP on the City's water resource needs, water use efficiency programs, water reliability assessment, and strategies to mitigate water shortage conditions. It also includes the City's updated 2025 Water Shortage Contingency Plan (WSCP) designed to prepare for and respond to water shortages. This 2025 UWMP contains all elements required by the Act. 1.1 Overview of UWMP Requirements The UWMP Act enacted by California legislature requires every urban water supplier (Supplier) providing water for municipal purposes to more than 3,000 customers or supplying more than 3,000 acre-feet (AF) of water annually to prepare, adopt, and file an UWMP with the DWR every five years in the years ending in six and one. For this 2025 UWMP cycle, DWR continues to place emphasis on achieving improvements for long term reliability and resilience to drought and climate change in California. Despite there being no new statutory requirements, Suppliers must now report progress on meeting their 2028 Water Loss Standards and continue to state compliance with Senate Bill (SB) X7-7 2020 Targets. Additional guidance on stored water accounting and recommendations on identifying the need for future or proposed water supply projects are provided by DWR as well. CITY OF TUSTIN 1-1 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 1.2 UWMP Organization This UWMP is organized into 10 chapters aligned with the DWR Guidebook recommendations. The sections within each chapter are customized to include the City's water supply reliability and future projections as well as plans to overcome any water shortages over a planning horizon of the next 25 years. The chapters for this UWMP are listed below: Chapter 1 Introduction and UWMP Overview gives an overview of the UWMP fundamentals and requirements for the 2025 UWMP. Chapter 2 UWMP Preparation identifies this UWMP as an individual planning effort of the City, lists the type of year and units of measure used and introduces the coordination and outreach activities conducted by the City to develop this UWMP. Chapter 3 System Description gives a background on the City's water system and its climate characteristics, population projections, demographics, socioeconomics, and predominant current and projected land uses of its service area. Chapter 4 Water Use Characterization provides historical, current, and projected water use by customer category for the next 25 years for the City and the projection methodology used by the City to develop the 25-year projections. Chapter 5 Conservation Target Compliance restates that the City's 2020 per capita water use in gallons per capita per day (GPCD) met the compliance target defined by SB X7-7. Chapter 6 Water Supply Characterization describes the current water supply portfolio of the City as well as the planned and potential water supply projects and water exchange and transfer opportunities. Chapter 7 Water Service Reliability and Drought Risk Assessment describes the assessment of the reliability of the City's water supply service to its customers for a normal year, single dry year and five consecutive dry years scenarios. This chapter also includes a Drought Risk Assessment (DRA) of all the supply sources for a consecutive five-year drought period beginning 2026. Chapter 8 Water Shortage Contingency Planning is a brief summary of the standalone WSCP document which provides a structured guide for the City to deal with water shortages, incorporating prescriptive information and standardized action levels, lists the appropriate actions and water use efficiency measures to be taken to ensure water supply reliability in times of water shortage conditions, along with implementation actions in the event of a catastrophic supply interruption. Chapter 9 Demand Management Measures provides a description of the City's current and planned measures and programs to help the retail customers in its service area be water efficient and comply with the City's urban water use reduction targets. Chapter 10 Plan Adoption, Submittal, and Implementation provides a record of the process the City followed to adopt and implement its UWMP. CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO CHAPTER 2 UWMP PREPARATION The City of Tustin's (City) 2025 Urban Water Management Plan (UWMP) is prepared to meet the California Water Code (Water Code) compliance as a retail water supplier to its customers. The development of this UWMP involved close coordination with its wholesale supplier, the Municipal Water District of Orange County (MWDOC), along with other key entities within the region. 2.1 Individual Planning and Compliance As described in Chapter 1, every urban water supplier providing water for municipal purposes to more than 3,000 customers or supplying more than 3,000 acre-feet (AF) of water annually must prepare, adopt, and file an UWMP with the California Department of Water Resources (DWR) every five years to meet the compliance requirements of the UWMP Act. As shown in Table 2.1. The City meets this requirement as it has 14,419 municipal connections and supplied 10,304 AF in fiscal year (FY) 2025. Table 2.1 Submittal Table 2-1 Retail: Public Water Systems Submittal Table 2-1 Retail: Public Water Systems Public Water System Public Water System Number of Municipal Volume of Water Supplied Number Name Connections 2025 2025 (AF) Add additional rows as needed CA3010046 City of Tustin 14,419 10,304 Total 14,419 10,304 DWR NOTES: Units of measure (AF, CCF, MG) must remain consistent throughout the UWMP as reported in Submittal Table 2-3. This table identifies the unit of measure selected in Table 2-3. NOTES: The City opted to prepare its own UWMP (Table 2.2) and comply with the Water Code individually, while closely coordinating with MWDOC and various key entities as discussed in Chapter 2.2 to streamline regional integration. The UWMP Checklist was completed to confirm the compliance of this UWMP with the Water Code (Appendix A). All Department of Water Resources (DWR) standardized tables are provided in Appendix B. The City has selected to report demands and supplies using fiscal year as the basis (Table 2.3). CITY OF TUSTIN 2-1 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Table 2.2 Submittal Table 2-2: Plan Identification Submittal Table 2-2: Plan Identification Select One or Type of Plan Name of Regional Alliance or RUWMP Both (Drop Down List) 0 Individual UWMP If Water Supplier is also a member of a SIB X7-7 Orange County 20x2020 Regional Alliance Regional Alliance, select name from the drop -down. ❑ Regional Urban Water Management Plan (RUWMP) If Supplier selected RUWMP, select name from the drop -down. Table 2.3 Submittal Table 2-3: Supplier Identification SupplierSubmittal Table 2-3: Type of Supplier (select one or both) ❑ Supplier is a wholesale supplier 0 Supplier is a retail supplier Fiscal or Calendar• ❑ UWMP Tables are in calendar years 0 UWMP Tables are in fiscal years If using fiscal years, provide month and date that the fiscal year begins (mm/dd) 7/1 Units of measure used in UWIVIP from • •• •• Unit AF DWR NOTES: Units of measure (AF, CCF, MG) must remain consistent throughout the UWMP as reported in Submittal Table 2-3. 2.2 Coordination and Outreach 2.2.1 Integration with Other Planning Efforts The City, as the retail supplier to its customers, coordinated the preparation of this UWMP with its water supplier wholesaler MWDOC, the Orange County Water District (OCWD) as the manager of the Orange County Groundwater Basin (OC Basin) ; Orange County Sanitation District (OC San), its regional wastewater management agency; and other key regional agencies including East Orange County Water District (EOCWD). The City also developed this Plan in conjunction with other regionally consistent efforts, such as population projections from the Center for Demographic Research at California State University, Fullerton (CDR), and the Orange County Water Demand Projection Model Technical Memorandum. CITY OF TUSTIN 2-2 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Key planning and reporting documents that were used to develop this UWMP are listed below: ■ Metropolitan Water District of Southern California's (MET) 2025 UWMP uses assumptions that fall within the plausible futures contemplated in MET's Integrated Water Resources Plan to evaluate MET's future imported water supply reliability. ■ MET's 2020 Integrated Resources Plan (IRP) Regional Needs Assessment is a long-term, scenario - based planning document that guides MET's programs and investments to ensure reliable water supplies in Southern California and provides a basis for water supply reliability in Orange County. ■ MET's Climate Adaptation Master Plan for Water (CAMP4W) is an ongoing planning and decision -making tool that accounts for the complexities and uncertainties of climate change. Part of the second phase of MET's long-term IRP planning process, CAMP4W incorporates the results and findings of MET's 2020 IRP Regional Needs Assessment into a collaborative process to identify and evaluate integrated regional solutions. ■ MET's 2025 Water Shortage Contingency Plan (WSCP) provides a water supply availability assessment and guide for MET's intended actions during water shortage conditions. ■ MWDOC's 2025 WSCP provides a water supply availability assessment and structured steps designed to respond to actual conditions that will help maintain reliable supplies and reduce the impacts of supply interruptions. ■ MWDOC's 2023 Orange County Water Reliability Study is a planning document to help guide planning for future water supply reliability for water providers in Orange County and provide input on regional water supply issues for MET. ■ 2025 Orange County Water Demand Projection Model Technical Memorandum is a collaborative effort amongst MWDOC, OCWD, and all retail water suppliers in Orange County that developed water demand projections to produce regionally consistent forecasts across all Orange County water agencies. ■ OCWD's Groundwater Resilience Plan (GRP - February 2025) is an adaptive strategies management plan outlining strategic projects to secure reliable future water supplies in the OC Basin. ■ OCWD's 2023-24 Engineer's Report provides information on the groundwater conditions, water supply, and basin utilization of the OC Basin. • 2022 Basin 8-1 Alternative is an alternative to the Groundwater Sustainability Plan (GSP) for the OC Basin, which provides significant information related to sustainable management of the basin in the past and hydrogeology of the basin, including groundwater quality and basin characteristics, and addresses DWR's recommendations to ensure long-term basin sustainability. • City of Tustin Draft Hazard Mitigation Plan (2019) provides the basis for the seismic and other natural disaster risk analysis of the water system facilities. 2.2.1.1 Statewide Water Planning In addition to regional coordination with the various agencies described above, the City, as a MWDOC member agency, is currently a part of MET's statewide planning effort to reduce reliance on the water imported from the Sacramento -San Joaquin Delta (Delta). It is the policy of the State of California to reduce reliance on the Delta in meeting California's future water supply needs through a statewide strategy of investing in improved regional supplies, conservation, CITY OF TUSTIN 2-3 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO technology innovation, partner collaborations, and water use efficiency measures. This policy is codified through the Delta Stewardship Council's Delta Plan Policy WR P1 (WR P1) and is measured through Supplier reporting in each Urban Water Management Planning cycle. WR P1 is relevant to water suppliers that plan to participate in multi -year water transfers, conveyance facilities, or new diversions in the Delta. Additionally, with the recent amendments to the Bay Delta Plan, tributary flow objectives to the Delta are being updated to account for quality and habitat improvements for local environmental resources. This results in reduced reliance on Delta water supplies. Since 2022, the Bay -Delta Plan Amendment update has been in development. This effort considers additional tributaries from the southern San Joaquin Valley, triggering a re-evaluation of Delta flow requirements and conservation objectives, which ultimately may impact available supply to the State Water Project (SWP). Through significant local investment, collaboration at both a local and regional scale, and integration with MWDOC's water use efficiency strategies and conservation programs, the City has demonstrated a reduction in Delta reliance. For member agencies of MWDOC that receive imported water from MET, these agencies have passively demonstrated a reduction in Delta reliance and a subsequent improvement in regional self-reliance by participating in MWDOC led regional strategies. A detailed description and documentation of the City's consistency with Delta Plan Policy WR P1 is included in Chapter 7.4 and Appendix C. 2.2.2 Wholesale and Retail Coordination The City developed its UWMP in conjunction with MWDOC's 2025 UWMP. As a retail water supplier, the City provided its historical water use and water use projections data to MWDOC (Table 2.4). The City also has been taking part in multiple regional programs administered by MWDOC to assist retail agencies in meeting various State compliance, such as the OC Regional Alliance for SB X7-7 compliance, regional water loss program or SB 555 compliance, and regional water use efficiency programs. Chapters 5 and 9 provide detailed information on these programs. Table 2.4 Submittal Table 2-4 Retail: Water Supplier Information Exchange Submittal Table 2-4 Retail: Water Supplier Information Exchange Water Code Section 10631(h) The retail Supplier has informed the following wholesale supplier(s) of projected water use. Wholesale Water Supplier Name Add additional rows as needed East Orange County Municipal- of Orange County Orange County Water • 2.2.3 Public Participation For further coordination with other key agencies, and to encourage public participation in the review and update of this Plan, the City held a public hearing on June 16, 2026, and notified key entities and the public per the Water Code requirements. Chapters 10.2 and 10.3 describe these efforts in detail. CITY OF TUSTIN 2-4 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO CHAPTER 3 SYSTEM DESCRIPTION The City of Tustin (City) was incorporated in 1927 and is governed by a Council -Manager form of government. The City lies in central east Orange County and is bounded by the City of Orange to the north, the City of Santa Ana to the west, the City of Irvine to the south, and unincorporated areas of Orange County to the east. The City's water service area covers 8.4 square miles and includes most of the incorporated area of the City and also the unincorporated county areas north of the City. The City operates 9 wells, 6 reservoirs with a combined storage capacity of approximately 13.83 million gallons (MG), and manages a 183-mile water mains system with 14,419 service connections. Lying in the South Coast Air Basin (SCAB), its climate is characterized by Southern California's "Mediterranean" climate with mild winters, warm summers, and moderate rainfall. In terms of land use, the City is almost built out with predominantly single- and multi -family residential units and a few commercial establishments. Moving forward, the City will continue planning for its Regional Housing Needs Assessment (RHNA) allocation requirements, and there may be an increase in the construction of accessory dwelling units (ADUs) as a means of affordable housing. The current population (2025) of 65,143 is projected to decrease by 1.6 percent over the next 25 years to 64,130. This equates to an annual decline rate of 0.06 percent. 3.1 Agency Overview This section provides information on the formation and history of the City, its organizational structure, roles, and relationship to the Municipal Water District of Orange County (MWDOC). 3.1.1 Formation and Purpose The City was incorporated in 1927 as a general law city in Orange County, California. Its formation followed the growth of an agricultural community established in the late 19th century, driven largely by citrus farming and regional rail connections. Incorporation enabled local residents to establish municipal governance, exercise land use authority, and provide essential public services in response to increasing development and population growth. 3.1.2 City Council The City has a Council -Manager form of government, which consists of an elected City Council responsible for policy making, and a professional City Manager appointed by the Council. The current members of the City Council are: ■ Austin Lumbard, Mayor. • Ray Schnell, Mayor Pro Tem. ■ Ryan Gallagher, Council Member. • Lee K. Fink, Council Member. ■ John Nielsen, Council Member. CITY OF TUSTIN 3-1 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 3.1.3 Relationship to MWDOC The City is one of MWDOC's 27 member agencies purchasing imported water from MWDOC, Orange County's wholesale water supplier, and a member agency of the Metropolitan Water District of Southern California (MET), through the East Orange County Water District (EOCWD). The City's location within MWDOC's service area is shown on Figure 3.1. 3.2 Water Service Area and Facilities 3.2.1 Water Service Area The City is located in central east Orange County. The City is bounded by the City of Orange to the north, the City of Santa Ana to the west, the City of Irvine to the south, and unincorporated areas of Orange County to the east. The City is approximately 35 miles south of Los Angeles and 10 miles inland from the Pacific Ocean. The City's water service area has an area of 8.4 square miles and an elevation of about 210 feet above sea level. The topography of the City combines generally flat areas with gradual rolling hills. The City provides potable water service to most of the incorporated area of the City and also to unincorporated county areas north of the City. A map of the City's water service area is shown as Figure 3.2. CITY OF TUSTIN 3-2 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 Los Angeles County La � I Bucna Piro Snn 8erntrrdino Counfy GdtlenSuu vgrya Wrrc, Ca��tiYa,cr scrrano Wale, 01 7rangt Count! water Uistrirt Riverside covn r, Golden Stale YWater Ca --a © mbum I-ne Ranch Canyon Water -. �;...gion :'arer 0, gnq t Eielrlcl at, El Tao Water fMtriCc N� t Beach Emerald Bay V M�qn tagunas [h Nlguel Water Santa Margerl[a CAuMy District Water 01strla 4Jater Bislri[t L11t DOD �T�ii}�' Sau[h Coas[ San elemrnte Water 6�srnrr MWDOC Service Area Sa11 Die -go County ra MWDOC is a wholesale water supplier that serves Orange County through 27 Memher agencies. The 26 water providers identified in the legend 4y a circle provide retail water services to the pvbliC- Figure 3.1 Regional Location of City of Tustin and Other MWDOC Member Agencies 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO City of Brea City of Buena Park City of fountain Valley 0 City of Garden Grove City of Huntington Beach City of La Habra 0 City of La Palma City of Newport Beach 10 City of Orange 0 City of San Clemente City of Seal Beach City of Tustin City of Westminster East Orange County Water District El Toro Water District Emerald Bay Service District Golden State Water Co. - OC Irvine Ranch Water District Laguna Beach County Water District Mesa Water District Moulton Niguel Water District Santa Margarita Water District Serrano Water District South Coast Water District Trabuco Canyon Water District Yorba Linda Water District 0 Orange County Water District (Groundwater Wholesaler) CITY OF TUSTIN 3-3 ms nEnveaR ID: agc 907-e73 58&SeSEc 4o mDF2 Ja URBAN WATER MANAGEMENT PLAN MAY maZFINAL DRAFZc Lo Figure3: City of Tustin WaelrS &a Area CITY of ms w a s Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 3.2.2 Water Facilities The City provides domestic and fire protection water service to most of the incorporated area of the City and also to unincorporated areas north of the City. The City has one untreated or "clear" groundwater well that pumps directly into the distribution system and two treatment facilities that treat groundwater from eight additional wells. Elevations in the City's service area are approximately 210 feet above mean sea level (MSL). The water system is divided into three pressure zones. The City delivers water supplies through 183 miles of 1.5-inch to 20-inch water mains and three booster stations. The City pumps its groundwater from nine active wells, including four wells that undergo nitrate and total dissolved solids (TDS) removal. Two wells go through the Main Street Plant for nitrate and TDS removal, while the other two wells go through the 17th Street Desalter Treatment Plant. The remaining four wells undergo per- and polyfluoroalkyl substances (PFAS) treatment through the Main Street Plant. Storage is required to balance variations in demand (operational or regulatory storage), to provide water for fighting fire (fire storage), and to provide water when normal supplies are reduced or unavailable due to unusual circumstances (emergency storage). The existing storage system consists of six reservoirs with a combined storage capacity of approximately 13.83 MG. 3.3 Climate The City's service area is located within the SCAB that encompasses all of Orange County, and the urban areas of Los Angeles, San Bernardino, and Riverside counties. The climate in the SCAB area is characterized by Southern California's "Mediterranean" climate: a semi -arid environment with mild winters, warm summers, and moderate rainfall. Local rainfall has limited impacts on reducing water demand in the City, except for the case of landscape irrigation demand. For example, in August 2023, Orange County as a region experienced the lowest seasonal water demand due to significant summer precipitation events from Tropical Storm Hilary. The increase in precipitation allowed landscape irrigation systems to be turned off, other municipal and industrial uses (e.g., consumption, processing, and washing) remained the same. Water that infiltrates into the soil may enter groundwater supplies depending on the local geography. However, due to the large extent of impervious cover in Southern California, rainfall runoff quickly flows to a system of concrete storm drains and channels that lead directly to the ocean. OCWD has successfully captured stormwater along the Santa Ana River and in recharge basins for years and used it as an additional source of supply for groundwater recharge. Based on the 2022 Basin 8-1 Alternative Plan Update, OCWD captured an average annual stormwater volume of approximately 54,000 AF over the period of five years, from Water Year 2016-17 to 2020-21. MET'S water supplies come from the State Water Project (SWP) and the Colorado River Aqueduct (CRA) are influenced by climate conditions in northern California and the Colorado River Basin, respectively. Both regions have variable hydrologic conditions that can significantly affect MET'S supplies from year to year. This past decade has seen dramatic swings in annual precipitation, especially in the form of snowpack, which directly affects SWP supply allocations. Similarly, the Colorado River Basin also experienced year-to-year swings in hydrology ,and due to the prolonged drought conditions since 2000, CITY OF TUSTIN 3-5 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO storage within the Colorado River system has declined to less than half of its reservoir capacity and has been fluctuating at that level (MET, 2025). 3.4 Population, Demographics, and Socioeconomics 3.4.1 Service Area Population The City serves a 2025 population of 65,143 according to the Center for Demographic Research at California State University, Fullerton (CDR). Overall, the population is projected to decrease by 1.6 percent by 2050. Table 3.1 shows the population projections in five-year increments out to the year 2050 within the City's service area. Table 3.1 Submittal Table 3-1 Retail: Population - Current and Projected 3.4.2 Demographics and Socioeconomics As shown below in Table 3.2, the total number of dwelling units in the City service area is expected to increase by 10.5 percent in the next 25 years, from 22,628 in 2025 to 25,004 in 2050. Table 3.2 City of Tustin Service Area Dwelling Units by Type Dwelling Units 20252030 2035 2040 2045 2050 Single Family 10,263 10,528 10,614 10,701 10,789 10,877 All Other() 12,365 14,079 14,091 14,102 14,112 14,127 Total 22,628 24,607 24,705 24,803 24,901 25,004 Notes: Source: Center for Demographic Research at California State University, Fullerton, 2025. (1) Includes duplex, triplex, apartment, condo, townhouse, mobile home, etc. Yachts, houseboats, recreational vehicles, vans, etc., are included if it is the primary place of residence. Does not include group quartered units, cars, railroad box cars, etc. In addition to the types and proportions of dwelling units, various socio-economic factors such as age distribution, education levels, general health status, income, and poverty levels affect the City's water management and planning. Based on the US Census Bureau's 2023 American Community Survey, the City has about 11 percent of population aged 65 years and over, 66 percent between the ages of 18 and 64 years, and 23 percent under the age of 18 years. Of the City's population over 25 years of age, 86.6 percent is at minimum a high school graduate, with 43.1 percent of this age group having at least a bachelor's degree. 3.4.3 Demographic Projection Methodology CDR is a collaborative research center established in 1996 to provide accurate and timely demographic data on population, housing, and employment in Orange County. CDR serves as Orange County's CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO authoritative source for demographic information. The City obtains its service area population and dwelling unit data from MWDOC via CDR. MWDOC contracts with CDR to update the 2010 population estimates through the current year and to provide an annual estimate of population served by each of its retail water suppliers within its service area. CDR uses geographic information system (GIS) mapping and data from the 2000, 2010, and 2020 US Decennial Censuses, State Department of Finance (DOF) population estimates, and the CDR annual population estimates and Housing Inventory System (HIS). These annual estimates incorporate annual revisions to the DOF annual population estimates, often for every year back to the most recent Decennial Census. As a result, all previous estimates are set aside and replaced with the most current set of annual estimates. Annexations and boundary changes for water suppliers are incorporated into these annual estimates. Demographic projections used for this UWMP reflect the most recently available set of projections developed by CDR based on its 2022 Orange County Projections. Demographic projections for Orange County are updated every 4 years, with the next set of projections expected in the late fall of 2026. The 2022 Orange County Projections accounted for Draft RHNA rezone sites with jurisdictions, including the number of dwelling units that are most likely to occur/get built by the end of 2050 under assumptions and trends existing at the time of the forecasting effort, including a parcel -level inventory of additional housing capacity from sites that were to be rezoned to accommodate the 6th RHNA cycle. In the summer of 2025, projections by the water supplier for population and dwelling units by type were estimated using the 2022 Orange County Projections dataset. Growth for each of the five-year increments was allocated using GIS and a review of the traffic analysis zones (TAZ) data with a 2023 aerial photo. The growth was added to the 2025 estimates for each respective water supplier. 3.5 Land Uses 3.5.1 Current Land Uses The City's service area can best be described as a predominantly single- and multi -family residential community located in central Orange County, and is mostly built out. Based on the zoning designation collected and aggregated by the Southern California Association of Governments (SCAG) in 2018, the current land use within the City's service area can be categorized as follows: ■ Single-family residential - 58.5 percent. • Multi -family residential - 16.5 percent. ■ Agriculture - 0.3 percent. ■ Commercial - 9.9 percent. ■ Industrial - 3.2 percent. ■ Institutional/Governmental - 9 percent. ■ Open space and parks - 0.6 percent. ■ Other - 1.8 percent (e.g., Undevelopable or Protected Land, Water, and Vacant). ■ No land use designations - 0.3 percent. CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 3.5.2 Projected Land Uses The City has identified the following major development projects that will change the City's total water demand in the future. It is possible that not every proposed project will get built in the next decade. • Compass at Red Hill - A residential development with 73 three-story full -electric townhomes. ■ Stafford Glen - A residential development with 42 condominium units plus 7 live/work units. • Cypress Grove - A residential development with 145 full -electric dwelling units, 62 detached cluster homes, and 83 townhomes. ■ Campo at 17th - A mixed -use development with 100 residential units, several commercial pads, 1-2 drive-thrus, and 1 car wash. It should be noted that the 2025 Orange County Water Demand Projection Model discussed in Chapter 4 was based on CDR's 2022 Orange County projections. The developments listed above may have been added or modified since. As a result, the future demands associated with these developments may increase the City's water demand beyond what is presented in this UWMP. In addition to the above developments, the City will continue planning for the RHNA allocation imposed by the State. Additionally, new developments may potentially include ADUs, while it is also anticipated that policy changes will make it easier for homeowners to add ADUs to existing residential properties. The following requirements and changes in laws will impact the City's future land use moving forward: Regional Housing Needs Assessment (RHNA) - State law requires jurisdictions to provide their share of the RHNA allocation. SCAG determines the housing growth needs by income for local jurisdictions through RHNA. The City's RHNA allocation for 2021-2029 is 6,782 dwelling units. This includes 1,724 units for very low-income households, 1,046 units for low-income households, 1,132 units for moderate -income households, and 2,880 units for above moderate -income households. The City's 2022 Housing Element provides an 8-year strategy to ensure the availability of adequate residential sites to accommodate these units. Accessory Dwelling Units (ADUs) - ADUs are separate small dwellings embedded within residential properties. There has been an increase in the construction of ADUs in California in response to rising interest to providing affordable housing. Since 2020, several landmark laws were passed by State Legislature, updating ADU law to simplify the construction, rental, and sale of ADUs in California. The most significant laws that have recently come into effect include: AB-1033 Accessory dwelling units: local ordinances: separate sale or conveyance which authorizes local governments to adopt ordinances permitting the sale of ADUs separately from the primary residence as condominiums. AB-976 Accessory dwelling units: owner -occupancy requirements that prohibit a local agency from requiring owner -occupancy for property owners to build and rent an ADU. AB-1154 Junior accessory dwelling units which no longer requires owner -occupancy for Junior ADUs (JADUs) as long as they have their own bathroom. AB-1332 Accessory dwelling units: preapproved plans that require local agencies to develop a program for pre -approved ADU plans, with projects using these plans having to be approved or denied within 30 days. CITY OF TUSTIN 3-8 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO SB-543 Accessory dwelling units and junior accessory dwelling units require local agencies to determine if an ADU/JADU application is complete within 15 business days of submittal, revise ADU size to now be measured by "interior livable space", and redefine a JADU to be no more than 500 square feet of interior livable space. SB-1211 Land use: accessory dwelling units: ministerial approval which authorizes multi -family property owners to build up to eight detached ADUs on a single lot, provided that the number of ADUs does not exceed the number of existing primary units. AB-2533 Accessory dwelling units: junior accessory dwelling units: unpermitted developments, which prohibit local agencies from denying permits for unpermitted ADUs/JADUs constructed before January 1, 2020, based on code violations unless the structure is a health or safety hazard. In 2024, a total of 6,162 new residential units were permitted in Orange County, including those for ADUs (CDR, 2025). CDR projects that by 2050, approximately 13,000 more ADUs will be built in Orange County, with 556 ADUs expected within the City's service area. The increase in ADUs is likely to result in an increase in the number of people per lot of land. Depending on whether the addition of ADUs results in a net replacement of irrigated area (or other high water use features such as swimming pools), ADUs could increase or decrease water demands. CITY OF TUSTIN 3-9 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO CHAPTER 4WATER USE CHARACTERIZATION One of the main objectives of an Urban Water Management Plan (UWMP) is to provide insight into the projected future water demands and supplies. This chapter describes the City of Tustin's (City) current and future water demands for their service area, factors that influence demands, and the methodology used to forecast future water demands over the next 25 years. For the 2025 UWMPs, water demand projections will span from planning year 2025 through planning year 2050. Known for its suburban coastal communities and densely populated inland areas, Orange County has evolved greatly from its beginnings as an agricultural region. As some of the earliest cities in Orange County, from 1928 to 1931, the Cities of Anaheim, Fullerton, and Santa Ana all joined with 10 other Southern California cities to form the Metropolitan Water District of Southern California (MET) with the ambitious dream to bring Colorado River water across the Mojave Desert. The Municipal Water District of Orange County (MWDOC) laterjoined MET as a member agency in 1951, and with the merger with the Coastal Municipal Water District in 2001, now represents the remainder of Orange County to provide and manage the imported water supplies within its service area. Orange County is now mostly comprised of residential, mixed -use, and commercial developments, with less industry in the region. Agriculture in the region has also declined significantly as Orange County has grown more suburban. Thus, modern-day water use within Orange County can be largely summarized by the following four demand sectors: ■ Single-family Residential. ■ Multifamily Residential. ■ Commercial, Industrial, and Institutional (CII). ■ Dedicated Irrigation (potable, recycled, and raw water). Figure 4.1 shows Orange County's overall historical water usage compared to population since 1990, when local water conservation programs were first established. As shown, from the early 1990s through the mid-2000s, Orange County's water usage increased as the population increased. Population figures slowed significantly in 2018 and began to decrease during the COVID-19 Pandemic in 2020-2021. Since 2007, retail, municipal, and industrial water use in Orange County has declined due to multiple contributing factors. Decades of sustained investments in water -use efficiency and public education have led to significant adoption of water -efficient appliances and fixtures, and increased public awareness of the need to use water wisely. Furthermore, in response to recurring droughts, growing urban demand, and increasingly limited water supplies, multiple regulatory requirements to promote water conservation have evolved and been implemented over the past several years throughout California and Orange County. CITY OF TUSTIN 4-1 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 800,000 700,000 600,00U H0,000 t C s 400,000 ! 300,000 200,000 1fl0,00Q n nr r,nl II I n 7 n n 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 6 & N cn '� LrS co r-- cc a, O r- N c,-, 't F Lr] co r� a6 a, O Z- N S? �2 ol���� ol� O O O O O O O O O O 4 L] cO f` 00 4) q t; oV c`7 4L7 6 r� 0Q c6 q N c'7 4Go ol ol ol ol ol ol ol ol ol cb O O O O O O O O O C) r- 4) 4) 4) 4) 4) 4) 4) 4) 4) 4) 4) q O O O O O O q O O q q O q q Fiscal Year a6 6) 6 N cn ' - Li] CV N CV f� op O) q v-- N cj 4 N N N N N R R N N R N N N Retail V&1 Water Usage (Includes Recycled Water) —OC Service Area Population Figure 4.1 Historical Water Use and Population in Orange County 3.50 3.00 2.50 2.00 a 1.60 n a 1.00 0.60 Orange County's trending decline in water usage can most notably be attributed to Orange County water agencies' past efforts to achieve regional and individual compliance with Senate Bill (SB) X7-7, the Water Conservation Act of 2009, through the Orange County 20x2020 Regional Alliance and compliance with Executive Order (EO) B-29-15 which mandated 25 percent reduction in potable water use in response to the 2013-2014 drought. Furthermore, Orange County water agencies' ongoing progress towards achieving SB 606 and Assembly Bill (AB) 1668, the "Making Conservation a California Way of Life" legislation, water use objectives continue to exemplify Orange County water agencies' commitment to water conservation, water use efficiency, and overall reduction in potable water usage in recent decades. In 2025, MWDOC and Orange County Water District (OCWD), in collaboration with MWDOC's member agencies and the Cities of Anaheim, Fullerton, and Santa Ana, led the effort to develop the 2025 Orange County Water Demand Projection Model. The Orange County Water Demand Projection Model (MWDOC, 2025) was used to project long-term water demand under three hydrologic conditions (normal year, single dry year, and five consecutive dry years) over a 25-year horizon in 5-year increments, consistent with the 2025 UWMP requirements. Although Orange County demands are forecast to be relatively flat into the future, with water use efficiency efforts counterbalancing new growth, Figure 4.2 shows that annual variations in weather could cause high fluctuations. Some examples of this are described below: • Single-family consumption is highly seasonal, and the model correlates well with seasonality and temperature by capturing fluctuations in single-family outdoor irrigation. • Multi -family use is generally less responsive to weather than single-family demands, as much of multi -family outdoor irrigation has been shifted into the irrigation -specific water use sector CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO (dedicated irrigation meters), and generally newer multi -family dwellings in Orange County have comparatively less landscaped area than generally older single-family dwellings due to Model Water Efficient Landscape Ordinances (MWELO) mandated since 1993. Seasonal price elasticity varies the least between months for the multi -family sector. • Commercial, Industrial, and Institutional use is positively correlated to each job proportion as well as gross domestic product throughout Orange County, which means a higher amount of CII jobs and production value trend in an increase in water demands. • Irrigation is the most responsive to temperature and precipitation compared to the other sectors. LL l9 V ib _ :5, v 0 700,000 550-000 600.000 550,000 �aa,aaa _�--- - - - - ------------. - ---- -------- - 450,000 Q N �4 00 a N ;I- -ID m Q IN V tF M Q N V 10 M g N N N N N N7 M n Cl) n q�? �r LO o a o 0 0 0 o a o 0 0 0 0 0 0 0 0 0 0 0 0 N N N N N N N N N N N N N N N N N N N N N —Historical --Baseline Normal Year Single HotUry Year —2nd HoVDry Year —3rd Hot]Dry Year 4th Hot/Dry Year —5thHot]DryYear ----High Demand Scenario ----Low Demand Scenario Figure 4.2 Projected Water Use Across All Orange County Water Agencies In terms of future development, North Orange County is substantially built out, with a majority of residential land uses, with some mixed -use areas dedicated to commercial, institutional, and governmental uses. Future developments planned in North Orange County are mainly redevelopment and infill projects. As for the City's service area specifically, a number of redevelopment projects, potential Accessory Dwelling Units (ADUs), and additional residential units to meet the City's Regional Housing Needs Assessment (RHNA) allocation, which will all shape the City's future water use. Water use within the City's service area has fluctuated in the past five years, with an annual average total water use of approximately 10,343 acre-feet (AF). Following one of the worst droughts in California history between 2017 and 2022, the significant wet year in 2023 saw a dramatic decrease in overall water use from fiscal year (FY) 2021-22 to FY 2022-23 in the City's entire service area. Water use in FY 2024-25 included 10,304 AF of potable water. The City's water use is primarily residential. The projected water use in 2050 is 9,717 AF for potable water. CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 4.1 Water Use in the Last Five Years The five-year average water use within the City's service area is approximately 10,343 AF provided by potable sources. Demand trends have regionally remained flat due to water -use efficiency efforts and increased precipitation in recent wet years, such as FY 2023. As mentioned in Chapter 3, the City is almost completely built out, and population projections are expected to slightly decrease. Total demands have slightly decreased due to ongoing water conservation programs and improved water use efficiency efforts. FY 2020-21 through FY 2021-22 saw the highest water uses over the last five years due to region -wide drought conditions. FY2022-23 proved to be one of the wettest years on record in the State, and the City saw a general decrease in water demand following this wet year, as precipitation offsets landscape irrigation demands. These year-to-year fluctuations in precipitation will continue to influence the City's annual demands. In general, the City saw a decrease in demand of 8.6 percent over the 5-year reporting period. Table 4.1 presents the City's service area existing water use by source for direct uses. There are no indirect uses within the City's service area. The City's service area total water usage in FY 2024-25 was 10,304 AF (Table 4.1). The total usage was met through a combination of potable sources, including groundwater and imported water. In FY 2024-25, about 68 percent of the total demand was met through the Orange County Groundwater Basin (OC Basin). Table 4.1 Submittal Table 4-1 Retail: Total Uses for Potable and Non -Potable Water — Actual PotableSubmittal Table 4-1 Retail: Total Uses for Non -Potable Water Code Section 10631 Use p- Drop down list May select each use multiple times Additional Description These are the only use types that will be (as needed) recognized by the WUE data online submittal tool 2025 Actual Water Potable or (OPTIONAL) (OPONA Drop down list Volume (AF) Add additional rows as needed Single Family Potable 5,247 Multi -Family Potable 2,404 Commercial Potable 783 Industrial Potable 81 Institutional/Governmental Potable 571 Landscape Potable 327 Agricultural Potable 27 Distribution System Water Loss Potable 863 Other (optional) Potable 2 Subtotal Potable 10,304 Subtotal Non -Potable 0 Total 10,304 DWR NOTES: Units of measure (AF, CCF, MG) must remain consistent throughout the UWMP as reported in Submittal Table 2-3. This table identifies the unit of measure selected in Submittal Table 2-3. NOTES: Distribution system water loss is calculated as the difference between potable supplies and demand for FY 2025. CITY OF TUSTIN 4-4 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Table 4.1 summarizes the City's potable water demand for FY2024-25; a total of 10,304 AF of potable water was used. The City has a mix of single and multi- family residential water use which account for 74.2 percent of their total potable water demand. Commercial, industrial, and institutional/governmental use accounts for a combined 13.9 percent of total potable demand. Landscape irrigation accounts for 3.2 percent of total potable demand, while agricultural and other uses account for almost 0.3 percent of total potable demand. The total distribution system water loss to match supply and demand was calculated to be 863 acre-feet per year (AFY) in FY 2024-25, or 8.4 percent of total potable water demand. It should be noted that this differs from the City's water loss reported in the American Water Works Association (AWWA) Water Loss Audit for Calendar Year (CY) 2024, as this reporting was done for a different timespan. Since the City is almost built out and with declining population rates and continual water conservation efforts, demands are not expected to increase significantly. 4.2 Projected Water Use The water use projection for this UWMP is separated into a near -term period covering the next five years (2026-2030) and a long-term period extending from 2030 through 2050. The water use projection is based on the 2025 Orange County Water Demand Projection Model Technical Memorandum (TM), which is included in Appendix H of this UWMP. The methodology used in this demand forecast links water use statistically to a set of explanatory variables through a regression, or econometric, model. Section 4.3 offers a description of the methodology used to calculate the City's demand projections. 4.2.1 Water Use Projections for 2026-2030 Total demands (direct) are met through imported water (treated) and groundwater. The City utilizes the projected total demands to incorporate the best available planning information when projecting the imported water demands of its service area. The City's total water demand projection for the next five years is shown in Table 4.2. As shown, the City's total service area water demands are expected to increase over the next five years (2026 to 2030), due to projected growth in the service area's M&I demands in the short term. The City does not project any non -potable demands for its service area in the next five years. Table 4.2 City of Tustin's Service Area Total Potable Demand for 2026-2030 Fiscal Year •• 1. 1111: 1• 1 1 Total Water Demand (AF) 9,638 19,642 9,667 9,648 9,665 4.2.2 Water Use Projections for 2030-2050 The City's service area's total water demands (by use type) for 2030-2050 are shown in Table 4.3. By 2050, total water demand is projected to be 9,717 AF, a 5.7 percent decrease from the 2025 demand of 10,304 AF. Table 4.4 indicates additional information for both future conservation efforts and low-income water demands included in the projections, while Table 4.5 presents the passive water savings included in Table 4.3 projections for 2030-2050. CITY OF TUSTIN 4-5 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Table 4.3 Submittal Table 4-2 Retail: Total Uses of Potable, and Non -Potable Water - Projected Submittal Table 4-2 Retail: Total Uses of Potable, and Non -Potable Water - Projected Water Code Section 10631 IrUse Type Projected Water Use (Report To the Extent that Records are Available) -M Drop down list Additional May select each use multiple Description (as Potable or Non- 2050 times needed) Potable 2030 2035 2040 2045 (opt) These are the only Use Types (OPTIONAL) (AF) (AF) (AF) (AF) (AF) that will be recognized by the Drop down list WUE data online submittal tool Add additional rows as needed. Single Family Potable 4,638 4,634 4,647 4,632 4,618 Multi -Family Potable 2,326 2,327 2,323 2,300 2,277 Commercial Includes Potable 1,325 1,390 1,426 1,433 1,441 Institutional and Industrial uses Landscape Includes Potable 328 328 329 328 328 Agriculture use Distribution System Water Includes Other Potable 1,048 1,055 1,061 1,057 1,053 Loss uses Subtotal Potable 9,665 9,735 9,785 9,751 9,717 Subtotal Non -Potable 0 0 0 0 0 Total 9,665 9,735 9,785 9,751 9,717 DWR NOTES: Units of measure (AF, CCF, MG) must remain consistent throughout the UWMP as reported in Submittal Table 2-3. This table identifies the unit of measure selected in Submittal Table 2-3. NOTES: Source — 2025 Orange County Water Demand Projection Model Forecast for the City of Tustin Table 4.4 Submittal Table 4-3 Retail: Inclusion in Water Use Projections Submittal Table 4-3 Retail: Inclusion in Water Use Projections Water Code Section 10631i. i. Are Future Water Savings Included in Projections? Yes Drop down list (yln) If "Yes" to above, state the section or page number, in the cell to the right, where citations of the codes, ordinances, or otherwise are utilized in demand projections are found. Chapter 4.3 Optional Suppliers may complete Optional Submittal Table 4-4 R to quantify the expected savings. Are Lower Income Residential Demands Included In Projections? Yes Drop down list (yln) Optional If the method for accounting Lower Income Residential Demands has been included, provide Chapter 4.3 page number where this accounting can be found. DWR NOTES: Additional guidance is provided in Appendix K. NOTES: Future water savings include passive conservation (defined as water savings that occur without incentives). Active conservation (defined as water savings that occur with incentives) is not included in the projections. The demand projection methodology accounted for the entire population of the service area (i.e., all income levels). CITY OF TUSTIN 4-6 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Table 4.5 Optional Submittal Table 4-4 Retail: Passive Water Savings Projections OPTIONAL Water Code Section 10631 Description Passive savings (Codes, Standards, Ordinances, or Plans) 2030 (AF) 2035 (AF) 12040 (AF) 2045 (AF) 2050 opt (AF) Add additional rows as needed 133 133 133 132 132 DWR NOTES: Units of measure (AF, CCF, MG) must remain consistent throughout the UWMP as reported in Submittal Table 2-3. This table identifies the unit of measure selected in Submittal Table 2-3. NOTES: Passive conservation is defined as water savings that occur without incentives. Based on the 2025 Orange County Water Demand Projection Model, passive conservation is assumed to equal a 1.9% decrease in residential demand due to conservation by 2030 (linearly extrapolated), then remains constant in subsequent years. Total potable water demands are projected to increase to 9,717 AF between the years 2030 and 2050, an increase of about 0.5 percent between 2030 and 2050 (Table 4.3). It is projected that combined single - and multi -family residential water use will account for 71 percent of total potable water demand. Combined commercial, institutional, and industrial water use is expected to account for 14.8 percent, and landscape irrigation water use will account for 3.4 percent of total potable water use in the City by 2050. Distribution system water loss and other uses will account for 10.8 percent of total potable water demands. 4.3 Water Demand Projection Methodology In 2025, MWDOC and OCWD, in collaboration with MWDOC's member agencies and the Cities of Anaheim, Fullerton, and Santa Ana, led the effort to develop the 2025 Orange County Water Demand Projection Model (MWDOC, 2025). This effort developed a demand model by regressing historical water consumption data provided by each Orange County water agency against several explanatory variables known to influence water demand (including weather, water price, regional economic conditions, and housing density). The water demand projections were for the Orange County region as a whole and provided retail agency -specific demands, spanning the years of 2025-2050. The full TM can be found in Appendix H. The demand projections created four econometric, or regression, demand models representing the following four water billing sectors for each Orange County retail agency: ■ Single-family Residential. • Multi -family Residential. ■ Commercial, Industrial, and Institutional (CII). ■ Dedicated Irrigation (potable, recycled, and raw water). Prior to developing the forecasts, model calibration and fine tuning for each of the four demand sectors occurred at the individual retail agency level. The demand across all four models, plus other uses for each agency, is summed to a total forecast for each agency, the MWDOC service area, the OCWD service area, and total Orange County. CITY OF TUSTIN 4-7 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO The demand projection methodology accounted for the entire population of each individual retail agency's service area (i.e., all income levels), thus accounting for the water demand projections for lower income households within the City's service area. 4.3.1 Econometric Approach, Data Acquisition, and Model Development A regression, or econometric, approach to demand forecasting statistically links retail level water use to weather, economic, and socioeconomic factors (explanatory variables). The model relies on a comprehensive dataset of historical water -use data for almost 40 different billing sectors collected from Orange County retail agencies. MWDOC obtained explanatory variables from reputable sources, including weather databases and Census -based reports. The explanatory variables used in the regression were based on industry experience regarding what factors affect water use nationwide and in Southern California. By statistically linking water use to explanatory variables, the econometric models provide a robust foundation for understanding variability and projecting future consumption patterns. Modeled water use is the product of the driver count (e.g., number of accounts) and the rate of water use per driver: Water Use = Driver Count x Rate of Use per Driver Each of the four demand sectors modeled (single-family, multifamily, CII, and irrigation) has a separate equation. Driver units change into the future based on housing, employment, and population projections. The rate of water use per driver is based on the historical response of the use rate to explanatory variables (measured by coefficients) and the future values of those same explanatory variables. Linear regression produces the coefficients for each explanatory variable to closely reproduce the historical rate of use per driver unit. The coefficients explain how (both in terms of magnitude and sign) water use responds to changes to explanatory variables. MWDOC identified driver units based on data provided by agencies and the Center for Demographic Research at Cal State Fullerton (CDR) that can be easily projected into the future. The rate of water use per driver is based on agency provided billing sector uses from 2010 through 2024. Table 4.6 shows the driver units and rate of use for each of the four models. Table 4.6 Summary of Demand Sectors Single-family Residential Multi -family Residential CII Dedicated Irrigation (potable, recycled, and raw water) Accounts Gallons/account/day Accounts Gallons/account/day Jobs Gallons/job/day Accounts Gallons/account/day The rates of water use for each sector model are based on the historical responses to explanatory variables and the future values of those explanatory variables. Addressing multiple influences on demand improves the accuracy and precision of all estimated parameters, and the modeling team identified a large range of explanatory variables based on past experience with demand modeling and available data. Table 4.7 displays the explanatory variables. CITY OF TUSTIN 4-8 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Table 4.7 Summary of Historical Data Collected for Model Development lataset t. Observed weather (monthly precipitation, Parameter -elevation Regressions on Independent Slopes Model monthly maximum temperature) (PRISM) Water Price Retail agency provided (2010 — 2024) Drought Restrictions State Water Resources Control Board Gross Domestic Product (GDP) Federal Reserve Bank of St. Louis Real Gross Domestic Product: All Industries in Orange County, CA Median Income US Census American Community Survey (ACS) Housing Density US Census American Community Survey (ACS), California State Persons Per Household University Fullerton Center for Demographics Research (CDR), Southern California Association of Governments (SCAG) land use data Relative Sectoral Economic Activity US Census LODES, CDR Passive Efficiency Estimates Analysis of trend indicators and MWDOC/FLUME insight COVID Binary Indicator Assumed active from March 2020 — May 2023 The MWDOC Water Use Efficiency Group provided annual water savings achieved by various active conservation measures. To avoid potential errors in the classification of historical conservation data, total historical conservation was modeled in each sectoral regression model using a linear trend to capture steady change over time. While historical conservation is captured in a linear trend, projected passive conservation is based on the best available data from the 2021 Orange County Residential Water Efficiency Potential and Opportunities Study and assumes a 1.9 percent decrease in annual residential demand from 2025 to 2030, at which point passive conservation is projected to remain constant. Future active conservation is not accounted for in baseline demand forecast, as water savings from active programs (programs that require customers to change behavior) are highly specific to retail agencies and to the formulation and timing of their implementation. The process of identifying the explanatory variables to include in the regression equation and developing coefficients that accurately measure the response of water use to changes in these variables is the most time -intensive part of the demand forecasting process. Prior to developing the forecasts, model calibration and fine tuning for each of the four demand sectors occurred at the individual retail agency level. The modeling team worked with each retail agency to calibrate sectoral model equations and quantify other uses (those not included in the single-family, multifamily, irrigation, or CII demand sectors). Figure 4.3 presents the iterative process undergone to develop the econometric demand forecasts. CITY OF TUSTIN 4-9 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Collect and process historical data a Develop econometric �i models a 0 Equations explaining historical water use aCollect and process o projected data 4 t Develop Demand Projections 0 The type and number of variables used is iteratively determined Figure 4.3 Econometric Demand Forecast Development Process 4.3.2 Forecasted Demands Forecasted demand is a function of both the change in driver units into the future as well as the change in explanatory variables. Table 4.8 summarizes the future drivers, variables, and assumptions for the baseline forecast. It should be noted that the CDR demographic forecast accounts for both the RHNA allocations and the projected increase in accessory dwelling units (ADUs). The 2022 Orange County Projections accounted for Draft RHNA rezone sites' with jurisdictions including the number of dwelling units that are most likely to occur/get built by the end of 2050 under assumptions and trends existing at the time of the forecasting effort. ' For the 2022 Orange County Projections, CDR collected initial draft input from local jurisdictions in September 2021 on their anticipated jurisdiction -level housing growth for each projection year. In December 2021-February 2022, CDR reviewed and extracted data from jurisdictions' draft housing elements to create a parcel -level inventory of additional housing capacity from sites that were to be rezoned to accommodate the 6th RHNA cycle. These were reviewed byjurisdictions in spring 2022. Jurisdictions completed the rezoning of the final sites after their housing elements were certified by the State Housing and Community Development Department starting in 2022. The final adopted rezone sites will feed into CDR's 2026 Orange County Projections. CITY OF TUSTIN 4-10 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Table 4.8 Future Model Parameters Driver Units Single-family and CDR Historical households per account; averages are multifamily accounts multiplied by households projected by CDR Irrigation accounts Agency Billing Data Accounts are assumed to be constant into the future Sectoral Employment CDR Proportion of jobs within CII sectors projected by CDR Explanatory Monthly Maximum PRISM 30-year historical normal weather Variables Temperature and Total Precipitation Water Price Retail Agencies Prices increase by 3% per year above inflation for 2025-2030 and keeps pace with inflation thereafter (zero difference from inflation trend) Water Use Restrictions State and Local None Restrictions Seasonality Sine/cosine functions to capture monthly pattern Median Income US Census Constant income at 2022 value (real dollars) Housing Density CDR Derived from CDR housing unit projections, assuming residential area remains at 2024 levels Persons Per Household CDR Gross Domestic Product Federal Reserve Relative Sectoral Employment Passive Efficiency Estimates COVID Binary Indicator Is] Q1V Flume Insight CDR projected demographics Long-term GDP trend Calculated based on CDR projections Assumes a 2% decrease in residential demand due to conservation by 2030 (linearly extrapolated), then no change None (occurred between March 2020 and May 2023) The normal year scenario was provided by the baseline forecast. In this model, the single dry year scenario used a hot -dry index (HDI) to identify the year with the most weather -sensitive demand, with 2014 selected for most agencies. The multiple dry year was developed to describe the potential impact of consecutive dry years. The forecasts for individual agencies, including the City's, were then summed to the regional level, providing regionally consistent forecasts for all of Orange County. 4.4 Water Loss The City has conducted annual water loss audits since 2015, per the AWWA (American Water Works Association) methodology, per SB 555, to understand the relationship between water loss, operating costs, and revenue losses. Non -revenue water for Calendar Year (CY) 2020-2024 consists of three components: real losses (e.g., leakage in mains and service lines, and storage tank overflows), apparent losses (unauthorized consumption, customer metering inaccuracies, and systematic data handling errors), and unbilled water (e.g., hydrant flushing, firefighting, and blowoff water from well start-ups). Table 4.9 summarizes the status of the last five years of water loss audit reporting for the water system. Reports can be found online at WUEdata - Water Audit Plans. Understanding and controlling water loss from a CITY OF TUSTIN 4-11 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO distribution system is an effective way for the City to achieve regulatory standards and manage their existing resources. Table 4.9 Submittal Table 4-5 Retail: Water Loss Audit Reporting TableSubmittal Reporting Water Code Section 10631 Public Water System ID # Reported in Table 2-1 R Reporting Period Submitted to DWR Water Loss Audit Program (yes/no) Report submittal status for all five years for each Public Water System as available. Add rows as needed CA3010046 2020 Yes 2021 Yes 2022 Yes 2023 Yes 2024 Yes DWR NOTES: Suppliers will provide a link to the WUEdata submittals of their Water Loss Audit Reports. NOTES: Water Loss Audits reported in Calendar Years (CY). Signed in 2018 and adopted in 2024, the "Making Conservation a California Way of Life" legislation (SB 606 and Assembly Bill 1668) establishes a new framework for long-term improvements in urban water use efficiency and drought planning as California adapts to climate change impacts. Under the regulation, Suppliers must annually calculate Urban Water Use Objectives based on standards applied at the service -area scale, including the Water Loss Performance Standard developed by the State Water Resources Control Board to minimize water waste through system leaks. The Water Loss Performance Standard requires that Suppliers must meet the real water loss standard and apparent water loss standard by 2028. Table 4.10 presents the City's progress towards compliance with the 2028 Water Loss Standard, as of the time of writing this UWMP. The most recent AWWA Water Loss Audit for CY 2024 was utilized for the calculations presented. CITY OF TUSTIN 4-12 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Table 4.10 Submittal Table 4-6 Retail: Progress Towards 2028 Water Loss Standard Water Code Section 10631 Water Loss ApparentReal lacMuateaaterStandard BoardState Water Most Recent AWWA State Water Board Most Recent AWWANUIC Water Loss Audit Standard Water Loss Audit Water Loss Standard for Number of Volume of Real Volume of Apparent System ID # y this Public Water 2028 Real Units for Units Total Real Water 2028 Total Water Reported in System? (y/n) Water Loss Real Water (Connections Loss (from Loss Per Apparent Units for Apparent Loss Loss Per Submittal Table 2-1 R If no, Supplier will not complete this Standard Loss or Miles AWWA Unit er p Water Loss Standard Apparent Number of Connections ( from AWWA Unit er p row. per Unit Drop down corresponding Water Loss Day Water Loss per Unit Water Loss Day per day list with units Audit) per Day Audit) selected) (AF) (AF) Add additional rows as needed. Gallons Gallons per Service per Service CA3010046 Yes 24.0 Connection 14,419 280.39 17.4 11.9 Connection 14,419 439.08 27.2 per Day per Day (GPSCD) (GPSCD) Water Board's Calculated Water Loss Standards DWR NOTES: Units of measure (AF, CCF, MG) for Water Loss MUST remain consistent with units reported in Submittal Table 2-3. The units reported in Submittal Table 2-3 are used in this table's calculations. NOTES: Uses the Water Board's calculated water loss standards updated as of 01/30/2026 and AWWA Water Loss Audit for CY 2024. Connection count may differ from what is reported in Table 2-1 R for FY 2025. CITY OF TUSTIN 4-13 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO CHAPTER CONSERVATION TARGET COMPLIANCE The Water Conservation Act of 2009, also known as Senate Bill (SB) X7-7, mandated a 20 percent reduction in urban per capita water use across California by 2020. To achieve this goal, the Act required each retail water supplier to establish an urban water -use target, contributing to the State of California's (State) collective efforts. The Legislature stated that the combined reductions from all retail suppliers would fulfill the statewide legislative mandate. The goal of this chapter is to allow the retail water supplier to report on their progress toward meeting their urban water -use targets in their Urban Water Management Plan (UWMP), pursuant to California Water Code Section 10608.40. Suppliers that did not meet their 2020 target in 2020 are required to compare their 2025 water use to the 2020 target. Retail water suppliers are required to comply with SB X7-7 individually or as a region in collaboration with other retail water suppliers or demonstrate they have a plan or have secured funding to be in compliance, in order to be eligible for water -related state grants and loans. When determining water use in a UWMP, two terms are often used interchangeably: Daily Per Capita Water Use. The amount of water used per person per day. In the UWMP calculations, this is the total water use within a service area, divided by population, and it is measured in gallons. Gallons Per Capita Per Day (gpcd). This is the "daily per capita water use" measured in gallons. Therefore, the term commonly used when referring to "daily per capita water use" is "gallons per capita per day" or gpcd.' 5.1 Reporting Requirements Municipal Water District of Orange County's (MWDOC) Water Use Efficiency (WUE) programs helped Orange County meet the state's 20x2020 mandate by coordinating conservation efforts across its member agencies, funding and implementing regionally cost-effective efficiency programs, and enabling compliance through the Orange County 20x2020 Regional Alliance. By aligning its WUE portfolio directly with SB X7-7 requirements, supporting high -impact measures (especially outdoor water savings), documenting eligible indirect potable reuse credits, and centrally handling regional target calculations and reporting, MWDOC allowed participating retailers to comply collectively rather than individually, resulting in regional per capita water use well below the required 2020 target. It is important to distinguish GPCD (as used in UWMPs) from the Residential Gallons Per Capita Per Day (R-GPCD) that is used in some reporting to the California State Water Resources Control Board (SWRCB). GPCD is the total water use from all sectors within a service area (residential, commercial, institutional, and any others) minus allowable exclusions (as defined in SB X7-7), then divided by the population. This is used in UWMPs. R-GPCD is only a part of the GPCD; it is the estimated residential water use in a service area divided by population. CITY OF TUSTIN 5-1 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO As a result of MWDOC's WUE program, all Orange County water retailers, including all MWDOC's member agencies and the participating cities of Anaheim, Fullerton, and Santa Ana, achieved compliance prior to 2020. The following table with information taken from the 2020 UWMP verifies that the City of Tustin met its SB X7-7 requirement. A discussion of programs implemented to support the achievement of the agency's per capita water reduction goals is covered in Section 9 - Demand Management Measures of this UWMP. Table 5.1 Submittal Table 5-1 Retail: SB X7-7 2020 Target Progress Submittal Table 5-1 Aetail:'36 A7-7 rr Water Code Section r.r ,r Check the box if the Supplier was not an Urban Water Supplier Proceed to the next table. during or before M the 020 UWIVIP reporting cycle. Only for suppliers that did not meet the Target in 2020 Was Supplier part of Regional Alliance Did Supplier See DWR NOTES below. a merger or Target or Achieve Targeted Individual 2020Target Actua12020GPCD consolidation since Target? Reduction for Actual 2025 GPCD Did Supplier meet ? 2020. Drop down list 2020. ? (From SB X7-7 the 2020 Target in Compliance Form) 2025? am No Individual Target 151 95 Yes NA DWR NOTES: Suppliers calculating a 2025 GPCD will need to complete and submit SB X 7-7 Compliance Tables to verify the use of SB X7-7 Methodologies. Suppliers that were part of a merger or consolidation since 2020 see Chapter 5 and Appendix P for guidance. NA=Not Applicable NOTES: Supplier met the 2020 target, actual 2025 GPCD not required. CITY OF TUSTIN 5-2 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO CHAPTER 6WATER SUPPLY CHARACTERIZATION Orange County has a water supply portfolio made up from a variety of local and imported sources. Groundwater is produced from the Orange County Groundwater Basin (OC Basin), which is managed by the Orange County Water District (OCWD). To enhance the reliability of groundwater, OCWD has implemented projects and programs over the years that include: (1) the Orange County Groundwater Replenishment System (GWRS), which is the world's largest water purification system for indirect potable reuse; (2) increased stormwater capture for groundwater recharge; and (3) participation in the Santa Ana River Conservation and Conjunctive Use Program (SARCCUP), a collaborative, watershed -scale approach for groundwater basin management, replenishment, and water transfers. Imported water is provided by the Metropolitan Water District of Southern California (MET), the wholesale water provider to 26 member agencies in Los Angeles, Orange, Riverside, San Bernardino, San Diego, and Ventura Counties. MET's imported water sources are delivered through its own Colorado River Aqueduct (CRA) and the California Aqueduct, under contract with the State Water Project (SWP). To enhance its reliability of its imported water, MET has implemented many programs such as canal lining and transfers of agricultural water, land fallowing programs with irrigation districts, water banking programs, and use of its storage reservoirs. Local and imported water sources in Orange County are managed in such a way that they complement each other. For example, during wet and normal years, additional MET water is purchased for groundwater replenishment in the OC Basin. During dry and drought years, when imported water is more limited, more groundwater can be produced to meet Orange County's water demands. This coordinated management of water supplies has resulted in reliable water service even during multi -year droughts. Based on the water supply assessment described in this chapter and in Chapter 7, the Orange County region will continue to receive a reliable water supply through the next 25 years. Specifically, this chapter includes: (1) descriptions of each water supply source and its management; (2) quantification of water supply sources through 2050 under normal, dry, and multi -dry weather conditions; (3) opportunities for exchanges and transfers; and (4) discussion regarding any planned or potential future water supply projects. This chapter also includes the energy intensity of the water service. 6.1 Water Supply Overview The City of Tustin (City) meets all of its demands with a combination of imported water and local groundwater to meet its water needs. The City works together with the Municipal Water District of Orange County (MWDOC), East Orange County Water District (EOCWD), and OCWD to deliver safe and reliable water supply that will continue to serve the community in periods of average, dry and drought hydrologic conditions. MWDOC is the Orange County wholesaler of imported water and one of MET's 26 member agencies. MET's imported water is delivered from the California SWP and MET's CRA to Southern California. The City purchases imported water through MWDOC and EOCWD to supplement its local supplies. Local sources presently account for 68 percent of the City's water supplies, whereby groundwater is the major source of local supply. The primary source of groundwater originates from the OC Basin, which is CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO located in the middle portion of MWDOC's service area and is managed by the OCWD. The GWRS is a joint project between OCWD and the Orange County Sanitation District (OC San). Using advanced treatment purification, recycled wastewater is transformed into a high -quality water supply for groundwater replenishment. The City's main source of water supply is groundwater from the OC Basin. Imported water makes up the rest of the City's water supply portfolio. In fiscal year (FY) 2024-25, the City relied on approximately 68 percent groundwater and 32 percent imported water (Table 6.1). Table 6.1 Water Supplies - 2025 Actual In 2025, MWDOC developed a water demand forecast model for its participating water agencies that statistically correlates municipal and industrial (M&I) water use with demographic, socioeconomic, conservation and weather variables —as reported in the 2025 Orange County Water Demand Projection Model TM (MWDOC, 2025). Because the model isolates weather, future water demand projects can be estimated under single and multiple -year droughts and under future climate change scenarios. It is projected that by 2050, the City's water portfolio will change to approximately 85 percent groundwater and 15 percent imported water (Table 6.2 and Figure 6.1). It should be noted that these representations of supply match the projected demand. However, the City can purchase more MET imported water through MWDOC/EOCWD, should the need arise. Note that the Groundwater Replenishment System (GWRS) supplies are included as part of groundwater pumping numbers. The following subsections provide a detailed discussion of the City's water sources as well as the future water supply portfolio for the next 25 years. CITY OF TUSTIN 6-2 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 100 % 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 2030 2035 204D 2045 2050 ■ Groundwater ■ Imported Water Figure 6.1 City's Projected Water Supply CITY OF TUSTIN 6-3 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Table 6.2 Water Supplies - Projected CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 6.2 Imported Water The City supplements its water supply with imported water purchased from MET through MWDOC and EOCWD. In FY 2024-25, the City relied on approximately 3,293 acre-feet per year (AFY)—approximately 32 percent of the City's water supply portfolio for FY 2024-25—of imported water from MET/MWDOC to meet its demands. MET's two principal sources of water are the Colorado River and the SWP. MET receives water from the Colorado River through the CRA and from the SWP through the California Aqueduct. For Orange County, the water obtained from these sources is treated at the Robert B. Diemer Filtration Plant located in the City of Yorba Linda. Typically, the Diemer Filtration Plant receives a blend of Colorado River water from Lake Mathews through the MET Lower Feeder and SWP water through the Yorba Linda Feeder. The City maintains three imported water connections to the MET system. Imported water is purchased from EOCWD through each of these connections. Water purchased through OC-43 is distributed directly into the City's system, while water purchased through the other two connections (OC-48 and OC-70) is also distributed to EOCWD's four other retail customers: the City of Orange, Golden State Water Company (GSWC), Irvine Ranch Water District (IRWD), and the EOCWD Retail Zone. 6.2.1 Metropolitan Water District of Southern California MET is the largest water wholesaler in California, serving approximately 19 million customers in a 5,200 square mile service area. MET wholesales imported water supplies to 26 member agencies located in the six southern California counties of Los Angeles, Orange, Riverside, San Bernardino, San Diego, and Ventura. MET is governed by a Board of Directors comprised of 38 appointed individuals with a minimum of one representative from each of MET's 26 member agencies. The allocation of directors and voting rights is determined by each agency's assessed valuation. Each member of the Board is entitled to cast one vote for each ten million dollars of assessed valuation of property taxable for district purposes, in accordance with Section 55 of the Metropolitan Water District Act. Directors may be appointed by the chief executive officer of the member agency or by a majority vote of the agency's governing board. Directors are not compensated by MET for their service (The Metropolitan Water District Act, 1969). MET is responsible for importing water into the region through its operation of the CRA, which brings Colorado River supply to its service area, and its SWP contract, which brings water from northern California via the California Aqueduct. MET supplements its direct deliveries of imported supplies with its storage reservoirs, water transfers, agricultural irrigation water conservation, and water banking programs. Major imported water aqueducts bringing water to Southern California are shown in Figure 6.3. It should be noted that the Los Angeles Aqueduct is owned and operated by the Los Angeles Department of Water and Power and is not part of MET's imported water supplies. Member agencies receive water from MET through various delivery points and pay for service through a rate structure comprising volumetric rates, capacity charges, and readiness -to -serve charges. Member agencies provide MET with estimates of imported water demand in April each year, indicating the amount of water they anticipate they will need to meet their demands over the next five years. CITY OF TUSTIN 6-5 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO In Orange County, MWDOC and the cities of Anaheim, Fullerton, and Santa Ana are MET member agencies that purchase imported water directly from MET. MWDOC purchases both treated potable and untreated water from MET to supplement its retail agencies' local water supplies and for groundwater replenishment. Figure 6.4 illustrates the MET feeders and major transmission pipelines that deliver water within Orange County. L`ke Map Legend er-vrva-l: Faculties m E o c rq e courlty � Eta— cif Ct71i=effa. — RivHr ppay WAT &R III. aoGewr�aa W M e 1 43.1 39 M M 410 91 MW Rod.[mivth�c UxoOa9 oIMVJMD]CI toJhrbfThe cart FdeaafCRFearn Gate %)%vm.. MVGX.. CDR. Ca8L AugustMfi WAIF BC'9 W^ACCk.K^a P&a,u aaLkV:ci,,w1 Crange County Metropol'tan`& 7 Colorado RlverAqueduol Figure 6.2 Major Aqueducts That Supply Imported Water to Southern California (MET, 2025) CITY OF TUSTIN 6-6 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO J ,If San BwnW�q Cwm>r IpMP,1 pAkpl PQyI .. RMMPf1 CCV FR. LOVLER FE R nuwm ! !• .. �QyLEAfE 2N0 L0NS>7 FEEDER •. MST OC FEEDER ppp PETER, l fi:'.'CR C�ANYpN RESERVOIR in SYPLID0, W. �A RESEENd � T' +; q,,£ryf VPPER OSO RESBWOIR 41 TRABUM DAM IRVINE RCSC RVOIR 0 PORTOLA RESERVOIR CROSSFEEDER Et TORO RESE IR .... ..... k17H RESE Eq C.4RYON RESE UPPER CRIOUITA RESERVOIR ryG 12 errs wr+.w,. 2 a *ODHERNAOpAABASIH • Recycled Water Reservoir """ C—ON-S---- . J ■ Water Treatment Facility REs IR sa t 0 Potable Water Reservoir �ivnr ReseRwiR --! Untreated Water Pipeline (Local) — Untreated Water Pipeline (MET) ��1 w MET Treated Water Pipeline ryr — Joint Local Agency Pipeline SCRLE3EL RESE RVO R Joint MET/Local Agency Pipeline (MET Operated) N Joint MET/Local Agency Pipeline (Locally Operated) Wp daplays Rew fttar Aq." LwuRd9ries. W+E •� errrcrwm Wray Lpx Ra wc>tt�caIXRl Hsu "v ""`OC 5 ❑-ia aovna MUOC C❑R '"Q'""° ❑ , ra as OC Water Retailers and Transmission Mains Figure 6.3 MET Feeders and Transmission Mains That Serve Orange County CITY OF TUSTIN 6-7 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 6.2.2 Colorado River Aqueduct 6.2.2.1 Background The Colorado River was MET's original source of water after MET's establishment in 1928. The original founding members created MET with the goal to build the CRA to bring water to Southern California. The CRA, which is owned and operated by MET, transports water from the Colorado River to its terminus, Lake Mathews, in Riverside County. The actual amount of water per year that may be conveyed through the CRA to MET's member agencies is subject to the availability of Colorado River water. Approximately 40 million people rely on the Colorado River and its tributaries for potable water, with 5.5 million acres of land using Colorado River water for irrigation. The CRA includes supplies from the implementation of the Quantification Settlement Agreement (QSA) and its related agreements to transfer water from agricultural agencies to urban uses. The 2003 QSA enabled California to implement major Colorado River water conservation and transfer programs to stabilize water supplies and reduce the state's demand on the river to its 4.4 million acre-feet (MAF) entitlement. Colorado River transactions are potentially available to supply additional water up to the CRA capacity of 1.25 MAF on an as -needed basis. Water from the Colorado River or its tributaries is available to users in California, Arizona, Colorado, Nevada, New Mexico, Utah, Wyoming, and Mexico. California is apportioned the use of 4.4 MAF of water from the Colorado River each year, plus one-half of any surplus that may be available for use collectively in Arizona, California, and Nevada. In addition, California has historically been allowed to use Colorado River water apportioned to, but not used by, Arizona or Nevada. MET has fourth -priority rights, with a basic entitlement of 550,000 AFY of Colorado River water, plus surplus water up to an additional 662,000 AFY when the following conditions exist (MET, 2025): ■ Water is unused by the California holders of priorities 1 through 3. ■ Water is saved by the Palo Verde land management, crop rotation, and water supply program. ■ When the US Secretary of the Interior makes available either one or both of the following: » Surplus water. Colorado River water that is apportioned to but unused by Arizona and/or Nevada. 6.2.2.2 Current Conditions and Supply The Colorado River supply faces current and future imbalances between water supply and demand in the Colorado River Basin due to reductions in snowpack, long-term drought conditions, and climate change. The last 25-year period has been called a megadrought, with Lake Mead's elevation dropping from a high of 1,215 feet in 2000 to its lowest level of 1,040 feet in July 2022. While extreme wet conditions resulted in lake levels exceeding 1,077 feet in February 2024, levels have been persistently hovering around 1,057 feet since May 2025. The United States Bureau of Reclamation (USBR) projects that there is a 53 percent likelihood that Lake Mead elevation could fall below 1,035 feet, which would trigger water shortages for MET under the current operating guidelines. As of August 2025, Lake Mead storage was approximately 31 percent of capacity per USBR's 24-Month Study, which also projected continued Lower Basin shortage conditions in 2026 (MET, 2025). The current operating guidelines for the Colorado River expire at the end of 2026, and a new, long-term operating plan must be in place by November 2026 to manage the river's water supply. The ongoing Colorado River allocation negotiations are focused on creating a post-2026 operating plan, with states CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO and the federal government aiming for consensus on how to manage the river's declining water supply due to the severe, prolonged drought in the Colorado River Basin. The drought on the Colorado River began around 2000 and has continued, in various degrees of severity, for over two decades, making it a historic megadrought that has significantly reduced water flow into the river and lowered water levels in reservoirs like Lake Powell and Lake Mead. Although some periods, like the wet winter of 2023, brought temporary relief with increased snowfall, they were not enough to fully replenish the system or overcome the prolonged lack of water and effects of climate change, such as aridification and increased evaporation, according to the US Geological Survey (USGS, 2024). Under the 2007 Interim Guidelines, together with the Lower Basin Drought Contingency Plan (2019), the Intentionally Created Surplus (ICS) program has allowed MET to store conserved water in Lake Mead for subsequent recovery; these frameworks sunset with the Guidelines at the end of 2026 and are expected to be addressed in the post-2026 rules (MET, 2025). The USBR, which is part of the U.S. Department of the Interior, is the federal agency leading the negotiations and responsible for managing the river system. The ongoing Colorado River negotiations aim to find a fair and sustainable way to allocate the available water, which is significantly less than in the past. Talks are centering on a "natural flow" proposal that divides water based on current river conditions, rather than historical allocations. However, states remain at odds over how much water to allocate to the Upper and Lower Basins, with the federal government planning to impose its own plan if an agreement is not reached by the November 2026 deadline. Some key challenges that remain to be resolved are the different interests of the Upper Basin states (Colorado, Utah, Wyoming, New Mexico) and the Lower Basin states (California, Arizona, Nevada) to reach consensus on how much water the Upper Basin should send downstream. In addition, Tribal nations are also seeking recognition of their rights and a role in the future management of the river. Given MET's junior priority status within California's Colorado River priority system, reductions to MET's supplies are a possibility under future operating criteria; MET's planning reflects this risk (MET, 2025). Consistent with MET's 2025 Urban Water Management Plan (UWMP), supply capability planning uses USBR's August 2023 Colorado River Simulation System (CRSS) assumptions, including a climate adjusted flow reduction factor of approximately 9.3 percent per 1 degree Celsius of warming over the planning horizon (2025-2050). MET continues to utilize supply, storage, transfer, and conservation programs, including ICS participation under the current Guidelines, to manage risk and buffer shortages. In addition, conserved QSA-related transfer water delivered at Lake Havasu (including Imperial Irrigation District and canal -lining exchanges) is categorized in MET's 2025 UWMP as Colorado River imported supply (previously treated as local supply), aligning accounting with current practice (MET, 2025). 6.2.2.3 MET Colorado River Current Programs Over the years, MET has helped fund and implement various programs to improve Colorado River supply reliability and help resolve the imbalance between supply and demand. Implementation of such programs has contributed to achievements such as a record -low diversion of the Colorado River in 2019, a level not seen since the 1950s. Colorado River water management programs include: ■ Lower Colorado Water Supply Projects - Authorized in the 1980s, this project provides up to 10,000 AFY of water to certain entities that do not have or have insufficient rights to use Colorado River water. A contract executed in 2007 allowed MET to receive project water left unused by the CITY OF TUSTIN 6-9 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO project contractors along the River - nearly 10,000 acre-feet (AF) were received in recent years when unused supplies were available. ■ Imperial Irrigation District / MET Conservation Program - Under agreements executed in 1988 and 1989, this program allows MET to fund water efficiency improvements within Imperial Irrigation District's service area in return for the right to divert the water conserved by those investments. An average of 105,000 AFY of water has been conserved since the program's implementation. ■ Management of MET -Owned Land in Palo Verde - Since 2001, MET has acquired approximately 21,000 acres of irrigable farmland that are leased to growers, with incentives to grow low water -using crops and experiment with low water -consumption practices. MET continues to evaluate opportunities to formally account for verified long-term water savings associated with these lands as part of its Colorado River supply reliability strategy. • Palo Verde Land Management, Crop Rotation, and Water Supply Program - Authorized in 2004, this 35-year program allows MET to pay participating farmers to reduce their water use, and for MET to receive the saved water. Over the life of the program, an average of 84,500 AFY has been saved and made available to MET. ■ Southern Nevada Water Authority (SNWA) and MET Storage and Interstate Release Agreement - Entered in 2004, this agreement allows SNWA to store its unused, conserved water with MET, in exchange for MET to receive additional Colorado River water supply. MET has relied on the additional water during dry years, especially during the 2011-2016 California drought, and SNWA is not expected to call upon MET to return water until after 2026. ■ Lake Mead Storage Program - Executed in 2006 and subsequently integrated with Lower Basin Drought Contingency Plan (DCP) operations, MET may intentionally leave conserved water in Lake Mead for exclusive future use. MET has significantly expanded its use of intentionally created surplus (ICS) storage in recent years, including record storage creation (450,000 AF) in 2023 under DCP-related conservation programs. ■ Quagga Mussel Control Program - Developed in 2007, this program introduced surveillance activities and control measures to combat quagga mussels, an invasive species that impacts the Colorado River's water quality. • Bard Seasonal Fallowing Program - Authorized in 2019 and subsequently expanded, this program allows MET to pay participating farmers in Bard to reduce their water use between the late spring and summer months of selected years. Under expanded program authorizations through 2026 (Quechan Seasonal Fallowing Program), this program can provide up to approximately 12,000 AFY in certain yea rs. ■ Lower Basin Drought Contingency Plan - Signed in 2019, this agreement incentivizes storage in Lake Mead through 2026, and overall, it increases MET's flexibility to fill the CRA as needed (MET, 2025). • Lower Basin Conservation and System Efficiency Programs - In recent years, MET has participated in new, multi -agency conservation and system efficiency programs implemented between 2023 and 2026. These programs incentivize agricultural conservation, system efficiency improvements, urban conservation, and groundwater storage in the Lower Colorado River Basin, with the goal of reducing system demands and increasing storage in Lake Mead during critically dry conditions. This includes programs such as the Quechan Diversion Forbearance program. CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO • Exchange Programs - MET is involved in separate exchange programs with the USBR, which takes place at the Colorado River Intake and with San Diego County Water Authority (SDCWA), which exchanges conserved Colorado River water. The Colorado River faces long-term challenges of water demands exceeding available supply with additional uncertainties due to climate change. Climate change impacts expected in the Colorado River Basin include the following: ■ More frequent, more intense, and longer lasting droughts, which will result in water deficits. • Continued dryness in the Colorado River Basin, which will increase the likelihood of triggering a first -ever shortage in the Lower Basin. ■ Increased temperatures, which will affect the percentage of precipitation that falls as rain or snow, as well as the amount and timing of mountain snowpack (MET, 2025). Given these uncertainties, MET plans to continue implementing and expanding Colorado River conservation, storage, exchange, and transfer programs, while also supporting increased water recycling and system efficiency improvements within the Colorado River Basin. MET continues to evaluate additional transfer and conservation opportunities to further enhance regional supply reliability through the 2025 UWMP planning horizon. 6.2.3 State Water Project 6.2.3.1 Background The SWP consists of a series of pump stations, reservoirs, aqueducts, tunnels, and power plants operated by the California Department of Water Resources (DWR) and is an integral part of the effort to ensure that business and industry, urban and suburban residents, and farmers throughout much of California have sufficient water. Water from the SWP originates at Lake Oroville, which is located on the Feather River in Northern California. Much of the SWP water supply passes through the Sacramento -San Joaquin Delta ("Delta"). The SWP is the largest state -built, multipurpose, user -financed water project in the United States. Nearly two-thirds of residents in California receive at least part of their water from the SWP, with approximately 70 percent of SWP's contracted water supply going to urban users and 30 percent to agricultural users. The primary purpose of the SWP is to divert and store water during wet periods in Northern and Central California and distribute it to areas of need in Northern California, the San Francisco Bay area, the San Joaquin Valley, the Central Coast, and Southern California (MET, 2025). The Delta is key to the SWP's ability to deliver water to its agricultural and urban contractors. All but five of the 29 SWP contractors receive water deliveries below the Delta (pumped via the Harvey O. Banks or Barker Slough pumping plants). However, the Delta faces many challenges concerning its long-term sustainability, such as climate change posing a threat of increased variability in floods and droughts. Sea level rise complicates efforts in managing salinity levels and preserving water quality in the Delta to ensure a suitable water supply for urban and agricultural use. Furthermore, other challenges include continued subsidence of Delta islands, many of which are already below sea level, and the related threat of catastrophic levee failure as water pressure increases or following a major seismic event. In May 2019, DWR withdrew its permit for the two -tunnel WaterFix project in favor of a smaller one -tunnel project alternative. In July 2022, the draft Environmental Impact Report (EIR) for the recommended Delta Conveyance Project alternative was issued, with the project potentially operational CITY OF TUSTIN 6-11 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO by 2045 (Delta Conveyance Design and Construction Authority, 2024), though its implementation faces strong opposition by environmental organizations and other interests in the Delta. The maximum value of the Delta Conveyance Project, when coupled with 250,000 AF of new regional storage, is estimated to be 367,000 AFY for MET, with 63,000 AFY of that amount for Orange County. The Delta Conveyance Project also reduces the probability that any shortage occurs by about 10 percent, meaning a doubling of the time between shortage conditions from once every 5 years to once every decade (MWDOC, 2023). 6.2.3.2 Current Conditions and Supply Just like the Colorado River, the amount of water that can be delivered from the SWP to its 29 contractors varies annually based on hydrology and reservoir storage along the SWP. The DWR publishes the maximum entitlement of SWP water for each water contracting agency in "Table A." DWR sets these allocations to balance the needs for human health and safety, agricultural, and municipal water, considering factors like reservoir storage, runoff forecasts, and Endangered Species Act (ESA) requirements. The primary drivers that influence allocations are hydrologic conditions (precipitation and snowmelt) along with storage levels, especially in Lake Oroville. Actual deliveries typically average less than 50 percent of Table A due to hydrologic and regulatory constraints (MET, 2025). MET's actual annual allocations based on springtime Table A values for the past UWMP cycles are summarized in Table 6.3. Table 6.3 MET SWP Program Capabilities 2015 0.38 2020 0.38 2025 0.96 Percent Change0) +252.6% Notes: (1) Percent change is between the years 2020 and 2025. Source: SWP Allocations 1996-2026. SWP contractors may additionally receive Article 21 water on a short-term basis in addition to Table A water if requested. Article 21 of SWP contracts allows contractors to receive additional water deliveries only under specific conditions, generally during wet months of the year (December through March). Because a SWP contractor must have an immediate use for Article 21 supply or a place to store it outside of the SWP, there are few contractors like MET that can access such supplies (MET, 2025). Carryover water is SWP water allocated to an SWP contractor and approved for delivery to the contractor in a given year but not used by the end of the year. The unused water is stored in the SWP's share of San Luis Reservoir, when space is available, for the contractor to use in the following year (MET, 2025). Turnback pool water is Table A water that has been allocated to SWP contractors who have exceeded their demands. This water can then be purchased by another contractor depending on its availability (MET, 2025). The following factors affect the ability to estimate existing and future water delivery reliability: ■ Water availability at the source: Availability can be highly variable and depends on the amount and timing of rain and snow that fall in any given year. Generally, during a single dry year or two, surface and groundwater storage can supply most water deliveries, but multiple dry years can result in CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO critically low water reserves. Fisheries issues can also restrict the operations of the export pumps even when water supplies are available. ■ Water rights with priority over the SWP: Water users with prior water rights are assigned higher priority in DWR's modeling of the SWP's water delivery reliability, even ahead of SWP Table A water. ■ Climate change: Mean temperatures are predicted to vary more significantly than previously expected. This change in climate is anticipated to bring warmer winter storms that result in less snowfall at lower elevations, reducing total snowpack. From historical data, DWR projects that by 2050, the Sierra snowpack will be reduced from its historical average by 25 to 40 percent. Increased precipitation as rain could result in a larger number of "rain -on -snow" events, causing snow to melt earlier in the year and over fewer days than historically, affecting the availability of water for pumping by the SWP during summer. Furthermore, water quality may be adversely affected due to the anticipated increase in wildfires. Rising sea levels may result in potential pumping cutbacks on the SWP and Central Valley Project (CVP). DWR's recent planning documents and the Draft 2025 Delivery Capability Report (DCR) describe climate -adjusted "existing conditions" baselines and future scenarios used by agencies for UWMPs. ■ Regulatory restrictions on SWP Delta exports: The Biological Opinions (BiOps) protect special - status species such as delta smelt and spring- and winter -run Chinook salmon and imposed substantial constraints on Delta water supply operations through requirements for Delta inflow and outflow and export pumping restrictions. Restrictions on SWP operations imposed by state and federal agencies contribute substantially to the challenge of accurately determining the SWP's water delivery reliability in any given year (DWR, 2020b). ■ Ongoing environmental and policy planning efforts: Following the 2019 withdrawal of WaterFix, DWR certified the Delta Conveyance Project Final EIR and approved the Bethany alignment in December 2023, a key modernization initiative for the SWP. EcoRestore and related habitat efforts continue to advance. Delta levee failure: The levees are vulnerable to failure because most original levees were simply built with soils dredged from nearby channels and were not engineered. A breach of one or more levees and island flooding could affect Delta water quality and SWP operations for several months. When islands are flooded, DWR may need to drastically decrease or even cease SWP Delta exports to evaluate damage caused by salinity in the Delta. It can be concluded that the federal regulatory framework affecting the Bay-Delta's ecosystem, species, and water supply is constantly evolving by adapting to new scientific information, changing climate conditions, and legal challenges. This dynamic and complex regulatory landscape, along with hydrologic and storage conditions along the SWP, continues to result in water supply uncertainties that impact all SWP contractors, including MET, MWDOC, and its member agencies (MET, 2025). 6.2.3.3 SWP Programs/Plans In the past five years, MET has updated and implemented planning, regulatory, infrastructure, and operational programs to improve the reliability of the SWP supplies while addressing environmental, seismic, and climate -related risks in the Delta and along the California Aqueduct. Key SWP programs and planning efforts include: CITY OF TUSTIN 6-13 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO • SWP Biological Opinions and California Incidental Take Permit (ITP) - Updated federal Biological Opinions and a California ITP issued in 2024 provide a new operating framework intended to improve flexibility and species protection. The 2025 MET UWMP characterizes the net reliability benefit at approximately +60,000 AFY relative to prior permits, subject to hydrologic and regulatory conditions. • Healthy Rivers and Landscapes (HRL) Voluntary Agreements - MET supports the State's proposed Healthy Rivers and Landscapes program, which establishes a voluntary framework for improving Delta ecosystem conditions through coordinated flow contributions and habitat restoration projects. The HRL approach is intended to provide regulatory stability while supporting environmental objectives consistent with SWP operations. 6.2.4 Storage, Transfers, and Conveyance Programs Storage is a major component of MET's dry year resource management strategy. MET's likelihood of having adequate supply capability to meet projected demands, without implementing its Water Supply Allocation Plan (WSAP), depends on its storage resources. Following a significant drawdown during the 2020-2022 drought, MET rebuilt storage as hydrologic conditions improved. By the end of 2023, MET had approximately 3.4 MAF of regional dry -year storage. Storage increased to 3.8 MAF by the end of 2024, with levels projected to reach approximately 3.9 MAF by the end of 2025. MET also maintains approximately 750 thousand acre-feet (TAF) of emergency storage dedicated to catastrophic supply interruption conditions, including a major seismic failure of the Delta levees. In its 2025 UWMP, MET evaluates storage based on median starting storage at the beginning of each five-year increment, representing a 50 percent probability that actual storage will be higher or lower. This approach differs from earlier UWMPs, which relied on average storage assumptions, and provides a more conservative and realistic representation of storage availability. All storage capability values incorporate conveyance and recovery constraints associated with SWP terminal reservoirs, the CRA, and MET's in -region and out -of -region groundwater banking programs. Lake Oroville continues to serve as the SWP's largest storage facility with a capacity of approximately 3.5 MAF. Water released from Oroville moves to the Feather River and then to the Sacramento River before being pumped south at the Harvey O. Banks pumping plant into the California Aqueduct. MET's storage portfolio includes surface reservoirs such as Diamond Valley Lake, Lake Mathews, and Lake Skinner; SWP terminal storage in San Luis Reservoir; groundwater banking programs including Semitropic, Arvin -Edison, the High Desert Water Bank, Kern Delta, and Mojave; and ICS storage in Lake Mead. These storage assets provide operational flexibility during dry years and help maintain supplies during extended droughts or emergency events. MET endeavors to increase the reliability of water supplies through the development of flexible storage and transfer programs, including groundwater storage (MET, 2025). These include: ■ Antelope Valley -East Kern (AVEK) Water Agency Exchange and Storage Program: Under the exchange program, for every 2 AF MET receives, MET returns 1 AF back to AVEK, and MET will also be able to store up to 30,000 AF in AVEK's groundwater basin, with a dry -year return capability of 10,000 AF. ■ Arvin -Edison Storage Program: The storage program is estimated to deliver 75,000 AF, and the specific amount of water MET can expect to store in and subsequently receive from the program depends on hydrologic conditions and any regulatory requirements restricting MET's ability to export CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO water for storage. During wet years, MET has the discretion to use to program to store portions of its SWP supplies which are in excess, and during dry years, the Arvin -Edison Water Storage District returns MET's previously stored water to MET by direct groundwater pump -in or by exchange of surface water supplies. • Diamond Valley Lake to Rialto Pipeline: Planned for completion in 2028, this project creates a new conveyance that improves the ability to move non-SWP supplies (120 cubic feet per second (cfs), including CRA and banked water) into areas historically dependent on SWP deliveries, increasing drought and seismic resilience. • High Desert Water Bank Program: Developed in partnership with AVEK, this regional groundwater banking program allows MET to store up to 280,000 AF of SWP Table A or other available supplies in the Antelope Valley groundwater basin. The program provides a put -and -take capability of up to approximately 70,000 AFY, with infrastructure including monitoring and production wells, California Aqueduct turnouts, pipelines, recharge basins, and pump facilities. Phase 1 became operational in 2023, with full build -out expected by approximately 2030. ■ Kern -Delta Water District Storage Program: This groundwater storage program has 250,000 AF of storage capacity, and water for storage can either be directly recharged into the groundwater basin or delivered to Kern -Delta Water District farmers in lieu of pumping groundwater. During dry years, the Kern -Delta Water District returns MET's previously stored water to MET by direct groundwater pump -in return or by exchange of surface water supplies. ■ Mojave Storage Program: MET entered into a groundwater banking and exchange transfer agreement with Mojave Water Agency that allows for the cumulative storage of up to 390,000 AF. The agreement allows for MET to store water in an exchange account for later return. ■ Richvale & Western Canal Water Transfers: These multi -year transfer options will provide supplemental dry -year supplies when available, with volumes up to approximately 54,000 AF (2025-2027). ■ San Bernardino Valley MWD Surplus SWP Program: Programmatic access to surplus SWP supplies (approximately 13 TAF) will be available from SBVMWD under certain hydrologic and operational conditions. • Semitropic Storage Program: The maximum storage capacity of the program is 350,000 AF, and the minimum and maximum annual yields available to MET are 34,700 AF and 236,200 AF, respectively. The specific amount of water MET can expect to store in and subsequently receive from the program depends on hydrologic conditions, any regulatory requirements restricting MET's ability to export water for storage and demands placed by other program participants. During wet years, MET has the discretion to use the program to store portions of its SWP supplies which are in excess, and during dry years, the Semitropic Water Storage District returns MET's previously stored water to MET by direct groundwater pump -in or by exchange of surface water supplies. ■ Sepulveda Feeder Pump Stations (Stage 1): This program includes pumping improvements that expand westward movement of CRA/SWP/banked supplies across service areas to address localized system constraints. Pumping capacity is expected to be 30 cfs upon completion of Stage 1 in 2027. ■ Yuba Accord Extension: This project is a continuation of an established dry -year transfer program from the Yuba watershed that can be accessed subject to hydrologic and regulatory conditions. As of 2025, the extension is under negotiation for approximately 250,000 AFY in supply. CITY OF TUSTIN 6-15 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 6.2.5 Potential Future Water Projects 6.2.5.1 Climate Adaptation Master Plan for Water In February 2023, the MET's Board directed its staff to integrate water resources planning, climate resilience planning, and financial planning into a Climate Adaptation Master Plan for Water (CAMP4W). Then, a Joint Task Force of Board Members and Member Agency Managers was convened to facilitate the development of CAMP4W in a timely and transparent process. The main elements of CAMP4W include: 1. Identify climate and growth scenarios, building from analyses conducted for MET's Integrated Resources Plan (IRP). 2. Develop time -bound targets for new regional water supplies and system improvements. 3. Establish a framework for decision -making and annual reporting. 4. Form policies, initiatives, and partnerships. 5. Evaluate business models and funding strategies. Because investments required for regional supply reliability and system resilience are significant, it is important that decisions are made through an adaptive management process to avoid the risks associated with over -investment or underperformance. Tracking signposts and progress towards time -bound targets is therefore critical for CAMP4W's annual reporting. Currently, regional projects being explored by MET include Pure Water Southern California, new reservoir storage in Southern California of up to 155,000 AFY, regional seawater desalination, and participation in California's Delta Conveyance Project. These projects will be scored against the following CAMP4W criteria: (1) reliability; (2) resilience; (3) financial; (4) adaptability/flexibility; (5) equity; and (6) environmental co -benefits. Pure Water Southern California - The potential Pure Water Southern California program, a partnership with the Sanitation Districts of Los Angeles County, would purify wastewater treatment effluent that currently flows to the ocean to produce high -quality recycled water. The purified water would be delivered to Metropolitan's member agencies to meet their groundwater replenishment and storage requirements. It should be noted that the 2025 MET UWMP does not include Pure Water yield in projected supplies (MET, 2025). Sites Reservoir - This potential project includes a water storage reservoir of 1.5 MAF and would require the construction of two large dams up to 310 feet high and nine smaller saddle dams. The water stored in the reservoir, located north of Sacramento, would be diverted from the Sacramento River during high flow events and returned to the Sacramento River during dry and critical years, thereby providing additional dry -year water for environmental flows and project partners, including SWP agencies south of the Delta. The current operations model estimates the annual water yield of the Sites Reservoir Project at approximately 270,000 AFY by 2032, when the Sites Reservoir Project is scheduled to be operational (MET, 2025). It should be noted that the 2025 MET UWMP does not include Sites Reservoir in projected supplies (MET, 2025). Delta Conveyance Project - Following DWR's withdrawal and subsequent termination of the California WaterFix project, the State advanced a new single -tunnel Delta Conveyance Project to address seismic risk, sea -level rise, extreme weather, and regulatory uncertainty while improving long-term SWP delivery reliability. The environmental review was completed in 2023, and DWR has approved the project. Potential yield used in planning analyses is on the order of approximately 400,000 AFY. It should be noted that the CITY OF TUSTIN 6-16 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 2025 MET UWMP does not include the Delta Conveyance Project yield in projected supplies pending future milestones and contracting decisions (MET, 2025). 6.2.6 Supply Reliability Within MET MET's 2025 UWMP reports on its water reliability and identifies projected supplies to meet the long-term demand within its service area. The MET 2025 UWMP discusses the current water supply conditions and long-term plans for supply implementation and continued development of a diversified resource mix. It describes the programs being implemented, such as the CRA, SWP, Central Valley storage/transfer programs, water use efficiency programs, local resource projects, and in -region storage that will enable the region to meet its water supply needs. MET's 2025 UWMP also presents MET's supply capacities from 2025 through 2050 for average year, single dry year, five consecutive dry years, and more frequent and severe droughts, as specified in the UWMP Act. Information concerning MET's UWMP, including the background, associated challenges, and long-term development of programs for each of MET's supply sources and capacities, has been summarized and included in the following subsections. Additional information on MET can be found directly in MET's 2025 UWMP. 6.2.6.1 MET's Water Service Reliability Assessment Results In MET's 2025 UWMP, MET evaluated supply reliability by projecting supply and demand under a normal year, single -dry year, and five-year consecutive dry years, based on conditions affecting the SWP (MET's largest and most variable supply). For this supply source, the average of 100 historical years, 1922-2021, most closely represents water supply conditions in a normal water year; the single driest year was 1977, and the five-year dry period was 1988-1992. The analyses also include Colorado River supplies under the same hydrological variations. MET also incorporated the SWP and Colorado River's reliability factors, such as water quality objectives set by the SWRCB, BiOps, and amendments to the Coordinated Operations Agreement for the SWP and QSAs for the Colorado River, into their assessment. MET has concluded that the region can provide reliable water supplies under normal, single -dry, and five-year consecutive dry conditions as presented in Table 6.4, Table 6.5, and Table 6.6, respectively. In each of the following tables, "Current Programs" supplies include: ■ In -Region Supplies and Programs: Metropolitan Surface Storage (Diamond Valley Lake, Lake Mathews, Lake Skinner). Flexible Storage in Castaic Lake and Perris Lake. Groundwater Storage for Conjunctive Use. ■ California Aqueduct (SWP), including Central Valley transfers and storage program supplies conveyed by the aqueduct. ■ Colorado River Aqueduct, including deliveries, programs, and exchanges with SDCWA. ■ These supplies are impacted - typically reduced - by the single dry year and multiple dry year scenarios. Though demands increase in these drought conditions, MET projects a reliable supply, even surplus, through 2050. MWDOC is a MET member agency, and MET's projections take into account CITY OF TUSTIN 6-17 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO the imported demands from Orange County. As such, MET'S water reliability assessments are used to determine that demands within MWDOC can be met for all three hydrological conditions. Table 6.4 MET's Projected Supply Capability and Demands Through 2050 for a Normal Year No rma I Year Supply Capability' and Projected Demands Average of 1522-2021 Hydrologies (acre-feet per year) Forecast Year Current Prowelins 2030 2035 2040 0.1 In-Regiun Supplies and Programs California Aq uedur-V CDloradD River Aqueduct Total Supply Available' Aqueduct Capacity Lr t4 Coloradfl River Aqueduct Ca a bi I ity 789,000 1.723.000 1.334.700 1,250,DW 1.250.000 776,000 1,6M,000 1,358,200 1,250,000 1,250,000 746,000 1,668,000 1,3 ,000 1.250.wo 1,250,000 733,000 1,641,000 1,323,500 1,250,000 1,250,000 827.000 1,-641.000 1.345,500 1-250,000 1.250.000 Capability of Current Programs 3,762,000 3,720,000 3,664,000 3,624,000 3,718.000 Demands rolal Demands on Metropolitan Excfian a w,th SDCWA 1,225,000 278,000 1ZI-8,000 278,000 1,266,000 278,000 1,265,000 276,000 1.3i 3.Ui:G 278.000 Total Metropolitan Ck llveilasd 1AW13,000 1,51$,OOO 1,S OOO 1,563,000 1.581:090 Surplus 2,299,000 ODO 2,120,000 2-061-000 2.137.000 Pro rams Under Development In-Regi-on Supplies and Programs California Aqueduct CDlorado River Aqueduct Total Supply Available? Aqueduct Capacity Z rWe Colorado RiverA uedu-ctCa a bi I ity 0 0 0 0 0 0 0 0 0 0 0 L 0 0 0 L {] 0 0 C v' Y Capability of Proposed Programs 0 0 0 0 0 Potential Surplus 2 259 000 2,204,000 2120 O00 2 061 O00 2.1 37.900 Notes: 1. Represents Supply Capability for resource programs under I isted year type. 2. California Aqueduct includes Central Valley transfers and storage program supplies conveyed by the aqueduct. 3. Colorado River Aq ueduct includes programs and Exchange with SDCVVA conveyed by the aqueduct- 4. Maximum GRA deliveries limited to 1.25 MAF including Exchange with SI GWA. 5. Total demands are adjusted to include Exchange with SDCWA. CITY OF TUSTIN 6-18 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Table 6.5 MET's Projected Supply Capability and Demands Through 2050 for a Single Dry Year Single Dry Year Supply Capabilityi and Projected Demands Repeat of 197T Hydrology (acne -feet per year) Ott Prognim 2040 In -Region Supplies and Programs California Aqueduc12 Colorado River Aqueduct TDtal SupplyAvailable" Aqueduct Capacity L;mie Colorado River Agueduct Capability 7199,000 662,00U 1,394,7M 1, 50,00D 1,250,000 776,000 649,000 1r358,200 1,260,060 1.250-000 746.040 635.000 1.336.000 1,250,000 1.250,000 7334000 62ZOOO 1,411,000 f,250,WO 1,25G.000 827,000 622.000 1,433.000 1.250,000 1.250.000 Capability of Current Programs 2,7",004 2,675,000 2,631,000 2,505,0010 2,M,000 Demands Total Demands on Metropolitan Exchance with SDGWA 1,3 ,000 278,000 1,375,000 278,000 1,4.01,000 278 000 1,419,000 278,000 1.436,000 278,000 Total Metropolitan Del iveriess 1,634,000 1,663,000 1,6T9,000 1,99T,000 1,714,000 Surplus 1,067,000 1,022,000 9d2 WG 908,000 985,000 Programs Under Development In -Region Supplies and Programs California Aqueduct Colorado River Aqueduct Total SupplyAvailable' ,4quaduct Gapaclty Limie Colorado River Ag ueduct Capability 0 0 t 0 0 0 0 0 0 O 0 0 1 ,9 v 1v v , Capability ofPTo aced Pro rams 0 0 0 0 Potential Surplus 1,06T-000 1.022-000 952,000 90 U00 985,040 Notes: 1. Represents Supply Capability for resource programs under listed yeartype. 2. Calrfomia Aqueduct includes Central Valley transfers and storage program supplies conveyed by the aqueduct. 3. Colorado River Aqueduct includes programs and Exchange with SDCWA oonveyed by the aqueduct. 4. Maximum CRA deliveries limited to 1.25 MAF including Exchange with SDCWA. 5. Total demands are adjusted to include Exchange with SDCUVA. CITY OF TUSTIN 6-19 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Table 6.6 MET's Projected Supply Capability and Demands Through 2050 for a Drought (5 Consecutive Water Years) Draught Lasting Fire Consecutive Years Supply Capability' and Projected Demands Repeat of 1988-1992 Hydrology (acre-feet per year) rorecast YearF Currant Programs 2035 2040 2049 2080 In -Region Supplies and Programs CaldomiaAgueductz Colorado River Aqueduct Total Supply AvailabO Aqueduct Capacity Lime Colorado Ri ver Aqueduct Capa bi I ity 160,000 733r200 1,189r200 1.250.000 1 189.200 156.000 720.400 1,241.700 1-250,OU0 1,241.700 149,000 690,400 1,204,500 1,250.000 1,204.500 146,000 660,400 1,197,000 1,250,000 1.197 000 165,000 579r400 1,245r50O 1,250.000 1,245.500 Capability of Current Programs 2A82r400 2,118,100 2,043,900 2,003,400 1,989,900 Demands Total Demands on Metropolitan Exchange vA[h SDCWA 1.324.000 278.000 1.390.000 278.Ob0 1.411r000 278,0b0 1.434.a00 278.000 1.453.000 270.000 Total Mittropollitan Dslivsriess 1 A02,000 1,668,000 1,689A00 1,712,000 1,731,000 3 urplus 480AGO 4S0100 364,900 291 AOO 258,900 Programs Under Development In -Region Supplies and Programs CaldomiaAgueduct Colorado River Ag ueducl Total Supply Available' Aqueduct Capacity!_rmrts Colorado River Aqueduct Ca a bi I ity 0 0 0 60.800 0 0 0 0 8,300 0 0 0 0 45,500 0 0 a a 53.00+0 0 0 0 0 4.WO ' Capablifty of Proposed Programs 0 0 0 0 4 Peandal Surplus 48DAN 40100 354,900 291 258.900 Notes: 1. Represents Supply Capability for resource programs under listed year type. 2. California Aqueduct includes Central Valley transfers and storage program supplies conveyed by the aquedL.cl. 3. Colorado River Aqueduct incudes programs and Exchange with 5aCWA conveyed by the aqueduct- 4. Maximum CRA deliveries limited to 1.25 MAF including Exchange with Sf]CWA. 5. Total demands are adjusted to include Exchange with SI7CINA. 6.2.6.2 MET's Drought Risk Assessment (DRA) Results For its DRA, MET assessed the reliability of each individual water supply source over the five -consecutive -year drought through a modeling method using the same historical hydrologic conditions as the water service reliability assessment: 1922 to 2021. MET used the five consecutive years of 1988 to 1992 to complete its DRA, because this represents the driest five -consecutive year historical sequence for MET's supply. As shown in Table 6.7, MET's total supplies are insufficient to fully meet projected demands under these drought conditions, resulting in annual shortfalls in four of the five years and a cumulative deficit of approximately 1.1 MAF by FY 2029-30. These results indicate that MET's SWP CITY OF TUSTIN 6-20 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO and CRA supplies alone cannot meet demands during this five-year drought period without additional actions. MET'S 2025 UWMP therefore identifies Water Shortage Contingency Plan (WSCP) actions as necessary tools to close the deficit and maintain service through the modeled drought sequence (Table 6.7). Table 6.7 MET's Water Use, Supply, and DRA for 2026-2030 Metropolitan's Drought Risk Assessment Water Use, Supply, and Risk Assessment for 2026 — 2030 (also included as Appendix 11 DWR Submittal Table 7-5) Submittal Table 7-5 Wholesale: Five -Year Drought Risk Assessment Water Code Section 10635(b)(3) 2026 Total Water Use (AF) Total 1,511,000 Total Supplies (AF) 973,000 Surplus/Shortfall w/o WSCP Action (538,000) OPTIONAL WSCP-supply augmentation benefit (AF) 539,000 WSCP - use reduction savings benefit (AF) 0 Revised Surplus/(shortfall) 0 2027 Total Water Use (AF) Total 1,633,000 Total Supplies (AF) 2,267,000 Surplus/Shortfall w/o WSCP Action 634,000 OPTIONAL Planned WSCP Actions (use reduction and su WSCP- supply augmentation benefit (AF) 0 WSCP - use reduction savings benefit (AF) 0 Revised Surplus/(shortfall) 634,000 Total Water Use (AF) Total 1,714,000 Total Supplies (AF) 1,169,000 Surplus/Shortfall w/o WSCPAction (545,000) OPTIONAL Planned WSCP Acti.supply WSCP- supply augmentation benefit (AF) 545,000 WSCP - use reduction savings benefit (AF) 0 Revised Surplus/(shortfall) 0 2029 Total Water Use (AF) Total 1,561,000 Total Supplies (AF) 1,197,000 Surplus/Shortfall w/o WSCP Action (364,000) OPTIONAL Planned WSCP Actions (use reduction and su WSCP- supply augmentation benefit (AF) 364,000 WSCP - use reduction savings benefit (AF) 0 Revised Surplus/(shortfall) ■ 0 Total Total Water Use (AF) 1,588,000 Total Supplies (AF) 1,301,000 Surplus/Shortfall w/o WSCP Action (287,000) supplyOPTIONAL Planned WSCP Actions (use reduction and WSCP- supply augmentation benefit (AF) 287,000 WSCP - use reduction savings benefit (AF) 0 Revised Surplus/(shortfall) DWR NOTES: Units of measure (AF, CCF, MG) must remain consistent throughout the NOTES: Totals may not foot due to rounding. See 2025 UWMP discussion in Chapter 2.4 Drought Risk Assessment regarding the supply augmentation actions that may be exercised to meet demands through 2030. CITY OF TUSTIN 6-21 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 6.3 Local Groundwater Among all local supplies available to the City's service area, groundwater supplies make up the majority, with the primary supply from the OC Basin. The water supply resources within the City's service area are enhanced by the existence of groundwater basins, which provide a reliable local source and, additionally, are used as reservoirs to store water during wet years and draw from storage during dry years. Table 6.8 shows a breakdown of historical groundwater production by the City. The City pumps groundwater through its nine operating wells. Of the City's wells, one is untreated groundwater wells and the remaining eight wells treat per- and polyfluoroalkyl substances (PFAS), nitrate, perchlorate, and TDS, thus earning a Basin Equity Assessment (BEA) exemption to pump over the BPP. This section describes the groundwater basin used by the City and provides a 25-year projection of the service area's groundwater supply. Table 6.8 Groundwater Pumped in the Past 5 Years Within the City's Service Area (AF) 6.3.1 Orange County Groundwater Basin This section describes the OC Basin and the management measures taken by OCWD, the basin manager and member agency of MWDOC, to optimize local supply and minimize overdraft. The OCWD was formed in 1933 by a special legislative act of the California State Legislature to protect and manage the County's vast, natural, groundwater supply using the best available technology and defend its water rights to the OC Basin. This legislation is found in the State of California Statutes, Water - Uncodified Acts, Act 5683, as amended. The OC Basin is managed by OCWD under the Act, which functions as a statutorily -imposed physical solution. The OCWD Management Area includes approximately 89 percent of the land area of the OC Basin, and 98 percent of all groundwater production occurs within the area. Approximately 2.5 million residents live within OCWD's boundaries and rely upon the basin for their primary water supply. OCWD manages water resource monitoring programs, land use elements related to basin management, groundwater elevation, groundwater quality, and coastal area monitoring through a number of monitoring programs. OCWD monitors the basin by collecting groundwater elevation and quality data from approximately 400 District -owned wells and manages an electronic database that stores water elevation, water quality, production, recharge, and other data on over 2,000 wells and facilities within and outside OCWD boundaries (OCWD, 2023). For detailed monitoring programs and management information, refer to the 2017 Basin 8-1 Alternative (Appendix D). Groundwater levels are managed within a safe basin operating range to protect the long-term sustainability of the OC Basin and to protect against land subsidence. OCWD, a member of agency of MWDOC, purchases untreated water from MET for basin recharge, as needed. In addition, OCWD CITY OF TUSTIN 6-22 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO regulates groundwater levels in the OC Basin by regulating the annual amount of pumping and setting the BPP for the water year. As defined in the District Act, the BPP is the ratio of water produced from groundwater supplies within the OCWD service area to all water produced within the area from both supplemental sources and groundwater within the OCWD (OCWD, 2020a). More information regarding the BPP is discussed in Section 6.3.1.3. 6.3.1.1 Basin Characteristics The OC Basin underlies the northern half of Orange County beneath broad lowlands. The OC Basin, managed by OCWD, covers an area of approximately 350 square miles, bordered by the Coyote and Chino Hills to the north, the Santa Ana Mountains to the northeast, and the Pacific Ocean to the southwest. The OC Basin boundary extends to the Orange County -Los Angeles Line to the northwest, where groundwater flows across the county line into the Central Groundwater Basin of Los Angeles County. A map of the OC Basin is shown on Figure 6.4. The total thickness of sedimentary rocks in the OC Basin is over 20,000 feet, with only the upper 2,000 to 4,000 feet containing fresh water. The OC Basin's estimated full storage volume is approximately 66 MAF. There are three major aquifer systems that have been subdivided by OCWD, the Shallow Aquifer System, the Principal Aquifer System, and the Deep Aquifer System. These three aquifer systems are hydraulically connected as groundwater can flow between each other through intervening aquitards or discontinuities in the aquitards. The Shallow Aquifer system occurs from the surface to approximately 250 feet below ground surface. Most of the groundwater from this aquifer system is pumped by small water systems for industrial and agricultural use. The Principal Aquifer system occurs at depths between 200 and 1,300 feet below ground surface. Over 90 percent of groundwater production is from wells that are screened within the Principal Aquifer system. Only a minor amount of groundwater is pumped from the Deep Aquifer system, which underlies the Principal Aquifer system and is up to 2,000 feet deep in the center of the OC Basin. CITY OF TUSTIN 6-23 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Figure 6.4 Map of the OC Basin (OCWD, 2022 (Basin 8-1 Alternative 2022 Update)) CITY OF TUSTIN 6-24 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 6.3.1.2 Sustainable Groundwater Management Act (SGMA) In 2014, the State of California adopted the SGMA to promote sustainable groundwater management and limit "undesirable results", including significant groundwater -level declines, land subsidence, and water quality degradation. SGMA requires all high- and medium -priority basins, as designated by DWR, to be sustainably managed. DWR designated the Coastal Plain of the OC Basin (Basin 8-1) as a medium -priority basin, primarily due to heavy reliance on groundwater as a water supply source. Compliance with SGMA can be achieved in one of the following two ways (OCWD, 2023): 1. Formation of a Groundwater Sustainability Agency (GSA) and adoption of a Groundwater Sustainability Plan (GSP). 2. Preparation and submittal of an Alternative to a GSP by eligible agencies, including special act districts such as OCWD. Agencies within Basin 8-1, including OCWD, the City of La Habra, and IRWD, collaborated to submit the original Alternative to a GSP in 2017, titled the "Basin 8-1 Alternative" to demonstrate compliance with SGMA. Under SGMA, alternatives must be updated and submitted every 5-years. OCWD prepared its first periodic update in 2022. For the remainder of this report, when the term "OC Basin" is used, it refers to the portion of Basin 8-1 that is within OCWD's service area (see Figure 6.5). SAN BERNARDINO �V a Habra � COUNTY �v Brea _ ® LOSANGELE Yorba nda COUNTY ` Fullerton Placentia Buen m L- alma Par RIVERSI Anahei COU N Cypress ' ® \ sAlamitos Sta ton Ora ge Garden Grove e� ® S I Beach e \ stm star Q° Santa Ana ustin ntain DWR Basin 8-1 0 Hunting n Va Management Areas Beac Irvine La Habra - Brea Management Area Costa Mesa OCWD Management Area Santa Ana Canyon Management Area Lake est t South East Management Area N each e a 3 5 `•� ORANGE COUNTY_ :'1,✓r- _ , Miles AWL I Figure 6.5 Basin 8-1 Management Areas (OCWD, 2023) CITY OF TUSTIN 6-25 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 6.3.1.3 Basin Production Percentage Background The OC Basin is not adjudicated; therefore, groundwater production is managed through a framework that uses financial incentives to encourage sustainable pumping. The framework is based on the BPP, which represents the percentage of each Producer's total water supply that comes from groundwater pumped from the OC Basin. Groundwater production at or below the BPP is assessed by the Replenishment Assessment (RA). While there is no legal limit as to how much an agency pumps from the OC Basin, there is a financial impact to pump above the BPP. The BPP is set uniformly for all Producers by OCWD on an annual basis. Agencies that pump above the BPP are charged the RA plus the BEA. The BEA is calculated so that the cost of groundwater production above the BPP is equivalent to the cost of importing potable water supplies. This approach ensures there is no financial advantage for production above the BPP. The BEA can be increased to discourage production above the BPP if necessary. The BPP is set annually by OCWD based on groundwater conditions, availability of imported water supplies, and OC Basin management objectives. The supplies available for recharge must be estimated for a given year. The estimated supplies of recharge water include: (1) stormflow from the Santa Ana River and Santiago Creek, (2) natural incidental recharge, (3) Santa Ana River baseflow, (4) GWRS supplies, and (5) other supplies such as imported water and recycled water purchased for the Alamitos Barrier. The BPP is a major factor in determining the cost of groundwater production from the OC Basin. For the 2026-27 water year, OCWD maintained a BPP of 85 percent. Under normal hydrologic conditions, groundwater production could reach approximately 315,000 AFY. However, OCWD actual production in FY 2026-27 will be approximately 299,000 AFY due PFAS-related impacts that continue to limit groundwater availability among several producers. BPP Adjustments for Basin Management OCWD has established management guidelines that are used to establish future BPPs, as seen in Table 6.9. Raising or lowering the BPP allows OCWD to manage the amount of pumping from the basin. OCWD has a policy to manage the groundwater basin within a sustainable range to avoid adverse impacts to the basin. OCWD seeks to maintain some available storage space in the basin to maximize surface water recharge when such supplies are available, especially in relatively wet years. By keeping the basin relatively full during wet years, and for as long as possible in years with near -normal recharge, the maximum amount of groundwater could be maintained in storage to support pumping in future drought conditions. During dry hydrologic years, when less water is available for recharge, the BPP could be lowered to maintain groundwater storage levels. A component of OCWD's BPP policy is to manage the groundwater basin so that the BPP will not fluctuate more than 5 percent from year to year. The OCWD's GWRS came online in 2008 with a capacity of approximately 70 million gallons per day (mgd) and was expanded to 100 mgd in 2015. In 2023, it was expanded again to a final capacity of 130 mgd. The GWRS provides a resilient local water supply that recharges the OC Basin with advanced treated wastewater. The additional yield supported OCWD's move to raise the BPP from the long-standing —77 percent level prior to 2023 to 85 percent beginning in February 2023. Monthly water -resources reports show agencies achieving 86 percent-88 percent pumping shares after the final expansion in late- 2024 to early-2025, which reflects increased reliance on local groundwater supplies enabled by GWRS production along with the reduced water demands of approximately 400,000 AFY. CITY OF TUSTIN 6-26 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Modeling and forecasts generate estimates based on historical averages. Consequently, forecasts use average hydrologic conditions, which smooth the dynamic and unpredictable local hydrology. Variations in local hydrology are the most significant impact to supplies of water available to recharge the groundwater basin. The current BPP of 85 percent is based on modeling of average annual rainfall weather patterns and estimated groundwater recharge volumes. If OCWD were to experience a relatively dry period, the BPP could be reduced to maintain water storage levels, along with other management actions shown in Table 6.9. Table 6.9 Management Actions Based on Changes in Groundwater Storage Less than 100,000 AF 100,000 to 300,000 AF 300,000 to 350,000 AF Greater than 350,000 AF Notes: (1) Amount below full basin condition. Basin Equity Assessment Exemptions Raise BPP Maintain and / or raise BPP towards 85% goal Seek additional supplies to refill basin and/or lower the BPP Seek additional supplies to refill basin and lower the BPP In some cases, OCWD encourages treating and pumping groundwater that does not meet drinking water standards to protect water quality. This is achieved by using a financial incentive called the BEA Exemption. A BEA Exemption is used to promote beneficial uses of poor -quality groundwater and reduce or prevent the spread of poor -quality groundwater into non -degraded aquifer zones. OCWD uses a partial or total exemption of the BEA to compensate a qualified participating agency or Producer for the costs of treating poor quality groundwater, which typically include capital, interest and operations and maintenance costs for treatment facilities (City of La Habra et al., 2017). Similarly, for proactive water quality management, OCWD occasionally exempts a portion of the BEA for their Coastal Pumping Transfer Program (CPTP). The CPTP encourages inland groundwater producers to increase pumping and coastal producers to decrease pumping to reduce the groundwater basin drawdown at the coast and protect against seawater intrusion. Inland pumpers can pump above the BPP without having to pay the full BEA for the amount pumped above the BPP (OCWD, 2015). Coastal pumpers receive BEA revenue from OCWD to assist in offsetting their additional water supply cost from taking less groundwater. OCWD Resilience Plan To address evolving conditions within OCWD's service area, it is important to anticipate potential challenges and proactively plan for strategies that sustain and enhance water supply reliability, water quality, and overall system resilience. The OCWD Resilience Plan is an adaptive management plan that evaluates future water demands and available supplies, while also identifying potential projects and response strategies to address risks to key District assets, including the groundwater basin, Santa Ana River, groundwater replenishment facilities, and natural resources. The plan builds on OCWD's historical planning efforts and provides a flexible, project -based framework to maintain sustainable basin conditions and strengthen the long-term resilience of the District's water resources over a 5- to 25-year planning horizon. CITY OF TUSTIN 6-27 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO The Resilience Plan also supports evaluation of future water supply projects, recharge strategies, and operational improvements to guide management of the OC Basin under changing hydrologic, regulatory, and demand conditions The Basin 8-1 Alternative submitted to DWR in 2017 showed that Basin 8-1 had been sustainably managed for the prior 10 years, which was a SGMA requirement. Based on avoiding undesirable results as defined in SGMA, the OC Basin has been sustainably managed since the construction of the Talbert Seawater Intrusion Barrier in the mid-1970s. Required annual reports and periodic updates submitted to DWR show that Basin 8-1 continues to be sustainably managed. Current water demand projections show a relatively slow increase over the 25-year planning horizon, which is generally of similar magnitude as the additional production from the GWRS since its final expansion in early 2023 to 130 mgd. This locally controlled, drought proof supply of water reduces the region's dependance on imported water. Historically, the Santa Ana River has served as the primary source of water to recharge the OC Basin. To determine the availability of future Santa Ana River flows, OCWD utilized surface water flow modeling of the upper watershed. Modeling was developed to predict the impacts future stormwater capture and wastewater recycling projects in the upper watershed would have on future Santa Ana River flow rates at Prado Dam. Santa Ana River base flows are expected to decrease as more water recycling projects are built in the upper watershed. OCWD continues to work closely with the US Army Corps of Engineers (USACE) to temporarily impound and slowly release up to approximately 20,000 AF of stormwater in the Prado Dam Conservation Pool. The amount of water than can be temporarily impounded in the conservation pool has grown over time and in 2025, it was increased to over 25,000 AF. To some extent, the losses in baseflow are partially offset through the capture of additional stormwater held in the Prado Dam Conservation Pool. When available, OCWD will continue to augment groundwater recharge through the purchase of imported water through MET. OCWD will diligently monitor and evaluate future water supply projects to sustainably manage and protect the OC Basin for future generations. OCWD Engineer's Report The OCWD Engineer's Report documents groundwater conditions and evaluates water supply and basin utilization within OCWD's service area. The most recent report is the 2024-25 Engineer's Report filed in March 2026. As reported, the BPP for the 2024-25 water year was maintained at 85 percent by the OCWD Board of Directors. The overall BPP achieved within OCWD for non -irrigation use was 83.8 percent, with the reduced achievement attributed primarily to PFAS-related well shutdowns. Groundwater stored in the basin decreased by 50,000 AF for the 2024-25 water year, and the annual overdraft was 165,300 AF, which reflects the amount by which natural replenishment was exceeded. The decrease in storage was reflected by a relatively dry year and the total groundwater recharge was 252,214 AF, which included contributions from supplemental water recharged by the GWRS. For the 2026-27 water year, OCWD is proposing to maintain a BPP of 85 percent. Under normal hydrologic conditions, groundwater production could reach approximately 315,000 AF; however, OCWD anticipates groundwater production during 2026-27 will be approximately 299,000 AF due to PFAS-related impacts that continue to limit groundwater availability among several producers. It is estimated that approximately 13,500 AF of additional production above the BPP will be undertaken by the City of Tustin, City of Huntington Beach, Mesa Water District, and IRWD to support groundwater CITY OF TUSTIN 6-28 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO quality improvement projects. As in prior years, groundwater produced above the BPP for these water -quality projects will be partially or fully exempt from the Basin Equity Assessment (BEA) due to the Basin -wide benefit of pumping and treating poor -quality groundwater. During the 2024-25 water year and current 2025-26 water year, MET untreated full -service water supplies were available for groundwater replenishment; however, OCWD did not purchase replenishment water due to favorable basin storage conditions. OCWD likewise does not plan to purchase untreated full -service water for replenishment in 2026-27. 6.3.1.4 Recharge Management Recharging water into the OC Basin through natural and artificial means is essential to support pumping from the OC Basin. Active recharge of groundwater began in 1936, in response to increasing drawdown of the OC Basin and, consequently, the threat of seawater intrusion. The OC Basin's primary source of recharge is supplied from the Santa Ana River, which is diverted into recharge basins and its main Orange County tributary, Santiago Creek. Other sources of recharge water include natural infiltration, recycled water, and imported water. Natural recharge consists of subsurface inflow from local hills and mountains, infiltration of precipitation and irrigation water, recharge in small flood control channels, and groundwater underflow to and from Los Angeles County and the ocean. Recycled water for OC Basin recharge is from two sources. The main source is the Groundwater Replenishment System (GWRS), which completed its final expansion in 2023 and now produces up to 130 mgd of advanced -purified water for recharge at the Talbert Seawater Barrier and in the Kraemer, Miller, Miraloma, and La Palma basins. The second source is recycled water purified at the Water Replenishment District of Southern California's (WRD) Leo J. Vander Lans Advanced Water Treatment Facility (LVL), which provides up to 8 mgd for injection at the Alamitos Seawater Barrier (owned and operated by the Los Angeles County Department of Public Works). In recent years, WRD's upgrades and operations have increased the use of recycled water at the Alamitos Barrier and reduced reliance on imported supplies. Injection of recycled water into these barriers is an ongoing effort by OCWD (in coordination with WRD and Los Angeles County) to control seawater intrusion into the OC Basin; operation of the injection wells forms a hydraulic barrier to seawater intrusion. OCWD also purchases imported water for recharge through MWDOC. Untreated imported water can be used to recharge the OC Basin through the surface recharge system at multiple locations, such as Anaheim Lake, the Santa Ana River, Irvine Lake, and San Antonio Creek, while treated imported water may be used for in -lieu recharge when appropriate. For current planning context and detailed recharge management strategies, refer to OCWD's most recent planning documents, including the 2024 OCWD Resilience Plan, in addition to prior foundational documents (Appendix E). 6.3.1.5 MET Imported Water for Groundwater Replenishment In the past, OCWD, MWDOC, and MET have coordinated water management to increase storage in the OC Basin when imported supplies are available for this purpose. MET's groundwater replenishment program was discontinued on January 1, 2013, and currently MET via MWDOC sells replenishment water to OCWD at the full -service untreated MET rate. Figure 6.6 shows MWDOC's imported water sales to OCWD since FY 1990-91, which averages approximately 27,888 AF per year. In three of the past five water years, OCWD did not need to purchase more imported water to replenish groundwater. CITY OF TUSTIN 6-29 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO ]adab"0 ■ f a ocffp _ o4 c N 5 ct , fff 0ao3ffi95ooff Af"# ■ f n oAp ; ATl a <4 o53ffjAfq_--f�ffg Figure 6.6 MWDOC Imported Water Sales for Groundwater Replenishment 6.3.2 Planned Future Groundwater Sources On a regional scale, OCWD regularly evaluates potential projects and conducts studies to review the feasibility of new projects or sources. Groundwater basin -related projects that are planned or in progress are described below: Forecast Informed Reservoir Operations (FIRO) at Prado Dam - Stormwater represents a significant source of water used by OCWD to recharge the OC Basin. Much of this recharge is made possible by the capture of Santa Ana River stormflows behind Prado Dam in the Conservation Pool. FIRO represents the next generation of operating water reservoirs using the best available technology. Advances in weather and stormwater runoff forecasting hold promise to allow USACE to safely impound more stormwater while maintaining equivalent flood risk management capability behind Prado Dam. Analyses indicate that FIRO would increase average annual recharge by approximately 4,000-6,000 AFY, and up to 23,000 AF in very wet years, consistent with earlier preliminary analyses. Federal and local partners have indicated FIRO at Prado Dam is moving from technical assessment toward implementation via Water Control Manual (WCM) updates. 6.4 Surface Water 6.4.1 Existing Surface Water Sources There are, currently, no direct surface water uses in the City's Service area. CITY OF TUSTIN 6-30 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 6.4.2 Planned Future Surface Water Sources As of 2025, there are no planned surface water uses in the City's service area. 6.5 Stormwater 6.5.1 Existing Stormwater Sources There are, currently, no direct stormwater uses in the City's Service area. 6.5.2 Planned Future Stormwater Sources As of 2025, there are no planned stormwater uses in the City's service area. 6.6 Wastewater and Recycled Water The City is not directly involved in wastewater services as it does not own or operate the wastewater collection system in its service area. The sewer collection system is owned and operated by EOCWD. Additionally, the City does not own or operate wastewater treatment facilities. Recycled water is wastewater that is treated through primary, secondary, and tertiary processes and is acceptable for most non -potable water purposes such as irrigation, and commercial and industrial process water per Title 22 requirements. Recycled water opportunities have continued to grow in Southern California as public acceptance and the need to expand local water resources continues to be a priority. Recycled water also provides a degree of flexibility and added reliability during drought conditions when imported water supplies are restricted. The City is indirectly involved in recycled water production, through its supply of wastewater for indirect potable reuse (IPR). The following sections expand on the existing agency collaboration involved in these efforts as well as the City's projected recycled water use over the next 25 years. 6.6.1 Agency Coordination The City does not own or operate wastewater treatment facilities and sends all collected wastewater to OC San for treatment and disposal. OC San provides treated water to OCWD, the manager of the OC Basin. OCWD is the manager of the OC Basin and strives to maintain and increase the reliability of the OC Basin through replenishment with imported water, Stormwater, and advanced treated wastewater. A full description of the OC Basin is available in Section 6.3.1. OCWD and OC San have jointly constructed and expanded two water recycling projects to meet this goal that include: (1) OCWD Green Acres Project (GAP) and (2) OCWD GWRS. 6.6.1.1 Orange County Sanitation District OC San collects wastewater from residential, commercial, and industrial customers in 21 cities, three special districts, and portions of unincorporated Orange County, totaling 479 square miles that serves more than 2.5 million residents in north and central Orange County. These flows include dry weather urban runoff collected from 15 diversion points and discharged into the sewer system for treatment and Santa Ana River Interceptor flows from the upper Santa Ana watershed (OCWD, 2023). CITY OF TUSTIN 6-31 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO OC San operates and maintains two treatment plants: Reclamation Plant No. 1, located in Fountain Valley with a capacity of 320 mgd, and Reclamation Plant No. 2 located in Huntington Beach with a capacity of 312 mgd. OC San also operates 572 miles of collection system pipelines along with 15 offsite pump stations. Approximately 150 mgd of secondary effluent undergoes advanced treatment at the GWRS facility operated by the OCWD and 7 mgd undergoes tertiary treatment at OCWD's GAP facility. Treated wastewater is discharged to the Pacific Ocean via an ocean outfall in compliance with state and federal requirements as set forth in OC San's National Pollutant Discharge Elimination System (NPDES) permit. OC San's ocean outfall is 120-inch diameter and extends four miles off the coast of Huntington Beach. A 78-inch diameter emergency outfall also exists that extends 1.3 miles off the coast. OC San Reclamation Plant No. 1 - Reclamation Plant No. 1 treats raw wastewater and has a maximum treatment capacity of 320 mgd. The plant provides primary and secondary treatment and supplies secondary effluent to OCWD for further tertiary treatment at their GAP facility and advanced treatment at their GWRS. Reclamation Plant No. 1 is the only plant that provides water to OCWD for additional treatment and recycling. An interplant pipeline allows flows to be conveyed to Treatment Plant No. 2. OC San Treatment Plant No. 2 - Treatment Plant No. 2 provides primary and secondary treatment to raw wastewater and has a maximum treatment capacity of 312 mgd. All secondary effluent from their plant is discharged to the ocean through the ocean outfall. 6.6.1.2 Orange County Water District OCWD is the manager of the OC Basin and provides water to 19 municipal water agencies and special districts. A full description of the OC Basin is available in Section 6.3.1. OCWD and OC San havejointly constructed and expanded two water recycling projects that include: (1) OCWD GAP and (2) OCWD GWRS. OCWD GAP OCWD owns and operates the GAP, a water recycling system that treats up to 7.5 mgd and provides up to 8,400 AFY of recycled water for irrigation and industrial uses. GAP provides an alternate source of water that is mainly delivered to parks, golf courses, greenbelts, cemeteries, and nurseries in the cities of Costa Mesa, Fountain Valley, Newport Beach, and Santa Ana. Approximately 100 customer sites use GAP water, current recycled water users include Mile Square Park and Golf Courses in Fountain Valley, Costa Mesa Country Club, Chroma Systems carpet dyeing, Kaiser Permanente, and Caltrans. OCWD GWRS OCWD's GWRS allows southern California to decrease its dependency on imported water and creates a local and reliable source of water. OCWD's GWRS purifies secondary treated wastewater from OC San to levels that meet and exceed all state and federal drinking water standards. The GWRS Phase 1 plant has been operational since January 2008 and uses a three -step advanced treatment process consisting of microfiltration (MF), reverse osmosis (RO), and ultraviolet (UV) light with hydrogen peroxide. A portion of the treated water is injected into the seawater barrier to prevent seawater intrusion into the groundwater basin. The other portion of the water is pumped to ponds where the water percolates into deep aquifers and becomes part of Orange County's water supply. The treatment process is described on OCWD's website. (OCWD, GWRS, 2020). CITY OF TUSTIN 6-32 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO The GWRS first began operating in 2008 producing 70 million gallons per day (mgd) of water and in 2015, it underwent a 30 mgd expansion. Approximately 39,200 AFY of the highly purified water is pumped into the injection wells and 72,900 AFY is pumped to the percolation ponds in the City of Anaheim where the water is naturally filtered through sand and gravel to deep aquifers of the groundwater basin. The OC Basin provides approximately 77 percent of the potable water supply for north and central Orange County. The design and construction of the first phase (78,500 AFY) of the GWRS project was jointly funded by OCWD and OC San; Phase 2 expansion (33,600 AFY) was funded solely by OCWD. The Final Expansion of the GWRS is the third and final phase of the project and was completed in 2023. The plant now produces 130 mgd and requires additional treated wastewater from OC San. This additional water comes from OC San's Treatment Plant 2, which is in the City of Huntington Beach approximately 3.5 miles south of the GWRS. The Final Expansion project included expanding the existing GWRS treatment facilities, constructing new conveyance facilities at OC San Plant No. 2, and rehabilitating an existing pipeline between OC San Plant No. 2 and the GWRS. Following completion, the GWRS plant now recycles 100 percent of OC San's reclaimable sources and produces enough water to meet the needs of over one million people. 6.6.2 Wastewater The City does not provide wastewater services within its water service area as the sewer collection system is owned and operated by EOCWD. The wastewater collected in the City's system is conveyed to OC San's extensive system of gravity flow sewers, pump stations, and pressurized sewers. Ultimately, the wastewater is treated at OC San treatment plants in Fountain Valley (Plant No. 1) and Huntington Beach (Plant No. 2). Table 6.10 summarizes the wastewater collected by the City and transported to OC San's system in 2025. Table 6.10 Wastewater Collected within the City's Service Area in 2025 Submittal Table 6-2 Retail: Wastewater Collected Water Code Section 10633(a) Within Service Area in 2025 Wastewater Collection Volume of Recipient of Collected Wastewater Wastewater Wastewater Name of Wastewater Volume Metered Collected from Name of Wastewater Treatment Is WWTP Collection Agency or Estimated? UWMP Service Plant (WWTP) and Place ID Located Within OPTIONAL Area 2025 Number UWMP Area? (AF) OCSD Plant 1, Place ID 758392 No EOCWD Estimated 6,698 OCSD Plant 2, Place ID 259158 No Total Wastewater Received from UWMP 6,698 Service Area in 2025: NOTES: Assumed a return rate of 65% (City of Tustin, 2015) CITY OF TUSTIN 6-33 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 6.6.3 Current Recycled Water Uses There are currently no direct recycled water uses within the City's service area. For indirect use, the City also benefits from OCWD's GWRS system that provides IPR through replenishment of the OC Basin with water that meets state and federal drinking water standards. 6.6.4 Projected Recycled Water Uses The City does not have any direct non -potable uses within their service area and does not currently have the potential for non -potable reuse because of nonexistent or planned recycled water infrastructure. The City will continue to supply wastewater to support the region's IPR via GWRS. The projected 2025 recycled water use from the City's 2020 UWMP are compared to the 2025 actual use in Table 6-7. 6.6.5 Potential Recycled Water Uses While the City recognizes the potential for beneficial reuse in their service area, there is no source of recycled water supply in proximity to the City. The City's wastewater is conveyed to OC San's regional treatment facilities where the wastewater is treated, recycled, or discharged to the ocean. Recycled water analyses performed over the years have shown that local treatment and reuse facilities are not feasible. The City supports, encourages, and contributes to the continued development of recycled water and potential uses throughout the region with OCWD's GWRS. 6.6.6 Optimization Plan Studies of water recycling opportunities within Southern California provide a context for promoting the development of water recycling plans. It is recognized that broad public acceptance of recycled water requires continued education and public involvement. Currently, most of the recycled water available being directed toward replenishment of the groundwater basin and improvements in groundwater quality. As a user of groundwater, the City supports the efforts of OCWD and OC San to use recycled water as a primary resource for groundwater recharge in Orange County. 6.6.6.1 Public Education The City participates in the MWDOC public education and school education programs, which include extensive sections on water recycling. MWDOC's water use efficiency public information programs are a partnership with agencies throughout the county. Through a variety of public information programs, MWDOC reaches the public, including those in the City, with information regarding present and future water supplies, the demands for a suitable quantity and quality of water, including recycled water, and the importance of implementing water efficiency techniques and behaviors. Through MWDOC, water education programs have reached thousands of students in the City with grade -specific programs that include information on recycled water. 6.6.6.2 Financial Incentives The implementation of recycled water projects involves a substantial upfront capital investment for planning studies, EIRs, engineering design and construction before recycled water is available to the market. The establishment of new supplemental funding sources through federal, state, and regional CITY OF TUSTIN 6-34 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO programs now provides significant financial incentives for water agencies to develop and make use of recycled water locally. Potential sources of funding include federal, state, and local funding opportunities. These funding sources include the USBR, California Proposition 13 Water Bond, Proposition 84 and MET Local Resources Program (LRP). These funding opportunities may be sought by the City or possibly more appropriately by regional agencies. The City will continue to support seeking funding for regional water recycling projects and programs. 6.6.6.3 Optimization Plan The City does not use recycled water, therefore, there is no need for a recycled water optimization plan. In other areas of Orange County, recycled water is used for irrigating golf courses, parks, schools, businesses, and communal landscaping, as well as for groundwater recharge. Analyses have indicated that present worth costs to incorporate recycled water within the City are not cost effective as compared to purchasing imported water from MWDOC or using groundwater. The City will continue to conduct feasibility studies for recycled water and seek out creative solutions such as funding, regulatory requirements, institutional arrangement, and public acceptance for recycled water use with MWDOC, OCWD, MET, and other cooperative agencies. 6.7 Desalination Opportunities 6.7.1 Ocean Water Desalination The City does not currently have any ocean desalination programs. 6.7.2 Groundwater Desalination The City is one of the producers of BEA-exempt groundwater. The projects consist of two groundwater treatment facilities that are allowed above the BPP and the charges are BEA-exempt. The first facility is the Main Street Treatment Plant, operating since 1989 to reduce nitrate levels from the groundwater produced by Wells No. 3 and 4 by blending untreated groundwater with treatment plant product water which undergoes ion exchange treatment processes. The second facility is the Tustin Seventeenth Street Desalter, operating since 1996 to reduce high nitrate and total dissolved solids concentration from groundwater produced by Well No. 4 and the Newport well using reverse osmosis (OCWD, 2015). 6.8 Water Exchanges and Transfers 6.8.1 Existing Exchanges and Transfers Interconnections with other agencies result in the ability to share water supplies during short term emergency situations or planned shutdowns of major imported water systems. Transfers of water can help with short-term outages but can also be involved with longer term water exchanges to deal with droughts or long-term emergency situations. The City maintains five emergency interconnections with GSWC (1); the City of Santa Ana (2); and IRWD (2). All five connections are 6 inches in diameter, need to be manually activated, and supply flow in both directions. CITY OF TUSTIN 6-35 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 6.8.2 Planned and Potential Exchanges and Transfers The City does not currently have plans to introduce new exchanges and transfers. However, MWDOC supports its retail agencies, such as the City, in developing both local and regional transfer and exchange opportunities that promote reliability within their systems. Examples of these future projects include: Santa Ana River Conservation and Conjunctive Use Project (SARCCUP) - The SARCCUP is a joint project established by five regional water agencies within the Santa Ana River Watershed (Eastern Municipal Water District, Inland Empire Utilities Agency, Western Municipal Water District, OCWD, and SBVMWD). In September 2021, the participating agencies, in coordination with MET, executed a regional agreement framework establishing SARCCUP as a watershed -scale groundwater banking program to improve drought reliability across Orange, Riverside, and San Bernardino counties. In 2016, SARCCUP received $55 million in Proposition 84 funding from DWR; however, implementation has since advanced with the 2021 agreements and subsequent program updates. The overall SARCCUP program consists of three main elements: (1) Watershed -Scale Cooperative Water Banking Program; (2) Water Use Efficiency —landscape design/irrigation improvements and water budget assistance; and (3) Habitat creation and Arundo donax removal within the Santa Ana River. The Watershed -Scale Cooperative Water Banking Program is the largest component of SARCCUP. Under MET's arrangement with SBVMWD, when SBVMWD declares surplus SWP water and offers it to MET, MET offers at least 50 percent of an equivalent amount to SARCCUP member agencies for storage and later use in the Santa Ana River watershed, consistent with MET policy. This structure formalizes the purchase and storage pathway that had been under development and aligns with MET's extraordinary supply policy during allocations. Program capacity planning identifies up to—137,000 AF of storage across six basins, including up to 36,000 AF in the OC Basin for use in dry years. Stored SARCCUP supplies may be designated "extraordinary supplies" during a MET allocation if managed consistent with MET's Water Supply Allocation Plan, thereby enhancing participating agencies' drought reliability. Within Orange County, extraordinary supply assignment agreements among MET, MWDOC/OCWD, and certain retail agencies (e.g., Anaheim, Fullerton, Santa Ana) document how SARCCUP extraordinary supply is assigned and delivered locally. Program implementation and participation details continue to be refined among OCWD, retail agencies, and MWDOC. 6.9 Future Water Projects The City continually reviews practices that will provide its customers with adequate and reliable supplies. Trained staff continue to ensure the water quality is safe and the water supply will meet present and future needs in an environmentally and economically responsible manner. Currently, there are no City -specific planned projects that have both a concrete timeline and a quantifiable increase in supply. 6.10 Energy Intensity The City owns and operates a water distribution system. East Orange County Water District manages the wastewater collection system used by the City. This section reports the energy intensity for each system CITY OF TUSTIN 6-36 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO using data from CY 2024. Water and energy resources are inextricably connected. Known as the "water -energy nexus", the California Energy Commission estimates the transport and treatment of water, treatment and disposal of wastewater, and the energy used to heat and consume water account for nearly 20 percent of the total electricity and 30 percent of non -power plant related natural gas consumed in California. In 2015, California issued new rules requiring 50 percent of its power to come from renewables, along with a reduction in greenhouse gas (GHG) emissions to 40 percent below 1990 levels by 2030. Consistent with energy and water conservation, renewable energy production, and GHG mitigation initiatives, the City reports the energy intensity of its water and wastewater operations. The methodology for calculating water energy intensity outlined in Appendix O of the UWMP Guidebook was adapted from the California Institute for Energy Efficiency exploratory research study titled "Methodology for Analysis of the Energy Intensity of California's Water Systems" (Wilkinson 2000). The study defines water energy intensity as the total amount of energy, calculated on a whole -system basis, required for the use of a given amount of water in a specific location. UWMP reporting is limited to available energy intensity information associated with water processes occurring within an urban water supplier's direct operational control. Operational control is defined as authority over normal business operations at the operational level. Any energy embedded in water supplies imparted by an upstream water supplier (e.g., water wholesaler) or consequently by a downstream water purveyor (e.g., retail water provider) is not included in the UWMP energy intensity tables. The City's calculations conform to methodologies outlined in the UWMP Guidebook and Wilkinson study. 6.10.1 Water Supply Energy Intensity In CY 2024, the City consumed approximately 2474.1 kilowatt-hour (kWh) per million gallons (MG) for water extraction, treatment, and delivery (Table 6.11). The basis for calculations is provided in more detail in the following subsections. CITY OF TUSTIN 6-37 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Table 6.11 Energy Efficiency Units for Water Extract and Place into 11 Conveyance Treatment Distribution Total Hydropower Net Utility Volume Divert Storage Utility Volume of Water Entering Process AF 6,133 0 0 2,028 8,816 8,816 0 8816 Energy Consumed (kWh) N/A 4,395,449 0 0 2,565,430 146,346 7,107,225 0 7,107,225 Energy Intensity (kWh/vol. converted to MG) N/A 2,199 0.0 0.0 3,883 51 2,474 0.0 2,474 Quantity of Self -Generated Renewable Energy 0 kWh Data Quality (Estimate, Metered Data, Combination of Estimates and Metered Data) Combination of Estimates and Metered Data Data Quality Narrative: Volume of Water Entering Process: Extraction data based on MWDOC Compiled Water Audits "Volume From Own Sources" and Distribution data based on MWDOC Compiled Water Audits "Authorized Consumption." Volume for treatment was assumed to be 23% of the distribution volume, a percentage taken from the City's 2020 UWMP. Non -revenue water was not considered in this calculation - the energy efficiency is based on water delivered to customers. Energy Consumption: Energy was estimated from metered data and the kWh/volume ratios from the Table 0-1A from the City's 2020 UWMP. Narrative: The City of Tustin relies on imported water, local groundwater, and recycled water to meet its customers' water needs. Operational control is limited to groundwater wells and potable water booster stations. CITY OF TUSTIN 6-38 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 6.10.1.1 Operational Control and Reporting Period As described throughout the report, the City is a retail agency that relies on groundwater and imported water. Water supply energy intensity was calculated for the 2024 calendar year. This is a standard for energy and GHG reporting to the Climate Registry, California Air Resources Board, and the US Environmental Protection Agency (EPA). Calendar year reporting provides consistency when assessing direct and indirect energy consumption within a larger geographical context, as fiscal year starting dates can vary between utilities and organizations. 6.10.1.2 Volume of Water Entering Processes According to the MWDOC Compiled Water Audits, the City extracted 6,133 AF of groundwater from the OC Basin, treated 2,028 AF of water, and distributed 8,816 AF of both groundwater and imported water. Water volume is based on water audit data. The extracted volume is based on the "Volume from Own Sources" data point while water deliveries are based on "Authorized Consumption." This calculation excludes water losses so that the final energy intensity is based on the water that is actually delivered to customers. 6.10.1.3 Energy Consumption and Generation According to Southern California Edison electricity bills and estimations based on the City's 2020 UWMP, groundwater wells consumed 4,395,449 kWh of electricity, treatment of some of the volume consumed 2,565,430 kWh of electricity, and pump stations along the distribution system consumed 146,346 kWh of electricity. Currently, the City does not generate renewable energy. Energy consumption is based on metered data and estimations. 6.10.2 Wastewater and Recycled Water Energy Intensity The City does not have energy data for the wastewater system readily available and has therefore chosen not to calculate an energy intensity for the wastewater system. 6.10.3 Key Findings and Next Steps Calculating and disclosing direct operationally controlled energy intensities is another step towards understanding the water -energy nexus. However, much work is still needed to better understand upstream and downstream (indirect) water -energy impacts. When assessing water supply energy intensities or comparing intensities between providers, it is important to consider reporting boundaries as they do not convey the upstream embedded energy or impacts energy intensity has on downstream users. Engaging one's upstream and downstream supply chain can guide more informed decisions that holistically benefit the environment and are mutually beneficial to engaged parties. Suggestions for further study include: Supply -chain engagement - The City relies on a variety of water sources for their customers. While some studies have used life cycle assessment tools to estimate energy intensities, there is a need to confirm this data. The 2025 UWMP requirement for all agencies to calculate energy intensity will help the City and neighboring agencies make more informed decisions that would benefit the region as a CITY OF TUSTIN 6-39 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO whole regarding the energy and water nexus. A similar analysis could be performed with upstream supply chain energy, for example, with State Project Water. ■ Internal benchmarking and goal setting - With a focus on energy conservation and a projected increase in water demand despite energy conservation efforts, the City's energy intensities will likely decrease with time. Conceivably, in a case where water demand decreases, energy intensities may rise as the energy required to pump or treat is not always proportional to water delivered. In the course of exploring the water -energy nexus and pursuing renewable energy goals, there is a need to assess whether energy intensity is a meaningful indicator or if it makes sense to use a different indicator to reflect the City's commitment to energy and water conservation. Current efforts could be expanded with the addition of a wastewater energy intensity evaluation. ■ Regional sustainability - Water and energy efficiency are two components of a sustainable future. Efforts to conserve water and energy, however, may impact the social, environmental, and economic livelihood of the region. In addition to the relationship between water and energy, overtime, it may also be important to consider and assess the connection these resources have on other aspects of a sustainable future. CITY OF TUSTIN 6-40 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO CHAPTER 7WATER SERVICE RELIABILITY AND DROUGHT RISK ASSESSMENT This chapter of the Urban Water Management Plan (UWMP) describes the City of Tustin's (City) water service reliability assessment for three long-term hydrological conditions: a normal year, a single dry year, and a drought period lasting five consecutive years. The Drought Risk Assessment (DRA) assesses water supply reliability during a severe drought lasting the next five consecutive years, from 2026 to 2030. Factors affecting reliability, such as water quality, regulations, and climate change, are also summarized in this assessment of reliability. 7.1 Water Service Reliability Overview As part of the UWMP, every urban water supplier is required to assess the reliability of their water service to its customers under a normal year, a single dry year, and multiple dry years. The City's water sources are from local groundwater and imported water purchased from the Municipal Water District of Orange County (MWDOC). MWDOC is one of 26 member agencies of the Metropolitan Water District of Southern California (MET), which imports water from the Colorado River through its own Colorado River Aqueduct (CRA) and from Northern California through the California Aqueduct managed by the State Water Project (SWP). MET has also invested in numerous programs and projects to augment its direct deliveries of imported water such as water transfers, groundwater banking, and use of its reservoir storage as summarized in Chapter 6. Local groundwater in the Orange County Groundwater Basin (OC Basin) is managed by the Orange County Water District (OCWD). As summarized in Chapter 6, OCWD has developed programs and projects to improve groundwater recharge and augment groundwater through recycled water, conjunctive use, and water transfers. OCWD assesses groundwater conditions and sets its Basin Production Percentage (BPP), which determines how much water will be pumped from the basin year, and the Basin Equity Assessment (BEA), which is a surcharge for exceeding the BPP. Currently, the BPP is set at 85 percent. Likewise, MET has also invested in numerous programs and projects to augment its direct deliveries of imported water, such as water transfers, groundwater banking, and use of its reservoir storage, as summarized in Chapter 6. MET's draft 2025 UWMP demonstrates that MET will be able to meet its projected water demands for the next 25 years under normal, dry, and multiple dry year conditions (MET, 2025). In 2025, all water agencies in Orange County, in collaboration with their wholesalers, MWDOC and OCWD, developed a water demand forecast model for their service areas that estimated water demand at the individual retail water agency level. The demand model statistically correlates municipal and industrial (M&I) water use with demographic, socioeconomic, conservation, and weather variables as reported in the 2025 Orange County Water Demand Projection Model TM (MWDOC, 2025). Because the model isolates weather, future water demand can be estimated under single and multiple -year droughts and under future climate change scenarios. The model used a 33-year dataset (1991-2024) to estimate demand under average (normal), single -dry year, and five consecutive dry years hydrologic conditions. Correlation CITY OF TUSTIN 7-1 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO coefficients between demand, temperature, and precipitation were applied to the hottest and driest historical sequences to calculate high -demand scenarios, which were expressed as scaling factors relative to the 33-year average demand. Table 7.1 Optional Submittal Table 7-1 Retail: Basis of Water Year Data (Reliability Assessment) OP Data (Reliability Assessment) SuppliesAvailable Year Type Repeats Base Year Check the box if quantification of available supplies is not If not using a calendar compatible with this table and is provided elsewhere in ❑ year, type in the last the UWMP. Year Type year of the fiscal, water year, or range of Location: [insert location from UWMP] years, for example, Quantification of available suppliesprovided - , water year 2024-2025, volumeeither percent use 2025 Volume Available % of Average Supply Average Year 1991-2024 100% Single -Dry Year 2014 106% Consecutive Dry Years 1st Year 1991-2024 106% Consecutive Dry Years 2nd Year 1991-2024 112% Consecutive Dry Years 3rd Year 1991-2024 113% Consecutive Dry Years 4th Year 1991-2024 115% Consecutive Dry Years 5th Year 1991-2024 117% 7.2 Factors Affecting Water Supply Reliability To prepare realistic water supply reliability assessments, various factors affecting reliability were considered. These include climate change and environmental requirements, regulatory changes, water quality impacts, and locally applicable criteria. In May 2025, DWR published a technical addendum to the 2023 State Water Project Delivery Capability Report (DCR) describing the impact of subsidence to future SWP deliveries. The study showed that SWP deliveries could be reduced by future subsidence. DWR recommends using the 2025 DCR to support long-term planning efforts because DWR has planned near -term fixes and is committed to restoring the conveyance capacity of the California Aqueduct. MET will continue to stay informed and incorporate any suitable subsidence modeling in the future. 7.2.1 Climate Change and the Environment Changing climate patterns are expected to shift precipitation patterns and affect water supply availability. Unpredictable weather patterns will make water supply planning more challenging. Although climate change impacts are associated with exact timing, magnitude, and regional impacts of these temperature and precipitation changes, researchers have identified several areas of concern for California water planners (CAMP4W, 2025). These areas include: ■ A reduction in Sierra Nevada Mountain snowpack. ■ Extreme heat threatens both infrastructure and the health and safety of human lives. CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO • Prolonged drought periods. ■ Water quality issues associated with an increase in wildfires. • Rising sea levels resulting in: Impacts to coastal groundwater basins due to seawater intrusion. Increased risk of damage from storms, high -tide events, and the erosion of levees. Potential pumping cutbacks to the SWP and Central Valley Project (CVP). Other important issues of concern due to global climate change include: ■ Effects on local supplies such as groundwater. • Changes in urban and agricultural demand levels and patterns. ■ Alterations to power generation and pumping regime. ■ Increases in ocean algal blooms affected seawater desalination supplies. Without additional surface storage, earlier and heavier runoff will flow to the ocean instead of being held as mountain snowpack, causing California to lose more water. California, therefore, needs to place a strong emphasis on expanding storage. As described in Chapter 6, the Colorado River Basin supplies have been inconsistent since about the year 2000, with precipitation near normal while runoff has been less than average in two out of every three years. Climate models are predicting a continuation of this pattern, whereby hotter and drier weather conditions will result in continuing lower runoff, pushing the system toward a drying trend that is often characterized as long-term drought. Dramatic swings in annual hydrologic conditions have affected water supplies available from the SWP over the last decade. The declining ecosystem in the Sacramento -San Joaquin Delta (Delta) has also led to a reduction in water supply deliveries, and operational constraints will likely continue until a long-term solution to these problems is identified and implemented (MET, 2025). Climate change is also projected to impact future water demands. The 2025 Orange County Water Demand Model TM developed a sensitivity for the water demand forecast based on using future climate variables from a subset of 15 downscaled global climate models (GCMs) from the World Climate Research Program (WCRP) Coupled Model Intercomparison Project (CMIP6). Future weather variables under two climate scenarios were substituted for baseline historical average weather, with the results indicating that projected water demands under one to five consecutive dry years could be 5 percent to 17 percent greater than baseline demands (MWDOC, 2025). 7.2.2 Regulatory and Legal Ongoing regulatory restrictions, such as those imposed by the Biological Opinions (BiOps) on the effects of SWP and the federal CVP operations on certain marine life, also contribute to the challenge of determining water delivery reliability. Endangered species protection and conveyance needs in the Delta have resulted in operational constraints that are particularly important because pumping restrictions impact many water resources programs — SWP supplies and additional voluntary transfers, Central Valley storage and transfers, and in -region groundwater and surface water storage. BiOps protect special -status species listed as threatened or endangered under the Endangered Species Act (ESA) and impose substantial constraints on Delta water supply operations through requirements for Delta inflow and outflow and export pumping restrictions. CITY OF TUSTIN 7-3 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO In addition, the State Water Resources Control Board (SWRCB) has set water quality objectives that must be met by the SWP, including minimum Delta outflows, limits on SWP and CVP Delta exports, and maximum allowable salinity level. SWRCB has implemented the new Lower San Joaquin River flow objectives from the Phase 1 Delta Plan amendments through adjudicatory (water rights) and regulatory (water quality) processes. The Lower San Joaquin River flow objectives are estimated to reduce water available for municipal water use. New litigation, listings of additional species under the ESA, or regulatory requirements imposed by the SWRCB could further adversely affect SWP operations in the future by requiring additional export reductions, releases of additional water from storage, or other operational changes impacting water supply operations. The Colorado River 2007 Interim Guidelines governing the Lower Basin water supply shortages and the operations of Lakes Mead and Powell are set to expire in 2026, and new operating guidelines will need to be developed for 2027 and beyond. At the time of this 2025 UWMP, negotiations over the successor post-2026 guidelines are ongoing, and the outcome is highly uncertain. It is anticipated that California will likely be required to reduce its supplies from the Colorado River, on average, under the new guidelines, and that, as thejunior priority, MET is at risk. A final EIS with a Selected Alternative is expected in the summer of 2026, with a record of decision to follow. The difficulty and implications of environmental review, documentation, and permitting pose challenges for multi -year transfer agreements, recycled water projects, and seawater desalination plants. The timeline and roadmap for getting a permit for recycled water projects are challenging and inconsistently implemented in different regions of the state. Indirect Potable Reuse projects face regulatory restraints such as treatment, blend water, retention time, and Basin Plan Objectives, which may limit how much recycled water can feasibly be recharged into the groundwater basins. New regulations and permitting uncertainty are also barriers to seawater desalination supplies, including updated Ocean Plan Regulations, Marine Life Protected Areas, and Once -Through Cooling Regulations (MET, 2025). 7.2.3 Water Quality The following sub -section describes the water quality of the region's water supplies and the measures being taken to continue delivering high -quality drinking water that meets federal and state regulations. 7.2.3.1 Imported Water MET is responsible for providing high -quality potable water throughout its service area. Over 250,000 water quality tests are performed per year on MET's water to test for regulated contaminants and additional contaminants of concern to monitor the safety of its waters (MET, 2025). MET's supplies originate primarily from the CRA and from the SWP. A blend of these two sources, proportional to each year's availability of the source, is then delivered throughout MET's service area. Although the CRA and SWP have different water quality characteristics, MET has implemented effective treatment and management strategies to maintain high -quality water. The CRA water source contains higher total dissolved solids (TDS), and the SWP contains higher levels of naturally occurring organic matter, lending to the formation of disinfection byproducts. To remediate the CRA's high level of salinity and the SWP's high level of organic matter, MET blends CRA and SWP supplies and has upgraded all its treatment facilities to include ozone treatment processes. CITY OF TUSTIN 7-4 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO In addition, MET has been engaged in efforts to protect its Colorado River supplies from threats of uranium, perchlorate, and chromium VI while also investigating the potential water quality impact of the following emerging contaminants: N-nitrosodimethylamine (NDMA), pharmaceuticals and personal care products (PPCP), microplastics, per- and polyfluoroalkyl substances (PFAS), and 1,4-dioxane (MET, 2025). PFAS is a group of widely used man-made "forever chemicals" that include both perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). MET has voluntarily monitored PFAS in its source and treated waters since 2017. Most samples have shown non -detect (ND) for all tested PFAS, including PFOA and PFOS. A limited number of other PFAS—such as PFHxA, PFBA, PFPeA, PFDoA, PFTA, and PFBS, have been detected only at trace levels below their method detection limits. PFOA and PFOS have not been detected in Metropolitan's imported or treated water supplies. Some member agencies, however, have detected these compounds in local groundwater wells, which may require treatment or source management to comply with emerging Division of Drinking Water (DDW) regulations. As DDW and the US Environmental Protection Agency (EPA) establish enforceable Maximum Contaminant Levels (MCLs) for PFOA and PFOS, some agencies may supplement their local supplies with increased purchases of Metropolitan water (MET, 2025). EPA finalized the first national drinking water standards for six PFAS compounds in April 2024. These standards include enforceable MCLs for PFOA and PFOS set at 4 parts per trillion (ppt). In May 2025, the EPA announced that it would extend the compliance deadline for PFOA and PFOS from 2029 to 2031 to provide additional time for testing, planning, and installation of treatment technologies. While MET and its member agencies continue to monitor and test PFAS in imported and local sources, the delay in the federal compliance date allows additional time to evaluate treatment options, coordinate funding, and plan system upgrades necessary to meet forthcoming federal PFAS standards. The presence of quagga mussels in water sources is a water quality concern. Quagga mussels are an invasive species that was first discovered in 2007 at Lake Mead, on the Colorado River. This species of mussels forms massive colonies in short periods of time, disrupting ecosystems and blocking water intakes. They can cause significant disruption and damage to water distribution systems. MET has had success in controlling the spread and impacts of the quagga mussels within the CRA; however, the future could require more extensive maintenance and reduced operational flexibility than current operations allow. It also resulted in MET eliminating deliveries of CRA water into Diamond Valley Lake (DVL) to keep the reservoir free from quagga mussels (MET, 2025). In addition, Golden Mussels, another invasive species capable of disrupting pipelines and altering ecosystems, were detected in the Delta in October 2024 and are now spreading through the SWP. These mussels pose similar concerns due to their ability to obstruct raw water conveyance facilities and negatively affect aquatic environments. Although their presence does not typically result in violations of drinking water standards, unmanaged infestations can degrade habitats, clog infrastructure, and reduce the aesthetic and recreational value of lakes and reservoirs. State and regional agencies continue to monitor golden mussel movement and evaluate appropriate response strategies to limit their spread (MET, 2025). CITY OF TUSTIN 7-5 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 7.2.3.2 Groundwater Groundwater is a reliable component of the water supply for Orange County, and the OCWD manages the basin to provide long-term quality and sustainability. The basin supports a significant portion of the region's water demands and is monitored through an extensive network of production, monitoring, and recharge wells that provide data on water levels and water quality conditions across the aquifer system. Orange County Groundwater Basin OCWD is responsible for managing the OC Basin. To maintain groundwater quality, OCWD conducts an extensive monitoring program that serves to manage the OC Basin's groundwater production, control groundwater contamination, and comply with all required laws and regulations. A network of nearly 700 groundwater wells provides OCWD with a source for samples, which are tested for a variety of purposes. OCWD collects samples each month to monitor basin water quality. The total number of water samples analyzed varies year-to-year due to regulatory requirements, conditions in the basin, and applied research and/or special study demands. These samples are collected and tested according to approved federal and state procedures as well as industry -recognized quality assurance and control protocols (City of La Habra et al., 2017). OCWD routinely tests for hundreds of regulated constituents, but the parameters discussed, PFAS, TDS, and nitrate, are of focus because they represent the most relevant regional and regulatory considerations that influence groundwater management and long-term supply planning. These issues do not indicate that the groundwater basin is unsafe; rather, they are discussed because they are key focus areas for state agencies and water suppliers throughout Southern California. PFAS are of particular concern for groundwater quality, and since the summer of 2019, the DDW requires testing for PFAS compounds in some groundwater production wells in the OCWD area. According to the EPA, the established federal Maximum Contaminant Levels (MCLs) for certain PFAS compounds in drinking water include 4 nanograms per liter (ng/L), or parts per trillion (ppt), for PFOA and PFOS. In addition, the California State Water Resources Control Board has established health -based Notification Levels (NLs) and Response Levels (RLs) for several PFAS compounds. The current NLs are 4 ng/L for PFOA and 4 ng/L for PFOS, while the RLs are 10 ng/L for PFOA and 40 ng/L for PFOS. If PFAS concentrations exceed the NL, water systems must notify their governing body; if concentrations exceed the RL, water systems are expected to take corrective actions such as removing the source from service or implementing treatment. PFAS have been detected in the OC Basin in very tiny amounts (parts per trillion), entering primarily via the Santa Ana River, whose flows infiltrate into the basin. Despite playing no role in releasing PFAS into the environment, OCWD is working with its cities and retail water districts to remove them from local water supplies in order to comply with new state and federal regulations. More than 100 wells have been impacted due to various state and federal regulations. Fifteen impacted agencies will have to temporarily purchase more costly imported water to replace PFAS contaminated supplies. As of 2025, 53 impacted wells are back online due to close to a billion dollars being spent on state-of-the-art testing, research, and piloting of different treatment systems, and design and construction of treatment plants that are now operational. By 2025, OCWD had restored 49 wells to service with operational treatment systems, with an additional 57 wells in planning, design, or construction stages (ACWA, 2025). These systems continue to rely primarily on granular activated carbon (GAC) and ion -exchange (IX) media operated in lead —lag CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO configuration to achieve non -detect PFAS levels consistent with evolving state and federal regulatory standards (Santa Ana Regional Water Quality Control Board and Orange County Water District, 2023.) Groundwater production in FY 2023-24 totaled 280,420 acre-feet (AF), with slight increases projected over the next two years as additional treatment systems come online, showing continued reductions associated with PFAS-impacted wells that remain offline across several agencies. Salinity is a significant water quality problem in many parts of southern California, including Orange County. Salinity is a measure of the dissolved minerals in water, including both TDS and nitrates. OCWD continuously monitors the levels of TDS in wells throughout the OC Basin. TDS currently has a California Secondary MCL of 500 milligrams per liter (mg/L). The portions of the OC Basin with the highest levels are generally located in the cities of Irvine, Tustin, Yorba Linda, Anaheim, and Fullerton. There is also a broad area in the central portion of the OC Basin where TDS ranges from 500 to 700 mg/L. Sources of TDS include the water supplies used to recharge the OC Basin and from onsite wastewater treatment systems, also known as septic systems. The TDS concentration in the OC Basin increased on average from 415 mg/L in 2022-23 to 432 mg/L in 2023-24 (OCWD, 2025). Nitrates are one of the most common and widespread contaminants in groundwater supplies, originating from fertilizer use, animal feedlots, wastewater disposal systems, and other sources. The MCL for nitrate in drinking water is set at 10 mg/L. OCWD regularly monitors nitrate levels in groundwater and works with producers to treat wells that have exceeded safe levels of nitrate concentrations. OCWD manages the nitrate concentration of water recharged by its facilities to reduce nitrate concentrations in groundwater. This includes the operation of the Prado Wetlands, which was designed to remove nitrogen and other pollutants from the Santa Ana River before the water is diverted to be percolated into OCWD's surface water recharge system. Although water from the deep aquifer system is of very high quality, it is amber -colored and contains a sulfuric odor due to buried natural organic material, requiring treatment before use as drinking water. The principal aquifer, which supplies most basin pumping, occurs at depths of roughly 300-1,200 feet below ground surface (OCWD, 2025). The total volume of amber -colored groundwater in the deep system is estimated at approximately 1 million acre-feet (MAF). 7.2.4 Locally Applicable Criteria Within Orange County, there are no significant local applicable criteria that directly affect reliability. Over the years, the water agencies in Orange County have made tremendous efforts to integrate their systems to provide flexibility for interchanging with different sources of supply. There are emergency agreements in place to provide an adequate supply of water in all parts of the County. In the northern part of the County, agencies can meet most of their demands from groundwater with very little limitation, except for the OCWD BPP. For the agencies in South Orange County, most of their demands are met with imported water, and their limitations are based on the capacity of their systems, which are very robust. However, if a major earthquake on the San Andreas Fault occurs, it can potentially be damaging to key water aqueducts and disrupt imported supplies to the entire Southern California for up to six months. The MET region would likely require a water -use reduction of 10 to 25 percent until the system is repaired. However, MET has taken proactive steps to handle such disruption, such as constructing DVL, which mitigates potential impacts. DVL, along with other local reservoirs, can store a six to twelve-month supply of emergency water (MET, 2025). CITY OF TUSTIN 7-7 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 7.3 Water Service Reliability Assessment This section assesses the reliability of the City's water service to its customers. This is completed by comparing the projected long-term water demand (Chapter 4) to the projected water supply sources available to the City (Chapter 6), in five-year increments, for a normal water year, a single dry water year, and a drought lasting five consecutive water years. 7.3.1 Normal Year Reliability In 2025, MWDOC and OCWD, in collaboration with Orange County retail agencies, developed water demand forecast models for individual retail water agencies in Orange County, as described in detail in Chapter 4. This 25-year demand forecast uses statistical models to account for demographic, socioeconomic, conservation, and weather variables (MWDOC, 2025). For normal year reliability, the demand forecast represents average weather conditions. Tustin is 100 percent reliable for normal year demands from 2025 through 2050. Tustin receives imported water from MWDOC via connection to MET's regional distribution system. Although pipeline and connection capacity rights do not guarantee the availability of water, they do guarantee the ability to convey water into the local system when it is available to the MET distribution system A comparison between the supply and demand for projected years between 2025 and 2050 is shown in Table 7.2, while a breakdown of potable supplies is presented in Table 7.3, respectively. The table demonstrates that projected supplies and demands are equal in every planning year, with no anticipated surpluses or shortfalls. As stated above, the available supply will meet projected demands due to a diversified supply and conservation measures limiting and reducing imported demands in the later years. Tustin's supplies are provided by MWDOC and OC Basin. In MWDOC's 2025 Urban Water Management Plan, they identify their wholesale supplies as 100 percent reliable under normal -year conditions (Submittal Table 7-2; MWDOC, 2025). Table 7.2 Submittal Table 7-2 Retail: Normal Year Supply and Use Comparison Submittal..le 7-2 Retail: Normal Year Supply. Use Comparison Water Code Section 10635 2030 2035 2040 2045 2050 (Opt) (AF) (AF) (AF) (AF) (AF) Supply totals (autofill from Submittal Table 6-9 R) 91665 9,735 9,785 9,751 9,717 Use totals (autofill from Submittal Table 4-2 R) 9,665 9,735 9,785 9,751 9,717 Surplus/(shortfall) 0 0 0 0 0 NOTES: This table compares the projected demand and supply volumes determined in Sections 4.3.2 and 6.1, respectively. 7.3.2 Single Dry Year Reliability A single dry year is defined as a single year of minimal to no rainfall within a period where average precipitation is expected to occur. Orange County's water demand projection model (described in Chapter 4) isolated the impacts that weather and future climate can have on water demand through the CITY OF TUSTIN 7-8 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO use of a statistical model. The impacts of hot/dry weather conditions are reflected as a percentage increase in water demands from the normal year condition. ( For a single dry year condition (FY 2013-14), the model projects a six percent increase in demand for Tustin's service area (MWDOC, 2025). Detailed information about the model is included in Appendix E. Tustin has documented that it is 100 percent reliable for single dry year demands from 2025 through 2050. As shown in Table 7.3, projected single dry year supplies and demands are equal from 2030 to 2050, resulting in no anticipated shortages. This assessment incorporates a 6 percent increase in demand above normal -year levels and shows the significant reserves and conservation measures available within MET. Table 7.3 Submittal Table 7-3 Retail: Single Dry Year Supply and Demand Comparison Water Code Section 10635(a) Table 7-3 Retail: Single Water Code Section 10635(a) Dry Year SupplySubmittal .. 2040 2045 2050 (Opt) 2030 2035 (AF) (AF) (AF) (AF) (AF) Supply totals 10,251 10,325 10,379 10,342 10,306 Use totals 10,251 10,325 10,379 10,342 10,306 Surplus/(shortfall) 0 1 0 1 0 1 0 0 NOTES: The single dry year projections estimate a 6% increase on imported M&I demand. 7.3.3 Multiple Dry Years Reliability Multiple dry years are defined as five or more consecutive dry years with minimal rainfall within a period of average precipitation. Orange County's water demand projection model (described in Chapter 4) isolated the impacts that weather and future climate can have on water demand through the use of a statistical model. The impacts of hot/dry weather conditions are reflected as a percentage increase in water demands from the normal year condition. During multiple dry years, the UWMP applies dry -year adjustment factors to reflect future climate conditions and retail level water demand. These increase 6 percent in single -dry and first multiple -dry years, going up to 12, 13, 15, and 17 percent in subsequent drought years, relative to average -year demand (see Table 7.1) (MWDOC, 2025). Rather than repeating the single -dry -year factor for all five years, the five-year multi -dry -year scenario applies the year -specific dry -year adjustment factors for each consecutive year, reflecting the increasing impacts of extended drought. Tustin has demonstrated that its water supplies remain fully reliable throughout a five -consecutive -year dry period from 2025 through 2050. Even assuming a conservative demand increase of 6 to 17 percent per year for over five consecutive years, Tustin is capable of meeting all customers' demands from 2025 through 2050 (Table 7.4), with significant reserves held by MET and conservation. The table includes treated water from MET for M&I and non-M&I demands. The multiple dry -year projections estimate a six percent increase on imported M&I demand. The 2030 column assesses supply and demand for FY 2025-26 through FY 2029-30; the 2035 column assesses FY 2030-31 through FY 2034-35 and so forth, to end the water service reliability assessment in FY 2045-50. CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Table 7.4 Submittal Table 7-4 Retail: Multiple Dry Years Supply and Demand Comparison SupplySubmittal Table 7-4 Retail: Multiple Dry Years Water Code Section 10635(a) 2030 .. 2035 2040 2045 2050 (Opt) (AF) (AF) (AF) (AF) (AF) Supply totals 10,251 10,325 10,379 10,342 10,306 First year Use totals 10,251 10,325 10,379 10,342 10,306 Surplus/(shortfall) 0 0 0 0 0 Supply totals 10,820 10,898 10,955 10,916 10,878 Second year Use totals 10,820 10,898 10,955 10,916 10,878 Surplus/(shortfall) 0 0 0 0 0 Supply totals 10,887 10,966 11,023 10,984 10,946 Third year Use totals 10,887 10,966 11,023 10,984 10,946 Surplus/(shortfall) 0 0 0 0 0 Supply totals 11,093 11,173 11,232 11,192 11,153 Fourth year Use totals 11,093 11,173 11,232 11,192 11,153 Surplus/(shortfall) 0 0 0 0 0 Supply totals 11,282 11,363 11,422 11,382 11,342 Fifth year Use totals 11,282 11,363 11,422 11,382 11,342 Surplus/(shortfall) 0 0 1 0 1 0 1 0 NOTES: The 2030 column assesses supply and demand for FY 2025-26 through FY 2029-30; the 2035 column assesses FY 2030-31 through FY 2034-35 and so forth, in order to end the water service reliability assessment in FY 2049-50. 7.4 Management Tools and Options Existing and planned water management tools and options that seek to maximize local resources and minimize the need to import water are described below. ■ Reduced Delta Reliance: Both MWDOC and MET have demonstrated consistency with Reduced Reliance on the Delta Through Improved Regional Water Self -Reliance (Delta Plan Policy WR P1) by reporting the expected outcomes for measurable reductions in supplies from the Delta. MET has improved its self-reliance through methods including water use efficiency, water recycling, stormwater capture and reuse, advanced water technologies, conjunctive use projects, local and regional water supply and storage programs, and other programs and projects. Similarly, Orange County water agencies have further invested in water use efficiency, local water supply projects, and advanced water technologies to increase regional self-reliance. In the near term (2030), regional self-reliance during a normal water year for the entire MET service area is projected to increase by approximately 601 TAF compared to the 2010 baseline, an improvement equal to nearly 20 percent of projected 2030 retail demands. Looking ahead to 2050, normal year regional self-reliance is expected to grow by more than 1.0 MAF above the 2010 baseline, representing an increase of roughly 20 percent of projected 2050 retail demands (MET, 2025). CITY OF TUSTIN 7-10 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO • The continued and planned use of groundwater: The water supply resources within Tustin's service area are enhanced by the existence of groundwater basins that account for the majority of local supplies available. As described in Chapter 4, the OC Basin is also used as a reservoir to store water during wet years and draw from storage during dry years, subsequently minimizing the MWDOC service area's reliance on imported water. Groundwater basins are managed within a safe basin operating range so that groundwater wells are only pumped as needed to meet water use. Although Buena Park does not manage any of the service area's groundwater basins, as a groundwater producer, Buena Park supports the efforts to maintain the health of the local basins through local groundwater recharge efforts such as OCWD's GWRS Groundwater Replenishment System (GWRS) program. ■ Groundwater storage and transfer programs: OCWD's involvement in the Santa Ana River Conservation and Conjunctive Use Program (SARCCUP) includes participation in a conjunctive use program that improves water supply resiliency and increases available dry -year yield from local groundwater basins. The groundwater bank has 137,000 AF of storage (Inland Empire Utilities Agency, 2021). MET has numerous groundwater storage and transfer programs in which MET endeavors to increase the reliability of water supplies, including the Antelope Valley -East Kern Water Agency (AVEK) Water Agency Exchange and Storage Program and the High Desert Water Bank Program. In addition, MET has encouraged storage through its cyclic and conjunctive use programs that allow MET to deliver water into a groundwater basin in advance of agency demands, such as the Cyclic Storage Agreements under the Main San Gabriel Basin Judgment. MWDOC Water Loss Program: The water loss audit program reduces Tustin's dependency on imported water from the Delta by implementing water loss control technologies after assessing audit data and leak detection. ■ Increased use of recycled water: OCWD's Groundwater Replenishment System (GWRS) and Green Acres Project (GAP) help southern California reduce its reliance on imported water by providing a local, reliable water supply that meets or exceeds all federal and state drinking water standards. OCWD is currently expanding the GWRS to increase production to 130 MGD, further strengthening regional water self-sufficiency. ■ Implementation of demand management measures during dry periods: During dry periods, water reduction methods to be applied to the public through the retail agencies, which will in turn reduce Tustin's overall demands on local and imported water. Buena Park met its conservation target of 20 percent by 2020 as part of the Orange County Regional Alliance as well as individually. 7.5 Drought Risk Assessment California Water Code (CWC) Section 10635(b) requires every urban water supplier to include, as part of its UWMP, a DRA for its water service as part of the information considered in developing its demand management measures and water supply projects and programs. The DRA is a specific planning action that assumes Tustin is experiencing a drought over the next five years and addresses water supply reliability in the context of presumed drought conditions. Together, the water service reliability assessment, DRA, and water shortage contingency plan (WSCP) allow Tustin to have a comprehensive picture of its short-term and long-term water service reliability and to identify the tools to address any perceived or actual shortage conditions. CITY OF TUSTIN 7-11 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO CWC Section 10612 requires the DRA to be based on the driest five-year historical sequence for Tustin's water supply. However, CWC Section 10635 also requires that the analysis consider plausible changes on projected supplies and demands due to climate change, anticipated regulatory changes, and other locally applicable criteria. The following sections describe the methodology and results from Tustin's DRA. 7.5.1 Methodology As described in more detail in Chapter 4, the water demand forecasting model prepared for Tustin isolated the impacts that weather and future climate can have on water demand through the use of an econometric model. In addition to weather related factors, the model incorporates explanatory variables that influence both historical and projected water use, including water price, gross domestic product (GDP), median household income, housing density, persons per household, households per account, sectoral employment mix (for Commercial, Industrial, and Institutional [CII] demand), seasonal patterns, historical conservation trends, drought restrictions, and COVID-19 behavioral effects. These variables allow the model to separately quantify how economic conditions, demographic shifts, land use characteristics, and institutional constraints affect demand across residential, commercial, industrial, institutional, and irrigation sectors (MWDOC, 2025). The impacts of hot/dry weather conditions are reflected as a percentage increase in water demands from the average condition. For a single dry year condition (FY 2013-14), the model projects a 6 percent increase in demand for Tustin's service area (MWDOC, 2025). The model used a 33-year dataset (1991-2024) to estimate demand under average (normal), single -dry year, and five consecutive dry years hydrologic conditions. Correlation coefficients between demand, temperature, and precipitation were applied to the hottest and driest historical sequences to calculate high -demand scenarios, which were expressed as scaling factors relative to the 33-year average demand. For Tustin, the five consecutive dry year demand scenario is based on the demand model's multiple dry year methodology. In accordance with the econometric demand model approach used to develop UWMP demand projections, a single hot/dry year was first identified based on weather conditions that produced the greatest demand response. Consecutive dry years were then represented by applying incremental scaling factors to this single hot/dry year demand to account for the compounding effects of persistent warm and dry conditions over time. These scaling factors show long-term relationships between regional water use and multi -year temperature and precipitation deficits and are applied sequentially to simulate second through fifth consecutive dry years. This approach is consistent with the demand modeling framework summarized in Tables 7.1 and 7.5. 7.5.1.1 Water Demand Characterization Tustin's water supplies consist of groundwater from the OC Basin and purchased water from MWDOC, regardless of hydrologic conditions. As described in Chapter 6, MET'S supplies are from the Colorado River, SWP, and in -region storage. In MET'S 2025 UWMP, the Drought Risk Assessment (DRA) concluded that even without activating WSCP actions. Beyond this, MET'S DRA indicated a surplus of supplies that would be available to all of its member agencies, including MWDOC, should the need arise. Therefore, any increase in demand that is experienced in MWDOC's service area is assumed to be met by MET'S water supplies. CITY OF TUSTIN 7-12 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Based on the water demand projection model, discussed in more detail in Chapter 4, in a single dry year, demand is expected to increase by 6 percent above a normal year (see Table 7.1). Tustin's DRA conservatively assumes that a drought from FY 2025-26 through FY 2029-30 is based on the FY 2025 normal year supply with the five-year consecutive dry year hydrology (from Table 7.1) (MWDOC, 2025). 7.5.1.2 Water Supply Characterization Tustin's assumptions for its supply capabilities are discussed and presented in 5-year increments under its water reliability assessment in Section 7.3. For Tustin's DRA, these supply capabilities are further refined and presented annually for the years 2026 to 2030, which the Orange County Demand Model (2025) applied a historical dry -year sequence from within the 1991-2024 dataset as an analog for five consecutive dry years. Groundwater is sustainably managed through the BPP and robust management measures (Section 6.3.4 and Appendix G), direct and indirect recycled water uses provide additional local supply (Section 6.6), and based on MET's and MWDOC's UWMP, imported water is available to close any local water supply gap (Section 7.5.1). For its DRA, the model assessed the reliability of supplies available to Orange County through MET using historical supply availability under dry -year conditions. MET's supply sources under the CR, SWP, and in -region supply categories are individually listed and discussed in detail in MET's UWMP. Future supply capabilities for each of these supply sources are also individually tabulated in Appendix 3 of MET's UWMP, with consideration for plausible changes on projected supplies under climate change conditions, anticipated regulatory changes, and other factors. In addition, Tustin may benefit from MET -implemented supply augmentation actions during regional shortages. These actions are planned and exercised by MET based on regional conditions and in accordance with the Water Supply Contingency Plan (WSCP) and are not assumed as baseline or guaranteed supplies for Tustin. Such actions may include the use of supplies and storage programs within the Colorado River, SWP, and in -region storage portfolios. 7.5.2 Total Water Supply and Use Comparison Tustin's anticipated total water use and supply under a five-year drought from FY 2025-26 through FY 2029-30 are compared in Table 7.5. Tustin's assessment reveals that its supply capabilities are expected to balance with its projected water use for the next five years, from 2026 to 2030. CITY OF TUSTIN 7-13 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Table 7.5 Submittal Table 7-5 Retail: Five -Year Drought Risk Assessment TableSubmittal Drought Code Section 10635(b)(3) 2026 Total Water Use (AF) Total 10,929 Total Supplies (AF) 10,929 Surplus/Shortfall w/o WSCP Action 2027 0 Total Total Water Use (AF) 11,535 Total Supplies (AF) 11,535 Surplus/Shortfall w/o WSCP Action 0 Total Water Use (AF) 11,607 Total Supplies (AF) 11,607 Surplus/Shortfall w/o WSCP Action 0 I Total Water Use (AF) am 11,827 Total Supplies (AF) 11,827 Surplus/Shortfall w/o WSCP Action 0 Total Water Use (AF) 12,028 Total Supplies (AF) 12,028 Surplus/Shortfall w/o WSCP Action 0 7.5.3 Water Source Reliability Tustin maintains a diverse and resilient water supply portfolio that includes groundwater from the OC Basin, indirect recycled water through OCWD's GWRS, and imported supplies available through MET and MWDOC. This combination of local and regional sources reduces Tustin's reliance on any single supply. With active basin management by OCWD and Tustin's continued investment in local production, the overall portfolio remains well -positioned to meet demands under a wide range of hydrologic conditions. As detailed in Chapter 8, Tustin has in place a robust WSCP and comprehensive shortage response planning efforts that include demand reduction measures and supply augmentation actions. However, since Tustin's DRA shows a balance, no water service reliability concern is anticipated, and no shortfall mitigation measures are expected to be exercised over the next five years. Tustin and its wholesale, MWDOC, will periodically revisit its representation of the supply sources and of the gross water use estimated for each year, and will revise the DRA if needed. CITY OF TUSTIN 7-14 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO CHAPTER 8WATER SHORTAGE CONTINGENCY PLANNING 8.1 Background Water shortage contingency planning is a strategic planning process that the City of Tustin (City) engages to prepare for and respond to water shortages. A water shortage is defined when water supply available is insufficient to meet the customer demand at a given point in time. This may occur due to water supply availability changes, water quality changes, and/or catastrophic events (e.g., earthquake). The Water Shortage Contingency Plan (WSCP), included in Appendix F and summarized in this chapter, provides a water supply availability assessment and structured steps designed to respond to actual conditions. This level of detailed planning and preparation is intended to help maintain reliable supplies and reduce the impacts of supply interruptions. The California Water Code (CWC) Section 10632 requires that every urban water supplier that serves more than 3,000 acre-feet per year or has more than 3,000 connections prepared adopt a standalone WSCP as part of its Urban Water Management Plan (UWMP). The WSCP is required to plan for a greater than 50 percent supply shortage. The WSCP may require updating based on new California Department of Water Resources (DWR) requirements every five years and will be adopted as a current update for submission to DWR by July 1, 2026. 8.2 Overview of the Water Shortage Contingency Plan The WSCP serves as the operating manual that the City will use to prevent catastrophic service disruptions through proactive, rather than reactive, mitigation of water shortages. The WSCP defines the processes and procedures that would be deployed when shortage conditions arise so that the City's governing body, its staff, and the public can easily identify and efficiently implement pre -determined steps to mitigate a water shortage to the level appropriate for the degree of water shortfall anticipated. The relationship between the three procedural documents related to planning for and responding to water shortages is graphically depicted in Figure 8.1. CITY OF TUSTIN 8-1 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO A comprehensive water •. • - • • • management action plan to assess 6��water supply reliability. Chapter 8: Water Shortage Contingency Plan loom E hortage Contingencyponse Ordinance A detailed plan to predict and •� • mitigate a water shortage condition. Provides the legal authority to enforce the Water Shortage Contingency Plan Figure 8.1 Purpose and Relationships of the UWMP, WSCP, and Water Shortage Response Ordinance A complete version of the City's WSCP is provided in Appendix F and includes the steps to assess if a water shortage is occurring, and what level of demand reduction actions to trigger the most appropriate response to the water shortage conditions. The WSCP has prescriptive elements, including an analysis of water supply reliability; the drought shortage actions that align with water shortage levels that correspond to water shortage percentages ranging from 10 percent to greater than 50 percent; an estimate of potential to close supply gap for each measure; protocols and procedures to communicate identified actions for any current or predicted water shortage conditions; procedures for an annual water supply and demand assessment; monitoring and reporting requirements to determine customer compliance; and reevaluation and improvement procedures for evaluating the WSCP. 8.3 Summary of Water Shortage Response Strategy and Required DWR Tables The WSCP is organized into the following three main sections with Section 3 aligned with the CWC Section 16032 requirements. ■ Section 1 Introduction and WSCP Overview gives an overview of the WSCP fundamentals. ■ Section 2 Background Information provides a background on the City's water service area. ■ Section 3 Water Shortage Contingency Preparedness and Response Planning. Section 3.1 Water Supply Reliability Analysis provides a summary of the water supply analysis and water reliability findings from the 2025 UWMP. Section 3.2 Annual Water Supply and Demand Assessment Procedures provides a description of procedures to conduct and approve the Annual Assessment. Section 3.3 Six Standard Water Shortage Stages explains the WSCP's six standard water shortage levels corresponding to progressive ranges of up to 10, 20, 30, 40, 50, and more than 50 percent shortages. CITY OF TUSTIN 8-2 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO >> Section 3.4 Shortage Response Actions describes the WSCP's shortage response actions that align with the defined shortage levels. Section 3.5 Communication Protocols addresses communication protocols and procedures to inform customers, the public, interested parties, and local, regional, and state governments, regarding any current or predicted shortages and any resulting shortage response actions. Section 3.6 Compliance and Enforcement describes customer compliance, enforcement, appeal, and exemption procedures for triggered shortage response actions. Section 3.7 Legal Authorities describes the legal authorities that enable the City to implement and enforce its shortage response actions. Section 3.8 Financial Consequences of the WSCP provides a description of the financial consequences of and responses for drought conditions. Section 3.9 Monitoring and Reporting describes monitoring and reporting requirements and procedures that ensure appropriate data is collected, tracked, and analyzed for purposes of monitoring customer compliance and to meet state reporting requirements. Section 3.10 WSCP Refinement Procedures addresses reevaluation and improvement procedures for monitoring and evaluating the functionality of the WSCP. Section 3.11 Special Water Feature Distinction provides a required definition for inclusion in a WSCP per the Water Code. Section 3.12 Plan Adoption, Submittal, Availability describes the process the City followed to adopt its WSCP. The WSCP is based on adequate details of demand reduction and supply augmentation measures that are structured to match varying degrees of shortage will aim to make the relevant stakeholders understand what to expect during a water shortage situation. The City adopted water shortage levels consistent with the requirements identified in CWC Section 10632 (a)(3)(A) (Table 8.1). The six shortage levels the City uses in their water shortage planning and documented in their WSCP are the same as DWR's six standard shortage levels, as indicated in Table 8.1. The water supply augmentation measures that align with each shortage level are described in Table 8.2 This table also estimates the extent to which that action will augment supplies to reduce the gap between supplies and demands. The demand reduction action measures that align with each shortage level and how each measure will reduce the shortage gap between expected supplies and the shortage level is summarized in Table 8.3. The purpose of Table 8.2 and Table 8.3 are to demonstrate the results the City can expect once shortage level actions are implemented to deliver the expected outcomes necessary to meet the requirements of a given shortage level. CITY OF TUSTIN 8-3 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Table 8.1 Cross -Reference for Standard vs Supplier Shortage Levels Submittal Table 8-1: Cross-reference for Standard vs Supplier Shortage Levels Water Code Section 10632(a)(3)(B) 0 Check the boxes if the Supplier uses the Standard six levels of water shortage. Proceed to the next table. Standard Shortage Percent Shortage Suppliers Shortage I Percent Shortage Levels Range Levels Range • • •' • • •' • to 4•% • Table 8.2 Supply Augmentation and Other Actions TableSubmittal .. Other Water Code Section 10632(a)(4)(A),(C) YesIs the Supplier• • - • this table using the standard How much is this going to reduce • the shortage gap? Supply Augmentation Methods and Other Actions by Water Supplier Shortage Gap Explanation or Shortage Drop down list ReductionAdditional Reference Level These are the only categories that Volume or a (OPTIONAL) will be accepted by the WUEdataPercentage, b. , online submittal tool Drop down range) (AF) Add additional rows as needed 1 through 6 Other Purchases Percentage 0 -100% Additional imported water purchases through MWDOC Additional groundwater 1 through 6 Other Purchases Percentage 0 -100% pumping in the Orange County Groundwater Basin DWR NOTES: Units of measure (AF, CCF, MG) must remain consistent throughout the UWMP as reported in Submittal Table 2-3. NOTES: Additional imported water and groundwater pumping may be subject to rate penalties from MWDOC and OCWD, respectively. CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Table 8.3 Demand Reduction Actions Submittal Table 8-3 Retail: Demand Reduction Actions Water Code Section 10632(a)(4)(B) YesIs the Supplier• • - • this table using the standard • Demand Reduction How much is this going to reduce the Actions shortage gap? Penalty, Charge, Drop down list or Other These are the only • _ Gap Reduction • Additional Explanation or Reference Enforcement? Level categories that will be Volume o (OPTIONAL) For Retail accepted by the Percentage - • - •range) Suppliers Only WUEdata online submittal tool. Select • • down (AF) Drop Down List those that apply. Add additional rows as needed 0 Other water feature or Statewide Prohibition is The operation of any ornamental fountain or similar structure is Yes swimming pool Required prohibited unless the foundation or structure internally recycles restriction the water it uses. 0 Other - Prohibit vehicle Statewide Prohibition is Washing or hosing down vehicles is prohibited except by use of a Yes washing except at Required handheld container, hand hose equipped with a positive shut off facilities using recycled nozzle, or at a commercial car wash. Further, such washing is or recirculating water exempted from these regulations where health, safety, and welfare of the public is contingent upon frequent vehicle cleaning such as a garbage truck and vehicles used to transport food and perishables. 0 Other - Prohibit use of Statewide Prohibition is Washing hard or paved surfaces is prohibited except to alleviate Yes potable water for Required safety or sanitary hazards using a handheld container, hose with washing hard surfaces an automatic shut off device, or a low -volume high pressure cleaning machine that recycles used water. 0 Landscape - Restrict or Statewide Prohibition is Watering vegetated areas in a manner that causes excessive Yes prohibit runoff from Required water flow or runoff onto an adjoining sidewalk, driveway, street, landscape irrigation alley, gutter, or ditch is prohibited. CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Water Code TableSubmittal Demand Section1. YesIs the Supplier. • - • this table• the standard • Demand Reduction How much is this going to reduce the Actions sh ortage gap? Penalty, Charge, Drop down list or Other Shortage _ _ These are the only • • • . • • categories that will be ", Additional Explanation or Reference Enforcement? Level • . • • _ , • _ accepted by the (OPTIONAL) For Retail WUEdata online � ' • Suppliers Only • • • • submittal tool. Select (AF) Drop Down List those that apply. 0 Landscape - Other Statewide Prohibition is No landscape watering shall occur within 48 hours after Yes landscape restriction or Required measurable precipitation. "Measurable precipitation" shall mean prohibition a one -quarter inch or more of rainfall within the City of Tustin within a twenty -four-hour period. 0 Landscape - Limit On -going Long -Term Between April 1 and October 31, lawn watering and landscape Yes landscape irrigation to Conservation Savings irrigation will be limited to 4 days per week. Watering and specific days Measure. Not applicable irrigation may only occur on Sunday, Tuesday, Thursday, and to Water Shortage Saturday. Between November 1 and March 31, lawn watering Contingency Plan and landscape irrigation will be further limited to 3 days per week. quantifiable savings. Watering and irrigation may only occur on Tuesday, Thursday, and Saturday. 0 Landscape - Limit On -going Long -Term Watering or irrigation with a device that is not continuously Yes landscape irrigation to Conservation Savings attended to is limited to 5 minutes per valve, per irrigation day. specific times Measure. Not applicable Low flow drip type systems, water efficient stream rotor systems, to Water Shortage and sensor/weather-controlled systems shall be limited to 15 Contingency Plan minutes per valve, per irrigation day. quantifiable savings. 0 Landscape - Limit On -going Long -Term Watering or irrigation of vegetated areas is prohibited between Yes landscape irrigation to Conservation Savings 8:00 a.m. and 4:00 p.m. except for when adjusting or repairing an specific times Measure. Not applicable irrigation system for short periods of time. to Water Shortage Contingency Plan quantifiable savings. CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Water Code TableSubmittal Demand Section1. YesIs the Supplier. • - • this table• the standard • Demand Reduction How much is this going to reduce the Actions sh ortage gap? Penalty, Charge, Drop down list or Other Shortage _ _ These are the only • • • . • • categories that will be ", Additional Explanation or Reference Enforcement? Level • . • • _ , • _ accepted by the (OPTIONAL) For Retail WUEdata online � ' • Suppliers Only • • • • submittal tool. Select (AF) Drop Down List those that apply. 0 Other - Customers must On -going Long -Term Fix all water leaks or faulty sprinklers immediately upon Yes repair leaks, breaks, Conservation Savings notification. and malfunctions in a Measure. Not applicable timely manner to Water Shortage Contingency Plan quantifiable savings. 0 CII - Restaurants may On -going Long -Term CII - Restaurants may only serve water upon request. Yes only serve water upon Conservation Savings request Measure. Not applicable to Water Shortage Contingency Plan quantifiable savings. 0 CII - Lodging On -going Long -Term CII - Lodging establishment must offer opt out of linen service Yes establishment must Conservation Savings and shall prominently display notice of this options in each offer opt out of linen Measure. Not applicable guestroom. service to Water Shortage Contingency Plan quantifiable savings. 0 CII - Other CII On -going Long -Term CII - Watering parks, school grounds, public facilities, and Yes restriction or prohibition Conservation Savings recreational fields are not permitted between the hours of Measure. Not applicable 8:00 a.m. and 4:00 p.m. to Water Shortage Contingency Plan quantifiable savings. CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Water Code TableSubmittal Demand Section1. YesIs the Supplier. • - • this table• the standard • Demand Reduction How much is this going to reduce the Actions sh ortage gap? Penalty, Charge, Drop down list or Other Shortage _ _ These are the only • • • . • • categories that will be ", Additional Explanation or Reference Enforcement? Level • . • • _ , • _ accepted by the (OPTIONAL) For Retail WUEdata online � ' • Suppliers Only • • • • submittal tool. Select (AF) Drop Down List those that apply. 0 Landscape - Other On -going Long -Term Customers that utilize turf for beneficial public use may apply for Yes landscape restriction or Conservation Savings an exemption from the permanent water restriction schedule. A prohibition Measure. Not applicable Water Management Plan shall be provided that demonstrates to Water Shortage specific actions that will be taken to manage potable water use Contingency Plan within the guidelines, requirements, and conservation standards quantifiable savings. set by the State Water Resources Control Board or City. Designated irrigation schedules shall remain in effect until the City has reviewed and approved the customers' water management plan. Exemptions may be revoked if customer does not comply or meet their defined conservation goals within the approved plan. 1 Expand Public Percentage 0-1% Community Outreach and Messaging (Expand Public Information Information Campaign Campaign) 1 Expand Public Percentage 0-1 % Encourage customers to wash only full loads when washing Information Campaign dishes or clothes. 1 Expand Public Percentage 0-1% Encourage customers to use pool covers to minimize Information Campaign evaporation. CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Water Code TableSubmittal Demand Section1. YesIs the Supplier. • - • this table• the standard • Demand Reduction How much is this going to reduce the Actions sh ortage gap? Penalty, Charge, Drop down list or Other Shortage _ _ These are the only • • • . • • categories that will be ", Additional Explanation or Reference Enforcement? Level • . • • _ , • _ accepted by the (OPTIONAL) For Retail WUEdata online � ' • Suppliers Only • • • • submittal tool. Select (AF) Drop Down List those that apply. 1 Landscape - Limit Percentage 5-10% Between April 1 and October 31, lawn watering and landscape Yes landscape irrigation to irrigation will be limited to 4 days per week. Watering and specific days irrigation may only occur on Sunday, Tuesday, Thursday, and Saturday. Between November 1 and March 31, lawn watering and landscape irrigation will be further limited to 3 days per week. Watering and irrigation may only occur on Tuesday, Thursday, and Saturday. 1 Landscape - Limit Percentage 0-5% Watering or irrigation with a device that is not continuously Yes landscape irrigation to attended to is limited to 5 minutes per valve, per irrigation day. specific times Low flow drip type systems, water efficient stream rotor systems, and sensor/weather-controlled systems shall be limited to 15 minutes per valve, per irrigation day. 1 Provide Rebates for Percentage 0-1% Expanded/Enhanced Rebate Programs offered through Municipal Landscape Irrigation Water District of Orange County. Efficiency 1 Offer Water Use Percentage 0-1 % Offer Water Use Surveys. Surveys 1 Provide Rebates on Percentage 0-1% Rebates on Plumbing Fixtures and Devices may be offered Plumbing Fixtures and through Municipal Water District of Orange County. Devices 1 Provide Rebates for Percentage 0-1 % Rebates for Turf Replacement may be offered through Municipal Turf Replacement Water District of Orange County. CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Water Code TableSubmittal Demand Section1. YesIs the Supplier. • - • this table• the standard • Demand Reduction How much is this going to reduce the Actions sh ortage gap? Penalty, Charge, Drop down list or Other Shortage _ _ These are the only • • • . • • categories that will be ", Additional Explanation or Reference Enforcement? Level • . • • _ , • _ accepted by the (OPTIONAL) For Retail WUEdata online � ' • Suppliers Only • • • • submittal tool. Select (AF) Drop Down List those that apply. 1 Increase Water Waste Percentage 0-1% Increase Water Waste Patrols. Patrols 2 Landscape - Limit Percentage 5-10% Between April 1 and October 31, lawn watering and landscape Yes landscape irrigation to irrigation will be limited to 3 days per week. Watering and specific days irrigation may only occur on Tuesday, Thursday, and Saturday. Between November 1 and March 31, lawn watering and landscape irrigation will be further limited to 2 days per week. Watering and irrigation may only occur on Tuesday and Saturday. 2 Water Features - Percentage 0-1 % Filling or refilling ornamental lakes and ponds with potable water Restrict water use for is prohibited. Ornamental lakes and ponds that sustain aquatic decorative water life of significant value and were actively managed prior to the features, such as storage declaration are exempt. fountains 2 Decrease Line Flushing Percentage 0-1% Decrease distribution system flushing. 2 Pools - Allow filling of Percentage 0-1 % Swimming pools may only be filled when an appropriate cover is swimming pools only in place. when an appropriate cover is in place. 2 Increase Water Waste Percentage 0-1% Increase Water Waste Patrols. Patrols CITY OF TUSTIN 8-10 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Water Code TableSubmittal Demand Section1. YesIs the Supplier. • - • this table• the standard • Demand Reduction How much is this going to reduce the Actions sh ortage gap? Penalty, Charge, Drop down list or Other Shortage _ _ These are the only • • • . • • categories that will be ", Additional Explanation or Reference Enforcement? Level • . • • _ , • _ accepted by the (OPTIONAL) For Retail WUEdata online � ' • Suppliers Only • • • • submittal tool. Select (AF) Drop Down List those that apply. 3 Pools - Allow filling of Percentage 0-1 % Existing pools shall not be emptied and refilled using potable Yes swimming pools only water unless required for public health and safety purposes. when an appropriate Swimming pools utilizing a cover may be topped off to prevent cover is in place. damage to pump and filter equipment. 3 Other water feature or Percentage 0-1 % Decorative water features that use potable water must be drained swimming pool and kept dry. restriction 3 Other - Prohibit vehicle Percentage 0-1 % Car washing is only permitted using a commercial carwash that washing except at recirculates water or by high pressure/low volume wash systems. facilities using recycled or recirculating water 3 Landscape - Limit Percentage 5-10% Between April 1 and October 31, lawn watering and landscape Yes landscape irrigation to irrigation will be limited to 2 days per week. Watering and specific days irrigation may only occur on Tuesday and Saturday. Between November 1 and March 31, lawn watering and landscape irrigation will be further limited to 1 day per week. Watering and irrigation may only occur on Tuesday. 3 Increase Water Waste Percentage 0-1% Increase Water Waste Patrols. Patrols 4 Other water feature or Percentage 0-1 % Pools shall not be emptied and refilled using potable water Yes swimming pool unless required for public health and safety purposes. restriction CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Water Code TableSubmittal Demand Section1. YesIs the Supplier. • - • this table• the standard • Demand Reduction How much is this going to reduce the Actions sh ortage gap? Penalty, Charge, Drop down list or Other Shortage _ _ These are the only • • • . • • categories that will be ", Additional Explanation or Reference Enforcement? Level • . • • _ , • _ accepted by the (OPTIONAL) For Retail WUEdata online � ' • Suppliers Only • • • • submittal tool. Select (AF) Drop Down List those that apply. 4 Landscape - Limit Percentage 5-10% Lawn watering and landscape irrigation will be limited to 1 day Yes landscape irrigation to per week. Watering and irrigation may only occur on Tuesday. specific days 4 Other - Prohibit vehicle Percentage 0-1 % Washing of autos, trucks, mobile homes, buses, trailers, boats, Yes washing except at airplanes, and any other type of mobile equipment is prohibited. facilities using recycled Washing is permitted at any time on the immediate premise of a or recirculating water commercial car wash. The use of water by all types of commercial car washes not using partially reclaimed or recycled water shall reduce water use in volume by twenty percent. 4 Landscape - Limit Percentage 0-1 % Agriculture users and commercial nurseries shall use water only Yes landscape irrigation to between hours of 6:00 p.m. and 6:00 a.m. and may be subject to specific times additional restrictions if the state, regional, or city jurisdiction deems necessary. The City will make good faith efforts to inform agricultural users and commercial nurseries of any such restrictions. Monetary penalties will be passed through to agricultural and commercial nursery customers, if assessed by the State Water Resources Control Board, Metropolitan Water District of Southern California, or Municipal Water District of Orange County. 4 Water Features - Percentage 0-1 % The operation of any ornamental fountain or similar structure is Yes Restrict water use for prohibited, even when recycled water is used. decorative water features, such as fountains CITY OF TUSTIN 8-12 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Water Code TableSubmittal Demand Section1. YesIs the Supplier. • - • this table• the standard • Demand Reduction How much is this going to reduce the Actions sh ortage gap? Penalty, Charge, Drop down list or Other Shortage _ _ These are the only • • • . • • Additional Explanation or Reference Enforcement? Level _ categories that will be • . • ", (OPTIONAL) For Retail accepted by the • , • _ � ' • Suppliers Only WUEdata online • • • • submittal tool. Select (AF) Drop Down List those that apply. 4 Other - Prohibit use of Percentage 0-1 % Construction water shall not be used for earthwork or road Yes potable water for construction purposes unless authorized as a mitigation, erosion construction and dust control, compaction, or backfilling work or as required by the Air control Quality Management Plan Control Measure F-4. 4 CII - Other CI I Percentage 0-1 % The use of water for commercial, industrial, institutional, Yes restriction or prohibition manufacturing, or processing purposes shall be essential use only. All outdoor irrigation is prohibited. 4 Increase Water Waste Percentage 0-1% Increase Water Waste Patrols. Patrols 5 Other Percentage 0-1 % Water for agricultural or commercial nursery purposes, except for Yes livestock watering, is prohibited. 5 Landscape - Prohibit all Percentage 5-10% All outdoor irrigation is prohibited. Yes landscape irrigation 5 Landscape - Prohibit Percentage 0-1 % Watering of all golf course areas is prohibited with the exception Yes certain types of of plant material, or turf classified to be rare or exceptionally landscape irrigation valuable. 5 Landscape - Prohibit Percentage 0-1 % Watering of parks, school grounds, public facilities, and Yes certain types of recreation fields is prohibited with the exception of plant material landscape irrigation classified to be rare, exceptionally valuable, or essential to the wellbeing of rare animals. CITY OF TUSTIN 8-13 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Water Code TableSubmittal Demand Section1. YesIs the Supplier. • - • this table• the standard • Demand Reduction How much is this going to reduce the Actions sh ortage gap? Penalty, Charge, Drop down list or Other Shortage These are the only _ _ • • • . • • Additional Explanation or Reference Enforcement? Level categories that will be • . • _ ", (OPTIONAL) For Retail accepted by the � ' • • , • _ Suppliers Only WUEdata online submittal tool. Select • • • • (AF) Drop Down List those that apply. 5 Moratorium or Net Zero Percentage 0-1% Moratorium or Net Zero Demand Increase on New Connections. Yes Demand Increase on Construction meters or permits for new water service New Connections connections will not be issued. 5 Other Percentage 0-1 % Water use from fire hydrants shall be limited to firefighting or Yes related activities necessary to maintain public health, safety, and welfare of the public. 5 Other - Prohibit vehicle Percentage 0-1 % Commercial car washing facilities shall reduce water usage by a Yes washing except at volume of fifty percent. facilities using recycled or recirculating water 5 Increase Water Waste Percentage 0-1% Increase Water Waste Patrols. Yes Patrols 6 Other Percentage 0-1 % Water for air conditioning is prohibited. Yes 6 Landscape - Prohibit all Percentage 0-5% All irrigation is prohibited. The City may shut off all non -essential Yes landscape irrigation water services. CITY OF TUSTIN 8-14 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 Yes Shortage Level Demand Reduction Actions Drop down list These are the only categories that will be accepted by the WUEdata online submittal tool. Select those that apply. How much is this going to reduce the shortage gap? (AF) 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Additional Explanation or Reference (OPTIONAL) Penalty, Charge, or Other Enforcement? For Retail Suppliers Only Drop Down List 6 CII - Other CII Percentage 0-15% Water for commercial, manufacturing, or processing purposes Yes restriction or prohibition shall be reduced in volume by up to 50% or exceeded if necessary for public health and safety purposes. 6 Other Percentage 0-70% Water use for public health and safety purposes only. Customer Yes rationing may be implemented. DWR NOTES: Final must remain consistent throughout the UWMP as reported in Submittal Table 2-3. NOTES: CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO CHAPTER9 DEMAND MANAGEMENT MEASURES Over the past several decades, water use efficiency and conservation have evolved from voluntary best practices into core regulatory requirements shaping urban water management throughout California and Orange County. In response to recurring droughts, growing urban demand, and increasing competition for limited water supplies, the California Urban Water Conservation Council (CUWCC) was formed in 1991 to promote statewide cooperation on urban water conservation. Through the development and implementation of the CUWCC Best Management Practices, water agencies established a consistent, voluntary framework for improving efficiency through locally tailored programs. This early foundation was later strengthened by legislative actions, most notably Senate Bill (SB) X7-7, the Water Conservation Act of 2009, which set enforceable urban water use reduction targets to cut per capita use by 20 percent by 2020 and required retail water suppliers to actively manage demand as part of long-term water planning. All Orange County water agencies came together to create the Orange County 20x2020 Regional Alliance and met compliance as a region. The City of Tustin (City) also met compliance individually. These efforts reflected a growing recognition that efficient water use is essential to ensuring reliability amid population growth, limited supplies, and increasing climate variability. Recurring drought conditions have further accelerated the pace and scale of conservation efforts in the last decade. The 2013-2014 drought prompted a statewide emergency response, culminating in an executive order mandating a 25 percent reduction in urban water use across California. All Orange County Water Agencies, including the City, met this reduction target as reported in Chapter 5 of this 2025 Urban Water Management Plan (UWMP). More recently, the 2021-2022 drought reinforced the need for sustained efficiency gains and durable demand management strategies beyond temporary emergency actions. These regulatory and hydrologic drivers ultimately led to the passing and adoption of SB 606 and Assembly Bill (AB) 1668, the "Making Conservation a California Way of Life" legislation (passed in 2018 and adopted in 2024). The legislation establishes long-term water use objectives for individual water suppliers and reinforces conservation as a permanent element of water management. Together, these milestones underscore the necessity for the Municipal Water District of Orange County (MWDOC) and the City to implement comprehensive demand management measures (DMMs) and meet established urban water use reduction targets to ensure regional water supply resilience. The goal of the DMMs chapter is to provide a comprehensive description of the water use efficiency programs that the City has implemented in the most recent five years, is currently implementing, and plans to implement to meet its urban water use reduction targets. Per the "Making California a Conservation Way of Life" Framework (Conservation Framework), each Urban Water Supplier is required to calculate and report their Urban Water Use Objective (UWUO) and to stay within their calculated annual water budget. The UWUO is an aggregate efficient water use of: ■ Indoor Residential Use (population x gallons per capita per day (GPCD) standard); ■ Outdoor Residential Use (measurements of irrigated/irrigable area, local weather data, and a landscape efficiency factor); ■ Outdoor Use with Dedicated Irrigation Meters (DIMS) (measurements of irrigated area, local weather data, and a landscape efficiency factor); ■ Distribution System Water Losses; CITY OF TUSTIN 9-1 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO ■ Approved Variances; and ■ Potable Reuse Bonus. Additionally, the Conservation Framework includes commercial, industrial, and institutional (CII) non -volumetric Performance Measures, including CII customer account classifications, thresholds for converting mixed -use CII meters (MUMS) irrigating over half an acre of landscape to DIMS or in lieu technologies, CII best management practices (BMPs), and identification of and information sharing with disclosable buildings. One of the City's top priorities since the adoption of the Conservation Framework has been to make progress toward compliance with the Conservation Framework. This chapter will describe the City's DMM activities, including those administered by its wholesaler and supplemental programs administered locally at the retail -level. 9.1 City of Tustin Demand Management Measures This section describes the specific DMMs performed by the City, including DMMs offered in partnership with MWDOC, its wholesale supplier, to encourage water conservation within their service area. Table 9.1 summarizes DMM implementation by the City as well as responsibilities of MWDOC. Table 9.1 DMM Implementation Responsibility and Regional Programs in Orange County of: MWDOC Regional Efficiency Measure Retailer MWDOCResponsibility Program• Wholesaler Operations Practices Wholesale Agency Assistance Programs - ✓ ✓ Conservation Pricing ✓ ✓ ✓ Conservation Coordinator ✓ ✓ ✓ Water Waste Prevention ✓ - ✓ Water Loss Control ✓ (System Water Audits, Leak Detection and Repair) Metering with Commodity Rates ✓ (�) (�) Education and Outreach Public Outreach Programs ✓ ✓ ✓ K-20 Water Education Initiatives and K-12 School Programs ✓ ✓ ✓ OC Scouts Boy Scouts of America (BSA) and OC Girl Scouts Programs ✓ ✓ ✓ Water Awareness Poster Contest ✓ ✓ ✓ Water Energy Education Alliance ✓ ✓ ✓ Qualified Water Efficient Landscaper (QWEL) Training Program ✓ ✓ ✓ Residential Indoor Implementation Residential Indoor Rebates ✓ - ✓ Flow Monitor Device Rebates ✓ - ✓ CITY OF TUSTIN 9-2 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Commercial, Industrial, and Institutional Implementation Water Savings Incentive Program ✓ - ✓ On -site Retrofit Program CII Indoor Rebates (High Efficiency Toilets and Urinals, Plumbing Flow Control Valve; Connectionless Food Steamers, Air-cooled Ice Machines, Food Defrosters, Cooling Tower Conductivity Controllers and pH Contro Dry Vacuum Pumps, Laminar Flow Restrictors) Landscape Programs Turf Replacement Program (including Tree Rebate) Spray -to -Drip Irrigation Rebate Program Landscape Rebates (Smart Timers, High Efficiency Sprinkler Nozzles, Large Rotary N( In -stem Flow Regulators) Residential Landscape Design Assistance Program ✓ - ✓ Notes: (1) MWDOC does not own or operate a distribution system; water wholesaled by MWDOC is delivered through the Metropolitan Water District of Southern California (MET) distribution system and meters. 9.1.1 Operations Practices 9.1.1.1 Wholesale Agency Assistance Programs MWDOC's Assistance Programs are described in Section 9.3. 9.1.1.2 Conservation Pricing December 5, 2023 Tustin City Council approved a Cost of Service Rate Study. Customers are billed bimonthly on the basis of a capital charge, a fixed charge based on meter size and, as of January 1, 2024, new water rates went into effect on a 5-year rate structure. All customers will be charged a consumption fee as follows: 1/1/2024 - $3.57, 1/1/2025 - $3.90, 1/1/2026 - $4.26, 1/1/2027 - $4.65, 1/1/2028 - $5.07 for each unit of water (748 gallons). Water rates are developed through a comprehensive cost -of -service study that examines the water rates to the actual cost of providing water service. To determine the appropriate rate structure for Tustin, the City's water rate consultant reviewed the current rate structure and consumption data along with ongoing operational, maintenance, capital, and bond obligations to determine the new rate structure approach. 9.1.1.3 Conservation Coordinator The City staff works closely with the Water Use Efficiency staff of MWDOC to provide successful execution of regional programs, and those conducted on behalf of the City. The City may either directly participate in or be represented by MWDOC in regional workgroups including the Water Use Efficiency Workgroup, Public Affairs Workgroup, County of Orange Supervisor's Water Task Force, and the Orange County Water CITY OF TUSTIN 9-3 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Use Efficiency Steering Committee. In addition, the City Municipal Code Enforcement Officer serves to educate the public and enforce the Water Conservation Management Plan. 9.1.1.4 Water Waste Prevention Ordinances City Council adopted the Ordinance No. 1477 on April 4, 2017 to amend the City's Water Management Plan in response to the State -mandated water conservation requirements and regulations including Executive Order B-29-15 signed April 1, 2015 instituting emergency actions and mandatory water use reductions for the State of California and Urban Water Suppliers, and Executive Order B- 37-16 signed May 9, 2016 instituting permanent, mandatory water use restrictions for the State of California. The ordinance establishes four stages of increasingly restrictive prohibitions as described below: • Stage 1 Water Watch (voluntary compliance) applies all elements of Stage 2 on a voluntary basis. ■ Stage 2 Water Alert (mandatory compliance) establishes water conservation measures associated with: Limit on lawn watering and landscape irrigation. Irrigation of landscapes shall not occur during 48 hours following measurable precipitation. No washing down hard or paved surfaces. Limit washing of autos, trucks, mobile homes, buses, trailers, boats, airplanes, and other types of mobile equipment to quick rinses. Limit on watering parks, school grounds, public facilities, and recreational fields. Restaurants shall not serve water to their customers except when specifically requested. Hotels and motels must provide guests with the option of choosing not to have towels and linens laundered daily. The operation of any ornamental fountain or similar structure is prohibited unless the fountain or structure internally recycles the water it uses. All water leaks shall be repaired immediately. Agriculture users and commercial nurseries as defined in the MET water code are exempt from STAGE 2 irrigation restrictions. The "dump and fill" practice of swimming pool maintenance is prohibited. Customers that use turf for beneficial public use may apply for an exemption from the designated irrigation day provision of Stage 2. ■ Stage 3 Water Warning (mandatory compliance) applies all of Stage 2 water conservation measures plus additional restrictive measures. ■ Stage 4 Water Emergency (mandatory compliance) applies all of Stage 3 water conservation measures plus additional restrictive measures. The provisions and water conservation measures to be implemented in response to each shortage level are described in the City's Water Shortage Contingency Plan (WSCP). The City issued Ordinance 1516 on December 7, 2021 to amend the City's water management plan to include the new water conservation provisions as listed in the 2020 WSCP. 9.1.1.5 Water Loss Control SB 555 signed into law in 2015 requires urban water suppliers to submit annual, validated water loss audit reports to the California Department of Water Resources (DWR). Water auditing is the basis for effective water loss control. DWR's UWMP Guidebook includes a water audit manual intended to help water CITY OF TUSTIN 9-4 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO utilities complete the AWWA Water Audit on an annual basis. Audits must be validated by a certified water auditor to ensure accuracy. As part of the City's water system Capital Improvement Program (CIP), a program has been developed and scheduling is in place to retrofit old distribution pipelines on an annual basis. The City maintains an emergency response program that aggressively repairs main breaks, hydrant leaks or breaks, and meter leaks. A team of the City's staff are available to permanently repair main or hydrant breaks, and promptly restore water service. Both proactive and "inform and response" approaches are used for addressing water meter leaks when next day service is performed. MWDOC helps member agencies evaluate and reduce their distribution systems' real and apparent losses through comprehensive Water Loss Control Programs. In October 2015, the MWDOC Board of Directors authorized staff to begin implementing a Water Loss Control Technical Assistance Program (TAP) to support member agency compliance with SBs 1420 and 555, both of which address distribution system Water Loss. The TAP program established a menu of technical assistance that water retailers can elect to participate in. These programs connect water retailers with industry experts who provide one on one technical assistance through data analysis, agency specific advising and assessment. The City has utilized the following TAP services: ■ Water Balance Compilation. ■ Component Analysis of Real and Apparent Losses. ■ Source/Production Meter Accuracy Testing. • Internal Water Loss Committee Planning. In 2019, the MWDOC Board authorized the implementation of a Water Loss Control Shared Services Business Plan (Business Plan). The City has utilized the following include: ■ Water Balance Validation. ■ Distribution System Leak Detection. ■ Suspected Leak Investigations. Working through this program, more than 172 miles of distribution system leak detection has been completed which resulted in discovery of 88 hidden leaks that have been located and repaired, approximately half the leaks discovered were at the water meter or found on the customer side of the water meter. As needed and randomly selected water meter accuracy tests have been completed, improving agency knowledge of meter performance and accuracy of water balance results. 9.1.1.6 Metering The City requires meters for all new water connections and bills by volume of use. All water service connections, with the exception of some dedicated fire services, are metered. The City will continue to require metering for all connections. The City has a proactive meter replacement program based on meter throughput, or volume of water that moves through the meter level. The City will replace a meter after it reaches a defined throughput level, which is 5,000 hundred cubic feet (HCF) for residential and 3,000 HCF for CII meters. CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 9.1.2 Public Education and Outreach The City implements several public education and outreach measures, including the programs administered by MWDOC, its wholesale supplier. The City develops, coordinates, and delivers a substantial amount of public information, education, and outreach programs aimed at elevating water agency and consumer awareness and understanding of current water issues as well as efficient water use and water - saving practices, sound policy, and water reliability investments that are in the best interest of the region. These efforts encourage good water stewardship that benefits all of the City's residents, businesses, and industries across all demographics. An outline of the City's public education initiatives is below. 9.1.2.1 K-20 Water Education Initiatives and K-12 School Programs Over the past several years, MWDOC's investment in K-20 water education has significantly grown, evolving to include programs and activities that support environmental literacy for all Orange County students. The effort has expanded beyond K-12 water education programs to include career and workforce development initiatives in higher education through the Water Energy Education Alliance (WEEA) described in more detail in Section 9.1.2.4. MWDOC's K-12 Water Education School Programs bring standards -aligned, engaging water lessons directly into classrooms and connect water to every part of students' lives. All elementary, middle, and high school programs meet California State Standards and Next Generation Science Standards, providing students with high -quality, relevant learning experiences that build both academic and real -world understanding. This includes a Grab -and -Go Water Activities program, developed in partnership with the Orange County Department of Education, that provides free, self -guided water activities for K-12 teachers, parents and students. 9.1.2.2 OC Scouts Boy Scouts of America and OC Girl Scouts Programs The City, in partnership with MWDOC, hosts multiple water education workshops each year to help Scouts BSA earn the Soil & Water Conservation Merit Badge and Girl Scouts earn the MWDOC Water Resources & Conservation Patch. These hands-on science, technology, engineering, and mathematics (STEM) clinics teach children of all ages where their water comes from, how to use water more efficiently, and how all life depends on the health and security of our natural resources, fostering water awareness and responsibility through fun, activity -based learning. 9.1.2.3 Water Awareness Poster Contest The City participates in MWDOC's annual Water Awareness Poster Contest, offered for students in grades K-12. The Poster Contest presents children with an opportunity to use their artistic talents to express the importance and value of water through artwork. Each year, hundreds of entries are collected from students and classrooms across the county, and from these entries, 40 winners are selected. 9.1.2.4 Water Energy Education Alliance The WEEA unites over 260 water, energy, and education leaders across the state to build and strengthen career pathways for all California students. Administered and led by the MWDOC, WEEA is comprised of a powerful statewide coalition of education leaders, workforce advocates, and industry experts to raise student awareness, forge strong partnerships, and cultivate a diverse, highly skilled talent pipeline. By CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO connecting students with high -impact opportunities, WEEA is shaping a workforce that fuels industry success, enhances worker well-being, and ensures a resilient, thriving California. 9.1.2.5 Qualified Water Efficient Landscaper Training Program Since 2018, MWDOC along with the City, has offered free QWEL certification classes designed for landscape professionals. Classes are open to any city staff, professional landscaper, water district employee, or maintenance personnel that would like to become a QWEL. The QWEL certification program provides 20 hours of instruction on water efficient areas of expertise such as local water supply, sustainable landscaping, soil types, irrigation systems and maintenance, as well as irrigation controller scheduling and programing. QWEL has received recognition from US Environmental Protection Agency (EPA) WaterSense for continued promotion of water use efficiency. To earn the QWEL certification, class participants must demonstrate their ability to perform an irrigation audit as well as pass the QWEL exam. Successful graduates will be listed as a Certified Professional on the WaterSense website as well as on MWDOC's landscape resources page, to encourage Turf Removal participants or those making any landscape improvements to hire a QWEL certified professional. Started in December 2020, a hybrid version of QWEL is available in conjunction with the California Landscape Contractors Association's Water Management Certification Program. This joint effort allows landscape industry an opportunity to obtain two nationally recognized EPA WaterSense Professional Certifications with one course and one written test. This option is offered through MET. 9.1.3 Residential Indoor Rebate Programs The City partners with MWDOC to implement residential measures that target indoor water use efficiency for single family and multifamily residential customers. 9.1.3.1 High Efficiency Clothes Washer and Toilet Rebate Programs The High Efficiency Clothes Washer (HECW) Rebate Program provides residential customers with rebates starting at $85 for purchasing and installing HECWs that use 35-50 percent less water than standard washer models. Devices must meet or exceed the Consortium for Energy Efficiency (CEE) Tier 1 Standard, and a listing of qualified products can be found at ocwatersmart.com. There is a maximum of one rebate per home. The Premium High Efficiency Toilet (HET) Rebate Program offers residential customers rebates starting at $40 for replacing their toilets using 1.6 gallons per flush (gpf) with Premium HETs. Premium HETs use just 1.1 gallons of water or less per flush, which is 20 percent less water than WaterSense standard toilets 9.1.3.2 Flow Monitor Device Pilot This pilot program provides rebates starting at $100, or more in select areas, per flow monitor device installed. These devices monitor a home's water use and can help detect leaks, making them a proactive tool for preventing expensive water bills and water damage due to unforeseen leaks. A list of residential rebate -eligible flow monitoring devices is provided. CITY OF TUSTIN 9-7 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 9.1.4 CII Programs The City provides a variety of financial incentives, in partnership with MWDOC, to help businesses, restaurants, institutions, hotels, hospitals, industrial facilities, and public sector sites achieve their efficiency goals. Water users in these sectors have options to choose from a standardized list of water efficient equipment/devices or may complete customized projects through a pay -for -performance where the incentive is proportional to the amount of water saved. Such projects include high efficiency commercial equipment installation and manufacturing process improvements. 9.1.4.1 Water Savings Incentive Program The Water Savings Incentive Program (WSIP) is designed for non-residential customers to improve their water efficiency through upgraded equipment or services that do not qualify for standard rebates. WSIP is unique because it provides an incentive based on the actual amount of water saved by the customers. This "pay -for -performance" design lets customers implement custom projects for their sites. The City partners with MWDOC and MET to offer this program. Projects must save at least 10 million gallons (MG) of water to qualify for the Program and incentives are paid by MET based on the amount of water saved. Payment amount is up to $0.60 per 1,000 gallons saved per year over the project life, up to a maximum of 10 years. Payments are limited to 50 percent of the eligible project costs while funding is available. Additional funding may be available through MWDOC, but it is limited. Examples of successful projects include but are not limited to: changing industrial process system water to capture and reuse process wastewater, capturing condensation and using it to supplement cooling tower water supply, and replacing water -using equipment with more efficient products. 9.1.4.2 Recycled Water On -site Retrofit Program Through the Recycled Water On -site Retrofit Program, the City in partnership with MWDOC and MET, offers incentives for CII properties to convert potable water irrigation or industrial systems to recycled water. Financial incentives of up to $1,950 per acre-foot (AF) of potable water saved are available for the customer -side on the meter retrofits. Projects may also be eligible for up to an additional $325 per AF of annual water savings from MWDOC. Recycled water conversion projects can help to ensure a more reliable water future for Orange County. 9.1.4.3 CII Rebates The City offers additional financial incentives under the SoCal Water$mart Rebate Program which offers rebates for various water efficient devices to CII customers. Core funding is provided by MET and supplemental funding is sourced from MWDOC via grant funds and/or retail water agencies. Devices include: HETs and Urinals, Plumbing Flow Control Valves, Connectionless Food Steamers, Air-cooled Ice Machines, Food Defrosters, Cooling Tower Conductivity Controllers and pH Controllers, Dry Vacuum Pumps, and Laminar Flow Restrictors. CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 9.1.5 Landscape Programs Some of the most active and effective water use efficiency programs the City provides are those that target the reduction of outdoor water use. With a large proportion of water consumed outdoors via landscape demands, this sector has been and will continue to be a focus for MWDOC and the City. 9.1.5.1 Turf Replacement Program The Orange County Turf Replacement Program offers incentives to replace existing turf grass with California -native, drought -tolerant plants and landscaping. Residential, commercial, and public properties in the City's service area are all eligible for this program. The goals of this program are to increase water use efficiency through sustainable landscaping practices that result in multi -benefit projects across Orange County. Participants are encouraged to utilize smart irrigation timers and furthermore, projects are required to include a stormwater capture feature, such as a rain garden or dry stream bed, and have a minimum of three plants per 100 square feet to increase plant density and promote healthy soils. These projects save water and reduce dry and wet weather runoff, increase urban biomass, and sequester more carbon than turf landscapes. Additionally, MWDOC is piloting a tree program that allows eligible trees to qualify as a sustainability feature in Turf Replacement projects. Beginning March 4, 2024, Turf Replacement Program participants became eligible for an additional incentive for planting trees as part of their Turf Replacement project. Participants can receive up to $100 per tree, for up to 5 trees ($500), in addition to the Turf Replacement rebate. The pilot goals include increasing the presence of trees in Turf Replacement projects and breaking down barriers to participation. It is anticipated that the pilot will be evaluated in 2026. 9.1.5.2 Spray -to -Drip Rebate Program The Spray -to -Drip Rebate Program offers residential, commercial, and public agency customers rebates for converting areas irrigated by traditional high -precipitation rate spray heads to low -precipitation rate drip irrigation. Drip irrigation systems are extremely water efficient. Rather than spraying wide areas subject to wind drift, overspray and runoff, drip systems use point emitters to deliver water to specific locations at or near plant root zones. Water drips slowly from the emitters either onto the soil surface or below ground. As a result, less water is lost to wind, evaporation, and overspray, saving water, and reducing irrigation runoff and non -point source pollution. The City partners with MWDOC to provide $1 per square foot of conversion area when replaced with eligible drip irrigation products. 9.1.5.3 SoCal Water$mart Rebate Program for Landscape The City also offers financial incentives under the SoCal Water$mart Rebate Program for a variety of water efficient landscape devices, such as Smart Irrigation Timers and Central Computer Irrigation Controllers, large rotary nozzles and rotating sprinkler nozzles, soil moisture sensors, irrigation master valves, and in - stem flow regulators. 9.1.5.4 Landscape Design Assistance Rebate This program is offered for residential customers who are participating in the turf replacement program and are seeking professional design services. Participants must hire a landscape design professional to CITY OF TUSTIN 9-9 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO provide a design that meets the rebate eligible design requirements. Participants will receive up to $1,000 upon completion of their turf replacement project if they have used a professional designer. 9.2 City of Tustin DMM Implementation (2020-2025) During the past five years, fiscal year (FY) 2020-21 to 2024-25, the City, with the assistance of MWDOC, has continued water use efficiency programs for its residential, CII, and landscape customers with the participation shown in Table 9.2. The City will continue to implement all applicable programs in the next five years. Table 9.2 City Water Use Efficiency Program Participation Program High Efficiency Clothes Washer (HECW) 1FY24/25 64 31 33 27 14 High Efficiency Toilets (HETs) 5 0 2 0 3 Flow Monitoring Devices (FMD) -- 0 0 0 2 Commercial Plumbing Fixtures (CII) 0 0 41 88 0 Water Savings Incentives Projects (WSIP) 0 0 0 0 0 Turf Replacement (Res.) 12,353 21,688 36,476 28,841 12,632 Turf Replacement (Comm.) 0 5,698 0 16,386 0 Landscape Design Rebate Program (LDAP) Landscape Design Rebate Program (LMAP) Spray -to -Drip (Res.) Spray -to -Drip (Comm.) 15 10 12 2 1 4 3 5 4 0 9,613 19,787 24,575 15,977 15,884 0 5,305 0 0 1,397 Rotating Nozzles (Small Res.) 30 0 0 42 75 Rotating Nozzles (Small Comm.) 0 0 0 0 0 Rotating Nozzles (Large Comm.) 0 0 0 0 0 Smart Timers (Res.) 52 29 41 27 25 Smart Timers (Comm.) 0 5 0 0 2 Rain Barrels Recycled Water Onsite Retrofits 3 2 8 4 0 0 0 0 0 0 9.3 MWDOC Demand Management Implementation Assistance Programs To help facilitate implementation of DMMs throughout Orange County, MWDOC's wholesale efforts focus on the following three areas: (1) State Water Conservation Compliance Assistance (e.g., Conservation Framework and Non -Functional Turf), (2) Regional Rebate Programs and Local Program Assistance, and (3) Research and Evaluation. This both complies with and goes beyond the Foundational BMPs of Utility Operations Programs requirements. CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 9.3.1 State Water Conservation Compliance Assistance To support Orange County retailers with compliance of SB 606 and AB 1668, MWDOC is providing multi -level support to assist agencies in meeting the primary goals of the legislation, including using water more wisely and to eliminate water waste. Beginning in 2023, urban water suppliers were required to calculate and report their annual UWUO, submit validated water audits annually, and implement and report BMP CII performance measures. MWDOC offers Orange County water suppliers a "Conservation Framework TAP" and "Meter Area Measurements Program" to assist them with compliance with the Conservation Framework. 9.3.1.1 Conservation Framework Technical Assistance Program This program provides Orange County water suppliers with support on tasks that are required as part of the Conservation Framework. An agency may opt in to receive support with any of the following: ■ Readiness Assessment - perform a retailer -specific readiness assessment, including task recommendations and pricing to help retail agencies understand what areas need to be addressed. ■ Conservation Framework Compliance Plan - create a customized Framework Compliance Plan that outlines (1) what the retailer needs to do to prepare for compliance and (2) what needs to be implemented to achieve the water savings necessary to comply with the UWUO. • Annual Report Compilation and Data Management - support the retailer with Annual Report preparation and assistance; and organize and manage data needed to comply with the reporting requirements of the Regulation. • CII Account Classification - classify CII customer accounts according to the Regulation requirements and create a guidance plan to keep classifications at 95 percent (or higher). ■ CII BMPs and In -Lieu Technologies Implementation Plan - create a customized implementation plan mapping compliance with the Conservation Framework regulation, including the CII BMP requirements of § 974, the in -lieu technologies and accompanying BMP requirements in § 973, and disclosable buildings requirements in § 974a. ■ Miscellaneous Framework Technical Assistance — various activities such as: Development of Development of metrics and annual targets to demonstrate progress. Additional training or technical support. Workshop or webinar facilitation to spur cross -team collaborations. Develop outreach and engagement plans and implement meetings to support engagement of internal and external collaborators. 9.3.1.2 Meter Area Measurements Program The Program assists Orange County water supplier in providing (1) landscape area measurements (LAM) associated with DIMS, which may include the creation of water efficiency budgets for dedicated landscape meter customers; (2) identification of MUMS irrigating landscapes greater than half acre and subject to the regulation; and (3) reconciliation of DIM and residential LAMS where areas may overlap. CITY OF TUSTIN 9-11 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 9.3.2 Regional Rebate Programs and Local Program Assistance MWDOC develops, obtains funding for, and implements regional water savings rebate programs on behalf of all retail water agencies in Orange County, such as the Turf Replacement Program. This approach minimizes confusion for consumers by providing the same programs with the same participation guidelines, maintains a consistent message to the public to use water efficiently, and provides support to retail water agencies by acting as program administrators for the region. As a leader of water efficiency in Orange County, MWDOC provides a holistic suite of programs that are accessible to all consumer groups in the region. When requested, MWDOC also assists retail agencies in developing and implementing local programs within their service areas. This assistance includes collaboration with each retail agency to design a program that fits that agency's local needs, including providing staffing, targeting customer classes, acquiring grant funding from a variety of sources, and implementing, marketing, reporting, and evaluating the program. On behalf of its member agencies, MWDOC also organizes and provides the following: ■ Monthly coordinator meetings. ■ Marketing materials. ■ Public speaking. ■ Community events. 9.3.3 Research and Evaluation An essential part of MWDOC's regional water use efficiency program is the ongoing research and evaluation of both existing and potential initiatives. Research allows an agency to measure the water savings benefits of a specific program and compare those benefits to the costs of implementing the program. This allows the agency to evaluate the economic feasibility of the program when compared to other efficiency projects or existing or potential sources of supply, before investing in new initiatives or continuing to implement existing programs. MWDOC routinely conducts statistical water savings (impact) evaluations and process evaluations to guide strategic investment and ensure the effective management of its regional water use efficiency programs. From 2021 to 2025, MWDOC conducted several research initiatives to support informed decision -making. In partnership with Flume Data Labs, MWDOC completed its Residential End Use Study in 2021, with subsequent updates in 2022 and 2024. This study provided detailed insights into disaggregated residential indoor and outdoor water use, significantly enhancing the understanding of water use patterns across Orange County. In 2023, MWDOC released its Potential and Opportunities study, which quantified the remaining water savings potential in the Orange County residential market, identified the most promising and cost-effective methods for reducing residential demand, and made recommendations on how best to direct financial and technical assistance to Retail Agencies and consumers for implementing residential water efficiency upgrades. To assess the economic impact of the Conservation Framework, MWDOC worked with M.Cubed and in 2023 published the Draft Water Use Efficiency Standards Economic Analysis: Impact Assessment of State -Mandated UWUOs. MWDOC continues to evaluate the impact of the regulation and Orange County retailer compliance. CITY OF TUSTIN 9-12 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Additionally, MWDOC is piloting a tree program that allows eligible trees to qualify as a sustainability feature in Turf Replacement projects. Pilot goals include increasing the presence of trees in Turf Replacement projects and breaking down barriers to participation. It is anticipated that the pilot will be evaluated in 2026. A pilot research program investigating water savings associated with the replacement of broken pressure regulating valves at residential homes wrapped up in 2025. The results of this study are expected in 2027. 9.4 Urban Water Use Objective and CII Performance Measure Compliance A large focus for the City is to implement DMMs that will help them to meet the requirements of the Conservation Framework. DMMs described in this chapter may help to support member agencies with meeting their required UWUO and achieving CII Performance Measure Compliance. In addition, MWDOC provides support to agencies to assist with the calculation of UWUOs and compliance with CII Performance measures via the Meter Area Measurement and TAP Programs, as described in section 9.3. 9.4.1 UWUO Components Table 9.3 describes MWDOC's programs that will assist agencies in meeting their UWUO, through both direct measures (programs/activities that result in directly quantifiable water savings) and indirect measures (programs that provide resources promoting water efficiencies to the public that are impactful but not directly measurable). Additionally, MWDOC provides technical assistance to support water suppliers with compliance. Table 9.3 MWDOC Programs to Help OC Retail Agencies Meet their Urban Water Use Objectives UWUO Calculation Program•. Component i Indoor Population and GPCD Direct Impact: Direct Impact: Residential standard High efficiency indoor fixtures Increased indoor residential and appliance rebates. efficiencies and reductions of GPCD use. Outdoor Irrigated/irrigable area Residential measurement and a landscape efficiency factor of local ETo and effective precipitation Direct Impact: ■ Turf Replacement. ■ High efficiency irrigation rebates. Indirect Impact: ■ Online resources such as OC Friendly Gardens Webpage. ■ Educational classes. Direct Impact: ■ Increase outdoor residential efficiencies and reductions of gallons per ftz of irrigated/ irrigable area used. Indirect Impact: ■ Provide information, resources, and education to promote efficiencies in the landscape. CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 Outdoor Dedicated Irrigation Meters Water Loss Irrigated area measurement and a landscape efficiency factor of local ETo and effective precipitation Technical Assistance: 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Technical Assistance: • DIM landscape classification and • measurement. Direct Impact: ■ Turf Replacement. ■ High efficiency irrigation rebates. Indirect Impact: ■ OC Friendly Gardens Webpage. ■ Educational training and resources. Agency -specific loss factor Technical Assistance: and number of connections ■ Water Balance Validation. Bonus Volume of indirect potable Incentives reuse water applied to residential and DIM irrigation uses; not to exceed 15% of UWUO ■ Customer Meter Accuracy Testing. ■ Distribution System Pressure Surveys. Direct Impact: ■ Distribution System Leak Detection. Direct Impact: ■ Groundwater replenishment system (GWRS). 9.4.2 CII Performance Measures Classification and measurement of landscapes associated with DIMs are required to complete the calculation. Direct Impact: ■ Increase outdoor residential efficiencies and reductions of gallons per ft2 of irrigated/ irrigable area used. Indirect Impact: ■ Provide information, resources, and education to promote landscape efficiencies. Technical Assistance: ■ The accuracy of the water loss audit is validated for submission to the State. Direct Impact: ■ Identify areas of the distribution system that need repair, replacement, or other actions to limit water loss. Direct Impact: ■ The GWRS (run by OCWD) recharges the groundwater basin with purified, highly treated wastewater, allowing OCWD-member agencies to access indirect potable reuse. Urban water supplies are required to report BMPs for CII customers. The City, in partnership with MWDOC, offers a broad variety of programs and incentives to help CII customers implement BMPs and increase their water efficiencies (Table 9.4). CITY OF TUSTIN 9-14 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 Table 9.4 City CII BMP and Water Efficiency Programs and Incentives CII Customer Account Classify each CII water user, Classifications based on the end -use of water for the water user, in accordance with Energy Star Portfolio Manager's 18 broad categories, in addition to 4 other categories. Large Landscape Identify all CII water users Identification associated with large landscapes — landscapes irrigated with a mixed -use meter greater than half an acre 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Technical Assistance: Technical Assistance: ■ CII Customer Classify customer accounts Account according to the specified Classification. categories to comply with the regulation. Technical Assistance: ■ Large Landscape identification. Best Management Practices Offer CII BMPs for Technical Assistance: (BMPs) customers that exceed the BMP Implementation recommended size, volume Plan. of water use, or another threshold Disclosable Buildings Identify disclosable buildings Technical Assistance: in service area according to . Disclosable buildings the list provided by the list. California Energy Commission Technical Assistance: ■ Identify and map landscapes associated with MUM landscapes that are greater than half an acre to comply with the regulation. Technical Assistance: ■ Provide a BMP Implementation Plan to guide water suppliers with a roadmap to compliance with the regulation. Technical Assistance: ■ Provide the California Energy Commission list of disclosable buildings by water supplier to comply with the regulation. CITY OF TUSTIN Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO CHAPTER 10PLAN ADOPTION, SUBMITTAL, AND IMPLEMENTATION The Water Code requires the Urban Water Management Plan (UWMP) to be adopted by the City of Tustin's (City) governing body. Before the adoption, the City must hold a public hearing allowing members of the public to provide input on the UWMP. Prior to the public hearing, the City must notify the public and surrounding cities, counties and water agencies within its service area of the scheduled public hearing. Upon completion of the public hearing, the City's governing body shall vote to adopt the UWMP. Post adoption, the City submits the UWMP to the Department of Water Resources (DWR) while also making it available for public access. This section provides a record of the process the City followed to adopt and implement its UWMP. 10.1 Overview Recognizing that close coordination among other relevant public agencies is key to the success of its UWMP, the City worked closely with many other entities to develop and update this planning document. The City also encouraged public involvement through its public review and hearing process, which provided residents with an opportunity to learn and ask questions about their water supply management and reliability. Through the public hearing, the public has an opportunity to comment and put forward any suggestions for revisions of the UWMP. Table 10.1 summarizes external coordination and outreach activities carried out by the City and their corresponding dates. The UWMP checklist to confirm compliance with the Water Code is provided in Appendix A. Table 10.1 External Coordination and Outreach Notified city or county within supplier's service area that water supplier is preparing an updated UWMP (at least 60 days prior to public hearing) Public Hearing Notice Held Public Hearing Adopted UWMP and WSCP Submitted UWMP to DWR (no later than 30 days after adoption) Submitted UWMP to the California State Library (no later than 30 days after adoption) Submitted UWMP to the cities and county within the supplier's service area (no later than 30 days after adoption) Notes: WSCP - Water Shortage Contingency Plan 2/23/2026 5/14/2026 and 5/21 /2026 6/16/2026 6/16/2026 7/1/2026 7/1/2026 7/1/2026 Appendix I Appendix I Appendix J This UWMP was adopted by the City Council on June 16, 2026. A copy of the adopted resolution is provided in Appendix J. CITY OF TUSTIN 10-1 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 10.2 Agency Coordination The Water Code requires the Suppliers preparing UWMPs to notify any city or county within their service area at least 60 days prior to the public hearing. As shown in Table 10.2, the City sent a Letter of Notification to the County of Orange and the cities within its service area on February 23, 2026, to state that it was in the process of preparing an updated UWMP. This notice of preparation is included in Appendix I. Table 10.2 Submittal Table 10-1 Retail: Notification to Cities and Counties Submittal Table 10-1 Retail: Notification Water ..e Section 1i. i.- to Cities and Counties City Name 60 Day Notice Notice of Public Hearing Drop Down (yes/no) Drop Down (yes/no) Add additional rows as needed Santa Ana Yes Yes County Name 60 Day Notice Notice of Public Hearing Drop Down List Drop Down (yes/no) Drop Down (yes/no) Add additional rows as needed Orange County Yes Yes The City's water supply planning relates to the policies, rules, and regulations of its regional and local water providers. The City is dependent on imported water from Metropolitan Water District of Southern California (MET) through Municipal Water District of Orange County (MWDOC), its regional wholesaler and East Orange County Water District (EOCWD). The City is also dependent on groundwater from Orange County Water District (OCWD), the agency that manages the Orange County Groundwater Basin (OC Basin). As such, the City involved the relevant agencies in this 2025 UWMP at various levels of contribution as described below. The City's 2025 UWMP leveraged data and regionally consistent analyses supplied by MWDOC, such as population projections from the California State University, Fullerton, Center for Demographic Research and the information quantifying water availability to meet the City's projected demands for the next 25 years, in five-year increments. This 2025 UWMP was developed in collaboration with MWDOC's 2025 UWMP to ensure consistency between the two documents. As a wholesale supplier, EOCWD provides imported potable water received from MWDOC to the City to help facilitate water supply to the City's service area. This 2025 UWMP was developed in conjunction with EOCWD's 2025 UWMP. As a groundwater producer who relies on supplies from the OCWD-managed OC Basin, the City coordinated the preparation of this 2025 UWMP with OCWD. Several OCWD documents, such as the Groundwater Reliability Plan, Engineer's Report, and Basin 8-1 Alternative were used to retrieve the required relevant information, including the projections of the amount of groundwater the City is allowed to extract in the 25-year planning horizon. The various planning documents of the key agencies that were used to develop this UWMP are listed in Chapter 2.2.1. CITY OF TUSTIN 10-2 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO 10.3 Public Participation The City encouraged community and public interest involvement in the Plan update through a public hearing and inspection of the draft document on June 16, 2026. As part of the public hearing, the City discussed adoption of the UWMP, key components of the UWMP and the conclusions that served as the basis of the UWMP. Copies of the draft 2025 UWMP were placed for public review at the City Clerk's and Utilities Department offices. Legal public notices for the meeting were published in the local newspaper and posted at City facilities. A copy of the Notice of Public Hearing is included in Appendix I. The hearing was conducted during a regularly scheduled meeting of the City Council. 10.4 UWMP Submittal The City Council reviewed and approved the 2025 UWMP at its June 16, 2026, meeting after the public hearing. See Appendix J for the resolution approving the UWMP. By July 1, 2026, the City's adopted 2025 UWMP was filed with DWR and sent directly to the California State Library, the County of Orange, and the City of Santa Ana. The submission to DWR was done electronically through the online submittal tool - WUE Data Portal. The City will make the UWMP available for public review on its website no later than 30 days after filing with DWR. 10.5 Amending the Adopted UWMP or WSCP Based on DWR's review of the UWMP, the City will make any amendments in its adopted UWMP, as required and directed by DWR and will follow each of the steps for notification, public hearing, adoption, and submittal for the amending the adopted UWMP. If the City revises its WSCP after UWMP is approved by DWR, then an electronic copy of the revised WSCP will be submitted to DWR within 30 days of its adoption. CITY OF TUSTIN 10-3 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO CHAPTER 11 REFERENCES California Department of Water Resources (DWR). (2026, January). Final Urban Water Management Plan Guidebook 2025. https:Hcwc.ca.gov/-/media/DWR-Website/Web-Pae esq /Programs/Water-Use- And-Efficiency/Urban-Water-Use-Efficiency/Urban-Water-Management-Plans/Final-2025-UWMP- Guidebook/Final-2025-UWM P-Guidebook-Accessible.pdf Center for Demographic Research (CDR). (2025, July). Orange County Progress Report 2025 Volume 54. City of Tustin (2021, June). 2020 Urban Water Management Plan. https://www.tustinca.orci/241/Water- ReDorts#docaccess-59979198a4Ob454b75deec4bdacf1 bl bOf21 f633ff6c0629fdeeff584dd93727 City of Tustin. (2018, November). City of General Plan. https://www.tustinca.org/396/General-Plan City of Tustin. (2019, March). Draft Hazard Mitigation Plan. https://www.tustinca.org/l019/Hazard M itigation-Plan#docaccess- 485a3af14a9c5Od53863e66ec386a631ccbe147411547cc25fce9763fa126318 Metropolitan Water District of Southern California (MET). (2025, December). 2025 Urban Water Management Plan Draft. https.-Ilwww-cidmin.mwdh2o.com/Media/5ratzxiV Metropolitan Water District of Southern California (MET). (2020, April). 2020 Integrated Water Resources Plan — Regional Needs Assessment. https://dlgOafigl2ywwq.cloudfront.net/media/sgvlkith/2020 irp needs assessment.pdf Metropolitan Water District of Southern California (MET). (2025, April). CAMP4W Climate Adaptation Master Plan for Water. httl2s://cawaterlibrary.net/wp-content/uploads/2025/03/CAMP4W-Climate- Adaptation-Management-Plan-for-Water.pdf Municipal Water District of Orange County (MWDOC). (2023, July). Orange County Water Reliability Study. https://www.mwdoc.com/wp-content/uploads/2025/06/MWDOC 2023-OC-Water-Reliability- Study-Final.pdf Municipal Water District of Orange County (MWDOC), Orange County Water District (OCWD), Hazen & Sawer. (2025, December). 2025 Orange County Water Demand Projection Model Technical Memorandum. https://www.mwdoc.com/your-water/water-reliability-planning Orange County Water District (OCWD). (2025, February). OCWD Resilience Plan —Adaptive Strategies for Securing Abundant and Reliable Water Supplies. https://www.ocwd.com/w - content/uploads/OCWD-Resilience-Plan.pdf Orange County Water District (OCWD). (2025, February). Engineer's Report on Groundwater Conditions, Water Supply and Basin Utilization in The Orange County Water District. https://www.ocwd.com/wp-content/uploads/2023-24-Engineers-Report Final.pdf CITY OF TUSTIN 11-1 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 2025 URBAN WATER MANAGEMENT PLAN MAY 2026 / FINAL DRAFT / CAROLLO Orange County Water District (OCWD), City of La Habra, Irvine Ranch Water District. (2022, February). Basin 8-7 Alternative 2022 Update. https://www.ocwd.com/wp-content/uploads/05cbasin-8-1- alternative-2022-update.pdf Southern California Association of Governments (SCAG). (2024, April). Connect SoCal 2024. https:Hscag.ca.gov/sites/default/files/2024-05/23-2987-connect-socal-2024-final-complete- 040424.pdf CITY OF TUSTIN 11-2 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 ATTACHMENT 2 Resolution No. 26-34 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 RESOLUTION NO. 26-34 A RESOLUTION OF THE CITY COUNCIL OF THE CITY OF TUSTIN, CALIFORNIA ADOPTING THE 2025 URBAN WATER MANAGEMENT PLAN WHEREAS, the California Urban Water Management Planning Act (California Water Code Sections 10610 et seq.) requires every urban water supplier providing water for municipal purposes to more than 3,000 customers or supplying more than 3,000 acre- feet of water annually to prepare and adopt an Urban Water Management Plan ("UWMP") every five years; and WHEREAS, the City of Tustin is an urban water supplier subject to the requirements of the Urban Water Management Planning Act; and WHEREAS, the City has prepared the 2025 Urban Water Management Plan in compliance with the requirements of the California Water Code; and WHEREAS, the 2025 Urban Water Management Plan provides a long-term assessment of the City's water supply reliability and identifies strategies to meet projected water demands during normal, single dry -year, and multiple dry -year conditions; and WHEREAS, the 2025 Urban Water Management Plan incorporates the City's Water Shortage Contingency Plan as required by State law; and WHEREAS, the City made the 2025 Urban Water Management Plan available for public review in accordance with California Water Code requirements; and WHEREAS, the City Council conducted a duly noticed public hearing on June 16, 2026, to receive public comments regarding the 2025 Urban Water Management Plan. NOW, THEREFORE, THE CITY COUNCIL OF THE CITY OF TUSTIN DOES RESOLVE AS FOLLOWS: SECTION 1. The City Council hereby finds that the foregoing recitals are true and correct and are incorporated herein by this reference. SECTION 2. The City Council hereby approves and adopts the City of Tustin 2025 Urban Water Management Plan, attached hereto and incorporated herein by reference. SECTION 3. The City Council authorizes and directs the City Manager, Director of Public Works, or their designee to submit the adopted 2025 Urban Water Management Plan to the California Department of Water Resources and to take such additional actions Resolution 26-34 Page 1 of 3 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 as may be necessary to implement this Resolution and comply with applicable State requirements. SECTION 4. The City Clerk shall certify as to the adoption of this Resolution. PASSED AND ADOPTED at a regular meeting of the City Council of the City of Tustin held on the 16t" day of June 2026. AUSTIN LUMBARD, Mayor ATTEST: ERICA N. YASUDA, City Clerk APPROVED AS TO FORM: `v-1K- DAVID E. KENDIG, City Attorney /msd/ Resolution 26-34 Page 2 of 3 Docusign Envelope ID: 358C2907-8737-8327-823E-C74D6AE09DF2 STATE OF CALIFORNIA ) COUNTY OF ORANGE ) SS CITY OF TUSTIN ) I, Erica N. Yasuda, City Clerk and ex-officio Clerk of the City Council of the City of Tustin, California, do hereby certify that the whole number of the members of the City Council is five; that the above and foregoing Resolution No. 26-34 was duly and regularly passed and adopted at a regular meeting of the City Council held on the 16t" day of June, 2026 by the following vote: COUNCILMEMBER AYES: COUNCILMEMBER NOES: COUNCILMEMBER ABSTAINED: COUNCILMEMBER ABSENT: ERICA N. YASUDA City Clerk Resolution 26-34 Page 3 of 3