Greater Kaweah GSA Combined RCC & SC Meeting - PDF document

5/16/2019 Greater Kaweah GSA Combined RCC & SC Meeting www.GreaterKaweahGSA.org Wednesday, May 16, 2019 ITEM 2: MINUTES 1

5/16/2019 ITEM 3: Summary of Kaweah Coordination • Subbasin Basin Setting Components Report – GEI responded to comments at May 6 th TAC meeting. • Numerical Model – Initial baseline model runs underway and scheduled for completion end of this week. – Management Actions only model run next, followed by Management Actions and Projects • Draft Coordination Agreement discussions are ongoing. Managers have agreed to make the Agreement available for review with draft GSPs. • Water Budget components have been applied to Water Supply Accounting Framework that has been agreed upon at the Subbasin-level. – To be included in each GSA’s GSP ITEM 3: Summary of Kaweah Coordination • 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 last 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. 2

5/16/2019 ITEM 3: Summary of Kaweah Coordination • DMS was to be made available for Admin Review last month but delivery has not yet occurred • Discussion surrounding coordinated approaches to measurement ongoing • TID/MKGSA/GKGSA have provided DWR with a proposal regarding tech funding for a pilot study • SkyTEM project completion report delivered to GSA managers – Very large document, currently under review but will be made available soon – Presentation by AGF provided to Mgmt Team Committee May 15 th ITEM 3: SkyTEM Investigation Objectives 1) Develop a 3D hydrogeological framework to assist in water resources management. 2) Produce maps of aquifer materials along the flight lines 3) Locate potential Managed Aquifer Recharge (MAR) areas along the flight lines 4) Provide information to identify optimal drilling locations for production, monitoring, and test wells 3

5/16/2019 ITEM 3: SkyTEM Helicopter AEM Operation Generator Usually 2-3 Flights/day Generator Totaling about 180-250 line-miles/day Approx. 100’ – 150’ above ground Along-Line Data Density Approximately Every ~ 10 ft ITEM 3: SkyTEM In Field QA/QC Abraham et al., 2016 4

5/16/2019 SkyTEM: Kaweah As Flown Flight Lines SkyTEM: Boreholes Near Flight Lines Blue dots- 440 Borehole with lithology only Yellow dots-52 Borehole with lithology and geophysical log 5

5/16/2019 SkyTEM: Interpretation of the Profiles Flight Line SkyTEM: Interpretation of the Profiles Water Table Flight Line 6

5/16/2019 SkyTEM: Example Fence Diagram Visalia Tulare N SkyTEM: Depth to Top of Basement 7

5/16/2019 SkyTEM: Depth to Top of Corcoran Clay SkyTEM: Thickness of Corcoran Clay 8

5/16/2019 SkyTEM: Recharge Potential Based on Results Poor Resistivity Greater than 25 ohm-m is optimal Good ITEM 3: SkyTEM Recommendations 1. Additional AEM mapping with high density block flights would allow for improved hydrogeologic framework for identifying recharge areas, managed aquifer recharge sites and estimating groundwater in storage and hydrogeologic boundary identification. 2. Siting new boreholes used for water quality and water quantity should use the results from this survey and future surveys to optimize locations. 3. Aquifer characteristic studies such as aquifer tests and other methods should be planned using the data from this study to optimize location for studies and observation- production well installation. 4. Improved geophysical bore hole logs will benefit current and future studies. This logging should use calibrated equipment for best results. 9

5/16/2019 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 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 10

5/16/2019 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 Management Actions • While projects address the “supply” side of the GSA’s water balance, management actions are geared toward the reduction of water demand. • Some actions could be taken by the GSA, regardless of the GSA/subbasin’s performance on SMCs. • Other actions are Sustainability Indicator driven, i.e. only implemented when the Measurable Objective is not met. • “Demand” side Management Actions are intended to be a “backstop” should projects fall short of meeting Measurable Objectives. 11

5/16/2019 Management Action Examples • Requiring landowners to take surface water when available, rather than pumping. • Incentivize on-farm recharge/spreading. • Incentivize changes in cropping or cultivation practices. • Incentivize on-farm water efficiency improvements. • Implement a fallowing/land retirement program. • Pumping restrictions (at the bottom of the list, but not off the table). Management Actions Discussion • Which actions would you consider for the 2020 GSP? • Are their any actions not listed in the examples presented that you would like to see considered in the GSP? 12

5/16/2019 Initial GW Model Runs 3) Future Management Actions Only: Pumping Reductions Percentage Of The Overdraft Issue To Solve For During Interim Periods Alt. 2020-25 2026-30 2031-35 2036-40 1 0 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 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  Focusing 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 13

5/16/2019 Sustainable Management Criteria • Criteria must be established for each sustainability indicator • Additional data and technical study will be required in the early years of implementation in order to gain confidence in our defining SMC • GKGSA TAC was unable to identify a reasonable, technical solution to establishing criteria for most sustainability indicators 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”. 14

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5/16/2019 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. 18