Overview of Conjunctive Management in California Let s Have a Frank Discussion

Transcription

1 Overview of Conjunctive Management in California Let s Have a Frank Discussion Mark S. Nordberg, P.G. Division of Integrated Regional Water Management North Central Region Office Geology and Groundwater Investigations Section February 22, 2013 for the Northern Sacramento Valley Water Forum, Oroville, CA

2 Outline Overview of Groundwater Overview of Conjunctive Management Benefits of Conjunctive Management Challenges of Conjunctive Management California Water Plan Update 2013 Groundwater Efforts Recommendations to Improve Conjunctive Management Questions and Discussion 2

3 Overview of Groundwater 3

4 General Groundwater Concept GROUNDWATER is the water that completely fills the void space in rocks or sediment CLIMATE (precipitation) controls the availability of water in an area GEOLOGY (rock type and structure) controls the capacity to store groundwater POROSITY is the ability of the ground to contain water PERMEABILITY is the ability of water to move through the ground USGS, Circular

5 Unconfined vs. Confined Aquifers USGS, Circular

6 This is groundwater from an UNCONFINED aquifer Source: 6

7 This is groundwater from a CONFINED aquifer 7

8 Groundwater Flow Paths Groundwater flow paths vary greatly in LENGTH, DEPTH and travel TIME Groundwater pumped from wells can be DAYS old or THOUSANDS of years old USGS, Circular

9 Groundwater Interactions with Streams USGS, Circular

10 Groundwater Interactions with Lakes A - Lakes can receive groundwater inflow B - Lakes can lose water as seepage to groundwater C - Or both USGS, Circular

11 Effects of Pumping on Streams A: Recharge at the water table equals groundwater discharge to the stream B: Pumping continues to allow for some discharge to stream C: Increased pumping induces flow from stream to aquifer USGS, Circular

12 Groundwater basins are identified in Bulletin 118 Update alluvial basins and subbasins delineated In California, groundwater provides: About 30% of water supply in normal years More than 40% in dry years California s Groundwater 12

13 Water Use Met by Groundwater in California: Statewide and by Hydrologic Region California Water Plan Update 2009 ( average annual data) 13

14 Overview of Conjunctive Management 14

15 Overview of Conjunctive Management Conjunctive Management: The coordinated and planned use and management of both surface water and groundwater resources to maximize the availability and reliability of water supplies in a region to meet various management objectives Involves the efficient use of both resources through the planned and managed operation of a groundwater basin and a surface water storage system combined through a coordinated conveyance infrastructure 15

16 Surface Water / Groundwater Interaction Assumptions Groundwater and surface water are connected Changes in either system will directly affect the other Effective conjunctive management seeks to understand the interconnection to maximize the beneficial uses of the system Unlike surface water, groundwater does NOT have a statewide management program or permitting process 16

17 Conjunctive Management and Groundwater Storage 17

18 Managed Aquifer Recharge Natural Infiltration (Passive): Rivers, streams Permeable outcrops Ground surface, agricultural fields, rice fields, etc. Wetlands, estuaries Yuba River: Surface water / groundwater interaction study 18

19 Managed Aquifer Recharge Direct Percolation (Managed): Engineered infiltration basins Stormwater detention or retention basins Temporary dams/reservoirs Bank storage Coachella Valley Water District: Whitewater River Spreading Facility in Coachella Valley Fresno Irrigation District: Waldron Pond Recharge Basin and monitoring well United Water Conservation District: Saticoy Spreading Grounds Recharge Facility 19

20 Managed Aquifer Recharge Direct Injection (Managed): Injection wells Saline intrusion barriers In-situ mixing/dilution Land subsidence prevention Aquifer Storage and Recovery (ASR) Generally involves potable or drinking water Recycled water for indirect potable reuse Calleguas Municipal Water District, Las Posas ASR Project Monterey Peninsula Water Management District 20

21 ASR Concept Single injection/extraction well into a confined aquifer Injection well and extraction well in an unconfined aquifer Source:

22 Managed Aquifer Recharge In-lieu Recharge: Providing surface water to groundwater users, leaving groundwater in storage for later use Groundwater elevations recover over time 120 foot change Yuba County Groundwater Well 14N05E06B001M Example of In-lieu Recharge 22

23 Fundamental Elements of Conjunctive Management Three fundamental elements: Project Construction Treatment and conveyance facilities; spreading basins; monitoring, production, and injection wells; test holes Groundwater Management AB 3030 (1992), SB 1938 (2002), AB 359 (2011), IRWMPs Capacity Building Education, financial and technical assistance, training 23

24 Conditions Necessary for a Conjunctive Management Project Project Components Water sources, conveyance systems, GW rechargeextraction-storage Institutional Structures Laws, regulations, ordinances; contracts; political support and governance; public-private partnerships Funding Sources State and federal grants and loans; State and local bonds; taxes, assessments and fees; partnerships 24

25 Objectives of Conjunctive Management A sustainable program consists of: Investigating the aquifer characteristics Estimating surface water and groundwater interactions Monitoring groundwater level and quality As well as: Reliable systems for ensuring environmental compliance Providing long-term maintenance Managing contractual and legal features of the program Optimizing beneficial uses while balancing objectives 25

26 Source: Benefits of Conjunctive Management

27 Benefits of Conjunctive Management Well planned conjunctive management: Increases the reliability and amount of water supply Provides benefits such as: Flood management Environmental water use Water quality improvements A greater benefit can usually be achieved when applied to multiple regions or statewide Dependent upon how well the resources are managed 27

28 POTENTIAL BENEFIT OF MANAGED GW STORAGE 1. Improved LOCAL water supply reliability EXAMPLE Imported SW supplies/flood flows are recharged to local GW basin during wet periods. MAJOR CONSTRAINTS Availability of SW supplies Limited capacity to capture and recharge Short duration flood flows Water quality concerns 2. Improved STATEWIDE water supply reliability 3. Drought relief for urban users and potential induced GW recharge 4. Salt water intrusion protection GW storage in the northern part of CA can be used as backup supplies to allow for more aggressive operation of SW storage. Groundwater substitution transfer and agricultural water transfer. Recharge GW in the vicinity of salt water interface to prevent intrusion of saline water into freshwater aquifers. Availability of CM tool to model SW-GW interaction and evaluate impacts Legal and water rights issues Lack of model to accurately quantify the impact to other water users and the environment Potential land subsidence and ability to evaluate Availability of fresh water supply Considerable infrastructure requirements 5. Improved flood control and GW storage Development of detention/retention basins in urban areas located in GW protection areas. Possible water quality issues requiring effective urban storm water management Requiring adoption of local ordinance or legislation to support implementation Source: CWP Update 2013, Table 8-1, Advisory Committee Draft (Unedited) 28

29 Challenges of Conjunctive Management Source:

30 Challenges of Conjunctive Management Uncertainty in surface water availability Uncertainty in evaluating impacts of GW pumping on SW flows Effects of land use changes or new/enlarged facilities Inconsistency and uncertainty in regulatory status Lack of data and tools Infrastructure and operational constraints Surface water and groundwater management inconsistencies Environmental concerns Climate change uncertainties Funding 30

31 Challenges of Conjunctive Management Potential Costs: The cost for water supply or delivery is variable Some projects require minor changes to existing infrastructure Other projects require extensive new facilities Projects require site-specific feasibility studies The wide range of costs result from: Project complexity; regional differences in construction and land costs; availability and quality of recharge water; availability of infrastructure; and treatment requirements. 31

32 California Water Plan Update 2013 Groundwater Enhancement Content

33 The California Water Plan Est First published in 1957 Updated 9 times; last one in 2009 DWR required by law (Water Code) to update the Water Plan every 5 years; next one in 2013 Growing interest by Legislature and stakeholders Not a mandate and No appropriation 33

34 CWP 2009 Resource Management Strategies Reduce Water Demand Agricultural Water Use Efficiency Urban Water Use Efficiency Improve Operational Efficiency & Transfers Conveyance Delta Conveyance Regional/Local System Reoperation Water Transfers Increase Water Supply Conjunctive Management & Groundwater Storage Desalination Brackish & Seawater Precipitation Enhancement Recycled Municipal Water Surface Storage CALFED Surface Storage Regional/Local Improve Flood Management Flood Risk Management Improve Water Quality Drinking Water Treatment and Distribution Groundwater/Aquifer Remediation Matching Quality to Use Pollution Prevention Salt & Salinity Management Urban Runoff Management Sediment Management *new for 2013 Practice Resource Stewardship Agricultural Lands Stewardship Economic Incentives Ecosystem Restoration Forest Management Land Use Planning & Management Recharge Areas Protection Water-Dependent Recreation Watershed Management Outreach & Education *new for 2013 Management of Cultural Water Resources & Practices *new for

35 Water Plan Update 2013 Groundwater Content Enhancement OBJECTIVE Expand information about statewide and regional groundwater conditions to better inform groundwater management actions through compilation and summarization of data and analysis

36 California Water Plan Update 2013: Groundwater Content Enhancement Deliverables Task 1: Compile Groundwater Information GWMP, CASGEM, IRWMP, UWMP, AGWMP, Water Transfer, Modeling Reports Task 2: Summarize Groundwater Information Task 3: Identify Groundwater Data Gaps Task 4: Groundwater Change in Storage Task 5: Groundwater Case Studies Task 6: Conjunctive Management Opportunities Task 7: Groundwater Banking and Flood Management Task 8: Groundwater Sustainability Indicators 36

37 Purpose of the 2013 Conjunctive Management Inventory CWP Update 2009 recommended a statewide inventory There is no comprehensive data monitoring network for conjunctive use or groundwater recharge programs Collect information to enable an informed decision making process for legislators and policy makers Identify areas where local agencies may need technical or financial assistance from state or local agencies To achieve better coordination among existing and future planning activities and to avoid potential conflict 37

38 Task #6: Conjunctive Management and Groundwater Storage Three Main Goals of CWP Update 2013 Survey: Inventory existing conjunctive use, recharge and groundwater banking projects Determine future conjunctive management potential Define program constraints 38

39 Task #6: Conjunctive Management and Groundwater Storage ACWA Survey Questions Location of project Year project developed Capital costs to develop project Annual operating costs (O&M) Administrator/Operator of the project Capacity of the project in acre-feet DWR Supplemental Questions Water received Put and take capacity of the groundwater storage project Type of groundwater recharge method Program goals and objectives Constraints on development of conjunctive management program 39

40 Methodology of the 2013 Conjunctive Management Survey Survey was conducted on-line using ACWA s webpage Performed along with the groundwater management plan survey Received approximately 8 responses statewide (not comprehensive) So DWR staff compiled its own list of known and funded programs Telephoned and ed agencies with a request for information Compiled a list of 89 active conjunctive management programs Programs in planning or feasibility stage were not included Some agencies requested anonymity 40

41 Inventory of Conjunctive Management Programs in California Hydrologic Region # Active Conjunctive Management Programs North Coast 0 San Francisco Bay 4 Central Coast 5 South Coast 32 Sacramento River 3 San Joaquin River 5 Tulare Lake 37 North Lahontan 0 South Lahontan 2 Colorado River 1 TOTAL PROGRAMS 89 Note: List may not be complete DRAFT MAP 41

42 Statewide: Source of Recharge Water 100% 90% 80% 70% 71% 60% 50% 53% 40% 30% 20% 24% 16% 26% 10% 5% 0% State Water Project Central Valley Project Recycled Water Local Surface Water Colorado River Water Other Note: 38 out of 89 programs reporting data 42

43 Statewide: Method of Groundwater Recharge 100% 90% 80% 70% 60% 50% 40% 30% 20% 10% 0% 77% 54% 23% Other: Injection only wells Seawater intrusion barriers Direct percolation In-lieu ASR Other 4% Note: 52 out of 89 programs reporting data 43

44 Statewide: Program Goals and Objectives 100% 90% 80% 70% 60% 54% 76% Other: Complying with regulations Meeting delivery demands Emergency storage Sustainable supply Flood management Cost reduction Drought planning 50% 40% 30% 20% 10% 22% 32% 11% 32% 0% Overdraft correction Salinity intrusion Water quality protection Part of CM program Meet climate change objectives Other Note: 37 out of 89 programs reporting data 44

45 Statewide: Program Constraints Political Legal Institutional Limited aquifer storage Rank: 1 = Minimal Constraint 3 = Moderate Constraint 5 = Significant Constraint Note: 25 out of 89 programs reporting data Water quality issues Cost Other Other: Economy Complex geology Environmental considerations Regulatory requirements 45

46 Conjunctive Management Survey Questions/Responses NOT Graphed 1. Capital Costs to Develop the Project 16 of 89 (18%) reported data 2. Annual Operating Costs 19 of 89 (21%) reported data Variable units: $$ per year vs. $$ per acre-foot 3. Capacity of the Project 34 of 89 (38%) reported data Incomplete responses per hydrologic region Actual vs. Estimated capacities 4. Put and Take Capacity 46 of 89 (52%) reported data Incomplete or variable responses per agency/program 46

47 Recommendations to Improve Conjunctive Management and Groundwater Storage

48 Recommendations to Improve Conjunctive Water Management and GW Storage 1. Encourage local agency cooperation 2. Continue to implement and improve CASGEM 3. Continue funding for local GW monitoring and management programs, as well as feasibility studies 4. Encourage local agencies to establish water budgets 5. Establish a System Reoperation Task Force 6. Develop a statewide comprehensive data management system about GW and conjunctive management programs 7. Assess existing GW management programs 48

49 Recommendations to Improve Conjunctive Water Management and GW Storage (cont) 8. Improve inter-agency coordination for GW programs 9. Promote multi-benefit projects that generate new water for recharge programs 10. Evaluate opportunities to reduce runoff and increase recharge 11. Link flood control and GW recharge goals 12. Streamline the environmental permitting process 13. Streamline the water rights permitting process 14. Consider changes to the Water Code to allow public access to groundwater information in well completion reports 49

50 Questions? Division of Integrated Regional Water Management Division of Statewide Integrated Water Management