CALIFORNIA S GROUNDWATER UPDATE 2013

Transcription

1 Development of New Groundwater Content for the California Water Plan Update 2013 CALIFORNIA S GROUNDWATER UPDATE 2013 Findings and Recommendations CWEMF Webinar January 8, 2015 Abdul Khan, Ph.D., P.E. Lead CWP 2013 Groundwater Work Team Division of Statewide Integrated Water Management California Department of Water Resources

2 The Team Prepared under the supervision of Abdul Khan (Lead) Supervising Engineer, WR Dan McManus (Co-lead) Supervising Engineering Geologist Lew Moeller Supervising Engineer, WR John Kirk Engineering Geologist Eric Gorman Engineering Geologist Francisco Guzman Environmental Scientist Karandev Singh, David Calo, and Michael O Connor Prepared by Roy Hull Engineering Geologist Mark Nordberg Engineering Geologist Jack Tung Engineering Geologist Charles McKenzie Engineer, WR Jose Alarcon Senior Engineer, WR With assistance from Cordi McDaniel Graphic Designer III Scott Olling Graphic Designer III Bill Brewster Engineering Geologist Bill Ehorn Senior Engineering Geologist Kelly Staton Senior Engineering Geologist (Retired) Chris Bonds Senior Engineering Geologist Dane Mathis Senior Engineering Geologist Bob Pierotti Supervising Engineering Geologist Tim Ross Senior Engineering Geologist California's Groundwater Update 2013 With contributions from Jon Mulder Engineering Geologist Debbie Spangler Engineering Geologist Mark Souverville Engineering Geologist Michael McGinnis Engineer, WR Evelyn Tipton Senior Engineer, WR Eric Senter Senior Engineering Geologist Brett Wyckoff Senior Engineering Geologist Mary Scruggs Supervising Engineering Geologist Jennifer Kofoid Senior Engineer, WR Megan Fidell Engineer, WR Salma Kibrya Research Program Specialist II Editorial Production Services by Charlie Olivares Research Writer Carole Rains Research Writer Bill O Daly Research Writer 2

3 Chronology of Groundwater Content in Previous Water Plans CWP UPDATE CHRONOLOGY OF GROUNDWATER CONTENT IN THE CALIFORNIA WATER PLAN 1957 Groundwater is discussed primarily in terms of additional storage capacity and water supply Discussed what is required to locally manage groundwater basins, including potential new regulations Discussed groundwater policy to limit development. Described groundwater basin by region. Provided map of San Joaquin Valley aquifer levels in wet and dry periods Acknowledged groundwater data limitations Discussed overdraft. Provided examples of managed basins. Mentioned conjunctive use and the Kern Water Bank. Provided groundwater supply estimates. Provided groundwater use by hydrologic region Described overdraft as unsustainable. Acknowledged relationship between overdraft rates and surface water supply availability Introduced groundwater-related resource management strategies. Recommended expanded groundwater content for future CWP updates. Expanded discussion of groundwater-related resource management strategies (RMS): o Conjunctive management and groundwater storage RMS o Groundwater and aquifer remediation RMS o Recycled Municipal Water RMS o Recharge Area Protection RMS Recommended expanded groundwater content for future CWP updates. California's Groundwater Update

4 A Comprehensive Report 1. Introduction, Findings, Gaps, Recommendations 2. Groundwater Supply and Development Alluvial and Fractured Rock Aquifers Well Infrastructure and Distribution ( ) CASGEM Groundwater Basin Prioritization 3. Groundwater Supply Average Annual Groundwater Supply ( ) Change in Annual Groundwater Supply ( ) 4. Groundwater Monitoring Groundwater Level Monitoring Groundwater Quality Monitoring Land Subsidence Monitoring California s Groundwater Update 2013 California's Groundwater Update

5 A Comprehensive Report 5. Aquifer Conditions Groundwater Occurrence and Movement Depth to Groundwater Groundwater Elevation Groundwater Level Trends Change in Groundwater in Storage ( ) Groundwater Quality Land Subsidence 6. Groundwater Management Planning GWMP Inventory GWMP Assessment Groundwater Ordinances Special Act District Court Adjudications Other Groundwater Management Planning Efforts 7. Conjunctive Management Inventory DWR/ACWA Survey 8. References California's Groundwater Update

6 Findings: Well Infrastructure/Distribution Wells completed between 1977 and 2010: - Total number: 432,000 - Low of 4,000 wells in N. Lahontan HR - High of 108,000 wells in Sac. River HR California's Groundwater Update 2013 Statewide Number of Well Logs, by Hydrologic Region and Well Type ( ) Hydrologic Region Total Number of Well Logs by Well Use Total Well Domestic Irrigation Public Supply Industrial Monitoring Other Records North Coast 24,710 1, ,155 1,352 34,955 San Francisco Bay 8,951 2, ,487 9,399 62,941 Central Coast 17,137 3, ,880 4,480 30,927 South Coast 10,414 4,067 1, ,935 5,444 37,149 Sacramento River 78,260 6,781 1, ,514 4, ,346 San Joaquin River 47,789 7,280 1, ,031 5,661 73,447 Tulare Lake 28,466 12,786 1, ,211 8,097 54,322 North Lahontan 3, ,069 South Lahontan 7, , ,329 1,380 13,112 Colorado River 8,096 1, , ,201 Total CA Well Logs: 234,281 41,526 9,077 1, ,200 41, ,469 6

7 Findings: Basin Prioritization 515 alluvial basins/subbasins underlying 61,900 square miles CASGEM Basin Prioritization: - 43 high - 84 medium - 27 low very low priority basins 127 high/medium priority basins account for: - 96% of avg annual GW supply - 88% of 2010 population overlying GW basin area California's Groundwater Update

8 Findings: Groundwater Supply Average Annual Total Supply: - 43 maf Tulare Lake HR: Largest user of groundwater 6.2 maf per year Average Annual Groundwater Supply: maf (38% of total supply) Central Coast HR - Most groundwater dependent. 86% of supply from GW California's Groundwater Update 8

9 Findings: Groundwater Supply Trend Groundwater Supply Trend ( ): - Low of 12 maf, 30% of total supply (2005) - High of 20 maf, 46% of total supply (2009) California's Groundwater Update 9

10 California s Groundwater Update 2013 Findings: Aquifer Conditions Change in Groundwater Storage, Central Valley ( ): - Total GW Storage Loss: 5.4 to 13.1 maf - Avg. Annual GW Storage Loss: 1.1 to 2.6 maf Tulare Lake HR: 3.6 to 8.8 maf of groundwater loss Sac River HR: 0.7 to 1.7 maf of groundwater storage loss San Joaquin R. HR: 1.1 to 2.6 maf groundwater loss California's Groundwater Update 10

11 Long-term Groundwater Level Trends Tell-a-Story Hydrographs: California's Groundwater Update

12 California s Groundwater Update 2013 Findings: Land Subsidence between 1926 and 1970 there was more than 24 feet of land subsidence in some areas (Ireland, 1984) subsidence rates were as high as 1 foot per year recent studies show renewed land subsidence (USGS) Appendix F references the 2014 Luhdorff & Scalmanini & CWF subsidence report and 2014 DWR Report on Subsidence Potential

13 Findings: Groundwater Management and Conjunctive Management 35 GWMPs include ALL SB 1938 requirements: - 17% of Bulletin alluvial basin area 24 Adjudicated Basins in California 89 agencies /programs operate conjunctive management or groundwater recharge projects California's Groundwater Update 13

14 Recommendations 1. Implement a program to promote public education about groundwater. 2. Improve collaboration, coordination, and alignment among agencies. 3. Develop a statewide GWMP Web site to promote easy access to information. 4. Build essential data to enable sustainable groundwater management by expanding and funding the CASGEM Program. 5. Under CASGEM Basin Prioritization, improve understanding of California s high and medium priority groundwater basins by conducting groundwater basin assessments. 6. Convene statewide GWMP advisory committee to develop a GWMP acceptance process. 7. Advance groundwater management within framework of integrated water management. 8. Review and assist local agencies in developing improved analytical tools to assess conjunctive management and groundwater management strategies. 9. Increase local and regional groundwater recharge and storage. California's Groundwater Update 14

15 Reference Docs. for Groundwater Contents Statewide Groundwater Contents: 1. California Water Plan Update 2013 Vol. 1, The Strategic Plan: Chapter 2: Pages 2-7 to 2-10; Chapter 3: Pages 3-37 to 3-44; Pages 3-47; Pages 3-87 to California s Groundwater Update 2013 Chapters 1 & 2: To be released (Feb-Apr, 2015). Hydrologic Region Groundwater Contents: 1. California Water Plan Update 2013 Vol. 2, Regional Reports: 2. California s Groundwater Update 2013 Chapters 3 through 12: To be released (Feb-Apr, 2015) Technical Aspects of Analysis: California s Groundwater Update 2013 Appendices A through F Appendix A Methods and Assumptions; Appendix C Groundwater Supply Data; Appendix E Change in Storage Data; California's Groundwater Update 2013 Appendix B CASGEM Basin Prioritization Appendix D Conjunctive Mgmnt Survey Appendix F Land Subsidence 15