4/26/2019 Greater Kaweah GSA Technical Advisory Committee Meeting www.GreaterKaweahGSA.org Friday, April 26, 2019 ITEM 2: ANNOUNCEMENTS 1
4/26/2019 ITEM 3: MINUTES ITEM 4: REVIEW OF DRAFT BASIN SETTING 2
4/26/2019 ITEM 5: UPDATE ON DRAFT GSP MONITORING NETWORK CHAPTER Monitoring Network Chapter • The Monitoring Network Chapter consists of 3 parts: – A description of existing monitoring programs and the data collected – Identification of data gaps with respect to the requirements of SGMA – Plans to address the data gaps identified in the 2020 GSP • Use of Existing Monitoring Programs • Development of a SGMA-Compliant Monitoring Network 3
4/26/2019 Monitoring Network Chapter • SGMA requires that a coordinated, subbasin wide monitoring network be developed and used for the evaluation of the subbasin’s performance in the Sustainability Indicators defined by SGMA. – SGMA allows for the use of Representative Monitoring Sites and Proxy Measurements for evaluating SI performance. Overview of Existing Monitoring The following have been identified at the Subbasin level: • Existing groundwater level monitoring programs • Existing groundwater quality programs • Existing land surface subsidence monitoring, and • Existing surface water flow monitoring 4
4/26/2019 Existing Groundwater Level Monitoring Period of Number of Known Number of Dual Frequency of Types of Wells Automated Agency Record for Wells Completion of Completion Monitoring Monitored Monitoring Monitoring (Approx.) Wells Monitored Wells Monthly to bi- Alta ID 1921 – 2011 Ag/ Domestic 5 None None Unknown annually Bureau of Monthly to bi- 1924 – 2008 Unknown 118 15 Unknown Unknown Reclamation annually Cal Water (City of Monthly 1971 – 2018 Municipal 104 None Unknown Unknown Visalia) Dept of Water Bi-annually 1930 – 2016 Various 182 7 Unknown Unknown Resources Exeter ID Bi-annually 1963 – 2016 Agricultural 40 None Unknown Unknown Monthly to Bi- KDWCD 1919 – 2018 Agricultural 425 30 4 Unknown Annually Kings County Bi-annually 2011 – 2018 Agricultural 6 3 Unknown Unknown Water District Lakeside ID Bi-annually 2012 – 2017 Agricultural 33 2 Unknown Unknown 5
4/26/2019 Groundwater Level Data Gaps • There are a total of 14 Dedicated Groundwater Level Monitoring Wells throughout the entire Subbasin. • An additional 6 wells are proposed with the TSS funding application at DWR, bringing the total to 20 wells. – The desired density of wells, according the DWR’s BMP on Monitoring Networks ranges between 4 and 10 wells per 100 sq. miles. • Between 28 wells and 70 wells for the entire Kaweah Subbasin. 6
4/26/2019 Existing Groundwater Quality Monitoring Water Quality Monitoring Participating Agencies Parameters Frequency Program Ag suitability analysis (limited suite of general AB 3030 and SB 1938 Exeter ID, KDWCD, Lakeside ID Annually to Once Every 3 Years minerals) Title 22 General Minerals & Metals, every 3 years Nitrates, annually (quartertlyif ≥ 5 ppm) City of Exeter, City of Farmersville, Ivanhoe Public Utility CA SDWIS All Title 22 regulated constituents VOCs and SOCs, every 3 years District, City of Woodlake Uranium, dependent on historical sampling. Varies between 1 sample every 3 (when ≥ 10 pCi/L), 6 (when < 10 pCi/L) or 9 (when no historical detection) years Most constituents sampled monthly, quarterly General Minerals from source water and annual General Minerals from waste discharge. CV-SALTS Kaweah is a Priority 1 Basin, meaning that management strategies will be initiated in 2019 Dept of Pesticide Regulation City of Exeter, City of Farmersville, Ivanhoe Public Utility Pesticides Annual District, City of Woodlake (DPR) The Priority Basin Project performed baseline and trend Constituents sampled vary by Program assessments, sampling 2,900 public and domestic wells Objectives statewide. GAMA SWRCB, Central Valley RWQCB, DWR, DPR, NWIS, LLNL USGS is typically the technical lead in The Domestic Well Project sampled over 180 wells in conducting the studies and reporting data Tulare County (29 wells were in the Kaweah Subbasin). Static Water Level, temperature, pH, electrical conductance, Nitrate as Nitrogen, dissolved Irrigated Lands Regulatory Varies; Annually to every 5 years (first samples Kaweah River Watershed Coalition Oxygen (Annually) Program (IRLP) collected in fall 2018) General Minerals suite (every 5 years) Water Quality Data Gaps • In areas with two aquifer systems, do the existing monitoring programs identify which aquifer is being monitored? – GEI and GSI have reviewed the well completion data available and identified the aquifers being monitored for water quality with the existing monitoring programs. • Implementation of CV-SALTS should help address areas beyond municipal and domestic groundwater use. – Use of information from the IRLP, which includes GWLs taken at the water quality sampling sites, will also help address coverage in rural areas. 7
4/26/2019 Existing Subsidence Monitoring Monitoring Entity Category Period of Record (Entities) National Geodetic Survey of Historical Monitoring benchmarks (repeat level 1926 – 1970 surveys) National Geodetic Survey of benchmarks (repeat level surveys). Installation and NGS: 1970 to present measurement of Deer Creek extensometer (8.5 miles south of Kaweah Subbasin, in the Tule Subbasin) KDWCD Land Surface Recent Monitoring Elevation Monitoring (local 2016 to present benchmark monitoring network) CGPS data from UNAVCO and CGPS: 2006 to Present CVSRN stations: P056, P566, (depending on station) CRCN, LEMA, and RAPT NASA: 2006 – 2017 (except NASA (InSAR and UAVSAR for 2011 – 2014) programs) 8
4/26/2019 Subsidence Data Gaps • While there is extensive coverage with the KDWCD Land Surface Elevation Monitoring Stations, the data has only been collected since 2016. – Continued collection of this data and use of other existing programs, with InSAR imagery, will need to be evaluated in the implementation of SGMA to determine if any additional monitoring is needed. – KDWCD has provided feedback and updates on the Land Surface Elevation Monitoring network and an up-to-date description of the procedures for GEI’s use in the Monitoring Network chapter. Representative Monitoring Sites • Can have multiple sites per Management Area • Can monitor multiple SIs at a Site 9
4/26/2019 Representative Monitoring Sites • Criteria for Selection of Representative Monitoring Sites: – Is there already a dedicated monitoring well at the location? – If not, are there wells of known construction that can be converted to monitoring wells or used for the interim? • In areas with two aquifer systems, in which system are these wells completed? – Is there adequate well density and distribution for the management area? – Is there a good record of hydrology for the well? • Of the Key Wells in the Basin Setting, 85 meet this criteria. Representative Monitoring Sites Completion No. of Wells Single Aquifer 56 Lower Aquifer 2 Upper Aquifer 27 TOTAL 85 10
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Management Area Concepts Management Area Concepts 4/26/2019 12
4/26/2019 ITEM 6: 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”. 13
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4/26/2019 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. 17
4/26/2019 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. 18
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