Greater Kaweah GSA Technical Advisory Committee Meeting - - PDF document

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Greater Kaweah GSA Technical Advisory Committee Meeting

Tuesday, July 2, 2019

www.GreaterKaweahGSA.org

ITEM 2: ANNOUNCEMENTS

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ITEM 3: MINUTES ITEM 4: UPDATE ON SUSTAINABLE MANAGEMENT CRITERIA DEVELOPMENT

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Subsidence Sustainable Management Criteria

• Annual Rate*
• Areal Extent*

*That substantially interferes with land uses and may lead to undesirable results.

Subsidence Approach to SMCs

• Subsidence correlates to change in groundwater storage
• Project observed groundwater levels (Fall 2006 to 2016) to 2040

due to maximum withdrawal of groundwater

• Estimate volume of groundwater storage due to maximum

withdrawal – 4,000,000 acre-feet

• Estimate potential subsidence, based on actual subsidence

during 5-year drought

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Subsidence versus Groundwater Storage

Correlation period

Not effected by differences in water years Stable or slight rebound during above-normal water years **

Subsidence during below-normal water years* *

**

87 inches of additional subsidence could result from removal of 4M AF of groundwater storage

Subsidence Minimum Threshold

• Interpolated between

GPS Stations CRCN and P566

87 inches versus 10 inches (2017 to 2040)

• Projected NW and SE to

KDWCD station

• 3.4 inches/year red shading
• 0.5 inches/year blue shading

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Water Quality Trends

• GAMMA database extraction for GKGSA area
• Arsenic
• Nitrate
• Total Dissolved Solids (TDS)

Constituent Time Period # of Results Detects Muni Dom Mon Unk Arsenic, ug/l

1968 – 2019

1,081 63% 91% 4% 2% 3% Nitrate, mg/l as N

1945 – 2019

3,917 96% 88% 1% 2% 9% TDS, mg/l

1945 - 2019

841 100% 67% 5% 3% 26%

Arsenic Trend

Median Values

• Significantly greater sampling during

2000s and 2010s

• Limited data before 2000,

variable results, high reporting limits

• Relatively stable trend 1990s to 2010s
• Percent samples exceeding

primary MCL of 10 ug/l

• 1990s: 31%
• 2000s: 23%
• 2010s: 23%

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Nitrate Trend

Median Values

• Significantly greater sampling during

2000s and 2010s

• Limited data before 1990,

variable results

• Steady increasing trend 1940s to 2010s
• Percent samples exceeding

primary MCL of 10 mg/l as N

• 1990s: 1%
• 2000s: 15%
• 2010s: 28%

TDS Trend

Median Values

• Fair amount of sampling during 1970s

through 1990s

• Significantly greater sampling during

2000s and 2010s

• Slight decreasing trend 1940s to 2010s
• Percent samples exceeding

secondary MCL of 1000 mg/l

• 1990s: 0%
• 2000s: 5%
• 2010s: 11% — Deep groundwater??

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Sustainability Goal and Undesirable Results: Groundwater Quality

• 1. Provide Education and Information

– Groundwater Basin Conditions – Funding Opportunities – Remediation/Treatment Technologies

• 2. Active GSA Coordination with Water Quality Agencies and Coalitions

– Participate in meetings (salinity prioritization & optimization study, management zones) as a contributor of information, but also seeking information – Exchange/Share GW quality data and information between GSAs and other GWQ leads. – Request information to better inform 5-year GSP updates, include data in DMS as it becomes publicly available

• 3. Identify, Pursue, Administer Grants in Partnership with Water Quality Agencies

Options for GSA Participation in Water Quality Improvement Programs

ITEM 5: UPDATE ON PROJECTS AND MANAGEMENT ACTIONS DEVELOPMENT

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Initial GW Model Runs

2) Future No Project Scenario: Base Case

– Assumes current water budget conditions exist in the future modified only by DWR provided climate data sets and forecasts of supply and demand. Distribution of groundwater pumping is consistent with current water budget period – GW model forecasts future groundwater levels for comparison against minimum thresholds

Initial GW Model Runs

3) Future Management Actions Only: Pumping Reductions

– Assumes current water budget conditions exist in the future modified only by DWR provided climate data sets and forecasts of supply and demand and pumping conforms to water allocations in water accounting framework – GW model forecasts future groundwater levels for setting groundwater level measurable objective and interim milestones

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Initial GW Model Runs

4) Future Management Actions Only: Pumping Reductions + Projects

– Assumes current water budget conditions exist in the future modified only by DWR provided climate data sets and forecasts of supply and demand, pumping conforms to water allocations in water accounting framework, and projects area implemented on planned schedule. – GW model forecasts future groundwater levels for setting groundwater level optimal measurable objective and interim milestones

 Focused on modeling projects that are currently under construction or that are eminent  Conceptual projects will be described in the GSP but will not be taken credit for initially

• 4. Projects and Management Actions

Greater Kaweah:

Possible Projects and/or Management Actions Alternatives Targets as a Percentage of Average Annual Sustainable Yield Deficit (overdraft + half of basin subsurface inflow)

Alt. 2020-25 2026-30 2031-35 2036-40 Total 1 0% 20% 35% 45% 100% 2 5% 25% 30% 40% 100% 3 5% 20% 35% 40% 100% 4 10% 20% 30% 40% 100% 5 10% 30% 30% 30% 100% 6 25% 25% 25% 25% 100%

Alternatives Apportionment of Average Annual Net Increase in Supply Minus Subsurface Inflow & Reduction in Demand in Average Annual Acre-Feet

Alt. 2020-25 2026-30 2031-35 2036-40 Total 1 1 14,985 26,224 33,716 2 2 3,746 18,731 22,478 29,970 3 3 3,746 14,985 26,224 29,970 4 4 7,493 14,985 22,478 29,970 5 5 7,493 22,478 22,478 22,478 6 6 18,731 18,731 18,731 18,731 Goal Optimal

• GKGSA’s Target (1997-2017 Water Budget Apportioned to WAF) = 42,675 acre-feet/year
• Annual Native Yield of the Basin and GKGSA = 363,784 acre-feet or 0.82 acre-feet/acre/year
• GKGSA’s share of net subsurface inflow from adjacent subbasins = 32,250 acre-feet/year

Average Annual Project & MA Targets and Goal/Optimal Goal Differences for Interim Periods (acre-feet)

2020-25 2026-30 2031-35 2036-40 Targets 24,975 33,577 70,769 83,615 Goal Diff 21,229 14,846 25,814 8,690 Opt Diff 17,482 11,099 25,814 8,690

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• 3. Projects and Management Actions

Greater Kaweah:

Annual Project & MA Targets For Input To The Model (Acre-Feet)

Water Year Projects Specific MAs Undefined MAs Annual Total Running Total 2020 9,400 9,400 9,400 2021 9,700 4,500 750 14,950 24,350 2022 9,700 4,000 1,000 14,700 39,050 2023 69,400 8,000 1,250 78,650 117,700 2024 10,200 4,000 1,500 15,700 133,400 2025 10,200 4,500 1,750 16,450 149,850 2026 10,200 4,000 3,857 18,057 167,907 2027 83,000 8,000 3,857 94,857 262,764 2028 10,300 4,000 3,857 18,157 280,921 2029 10,300 4,500 3,857 18,657 299,578 2030 10,300 4,000 3,857 18,157 317,735 2031 94,100 8,000 19,149 121,249 438,984 2032 10,500 4,000 19,149 33,649 472,633 2033 10,500 4,500 19,149 34,149 506,782 2034 10,500 4,000 19,149 33,649 540,431 2035 104,000 8,000 19,149 131,149 671,580 2036 10,600 4,000 48,715 63,315 734,895 2037 10,600 4,500 48,715 63,815 798,710 2038 10,600 4,000 48,715 63,315 862,025 2039 107,600 8,000 48,715 164,315 1,026,340 2040 10,600 4,000 48,715 63,315 1,089,655

MT Preliminary Projects & Management Actions Model Run Results

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MT Preliminary Projects & Management Actions Model Run Results MT Preliminary Projects & Management Actions Model Run Results

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ITEM 6: TECH SERVICES UPDATE

ITEM 6: Technical Services Update Summary of Kaweah Coordination

• Subbasin Basin Setting Components Report

– Completed incorporation of clean up comments

• Numerical Model

– GSI completed Base Run Scenarios – GSI completed initial run of scenarios with Projects and Management Actions

• Draft Coordination Agreement discussions are ongoing.
• Completion of SkyTEM study

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• DMS funds from GSP grant to be reallocated to Basin contract
• Recent Management Team Committee meeting agenda included:

– Groundwater Quality suggested approach by GEI, and CV-SALTS presentation by Richard Meyerhoff (GEI) – Preliminary modeling results – DMS update and walk-through – Prop 68 funding discussion

ITEM 6: Technical Services Update Summary of Kaweah Coordination

Objective: Develop a coordinated data storage, analysis, visualization, and reporting tool for groundwater-related information within the entire Kaweah Sub-Basin Key Features: 1) Store and display information from previous, ongoing, and future groundwater studies and monitoring programs 2) Protect against the loss of invaluable data 3) Facilitate direct production of tables, charts, maps, and graphs

ITEM 6: Technical Services Update Kaweah Data Management System (DMS)

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External Data

(DWR, USGS, SWRCB, CDEC) Well Information GW Level Water Quality GW Pumping Water Supply Surface Water Geology Soil Land use

GDC Database

Data Input/Storage Graphic user Interface

GSP Reporting Water Budget Analysis GW Model Supporting Outreach Data Sharing/Exchange Data Exporting Mapping Hydrograph

System Overview

What Will the DMS Do Near Term?

 Populated with key data required by SGMA  Chart GW levels  Chart GW pumping  Well searches – well location, construction, depth, production capacity, etc….  Data downloads  Limited charting of water quality  Support reporting to DWR  Support GSP Development  Integrate data through DWR SGMA Data Viewer

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Consumptive use table ET table Inventory of all facilities DMS Data Model – Identify and Agree on Initial Data Sets to be Uploaded

DMS During the SGMA Implementation Period

(As Funds Become Available)

Illustrate water budget components Be used as water allocation tool Auto generate geologic cross-sections Illustrate 3-dimentional information

– Basin storage and storage change calculations – Hydrogeologic conceptual model – Water quality imagery (i.e. shape and size of plumes)

Annual Reporting Tool Expansion in type and volume of data

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DMS Water Level Hydrograph

SMC Thresholds and Objectives – Iterative Process Developed by Stakeholders Informed by technical information including groundwater modeling Basin Setting/Water Budget Refinements Projects and Management Actions

SUBBASIN ACTIVITIES

Groundwater Model Refinement SMC Goal and SI Assessment Complete Basin Setting Chapter Groundwater Model Simulations

GSA Deliverable

Define Management Areas Develop Thresholds and Objectives for MAs Water Level Projections Draft Monitoring Network Chapter Complete Monitoring Network Chapter Complete SMC Chapter

Jan Feb Mar Apr May Jun

Water Supply Accounting Framework Draft Water Supply Accounting Chapter

Draft GSP Development Schedule

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GSP Public Review Draft

• Goal is to have Board approval of Public Review Draft GSP at a special

meeting in late July (Mid-Kaweah mid-July, East Kaweah late-July)

• 90-day notice of public hearing (late October)
• Schedule allows 2 months to address comments (comments will be

addressed as they come in) followed by one month to adopt and submit the GSP to DWR

• DWR is required to establish its own GSP public comment period of no less

than 60 days for an adopted plan

• A GSP that is determined to be incomplete after the deadline may be

revised and resubmitted to DWR within 180 days from the date DWR issues the assessment

ITEM 8: GKGSA MEETINGS REPORT

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ITEM 9: FUTURE AGENDA ITEMS AND MEETING DATE(s)