Greater Kaweah GSA Technical Advisory Committee Meeting - - PDF document

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Greater Kaweah GSA Technical Advisory Committee Meeting

Monday, May 6, 2019

www.GreaterKaweahGSA.org

ITEM 2: ANNOUNCEMENTS

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ITEM 3: MINUTES ITEM 4: UPDATE ON DRAFT GSP MONITORING NETWORK CHAPTER

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ITEM 5: UPDATE ON SUSTAINABLE MANAGEMENT CRITERIA DEVELOPMENT

SMCs Approach for Groundwater Levels

• For each Representative Monitoring Site, the Minimum

Threshold for Groundwater Levels would be established at the projected 2040 GWL.

– This approach is meant to account for a “worst-case scenario” in which we experience worse drought conditions than we have historically.

• The Measurable Objective for Groundwater Levels would be

the projected 2030 GWL.

– Provides 10 years of drought storage in the “worst-case scenario”.

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SMCs for Change in Storage

• The change in groundwater storage is correlated to the chronic

decline in groundwater levels. Therefore, the SMCs for groundwater levels will be used as a proxy for the change in storage.

SMCs for Water Quality

• The Basin Setting has identified existing water quality issues.

However, undesirable results related directly to groundwater levels have not been observed to-date.

• To re-evaluate a Minimum Threshold and Measurable

Objective for each of the Constituents of Concern discussed in the Basin Setting, ongoing and future water quality monitoring will coincide with GWL measurements.

– e.g. The Kaweah Watershed Coalition has begun to collect water quality samples coincidental with GWL measurements.

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SMCs for Water Quality

• In addition to the IRLP, there are other existing programs (i.e.

Title 22 Drinking Water Program) which monitor water quality and will be used to determine the occurrence of an Undesirable Result, due to the migration of existing groundwater contamination.

SMCs for Subsidence

• The Basin Setting identifies Land Subsidence as a current condition

in the subbasin. However, damage to critical infrastructure within the Kaweah Subbasin has not been observed to-date.

• To establish an Minimum Threshold and Measurable Objective for

subsidence, one method would use the change in storage (with respect to the SMCs for GWLs) to develop correlations between change in storage and rates of subsidence.

• Another method would be to calculate the potential land

subsidence, based on the change in storage, and set a land elevation for Minimum Thresholds and Measurable Objectives at the Representative Monitoring Sites.

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ITEM 6: Measurement & Monitoring Options

Vendor Product Accuracy Pros Cons Unit Cost Rosemount 8750 Mag Meter 0.25% - 0.5%

• Proven Record
• Expandable Wireless Network

Capabilities for Remote Communication

• Cost
• Wireless network will be an

add’l cost ~ $5200/unit PowWow +/- 4%

• Inexpensive
• No Add’l Installation Cost
• Bulk Discounts up to ~60%
• Maintains Title 23 Certification

(< 10% error)

• Yearly recurring payments
• No option to add GWL

monitoring instruments to system $500/unit $200-$300/unit on bulk orders McCrometer

• FPI Mag

Meter

• Ultra Mag

Meter 0.5% - 1.0% 0.5%

• Meter installed on Pump
• Multiple Meters can track flow

to individual fields/crops

• Cost
• Add’l installation cost
• May not fit for all

applications

• Add’l cost for network

~$5500/unit McCrometer Propeller Meters 2%

• Inexpensive, compared to mag

meters

• Moving parts that can be

damaged/become worn

• Require longer pipe runs for

installation

• Add’l installation cost

~$2,800/unit

TSS Funding for Monitoring Wells

• The Kaweah Subbasin was approved for TSS funding to provide

additional, SGMA-compliant monitoring wells.

– In February, the GSAs were notified that DWR was still working with its drilling contractor to develop the schedule and negotiating on the costs to be able to complete as many wells as possible in this first round of funding. – As of earlier this week, the draft language for the Agreement was provided to the GSAs for their review. – DWR will provide the Agreement documents, completed with information provided in the TSS application in the coming weeks. – DWR is also asking each basin to prioritize the order of wells to be drilled, in case there is not sufficient funding to complete all wells in the basin.

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ITEM 7: TECH SERVICES UPDATE

Kaweah Subbasin Activities

• Subbasin Basin Setting Components Report

– Delivered to GSA Managers and discussed at Subbasin Management Team meeting on March 20th. – Further discussion at the TAC meeting on April 26th. GEI to respond to comments for May 6th TAC meeting.

• Numerical Model

– Refined with water budget refinements, discussed at Management Team

• meeting. GSAs managers discussing which simulations to run in the model.
• Draft Coordination Agreement discussions are ongoing.
• Water Budget components have been applied to Water Supply Accounting

Framework that has been agreed upon at the Subbasin-level. Currently under review with the GSA managers.

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Kaweah Subbasin Coordination (cont.) KSB Basin Setting Status

• KSB Managers and GSA TAC recently completed review of

December 1, 2019 Draft Basin Setting

• Approved Amended Task Order KSB-05.2018 – Basin Setting at

February Meeting

• GEI Team has incorporate KSB Managers comments

addressing these issues: 1. Decrease Kaweah River and CVP Water deliveries 2. Decrease Mountain Front Recharge in EKGSA and portions of GKGSA 3. Recalculate percolation or precipitation and applied water during period 1981-1999 using different methodology 4. Improve boundary flux estimates using numerical groundwater model 5. Document the specific yield method for calculating change in groundwater basin storage

Kaweah Subbasin Coordination (cont.) Revised Water Budgets

Each of these three water budgets periods have been refined with the recent Basin Setting Update

• Historic Period – 1981 to 2017
• Current Period – 1997 to 2017
• Projected Future – 2017 to 2070

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Kaweah Subbasin Coordination (cont.) QC Checks on Water Budget Accounting

Specific Yield Analysis Groundwater Modeling

Method Historic Period Modeling Period Water Budget (Inventory)

• 2,428,500
• 2,715,500

Specific Yield

• 3,127,300
• 2,948,600

Numerical Model

• 2,656,000

Kaweah Subbasin Coordination (cont.) Ave Overdraft – Historical vs. Current

Historical Average Overdraft: 65,600 AF/Y Current Average Overdraft: 77,591 AF/Y

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Kaweah Subbasin Coordination (cont.) Projected Water Budget

Water Supply Accounting Framework

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Native Water (Segregated by GSA Acreage)

East Greater Mid Total Perc of Precip (Ag and 'Native' non-Ag land) 23,666 44,213 20,974 88,854 Streambed Perc from Kaweah River Sources 16,767 31,324 14,860 62,952 Irrigation Ret. Flow from Pumped GW 41,484 77,501 36,766 155,752 Mountain Front Recharge 14,976 27,978 13,273 56,227 Total Native 96,894 181,017 85,874 363,784 GSA % of Total Native 27% 50% 24% Native Water

Foreign Water (Segregated by Appropriator)

East Greater Mid Total Streambed Perc from Imported Sources 1,638 12,615 14,253 Ditch Perc from Imported Sources 1,204 21,745 22,949 Basin Perc from Imported Sources 1,050 14,305 15,355 Irrigation Ret. Flow from Imported Sources 12,073 1,241 7,140 20,453 Total Foreign 12,073 5,133 55,805 73,010 GSA % of Total Foreign 17% 7% 76% Foreign Water

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Salvaged Water

(Segregated by Appropriator)

East Greater Mid Total Ditch Perc from Kaweah River Sources 8,835 49,771 34,880 93,486 Additional Recharge 226 6,892 5,697 12,815 Stormwater Return Flows 508 2,370 8,491 11,368 WWTP Return Flows 1,470 3,129 13,878 18,477 Basin Perc from Kaweah River Sources 16,005 23,479 39,484

• Irrig. Ret. Flow from

Kaweah River Sources 4,555 31,039 11,981 47,574 Total Salvaged 15,593 109,205 98,406 223,205 GSA % of Total Salvaged 7% 49% 44% Salvaged Water

Allocation Summary

Allocation Bucket East Greater Mid Total Total Native 96,894 181,017 85,874 363,784 Total Foreign 12,073 5,133 55,805 73,010 Total Salvaged 15,593 109,205 98,406 223,205 Grand Total 124,560 295,355 240,084 659,999 GSA % of Total 19% 45% 36%

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Initial GW Model Runs

1) Water Allocation Verification

– Purpose of this run is to verify and refine the water allocation results just presented derived from the inventory method water budget

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

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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

Initial GW Model Runs

3) Future Management Actions Only: Pumping Reductions What should the pumping reduction only (worst case scenario) interim milestones look like?

Management Action Pumping Reduction (%) Alternatives Alt. 2020-25 2026-30 2031-35 2036-40 1 20 35 45 2 5 25 30 40 3 5 20 35 40 4 10 20 30 40 5 10 30 30 30 6 25 25 25 25

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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

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 GSA Specific Model Simulations

SUBBASIN ACTIVITIES

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

GSP Development Schedule

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

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GSP Development Milestones

GSP Section/Sub Section Completion Date Revised Completion Date (04/30/19) Percent Complete

1. Introduction Draft in for Review Friday, April 5, 2019 95% 2. Basin Setting Friday, April 12, 2019 Friday, May 10, 2019 80% 3. Sustainability Goal & Undesirable Results Friday, April 19, 2019 Friday, April 26, 2019 75% 4. Monitoring Networks Friday, April 12, 2019 Friday, May 10, 2019 80% 5. Minimum Thresholds, Measurable Objectives, & Interim Milestones Friday, April 26, 2019 Thursday, May 2, 2019 80% 6. Water Supply Accounting Friday, April 19, 2019 Tuesday, May 7, 2019 65% 7. Projects, Management Actions and Adaptive Management Friday, April 26, 2019 Tuesday, April 30, 2019 60% 8. GSP Reporting Friday, April 26, 2019 Tuesday, April 30, 2019 75%

GSP Development

• Basin Setting Chapter

– GKGSA Basin Setting Chapter to be completed with Basin Setting Components Report that was provided to GSA Managers on March 20th. Comments received from TAC members are being reviewed.

• Monitoring Network Chapter

– Comments received from GKGSA TAC members and being addressed. Current draft is being revised and should be available for committee by May 10th .

• Sustainability Goal and Undesirable Results Chapter

– To be completed with incorporation of GSAs’ feedback and approval of Undesirable Results definitions and adoption of Sustainability Goal for the Subbasin.

• Sustainable Management Criteria Chapter

– Draft chapter write-up is being revised per discussions with TAC members and other GSAs.

• Projects and Management Actions Chapter

– Draft chapter has been populated with Projects. – Management Actions to be discussed in committees for consideration in the GSP.

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ITEM 8: GKGSA MEETINGS REPORT ITEM 9: FUTURE AGENDA ITEMS AND MEETING DATE(s)