2015 Urban Water MANAGEMENT PLAN UPDATE June 2016 Prepared by: 2015 Urban Water Management Plan Calaveras County Water District Table of Contents 1 Introduction and Executive Summary ................................................................................................................. 1-1 1.1 Plan Preparation .......................................................................................................................................... 1-1 1.2 District Overview .......................................................................................................................................... 1-1 1.3 District Supplies and Water Use ............................................................................................................... 1-2 1.4 SB X7-7 Reporting ....................................................................................................................................... 1-3 1.5 Demand Management Measures .............................................................................................................. 1-3 1.6 Supply Reliability and Contingency Planning ......................................................................................... 1-3 1.7 Plan Adoption, Submittal, and Implementation ...................................................................................... 1-4 1.8 Plan Organization ........................................................................................................................................ 1-4 2 Plan Preparation.................................................................................................................................................... 2-1 2.1 Basis for Preparing a Plan ......................................................................................................................... 2-1 2.2 Regional Planning ......................................................................................................................................... 2-3 2.3 Individual or Regional Planning and Compliance .................................................................................. 2-4 2.4 Fiscal or Calendar Year and Units of Measure ..................................................................................... 2-4 2.5 Coordination and Outreach ....................................................................................................................... 2-5 3 System Description ................................................................................................................................................ 3-1 3.1 District History and Background ................................................................................................................ 3-1 3.2 General System Description ....................................................................................................................... 3-2 3.3 Climate ........................................................................................................................................................ 3-14 3.4 Service Area Population and Demographics ....................................................................................... 3-17 4 Water Use .............................................................................................................................................................. 4-1 4.1 Current Water Uses by Sector .................................................................................................................. 4-1 4.2 Water Use Projections ................................................................................................................................. 4-6 4.3 Distribution System Water Losses .......................................................................................................... 4-18 4.4 Estimating Future Water Savings ........................................................................................................... 4-19 4.5 Water Use for Lower Income Households ............................................................................................ 4-19 4.6 Climate Change ......................................................................................................................................... 4-20 5 Baselines and Targets ........................................................................................................................................... 5-1 5.1 Updating Calculations from the 2010 UWMP ....................................................................................... 5-1 5.2 Service Area Population ............................................................................................................................. 5-1 5.3 Gross Water Use ......................................................................................................................................... 5-1 5.4 Baseline Daily per Capita Water Use ..................................................................................................... 5-1 5.5 Water Use Targets ...................................................................................................................................... 5-3 5.6 2015 Compliance......................................................................................................................................... 5-5 6 System Supplies ..................................................................................................................................................... 6-7 i 2015 Urban Water Management Plan Calaveras County Water District 6.1 Purchased Water ......................................................................................................................................... 6-7 6.2 Groundwater ................................................................................................................................................. 6-7 6.3 Surface Water ........................................................................................................................................... 6-11 6.4 Stormwater ................................................................................................................................................. 6-15 6.5 Wastewater and Recycled Water ........................................................................................................ 6-15 6.6 Desalinated Water Opportunities ......................................................................................................... 6-44 6.7 Exchanges and Transfers ......................................................................................................................... 6-44 6.8 Future Water Projects .............................................................................................................................. 6-44 6.9 Summary of Existing and Planned Sources of Water ........................................................................ 6-48 6.10 Climate Change Impacts to Supply ....................................................................................................... 6-56 7 Supply Reliability Assessment ............................................................................................................................. 7-1 7.1 Constraints on Water Sources .................................................................................................................... 7-1 7.2 Reliability by Year Type ............................................................................................................................ 7-4 7.3 Supply and Demand Assessment ............................................................................................................... 7-8 7.4 Regional Supply Reliability ..................................................................................................................... 7-15 8 Water Shortage Contingency Planning ............................................................................................................ 8-1 8.1 Stages of Action ........................................................................................................................................... 8-1 8.2 Prohibitions on End Uses .............................................................................................................................. 8-2 8.3 Enforcement of Prohibitions ........................................................................................................................ 8-8 8.4 Consumption Reduction Methods ............................................................................................................ 8-10 8.5 Determining Water Shortage Reductions ............................................................................................. 8-11 8.6 Revenue and Expenditure Impacts ......................................................................................................... 8-11 8.7 Resolution or Ordinances ......................................................................................................................... 8-11 8.8 Catastrophic Supply Interruption ........................................................................................................... 8-12 8.9 Minimum Supply Next Three Years ....................................................................................................... 8-13 9 Demand Management Measures ......................................................................................................................