California’s Groundwater Update 2013 A Compilation of Enhanced Content for California Water Plan Update 2013 April 2015 State of California Natural Resources Agency Department of Water Resources SOUTH COAST HYDROLOGIC REGION Table of Contents Contents Chapter 6. South Coast Hydrologic Region Groundwater Update ........................................................ 1 Introduction ................................................................................................................................................... 1 Findings, Data Gaps, and Recommendation ................................................................................................. 2 Findings................................................................................................................................................. 3 Groundwater Supply and Development ................................................................................................ 3 Groundwater Use and Aquifer Conditions ........................................................................................ 3 Groundwater Monitoring Efforts ...................................................................................................... 4 Groundwater Management and Conjunctive Management ............................................................... 4 Data Gaps .............................................................................................................................................. 4 Data Collection and Analysis ............................................................................................................ 5 Basin Assessments ............................................................................................................................ 5 Sustainable Management .................................................................................................................. 5 Recommendations ................................................................................................................................. 5 Groundwater Supply and Development ........................................................................................................ 6 Alluvial Aquifers .................................................................................................................................. 7 Coastal Plains of the Los Angeles and Orange County Groundwater Basins ................................... 7 Upper Santa Ana Valley Groundwater Basin ................................................................................. 12 Santa Clara River Valley Groundwater Basin ................................................................................ 13 Fractured-Rock Aquifers..................................................................................................................... 15 Well Infrastructure .............................................................................................................................. 15 CASGEM Basin Prioritization ............................................................................................................ 19 Groundwater Use ........................................................................................................................................ 20 2005-2010 Average Annual Groundwater Supply .............................................................................. 22 Groundwater Use by Planning Area Boundaries ............................................................................ 23 Groundwater Use by County Boundaries ....................................................................................... 25 Change in Annual Groundwater Use .............................................................................................. 27 Groundwater Monitoring Efforts ................................................................................................................ 28 Groundwater-Level Monitoring .......................................................................................................... 29 Groundwater Quality Monitoring ....................................................................................................... 32 Land Subsidence Monitoring .............................................................................................................. 33 Aquifer Conditions ...................................................................................................................................... 33 Groundwater Occurrence and Movement ........................................................................................... 35 Depth to Groundwater ..................................................................................................................... 36 Groundwater Elevations .................................................................................................................. 36 Groundwater-Level Trends ............................................................................................................. 37 Hydrograph 04N18W29M002S .................................................................................................. 37 Hydrograph 03S09W32P003S .................................................................................................... 39 Hydrograph 01S03W21H001S ................................................................................................... 40 Change in Groundwater in Storage ..................................................................................................... 41 Groundwater Quality .......................................................................................................................... 41 Groundwater Quality at Community Drinking Water Wells .......................................................... 42 Groundwater Quality at Domestic Wells ........................................................................................ 42 Groundwater Quality — GAMA Priority Basin Project ................................................................. 46 Groundwater Quality Protection ..................................................................................................... 47 Salt and Nutrient Management Plans .......................................................................................... 47 San Gabriel Valley and San Fernando Valley Well Investigation Program ............................... 49 i California's Groundwater Update 2013: A Compilation of Enhanced Content for California Water Plan Update 2013 Land Subsidence ................................................................................................................................. 50 Groundwater Management .......................................................................................................................... 51 Groundwater Management Plan Inventory ......................................................................................... 52 Groundwater Management Plan Assessment ...................................................................................... 55 Required GWMP Components ....................................................................................................... 56 Basin Management Objectives .................................................................................................... 57 Agency Cooperation ................................................................................................................... 57 Mapping ...................................................................................................................................... 57 Monitoring Protocols .................................................................................................................. 58 Voluntary GWMP Components ...................................................................................................... 59 Bulletin 118-2003–Recommended GWMP Components ............................................................... 60 DWR/ACWA Survey — Key Factors for Successful GWMP Implementation ............................. 61 Groundwater Ordinances .................................................................................................................... 63 Special Act Districts ........................................................................................................................... 63 Court Adjudication of Groundwater Rights ........................................................................................ 64 Other Groundwater Management Planning Efforts ............................................................................ 64 Urban Water Management Plans .................................................................................................... 68 Agricultural Water Management Plans ........................................................................................... 69 Conjunctive Management Inventory ........................................................................................................... 70 Conjunctive Management Inventory Results .................................................................................. 71 References ................................................................................................................................................... 72 Tables Table 6-1 Alluvial Groundwater Basins and Subbasins in the South Coast Hydrologic Region ................ 9 Table 6-2 Number of Well Logs, According