The MTs are set as a new exceedance of the maximum contaminant level (MCL) at a potable supply well for any of the seven constituents of concern (COC): nitrate, uranium tetrachloroethene (PCE), 1,2,3-trichloropropane (TCP), Dibromochloropropane (DBCP), total dissolved solids (TDS), and arsenic.
The SWRCB and other agencies have the primary responsibility for water quality and the GSAs do not intend to duplicate this authority. Numerous regulated water quality monitoring programs exist in the Modesto Subbasin, providing data from hundreds of monitoring sites over time. Accordingly, the monitoring network for this sustainability indicator will incorporate existing monitoring data. The MTs will be quantitively monitored #25..
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TODD GROUNDWATER
by public agencies (and others) in representative monitoring wells for each Principal Aquifer in accordance with other water quality regulatory monitoring program requirements. The GSAs will download water quality data from the State GeoTracker website each year and analyze any new exceedances of the seven COCs in potable supply wells. New exceedances or further degradation of the wells with prior exceedances will be evaluated in relation to GSA management of water level and groundwater extractions, as well as GSA projects and management actions, to determine whether these exceedances were caused, or exacerbated, by the GSAs. This analysis will be included in the GSP annual reports.
The monitoring network consists of drinking water supply wells, monitoring wells at regulated facilities, and monitoring sites associated with other regulatory water quality programs such as GAMA. Data from two specific regulatory water quality programs, CVSALTS and the Nitrate Control Program (implemented by the Valley Water Collaborative – see Section 2.4.4), will be compiled separately if not already included in the GeoTracker data. These two programs are regulated through the CVRWQCB and provide water quality data for nitrate and total dissolved solids in groundwater throughout the Subbasin.
Collectively, this dataset represents a comprehensive network for ongoing tracking and evaluation with respect to the sustainable management criteria.
The monitoring network will vary from year-to-year based on regulatory requirements for each water quality program. Water quality data collected in Subbasin wells during water year 2020 (October 2019 to September 2020) for the COCs were downloaded from GeoTracker as an example dataset. The wells with this water quality data are represented on Figure 7-4 and tabulated in Appendix H. During this time, water quality data for the COCs were collected from over 300 wells in the Subbasin. Most of the data are from municipal drinking water systems and are therefore clustered in and around the municipalities. As indicated by the numbers of wells sampled for each of the COCs on Figure 7-4 and tabulated in Appendix H, there is sufficient data to track and characterize water quality COCs to meet beneficial uses across the Subbasin.
7.1.5. Land Subsidence
Although impacts from land subsidence have not been documented in the Modesto Subbasin, future land subsidence is most likely to occur as a result of the dewatering/depressurization of clays within and below the Corcoran Clay. As described in Section 6.7, the sustainable management criteria for chronic lowering of groundwater levels will be used as a proxy for land subsidence. Accordingly, the monitoring network for land subsidence is the same as the monitoring network for the chronic lowering of groundwater levels. This monitoring network is described above in Section 7.1.1, summarized in Table 7- 1, and illustrated on Figures 7-1, 7-2, and 7-3.
Static depth to water will be measured twice a year in the monitoring network wells to represent seasonal high and seasonal low groundwater conditions. The wells in this monitoring network will be monitored by one of the STRGBA GSA member agencies. #25..
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Remote sensing data will be used as a screening tool to evaluate land subsidence in the Modesto Subbasin as a supplemental monitoring program, but MTs and MOs will not be assigned to these data. As summarized in Section 3.2.6, vertical displacement data has been collected using Interferometric Synthetic Aperture Radar (InSAR) since 2015 by TRE Altamira Inc., under contract with DWR. This data set is available on the SGMA Data Viewer (https://sgma.water.ca.gov/webgis/?appid=SGMADataViewer#landsub). Data collected from June 2015 to June 2018 in the Modesto Subbasin is illustrated on Figure 3-59. As shown on this figure, vertical displacement data covers the full extent of the Modesto Subbasin. Land subsidence will be monitored in the Subbasin by updating and evaluating this InSAR data on an annual basis. This evaluation will be included in the GSP annual reports.
7.1.6. Depletions of Interconnected Surface Water
The monitoring network for depletions of interconnected surface water, summarized in Table 7-2 and presented on Figure 7-5, includes 20 wells along the San Joaquin River, Stanislaus River and Tuolumne River. The wells are screened in the Western Upper Principal Aquifer and the Eastern Principal Aquifer and include CASGEM wells and Proposition 68 monitoring wells.
Groundwater data will be supplemented with surface water data monitored by others. Data include releases and diversions on the Tuolumne and Stanislaus rivers (Tables 3 and 4 in Appendix D), coupled with stream gauge data monitored by USGS (Table 7 in Appendix D).
These data have been used in model calibration to analyze streamflow depletions in this GSP as documented in Appendix D (see Sections 2.1.2 and 3.4 in Appendix D).
The wells in this monitoring network were chosen because they are relatively close to the rivers and will be accessible for water level measurement in the future. The wells have known locations with depth-discrete screen intervals and will enable monitoring of the unconfined water level surface adjacent to the river boundaries.
The following summarizes the monitoring network wells along each of the rivers.
7.1.6.1. San Joaquin River
Two CASGEM wells are part of the monitoring network along the San Joaquin River. These wells are approximately 0.75 and 2.0 miles from the San Joaquin River and are the closest wells to the river screened in the Western Upper Principal Aquifer that are accessible for future monitoring. These wells have known construction, with discrete screened intervals from 13 to 148 ft bgs (Table 7-2). Each of these wells has historical water level data (hydrographs in Appendix G).
As shown on Figure 7-5, these two wells are along the Subbasin’s central reach of the San Joaquin River and there is a gap in well coverage along the upstream and downstream reaches. This is consistent with the data gap in groundwater conditions along the river boundaries that was identified and described in Section 3.2.9. #25..
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As described in Section 6.8.2, the MT for the San Joaquin River is defined as the low groundwater elevation observed in Fall 2015. The MO is the midpoint between the historical high groundwater elevation and the MT (Table 7-2). As noted on Table 7-2, the MT and MO are close together (about 6 feet or less), providing relatively small amounts of operational flexibility; however, historical groundwater elevations have been relatively stable in this part of the Subbasin. The MTs and MOs at each of these wells is based on measured data, as shown on the hydrographs in Appendix G.
Static groundwater elevations will be measured twice a year, in spring and fall, to represent seasonal high and low groundwater conditions. The wells along the San Joaquin River will be monitored by one of the STRGBA GSA member agencies.
7.1.6.2. Stanislaus River
Eight wells are part of the monitoring network along the Stanislaus River. As shown on Figure 7-5, these include CASGEM wells and one Proposition 68 monitoring well. These wells were chosen for the monitoring network because they are close to the Stanislaus River (one mile or less from the river) and will be accessible for future water level monitoring.
The wells in this monitoring network are in the Eastern Principal Aquifer. The screen intervals of these wells range from ground surface to 550 ft bgs. The wells are along the central reach of the Stanislaus River, with gaps in well coverage along the upstream and downstream reaches. Data gaps in the monitoring network are being addressed with a data gap analysis incorporated into the GSP Implementation Plan to improve future GSP monitoring (see Section 9.5.1).
As described in Section 6.8.2, the MT for the Stanislaus River is defined as the low groundwater elevation observed in Fall 2015. The MTs at the CASGEM wells are observed water levels in Fall 2015. The Proposition 68 monitoring well (MW-4S) was constructed in 2021 and its MT is estimated from the October 2015 groundwater elevation contour map (see Figure 3-27).
Static groundwater elevations will be measured twice a year, in spring and fall, to represent seasonal high and low groundwater conditions. The wells will be monitored by one of the STRGBA GSA member agencies.
7.1.6.3. Tuolumne River
As shown on Figure 7-5, the monitoring network along the Tuolumne River includes 10 wells: 6 CASGEM wells and 4 Proposition 68 monitoring wells. These wells were chosen for the monitoring network because they are close to the Tuolumne River and will be accessible for future monitoring. Well data are summarized in Table 7-2.
Most of the wells in this monitoring network are within 1.0 mile of the Tuolumne River, with some between 1.0 and 1.5 miles from the river. Three of the wells (Paradise 235, Philbrick 201 and MW-2S) are within the Corcoran Clay extent and screened within the Western Upper Principal Aquifer. Screens in these three wells range from a depth of 58 ft bgs to 132 ft bgs. The remaining wells are in the Eastern Principal Aquifer, with screens ranging from #25..
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 7-17
Revised July 2024
TODD GROUNDWATER
113 ft bgs to 360 ft bgs. Although MW-3S appears on Figure 7-5 to be on the edge of the Corcoran Clay as mapped by the USGS (Burow et al., 2004), Corcoran Clay was not encountered during well drilling.
As shown on Figure 7-5, these wells are spaced apart along the full extent of the Tuolumne River. There is less well coverage, however, along the upstream reach of the river. The recently constructed MW-9 helps to fill a previous gap in the upstream reach. As stated previously, groundwater conditions along the river boundaries were identified as a data gap in Section 3.2.9.
As described in Section 6.8.2, the MT for the Tuolumne River is defined as the low groundwater elevation observed in Fall 2015. The MTs at the CASGEM wells are based on measured data in Fall 2015. The MTs at the Proposition 68 monitoring wells are based on either the Fall 2015 contour map (see Figure 3-27) or nearby wells with historical water level data. Due to a lack of data in the eastern Subbasin, the MT at MW-9 is based on the limited measured water levels at the well since it was constructed in March 2021. Hydrographs with MTs and MOs are in Appendix G.
Static groundwater elevations will be measured twice a year, in spring and fall, to represent seasonal high and low groundwater conditions. The wells will be monitored by one of the STRGBA GSA member agencies.
7.2. PROTOCOLS FOR DATA COLLECTION AND MONITORING
As required by the GSP regulations, protocols are provided for groundwater elevation monitoring in the representative monitoring wells in the monitoring network. Applicable portions of DWR’s best management practices (BMP) for monitoring protocols have been considered and incorporated. As required by the regulations, monitoring protocols will be reviewed at least every five years as part of the periodic evaluation of the GSP, and modified as necessary.
Protocols are focused on groundwater elevation monitoring standards because that is the only monitoring method applicable to the monitoring network for the Modesto Subbasin (see justification and rationale for the use of groundwater elevations for applicable sustainability indicators described in Chapter 6). As discussed in Section 7.1.4., water quality monitoring will be conducted by others, and therefore water quality sampling protocols are not included in this section.
This section describes general procedures for documenting wells in the monitoring program and for collecting consistent high quality groundwater elevation data. In general, the methods for establishing location coordinates (and reference point elevations) follow the data and reporting standards described in the GSP Regulations (§352.4) and the guidelines presented by USGS Groundwater Technical Procedures. These procedures are summarized below.
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Revised July 2024
TODD GROUNDWATER
7.2.1. Field Methods for Monitoring Well Surveying
As described previously, further improvements to the monitoring network will be made in the future. When new monitoring wells are constructed, the following survey procedures will be followed:
• Location coordinates will be surveyed with a survey grade Global Positioning System (GPS). The coordinates will be in Latitude/Longitude decimal degrees and reference the NAD83 datum.
• Reference point elevations will be surveyed with a survey grade GPS with elevation accuracy of approximately 0.5 feet. During surveying, the elevations of the reference point and ground surface near the well will be measured to the nearest
0.5 foot. All elevation measurements will reference NAVD88 vertical datum.
7.2.2. Additional Well Standards
Additional standards and information applicable to new and existing wells are also incorporated into the monitoring network as required by the GSP regulations. This information is summarized on Tables 7-1 and 7-2 and includes the following:
• CASGEM Well ID (as applicable),
• Well location, ground surface elevation and reference point elevation, • Description of the well use and status (i.e., active irrigation well or monitoring well), • Well depth and screen interval depth, and
• Principal Aquifer that is being monitored.
Additional information will be provided on the DWR templates for wells and water levels.
For example, well completion report number, well construction diagram and geophysical log will be provided, if available. Additional well details such as boring total depth and well casing diameter, if available, will also be provided on the DWR templates.
There are three representative wells in the monitoring network for which the screen interval information is unknown: CASGEM wells Gates Road 101, Machado 23 and Warnock 46 (see Tables 7-1 and 7-2). But, based on the total depths of these wells, they are completed in the Western Upper Principal Aquifer.
7.2.3. Field Methods for Groundwater Elevation Monitoring Field methods for collecting depth to water measurements at representative monitoring wells in the Modesto Subbasin GSP monitoring network are described below:
• Active production wells will be turned off prior to collecting a depth to water measurement.
• The standard period of time that a well needs to be off before a static measurement is taken is 48 hours; field personnel will attempt to verify the time that the pump last ran and record that time in the field notes.
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Revised July 2024
TODD GROUNDWATER
• To verify that the wells are ready for measurement, STRGBA GSA will coordinate with well operators and/or owners as necessary.
• Coordination with well operators/owners should occur approximately four days prior to the expected measurement date.
• Each well has a unique manner to access the well bore (e.g., inspection port, sounding tube, hole drilled into the side of the casing). • Depth to groundwater will be measured relative to the established reference point elevation, which will be marked with a marker or notch in the top of the well casing.
In the absence of a mark or notch, the groundwater elevation will be measured from the north side of the well casing and then marked for future measurements. • If a pressure release is observed when the well cap or sounding port plug is removed, the water level will be allowed to stabilize for a short period of time before the depth to groundwater measurement is taken.
• Depth to groundwater measurements are collected by either electric sounding tape (Solinst or Powers type sounders) or by steel tape methods. The depth to water measurement methods described in DWR’s Groundwater Elevation Monitoring Guidelines, will apply to the Modesto Subbasin monitoring network for wells monitored with electric sounding tape or a steel tape (DWR, 2010). • Depth to groundwater will be measured and reported in feet to the nearest 0.01 foot relative to the reference point.
• The measurement will be recorded on a field sheet with the date and time the measurement was made. Any factor that may influence the depth to water measurement will be noted, such as well condition or local flooding. • The well cap or sounding port cap will be placed back on the well, and the well will be secured and locked.
7.2.4. Frequency and Timing of Groundwater Elevation Monitoring • Semi-annual monitoring is determined to be appropriate to capture the seasonal high and low groundwater elevations associated with the irrigation pumping cycle. • Groundwater elevations will be measured in monitoring network wells within as short a time as possible, preferably within a 1 to 2 week period (DWR, 2016c), in order to:
o provide a snapshot of elevations in time to support mapping and management;
o capture the seasonal high and low elevations in the Subbasin; and o meet reporting requirements for semi-annual monitoring data as required by DWR.
• Based on historical data and current land uses in the Modesto Subbasin, the following measurement time intervals are established:
o Seasonal high: February 1 through April 15 for reporting to DWR by July 1. o Seasonal low: September 1 through November 30 for reporting to DWR by January 1. Although October and November are technically part of the subsequent water year, they are included in the fall monitoring event to ensure that the seasonal low water level can be measured. Depending on #25..
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Revised July 2024
TODD GROUNDWATER
the hydrology, agricultural fields may be irrigated through October in the Modesto Subbasin.
• Water level measurements may be adjusted within the time intervals based on hydrologic and land use conditions at that time. The timing for the monitoring events will be coordinated among the GSAs.
7.3. ASSESSMENT AND IMPROVEMENT OF MONITORING NETWORK
The Modesto Subbasin took a big step towards improving the monitoring network by constructing 17 monitoring wells at 11 locations throughout the Subbasin in 2021 with Proposition 68 grant funding. However, as described in Section 3.2.9, data gaps still exist in the Western Lower Principal Aquifer, Eastern Principal Aquifer and along the river boundaries. These data gaps are consistent with the gaps in well coverage in the monitoring networks, described in Section 7.1. The following specific data gaps have been identified for the GSP monitoring network, organized by each sustainability indicator:
• Chronic Lowering of Groundwater Levels: Insufficient number and location of accessible and representative wells screened in the Western Lower Principal Aquifer and in the eastern region of the Eastern Principal Aquifer. • Reduction of Groundwater in Storage: Insufficient number and location of accessible and representative wells screened in the Western Lower Principal Aquifer and in the eastern region of the Eastern Principal Aquifer.
• Seawater Intrusion: Not applicable.
• Degraded Water Quality: No data gaps. GSAs will rely on a robust water quality monitoring network that combines numerous ongoing monitoring programs conducted by others (see Section 7.1.4 and Figure 7-4). • Land Subsidence: Insufficient number and location of accessible and representative wells screened in the Western Lower Principal Aquifer.
• Depletions of Interconnected Surface Water: Insufficient number and location of appropriately constructed, accessible, and representative wells along various segments of all three river boundaries to measure the water table in the Western Upper Principal Aquifer and Eastern Principal Aquifer.
The GSAs have committed to a data gap analysis to make ongoing improvements to the current GSP monitoring network (see Section 9.5.1). Additional improvements to the monitoring network are envisioned in the first five years of GSP implementation as described in Section 9.5.1. In addition, the monitoring network will be reviewed and evaluated in each five-year assessment in compliance with GSP regulations (§354.38, see Section 9.4.4).
7.4. DATA MANAGEMENT SYSTEM
Groundwater elevation data measured in the representative monitoring wells and the additional SGMA wells will be recorded in the data management system (DMS) developed for the GSP. The data collected for the GSP from the GSA member agencies, and other #25..
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Revised July 2024
TODD GROUNDWATER
sources, currently resides in relational databases, which consist of an Access database, GIS geodatabase, and Excel workbooks. Future upgrades to this DMS are being considered by the GSAs. The DMS will be updated with the monitoring data annually and provided in the GSP annual reports. Monitoring data will also be submitted to DWR on the Monitoring Network Module of the online SGMA portal.
#25..
- 2021 -
A@A@
A@A@
A@
MW-2S
(34 / 41)
MW-1S
(33 / 43)
MRWA-2
(36 / 43)
Young 76
(36 / 42)
Katen 69
(27 / 33)
MOD-MWD-1
(30 / 40)
MOD-MWB-1
(40 / 49)
Warnock 46
(35 / 42)
Machado 23
(31 / 40)
Paradise 235
(34 / 41)
Hart Road 88
(35 / 40)
Canfield 90
(32 / 36)
North Ave 103
(41 / 50)
Curtis #2 100
(34 / 41)
Gates Road 101
(24 / 33)
Philbrick 201
(34 / 41)
Van Buren 43
(38 / 45)
Path: T:\Projects\Modesto GSP 74305\GIS\Figures\Section 7\Figure 7-1 Chronic Lowering Western Upper PA.mxd Figure 7-1
Monitoring Network, Chronic
Lowering of Water Levels,
Western Upper Principal Aquifer
December 2021
("N
03 Miles
Note:
This monitoring network is used as a proxy for the reduction of groundwater in storage and land subsidence sustainability indicators.
Legend
CASGEM Well -- Western Upper (12)
A@ City of Modesto Monitoring Well (2) A@ Prop 68 Monitoring Well (2) A@ USGS Monitoring Well (1) Corcoran Clay Extent (Burow et al., 2004)
Management Area
Modesto ID (17)
Oakdale ID (0)
Non-District West (0)
Non-District East (0)
(MT / MO) MT = minimum threshold, MO = measurable objective Values in parentheses in legend represent number of wells #25..
- 2022 -
A@
A@
A@
A@
A@
MW-2D
(35 / 40)
MW-1D
(14 / 27)
MRWA-3
(28 / 36)
MOD-MWD-3
(30 / 37)
MOD-MWB-2
(26 / 34)
Path: T:\Projects\Modesto GSP 74305\GIS\Figures\Section 7\Figure 7-2 Chronic Lowering Western Lower PA.mxd Figure 7-2
Monitoring Network,
Chronic Lowering of Water Levels,
Western Lower Principal Aquifer
December 2021
(
"N
0 3
Miles
Note:
This monitoring network is used as a proxy for the reduction of groundwater in storage and land subsidence sustainability indicators.
Legend
A@ City of Modesto Monitoring Well (2)
A@ Prop 68 Monitoring Well (2)
A@ USGS Monitoring Well (1)
Corcoran Clay Extent (Burow et al., 2004)
Management Area
Modesto ID (5)
Oakdale ID (0)
Non-District West (0)
Non-District East (0)
(MT / MO) MT = minimum threshold, MO = measurable objective Values in parentheses in legend represent number of wells #25..
- 2023 -
A@
A@
A@ A@
A@
A@
A@
A@
A@
A@
A@
A@
A@ MW-11
(35 / 48)
MW-8
(75 / 110)
MW-7
(75 / 110)
MW-6S
(65 / 83)
MW-5S
(69 / 89)
MW-4S
(56 / 67)
MW-3D
(25 / 31)
MW-3S
(25 / 31)
FPA-2
(38 / 48)
MW-10
(72 / 101)
MW-9
(150 / 180)
OFPB-2
(35 / 53)
Wood 210
(52 / 66)
MOD-MWC-3
(40 / 50)
MOD-MWA-2
(30 / 36)
Cavil 214
(53 / 73)
Perley 202
(36 / 45)
Albers 232
(60 / 76)
Schmidt 227
(59 / 78)
Blossom 230
(61 / 78)
Crane OID-06
(66 / 77)
American 208
(48 / 55)
Allen OID-01
(72 / 81)
Wellsford 233
(62 / 77)
Jones WID 228
(55 / 75)
Bangs Ave 243
(32 / 46)
Marquis OID-10
(85 / 91)
Furtado OID-07
(69 / 81)
Bentley OID-02
(71 / 85)
Lateral one 195
(42 / 52)
Birnbaum OID-03
(72 / 86)
Quesenberry 223
(89 / 110)
Paulsell 2 OID-12
(94 / 123)
Paulsell 1 OID-11
(88 / 117)
Head Lateral 8 194
(40 / 47)
Head Lateral 3 215
(56 / 73)
Langdon Merle 241
(50 / 62)
Riverbank OID-13
(42 / 54)
Claribel 206
(49 / 62)
Path: T:\Projects\Modesto GSP 74305\GIS\Figures\Section 7\Figure 7-3 Chronic Lowering Eastern PA.mxd Figure 7-3
Monitoring Network, Chronic
Lowering of Water Levels,
Eastern Principal Aquifer
December 2021
(
"N
0 3
Miles
Note:
This monitoring network is used as a proxy for the reduction of groundwater in storage and land subsidence sustainability indicators.
Legend
CASGEM Well -- Eastern (25)
A@ City of Modesto Monitoring Well (2)
A@ Prop 68 Monitoring Well (10)
A@ USGS Monitoring Well (2)
Corcoran Clay Extent (Burow et al., 2004)
Management Area
Modesto ID (24)
Oakdale ID (7)
Non-District West (1)
Non-District East (7)
(MT / MO) MT = minimum threshold, MO = measurable objective Values in parentheses in legend represent number of wells #25..
- 2024 -
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X
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X
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Path: T:\Projects\Modesto GSP 74305\GIS\Figures\Section 7\Figure 7-4 Water Quality Monitoring Sites October 2019 - September 2020.mxd Figure 7-4
Water Quality Monitoring
Sites, October 2019 to
September 2020
December 2021
("N
03 Miles ("N
03 Miles
Note
Legend
Nitrate as N (323)
Ë
Uranium (57)
PCE (162)
1,2,3-TCP (88)
X DBCP (144) #* TDS (150)
Arsenic (174)
Corcoran Clay Extent (Burow et al., 2004)
Values in parentheses in legend represent number of wells #25..
- 2025 -
A@
A@
A@
A@ A@
MW-9
(150 / 180)
Quesenberry 223
(89 / 110)
Schmidt 227
(59 / 78)
MW-6S
(65 / 83)
Jones WID 228
(55 / 75)
Lateral one 195
(42 / 52)
Marquis OID-10
(86 / 92)
Birnbaum OID-03
(74 / 87)
Allen OID-01
(75 / 83)
Paradise 235
(34 / 41)
Philbrick 201
(38 / 43) MW-2S
(38 / 43)
MW-3S
(26 / 32)
MW-4S
(56 / 67)
Riverbank OID-13
(42 / 54)
Langdon Merle 241
(50 / 62)
Head Lateral 8 194
(40 / 47)
American 208
(48 / 55)
Katen 69
(27 / 33)
Canfield 90
(33 / 37)
Path: T:\Projects\Modesto GSP 74305\GIS\Figures\Section 7\Figure 7-5 Interconnected Surface Water.mxd Figure 7-5
Monitoring Network,
Interconnected Surface Water
December 2021
(
"N
0 3
Miles
(
"N
0 3
Miles
Legend
CASGEM Well -- Western Upper (4)
CASGEM Well -- Eastern (11)
A@ Prop 68 Monitoring Well (5)
Corcoran Clay Extent (Burow et al., 2004)
Management Area
Modesto ID (13)
Oakdale ID (3)
Non-District West (2)
Non-District East (2)
(MT / MO) MT = minimum threshold, MO = measurable objective Values in parentheses in legend represent number of wells Western Upper Principal Aquifer (5)
Eastern Principal Aquifer (15)
#25..
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-1
Revised July 2024
TODD GROUNDWATER
8. PROJECTS AND MANAGEMENT ACTIONS
The GSA acknowledges that during the 20-year GSP implementation period it will be necessary to implement Projects and Management Actions (PMA)s to achieve and maintain sustainable groundwater conditions in the Subbasins by or before 2042. Therefore, multiple PMAs have been identified and considered by the GSAs that are designed to avoid undesirable results over the remainder of a 50-year planning horizon, as required by SGMA regulations.
Descriptions of PMAs that will contribute to the achievement of sustainability goals in the Subbasin are provided herein. PMAs are described in accordance with §354.42 and §354.44 of the SGMA regulations. Evaluations of the benefits and/or impacts on groundwater levels and storage volumes are also provided for their respective projects. “Projects” refer to physically constructed (structural) features whereas “Management Actions” refer to non‐structural programs or policies designed to incentivize reductions in groundwater pumping or optimize management of the Subbasin. Chapter 9: Plan Implementation of the GSP describes the plan for implementing the PMAs detailed in this chapter.
The STRGBA GSA approved a resolution23 adopting the revised GSP and commitment to implementing demand management actions (Resolution) on July 10, 2024, to develop and implement management actions in order to arrest groundwater level declines by 2027 and raise groundwater levels after 2027, and to manage the Subbasin in a sustainable manner.
The Tuolumne County GSA approved the same resolution on June 18, 2024. The GSAs are committed to developing management actions no later than January 31, 2026, and implementing these management actions no later than January 31, 2027. However, the GSAs may decide that one or more management actions will be rolled out in 2026 to ensure that groundwater level inflection is achieved in 2027. The Resolution approves the revised Modesto Subbasin GSP, commits to developing and implementing a well mitigation plan, and commits to developing and implementing management actions. The full text of the Resolution can be found in Appendix C.
The management actions to be considered include, but are not limited to:
• A groundwater allocation and pumping management program • A groundwater extraction and surface water reporting program • Groundwater extraction fees
• A groundwater pumping credit market and trading program • Voluntary conservation/land fallowing, and
23 Stanislaus and Tuolumne Rivers Groundwater Basin Association Groundwater Sustainability Agency Resolution Adopting a Revised Groundwater Sustainability Plan and Documenting the Commitment to Develop and Implement a Well Mitigation Program and Demand Management Actions in the Modesto Groundwater Subbasin: Appendix C
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Revised July 2024
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• Conservation practices
• A dry well mitigation program
Management actions will be developed to include triggers, based on sustainable management criteria established in the GSP, so the GSAs have the ability to readily respond to changing hydrologic conditions within the Subbasin. Development of management actions and their components are discussed in Section 8.4.
A range of PMAs are presented to allow the GSAs flexibility in their response to changing hydrologic and groundwater conditions. It is anticipated that a subset of projects will provide the Subbasin with a suitable amount of groundwater needed for the Subbasin to achieve its sustainability goal. As a result, certain PMAs may not need to be implemented for the Subbasin, however, the GSAs will consider these PMAs for future initiatives or as means to achieve local goals and support the sustainability goal. Given their commitment to tangible results by 2027, the GSAs will place highest priority on implementation of PMAs with most rapid results, to be demonstrated with empirical data.
PMAs will be evaluated periodically during the GSP implementation period. PMAs, specifically management actions, are in early stages of development. Complete information on construction requirements, operations, costs, permitting requirements, and other details are not uniformly available for all the PMAs. Implementation schedules, costs, and funding mechanisms are provided for each PMA based on the latest information available.
Information related to PMAs still in development will be reported in Annual Reports and Periodic Evaluations of the GSP. For more detailed information, refer to Chapter 9: Plan Implementation.
8.1. MANAGEMENT ACTIONS
This section identifies and describes proposed Management Actions (MA) that will be undertaken by the GSAs as an element of GSP implementation. Management Actions refer to non-structural programs or policies designed to incentivize or enforce reductions in groundwater pumping, optimize management of the Subbasin, or implement GSA management authorities. Table 8-1 shows a list of the seven MAs organized into two categories: pumping management framework (Section 8.1.1) and demand reduction strategies (Section 8.1.2). The pumping management framework provides a suite of administrative procedures, programs, and policies that describe how the GSAs will manage and monitor groundwater extractions. Implementation activities such as monitoring, annual reporting, and GSP updates are discussed in further detail in Chapter 9. Demand reduction strategies are a broad and strategic set of actions intended to reduce water demand, some of which may be incentivized by State programs or policies, or by a pumping management framework.
As described in Chapter 5, the Subbasin has experienced overdraft conditions. Per § 354.44(b)(2), the GSP must describe Projects or MAs, including a quantification of demand reduction or other methods, for the mitigation of overdraft. Several Projects identified in #25..
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-3
Revised July 2024
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earlier sections of this chapter would increase the available water in the Subbasin through increased recharge or use of alternate supplies and are expected to reduce the groundwater deficit sufficiently to achieve the Subbasin’s sustainability goal. Additionally, Supplemental Projects may contribute to further improve groundwater conditions. MAs presented in the GSP are designed for the GSA to promptly implement, while Projects are being designed and implemented. The extent and effectiveness of the MAs described in Sections 8.1.1 and 8.1.2 are not yet known, however, these programs will be developed for the GSAs to readily arrest groundwater level decline and storage deficits.
While the tools described in this section will be available for implementation Subbasin-wide, implementation may be prioritized in areas based on groundwater conditions. As such, it is anticipated that responsibility for implementing MAs will correspond with the relative contribution of each Management Area to overdraft and impacts associated with other sustainability criteria.
Multiple MAs are presented to allow the GSAs flexibility in their response to changing groundwater conditions and as data gaps and uncertainties are addressed during GSP implementation. However, it is anticipated that not all MAs will need to be applied during the GSP implementation period. In addition, implementation and/or escalation of MAs will be based on ongoing monitoring of groundwater conditions using the monitoring network.
Monitoring data will be used to assess the need for MAs in the Subbasin as a whole and in specific areas. In general, the potential for undesirable results to be approached, exceedances of minimum thresholds, and poor Project performance will serve as triggers for scaling and implementing MAs in both a targeted and proportional manner, consistent with conditions observed in the Subbasin. The full scope of MAs including program descriptions, triggering criteria, GSA authorities, costs and funding, management of water sources, monitoring processes, and applicable areas will be developed by January 31, 2026, in accordance with the resolution.
Table 8-1 lists the MAs described in the sections that follow. Each MA description is organized to address the applicable regulatory requirements:
• Management Action Description: 23 CCR §354.44(b)
• Public Notice: 23 CCR §354.44(b)(1)(B)
• Permitting and Regulatory Process: 23 CCR §354.44(b)(3) • Expected Benefits: 23 CCR §354.44(b)(4), §354.44(b)(5) • Implementation Criteria, Status, and Plan: 23 CCR §354.44(b)(1)(A); §354.44(b)(4); §354.44(b)(6)
• Water Source and Reliability: 23 CCR §354.44(b)(6)
• Legal Authority: 23 CCR §354.44(b)(7)
• Estimated Costs and Funding Plan: 23 CCR §354.44(b)(8) • Management of Groundwater Extractions and Recharge: 23 CCR §354.44(b)(9) Summary of Criteria for Project Implementation (23 CCR §354.44(b)(1)(A)) #25..
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-4
Revised July 2024
TODD GROUNDWATER
MAs described in this section will be fully developed into MA-specific policies, resolutions, and/or implementation plans during the first years of GSP implementation as discussed in the subsequent sections. These MAs will be implemented by the GSAs, indicated by forthcoming triggering criteria, to achieve and maintain long-term sustainable groundwater management across the Subbasin. The GSAs will prioritize development of the Pumping Management Framework MAs. These MAs are based on authorities granted to the GSAs through SGMA as a means to establish groundwater extraction limitations and allocations, regulate the pumping of groundwater, and implement special taxes, assessments, and user fees. The Pumping Management Framework provides the GSAs with readily implementable methods to restrict groundwater extraction throughout the entire or portions of the Subbasin. This approach will be informed by continued monitoring of groundwater conditions, using the monitoring network and methods that will be established in forthcoming MA-specific policies, resolutions, and/or implementation plans. MA’s and MAspecific policies will be developed with public participation and input from stakeholders within the Subbasin.
Table 8-1: List of Management Actions
Category Number Proponent2 Management
Action
Primary
Mechanism(s)1 Partner(s)
Pumping
Management
Framework
1 Modesto
Subbasin
GSAs
Groundwater
Allocation and
Pumping
Management
Program
Pumping
Reduction N/A
2 Modesto
Subbasin
GSAs
Groundwater
Extraction and
Surface Water
Reporting Program
Pumping
Reduction N/A
3 Modesto
Subbasin
GSAs
Groundwater
Extraction Fee
Pumping
Reduction N/A
4 Modesto
Subbasin
GSAs
Groundwater
Pumping Credit
Market and Trading
Program
Pumping
Reduction N/A
Demand
Reduction
Strategies
5 Modesto
Subbasin
GSAs
Voluntary
Conservation
and/or Land
Fallowing
Conservation/
Land Fallowing N/A
6 Modesto
Subbasin
GSAs
Conservation
Practices Conservation N/A
Dry Well
Mitigation 7
Modesto
Subbasin
GSAs
Dry Well Mitigation
Program (multiple) N/A
1The primary mechanism of the MA as conceptualized. MAs may support groundwater sustainability through multiple mechanisms during implementation.
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-5
Revised July 2024
TODD GROUNDWATER
2 It is anticipated that MAs will be implemented by the GSAs or by each GSA member agency as needed to mitigate overdraft within their jurisdictional areas and assure that the SMC adopted in Chapter 6 are met.
8.1.1. Pumping Management Framework
The Pumping Management Framework consists of four tiered MAs that would be implemented in a prioritized order as determined by the GSAs. Not all MAs may be needed – Subbasin conditions will be evaluated against the sustainability management criteria when considering whether an additional tiered MA is needed. The tiered order of implementing Pumping Management Framework MAs is:
1. Groundwater Allocation Program (MA 1) – see Section 8.1.1.1
2. Groundwater Extraction and Surface Water Accounting Reporting or Monitoring Program (MA 2) – see Section 8.1.1.2
3. Groundwater Extraction Fee (MA 3) – see Section 8.1.1.3
4. Groundwater Pumping Credit Market and Trading Program (MA 4) – see Section
8.1.1.4 8.1.1.1. Groundwater Allocation Program (Management Action 1)
8.1.1.1.1. Management Action Description
As previously discussed, the Subbasin has overdraft conditions. While the Projects identified in Section 8.2 may provide the Subbasin with water necessary to achieve the sustainability goal, management actions will be necessary. As a result, GSAs will develop a Groundwater Allocation Program (Management Action) to allocate the sustainable yield of native groundwater in the Subbasin as a policy-driven approach to arrest groundwater level declines. The GSAs are currently in the process of evaluating and developing methods for the Management Action. In accordance with the Resolution, management actions will be developed by January 31, 2026, and implemented by January 31, 2027.
Outlined here is a framework for how the Modesto Subbasin GSAs might develop and implement pumping allocations in the Subbasin based on the magnitude of projected overdraft estimated by Subbasin modeling.
There are four key steps to developing pumping allocations:
1. Identify the sources of water contributing to the native yield and estimate the quantity of native yield for the Subbasin annually (see Chapter 5 of this GSP)
2. Estimate the amount of native yield that can be used annually consistent with the Sustainable Yield
3. Allocate native yield to groundwater right holders based on:
a. Priority of right
b. Prescription
c. Other legal principles, such as reasonable use
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-6
Revised July 2024
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4. Determine how to account for new/additional supplies.
5. Develop a timeline for reducing pumping to achieve allocations over time.
The Groundwater Allocation Program is currently conceptual and actively being evaluated and developed. There are numerous ways to structure and implement an allocation program which will need to be further evaluated, developed, and refined by the GSAs prior to implementation.
8.1.1.1.2. Public Noticing
Development of a Groundwater Allocation Program requires substantial public input to understand the potential impacts of groundwater allocations and baseline needs that should be accounted for. The Modesto Subbasin GSAs anticipates that public outreach would include multiple public workshops and meetings, potential website and/or email announcements, along with other public notices for the workshops. The Groundwater Allocation Program would be circulated for public comment before finalized, though final approval of the plan would be made by the Modesto Subbasin GSAs in partnership with their respective member agencies. Implementation of the program may be confined to specific Management Areas.
8.1.1.1.3. Permitting and Regulatory Process
Development of a Groundwater Allocation Program would not require any permitting but would require consideration of existing water rights and applicable permits and regulations associated with groundwater pumping in the Subbasin.
8.1.1.1.4. Expected Benefits
Benefits to Sustainability Indicators
Sustainability indicators benefitting from the Groundwater Allocation Program include:
• Chronic lowering of groundwater levels – By reducing groundwater demand, this MA would reduce pumping and pumping-related contributions to chronic lowering of groundwater levels.
• Reduction of groundwater storage – Reduced pumping throughout the Subbasin contributes to a smaller rate of reduction in groundwater storage. • Degraded water quality – This MA does not impact this sustainability indicator. • Land subsidence – Reduced groundwater pumping may reduce the risk of subsidence associated with lowering of groundwater levels. • Depletion of interconnected surface water – Reduced pumping would reduce the potential for negative impacts to surface water flows associated with lowering groundwater levels.
Benefits to Disadvantaged Communities
Benefits to disadvantaged communities overlap with the benefits described above for sustainability indicators.
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-7
Revised July 2024
TODD GROUNDWATER
Volumetric Benefits to Subbasin Groundwater System
The volumetric benefit to the groundwater system will depend on the structure of the allocation framework and will be further studied when the program is fully developed by the GSAs.
8.1.1.1.5. Implementation Criteria, Status, and Plan
The allocation program and its criteria for implementation are still under development. It is anticipated that the program will be implemented after groundwater conditions in the Subbasin do not improve as expected in conjunction with implementation of Group 1 and Group 2 Projects. These conditions may include unstable groundwater levels, groundwater levels observed consistently nearing interim milestones, continued overdraft conditions, or increased amounts of pumping beyond the sustainable yield.
The program will be developed by January 31, 2026, and implemented by January 31, 2027, in accordance with the Resolution. The intent is that groundwater users will have a year to adapt and adjust their pumping operations as necessary to meet the requirements of the program. This Resolution was adopted by the STRGBA GSA and the Tuolumne County GSA and can be found in Appendix C. The progress of this program will be presented in Annual Reports and is expected to be completed by the forthcoming periodic evaluation.
8.1.1.1.6. Water Source and Reliability
This program does not rely on the supplies from outside the Subbasin because it is a planning effort that will result in conservation. It will support overall supply reliability by reducing overdraft in the Subbasin and moving the Subbasin towards sustainability.
8.1.1.1.7. Legal Authority
Under SGMA, GSAs have authority to establish groundwater extraction allocations.
Specifically, SGMA authorizes GSAs to control groundwater by regulating, limiting, or suspending extractions from individual wells or extractions in the aggregate.24 SGMA and GSPs adopted under SGMA cannot alter water rights.
8.1.1.1.8. Estimated Costs and Funding Plan
Development and initiation of an allocation program is expected to include upfront costs to conduct the analysis, set up the tracking system, and conduct outreach. Costs to implement the plan would depend on the level of enforcement required to achieve allocation targets and the level of outreach required annually to remind users of their allocation for a given year. The Groundwater Allocation Program would also include an annual cost that covers ongoing enforcement and implementation. Because the Groundwater Allocation Program is in the preliminary stages of development, no costs have been estimated. Sources of funding will be determined during the development of the program. 24 California Water Code § 10726.4(a)(2)
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-8
Revised July 2024
TODD GROUNDWATER
8.1.1.1.9. Management of Groundwater Extractions and Recharge The Groundwater Allocation Program would include provisions for the recovery of groundwater levels and groundwater storage during non-drought periods.
8.1.1.2. Groundwater Extraction and Surface Water Accounting Reporting or Monitoring Program (Management Action 2)
8.1.1.2.1. Management Action Description
As required in SGMA regulations, groundwater extractions have been calculated by the GSAs for this GSP using the CV2SIM-TM model (Appendix D). Presently, the GSAs intend to continue with their current data collection and groundwater extraction monitoring techniques. This MA is provided as an alternative to allow the GSAs flexibility and additional options in the event more or alternative forms of data are needed in the future.
There are several ways that this MA could be implemented by the GSAs. For this plan, two potential components have been developed which include a voluntary program and a comprehensive program. However, these two potential components are provided only as options, and likely would be implemented in Management Areas if the triggering criteria is met. If initiated, the GSAs will further develop options before implementation. • Voluntary program - This program is intended to provide an annual reporting of groundwater use by agricultural and other well owners and surface water transfers for in-lieu use. The Data Management System will be set up with appropriate input data forms for voluntary reporting of groundwater use as well as other relevant information, such as irrigated acreage, crop type, and sources of water. • Comprehensive program - This program is a more robust and elaborate strategy for reporting groundwater extraction that is intended to cover all groundwater users and surface water transfers for in-lieu use. Implementation of this program may incorporate satellite imagery to estimate the evapotranspiration of crops by parcel.
Additionally, this strategy can take the form of requiring the installation of meters at all agricultural and other non-exempt wells.
The Groundwater Extraction Reporting Program would exclude de minimis extractors (domestic use of 2 AF or less per year) but may also include surface water accounting in the Subbasin due to the amount of surface water transferred from MID and OID to the NDE area used for in-lieu and direct recharge.
8.1.1.2.2. Public Noticing
Successful implementation of either component of this program would require the support and coordination of member agencies, well owners throughout the Subbasin, and other stakeholders.
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-9
Revised July 2024
TODD GROUNDWATER
The voluntary program would be noticed via public outreach and education about the logistics of participating in the program as well as the purpose and importance of doing so.
Outreach may include public notices, meetings, potential website presence and email announcements.
The comprehensive program would involve more of a robust planning process. The Modesto Subbasin GSAs anticipate that public outreach and education on the potential structure of this program would be necessary, including public notices, meetings, potential website presence and email announcements.
8.1.1.2.3. 8.1.1.2.3 Permitting and Regulatory Process
The Groundwater Extraction Reporting Program is not expected to require any permitting or regulatory involvement.
8.1.1.2.4. Expected Benefits
Benefits to Sustainability Indicators
Direct measurement of groundwater extractions may not have direct impacts on sustainability indicators but would improve future water budget and sustainable yield refinement. The accurate and widespread collection of extraction data would provide the Modesto Subbasin GSAs with critical information to assist in management of the Subbasin, development of additional MAs, and monitoring the success of the GSP against the sustainable management criteria.
Benefits to Disadvantaged Communities
The Groundwater Extraction Reporting Program would exclude de minimis extractors, including those in disadvantaged communities.
Volumetric Benefits to Subbasin Groundwater System
Additional measurements and reporting of groundwater extractions would provide a higher resolution of groundwater use in the Subbasin. The addition of these data would provide the GSAs with the ability to further improve current and projected water budgets and basin storage calculations.
8.1.1.2.5. Implementation Criteria, Status, and Plan
The Modesto Subbasin GSAs will develop Annual Reports to evaluate progress toward meeting the sustainability goal. If monitoring efforts demonstrate that the Projects and MAs being implemented are not effective in achieving stated targets, the GSAs will convene a working group to evaluate the implementation of additional supply-side and demand-side actions, such as the implementation of tiered approaches of the Water Accounting Framework.
8.1.1.2.6. Water Source and Reliability
This management action is an accounting and monitoring program and as such does not rely on water availability. The Groundwater Extraction and Surface Water Accounting Reporting or Monitoring Program is a planning effort that will support overall supply reliability by #25..
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-10
Revised July 2024
TODD GROUNDWATER
providing additional information for better management of the Subbasin and moving the Subbasin towards sustainability.
8.1.1.2.7. Legal Authority
SGMA provides GSAs with the authority to regulate the pumping of groundwater in order to stabilize the region’s water supply and recharge aquifers. As such, the GSAs have the authority to: “control groundwater extractions by regulating, limiting, or suspending extractions from individual groundwater wells or extractions from groundwater wells in the aggregate, . . . or otherwise establishing groundwater extraction allocations” (CWC, §10726.4(a)).
8.1.1.2.8. Estimated Costs and Funding Plan
The estimated costs for the Groundwater Extraction Reporting Program would vary depending on the components that are implemented:
• The costs for the voluntary component are minimal and include:
o One-time costs for initial public outreach and setup of tools and procedures to receive and compile voluntary submitted data
o Ongoing annual administrative costs to review and compile the voluntarily submitted data as well as continued outreach
• The costs for implementing the more comprehensive program would be larger as they may include:
o One-time costs to develop a remote sensing system or a more comprehensive program to track and monitor well meters, in addition to public outreach
o Ongoing annual costs to administer the program, whether via purchase and analysis of the latest remote sensing data or to track and collect data from well meters
The Groundwater Extraction Reporting Program is in the preliminary stages of discussion and possible consideration. Therefore, no costs have been estimated for its development and implementation. Such costs would be developed should the Modesto Subbasin GSAs decide to pursue a program in the future.
8.1.1.2.9. Management of Groundwater Extractions and Recharge This program would directly develop and expand the reporting of groundwater extractions, including during both dry and wet periods, to support better management of the Subbasin.
8.1.1.3. Groundwater Extraction Fee (Management Action 3)
8.1.1.3.1. Management Action Description
This strategy entails setting up a Groundwater Extraction Fee structure for each groundwater user. The fee structure could work in conjunction with the groundwater allocation and reporting programs, such that groundwater use above a certain allocation can #25..
- 2036 -
Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-11
Revised July 2024
TODD GROUNDWATER
be subject to a fee. This strategy could be implemented within areas of the Subbasin where triggering criteria has been met, as needed to achieve the sustainability goals.
Revenue from these fees could then be used to pay for a variety of activities, such as the construction of water infrastructure, protection of groundwater, proper construction and destruction of wells to prevent contamination, groundwater recharge and recovery projects, purchase of imported water or other supplies to replenish the groundwater basin, and/or purchasing and permanent fallowing of marginally productive agricultural lands dependent on groundwater. Fees could also be used to pay for administration, enforcement, and implementation of the MA.
8.1.1.3.2. Public Noticing
Development of a Groundwater Extraction Fee would require substantial public input to understand the potential impacts and needs that should be considered. The Modesto Subbasin GSAs anticipate that public outreach would include multiple public workshops and meetings, potential website and/or email announcements, along with other public notices for the workshops. The Groundwater Extraction Fee framework would be circulated for public comment before being finalized, though final approval of the plan would be made by the Modesto Subbasin GSAs in partnership with their member agencies.
Additional noticing for the public would be conducted consistent with permitting requirements in the case of the enactment of fees. GSA outreach may include public notices, meetings, website or social media presence, and email announcements. Prior to implementing any fee or assessment program, the GSAs would complete a rate assessment study or other analysis if required by the regulatory requirements.
Per Water Code §10730, prior to imposing or increasing a fee, a groundwater sustainability agency shall hold at least one public meeting, at which oral or written presentations may be made as part of the meeting. Notice of the time and place of the meeting shall include a general explanation of the matter to be considered and a statement that the data required by this section is available. The notice shall be provided by publication pursuant to §6066 of the Government Code, by posting notice on the Internet Web site of the groundwater sustainability agency, and by mail to any interested party who files a written request with the agency for mailed notice of the meeting on new or increased fees. A written request for mailed notices shall be valid for one year from the date that the request is made and may be renewed by making a written request on or before April 1 of each year. At least 20 days prior to the meeting, the groundwater sustainability agency shall make available to the public data upon which the proposed fee is based. Any action by a groundwater sustainability agency to impose or increase a fee shall be taken only by ordinance or resolution.
8.1.1.3.3. Permitting and Regulatory Process
Fees imposed pursuant to Water Code §10730 shall be adopted in accordance with all applicable laws.
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-12
Revised July 2024
TODD GROUNDWATER
A fee or charge shall not be extended, imposed, or increased by any agency unless it meets all of the following requirements:
• Revenues derived from the fee or charge shall not exceed the funds required to provide the property related service.
• Revenues derived from the fee or charge shall not be used for any purpose other than that for which the fee or charge was imposed.
• The amount of a fee or charge imposed upon any parcel or person as an incident of property ownership shall not exceed the proportional cost of the service attributable to the parcel.
• No fee or charge may be imposed for a service unless that service is actually used by, or immediately available to, the owner of the property in question. Fees or charges based on potential or future use of a service are not permitted. Standby charges, whether characterized as charges or assessments, shall be classified as assessments and shall not be imposed without compliance with Section 4 of the California Water Code (Water Code §10730).
• No fee or charge may be imposed for general governmental services including, but not limited to, police, fire, ambulance or library services, where the service is available to the public at large in substantially the same manner as it is to property owners.
8.1.1.3.4. Expected Benefits
Benefits to Sustainability Indicators
Collection of groundwater extraction fees incentivizes the use of supplemental or alternative water supplies where fees can also fund activities/projects that increase groundwater supplies, such as groundwater recharge, thus reducing declines in groundwater elevations and groundwater storage. Other sustainability indicators benefitting from the Groundwater Extraction Fee program include:
• Degraded water quality – Funded activities and projects can also reduce degradation of groundwater quality (such as proper construction/destruction of wells to prevent contamination).
• Land subsidence – Reduced groundwater pumping would reduce the risk of subsidence associated with lowering of groundwater levels. • Depletion of interconnected surface water – Reduced pumping would reduce the potential for negative impacts to surface water flows associated with lowering groundwater levels.
Benefits to Disadvantaged Communities
Any fees would comply with CWC, §10730(a) and shall exclude de minimis extractors from fees, where appropriate.
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-13
Revised July 2024
TODD GROUNDWATER
Volumetric Benefits to Subbasin Groundwater System
The volumetric benefit to the groundwater system would depend on the framework of the fee implemented and would be further studied as the Groundwater Extraction Fee framework was developed by the GSAs.
8.1.1.3.5. Implementation Criteria, Status, and Plan
The Modesto Subbasin GSAs will develop Annual Reports to evaluate progress toward meeting the sustainability goal. If monitoring efforts demonstrate that the Projects and MAs being implemented are not effective in achieving stated targets, the GSAs will convene a working group to evaluate the implementation of additional supply-side and demand-side actions, such as the implementation of tiered approaches in the Water Accounting Framework.
8.1.1.3.6. Water Source and Reliability
The Groundwater Extraction Fee program will apply in both drought and non-drought periods.
8.1.1.3.7. Legal Authority
The GSAs possess the legal authority to implement special taxes, assessments, and user fees within the Project proponent service area or area of Project benefit. Fees imposed include fixed fees and fees charged on a volumetric basis, including, but not limited to, fees that increase based on the quantity of groundwater produced annually, the year in which the production of groundwater commenced from a groundwater extraction facility, and impacts to the basin.
8.1.1.3.8. Estimated Costs and Funding Plan
While there are certain administrative costs anticipated with the development and implementation of a Groundwater Extraction Fee, the Groundwater Extraction Fee itself is a potential mechanism to fund the costs of groundwater management. This includes, but is not limited to, the following:
• Administration, operation, and maintenance, including a prudent reserve • Acquisition of lands or other property, facilities, and services • Supply, production, treatment, or distribution of water • Other activities necessary or convenient to implement the plan
8.1.1.3.9. Management of Groundwater Extractions and Recharge This program, in conjunction with the Groundwater Extraction Reporting Program, would directly develop and expand the reporting of groundwater extractions, including during both drought and non-drought periods, to support better management of the Subbasin. #25..
- 2039 -
Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-14
Revised July 2024
TODD GROUNDWATER
8.1.1.4. Groundwater Pumping Credit Market and Trading Program (Management Action 4)
8.1.1.4.1. Management Action Description
Groundwater credit markets and trading programs can be used to exchange and trade the allocation of groundwater use by each landowner within the Subbasin. This strategy is contingent upon implementation of the groundwater reporting and allocation programs (MAs 1 and 2), so that the credit and trading market can monitor the exchange of groundwater allocations among the landowners and/or the GSAs. Should the Modesto Subbasin GSAs decide to pursue a program in the future, they would seek guidance from agencies with experience in water markets to identify options for communications and outreach with stakeholders, program design, and mechanisms to ensure that nonparticipating stakeholders are not adversely impacted by the program.
8.1.1.4.2. Public Noticing
Development and implementation of a Groundwater Pumping Credit Market and Trading Program would require substantial public input to understand the potential impacts and nuances of implementing such a program. The Modesto Subbasin GSAs anticipate that public outreach would include multiple public workshops and meetings, potential website and/or email announcements, along with other public notices for the workshops. The program plan would be circulated for public comment before being finalized, though final approval of the plan would be made by the Modesto Subbasin GSAs in partnership with their member agencies.
8.1.1.4.3. Permitting and Regulatory Process
Permitting and other regulatory compliance issues will be identified and addressed when the program is being further explored and developed, consistent with SGMA §10726.4 (a) (3 & 4).
8.1.1.4.4. Expected Benefits
Benefits to Sustainability Indicators
Sustainability indicators benefitting from the Groundwater Pumping Credit Market and Trading Program include:
• Chronic lowering of groundwater levels – By reducing groundwater demand, this MA would reduce pumping and pumping-related contributions to chronic lowering of groundwater levels.
• Reduction of groundwater storage – Reduced pumping throughout the Subbasin contributes to a smaller rate of reduction in groundwater storage. • Degraded water quality – This MA does not address this sustainability indicator. • Land subsidence – Reduced groundwater pumping would reduce the risk of subsidence associated with lowering of groundwater levels. #25..
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-15
Revised July 2024
TODD GROUNDWATER
• Depletion of interconnected surface water – Reduced pumping would reduce the potential for negative impacts to surface water flows associated with lowering groundwater levels.
Benefits to Disadvantaged Communities
Benefits to disadvantaged communities overlap with the benefits described above for sustainability indicators.
Volumetric Benefits to Subbasin Groundwater System
The volumetric benefit to the groundwater system will depend on the framework of the credit market and trading program implemented and would be further studied when the program was developed by the GSAs.
8.1.1.4.5. Implementation Criteria, Status, and Plan
The Modesto Subbasin GSAs will develop Annual Reports to evaluate progress toward meeting the sustainability goal. If monitoring efforts demonstrate that the Projects and MAs being implemented are not effective in achieving stated targets, the GSAs will convene a working group to evaluate the implementation of additional supply-side and demand-side actions, such as the implementation of tiered approaches in the Pumping Management Framework.
8.1.1.4.6. Water Source and Reliability
The Subbasin area will be the source of groundwater and will be limited by the hydrology of the region.
8.1.1.4.7. Legal Authority
SGMA §10726.4 (a) (3 & 4) provide legal authority for groundwater transfer and accounting programs.
8.1.1.4.8. Estimated Costs and Funding Plan
The Groundwater Pumping Credit Market and Trading Program is in preliminary stages of discussion and possible consideration. Therefore, no costs have been estimated for its development and implementation. Such costs would be developed should the Modesto Subbasin GSAs decide to pursue a program in the future. Costs would likely include additional staffing required to administer the program and would be borne by the participants.
8.1.1.4.9. Management of Groundwater Extractions and Recharge The implementation of a Groundwater Pumping Credit Market and Trading Program will include provisions for the recovery of groundwater levels and groundwater storage during non-drought periods.
8.1.2. Demand Reduction Strategies
Demand reduction strategies will be developed to manage the agricultural and urban water demands in the Subbasin. These strategies could be implemented in the form of voluntary #25..
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-16
Revised July 2024
TODD GROUNDWATER
conservation and/or land fallowing (see Section 8.1.2.1) or other urban and agricultural conservation practices (see Section 8.1.2.2). While conservation practices are expected to be implemented throughout GSP implementation, specific strategies are in preliminary stages of discussion and possible consideration. Should the Modesto Subbasin GSAs decide to pursue a program in the future, the program would be implemented as necessary in a targeted and proportional manner consistent with conditions observed in the Subbasin.
Similarly, the Conservation Practices MA is expected to be implemented adaptively.
8.1.2.1. Voluntary Conservation and/or Land Fallowing (Management Action 5)
8.1.2.1.1. Management Action Description
Voluntary Conservation and/or Land Fallowing covers several strategies that can be designed to achieve both temporary and permanent water demand reduction. Should the Modesto Subbasin GSAs decide to pursue such strategies, this MA would assess options and develop a program to incentivize voluntary conservation and/or fallowing strategies in close coordination and collaboration with the landowners. Examples of this strategy could include repurposing of lands growing lower value crops. These lands could be dry farmed, fallowed in rotation, or used for recreation, habitat restoration, groundwater recharge, or solar power generation. This MA would also try to prioritize those lands that are more favorable for groundwater recharge projects.
Temporary or permanent land fallowing could also be combined with recharge projects through the application of surplus surface water supplies to the fallowed lands.
8.1.2.1.2. Public Noticing
A successful Voluntary Conservation and/or Land Fallowing program will require a comprehensive and strategic outreach effort, including multiple public workshops and meetings, potential website and/or email announcements, along with other public notices for the workshops. The outreach will be targeted to both potential participants of the program (landowners) as well as other stakeholders who may be impacted by changes to land and water use.
8.1.2.1.3. Permitting and Regulatory Process
Preparation of a CEQA evaluation for a fallowing program will identify potential environmental impacts and identify feasible alternatives or feasible mitigation measures.
Establishment of a voluntary land fallowing program is expressly authorized under SGMA (CWC, §10726.2(c)). The fallowing program, including program standards, will be developed and undergo CEQA review as necessary.
8.1.2.1.4. Expected Benefits
Benefits to Sustainability Indicators
Sustainability indicators that could benefit from Voluntary Conservation and/or Land Fallowing include:
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Modesto Subbasin GSP
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Revised July 2024
TODD GROUNDWATER
• Chronic lowering of groundwater levels – By reducing groundwater demand, this MA would reduce pumping and pumping-related contributions to chronic lowering of groundwater levels.
• Reduction of groundwater storage – Reduced pumping throughout the Subbasin contributes to a smaller rate of reduction in groundwater storage. • Land subsidence – Depending on the location of land fallowing or conservation, reduced pumping stress on local aquifer(s) may reduce the potential for subsidence. • Depletion of interconnected surface water – Reduced pumping would reduce the potential for negative impacts to surface water flows associated with lowering groundwater levels.
Benefits to Disadvantaged Communities
Benefits to disadvantaged communities overlap with the benefits described above for sustainability indicators. Land repurposing can also provide other ancillary benefits to local communities, such as recreation.
Volumetric Benefits to Subbasin Groundwater System
The volumetric benefit to the groundwater system would depend on the extent to which a Voluntary Conservation and/or Land Fallowing program is adopted and would be further studied when the program is implemented by the GSAs.
8.1.2.1.5. Implementation Criteria, Status, and Plan
Temporary fallowing is a quick way to reduce demand with no capital costs or infrastructure needed. Because it is inexpensive, it can be implemented earlier and quicker while other long-term solutions like land repurposing are investigated. The Modesto Subbasin GSAs may explore options for encouraging voluntary and temporary fallowing during GSP implementation while developing a more structured program and exploring funding opportunities.
The Voluntary Conservation and/or Land Fallowing program is in preliminary stages of discussion and consideration. Should the Modesto Subbasin GSAs decide to pursue a program in the future, the program would be implemented as necessary in a targeted and proportional manner consistent with conditions observed in the Subbasin. To maximize recharge potential, the preservation lands that are more favorable for recharge projects could be prioritized while developing this MA. The implementation timeline has yet to be determined but will be provided in GSP Annual Reports and five-year updates when known.
Any future changes in implementation would be communicated with the public and other agencies and would be documented in GSP Annual Reports and five-year updates.
8.1.2.1.6. Water Source and Reliability
This program does not rely on the supplies from outside the Subbasin because it is a planning effort that will result in conservation. It will support overall supply reliability by reducing overdraft in the Subbasin and moving the Subbasin towards sustainability. #25..
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-18
Revised July 2024
TODD GROUNDWATER
8.1.2.1.7. Legal Authority
The GSAs have authority to “provide for a program of voluntary fallowing of agricultural lands or validate an existing program” (CWC, §10726.2(c)).
This MA carries forward the policy of the state and satisfies SGMA requirements by establishing a voluntary program that encourages water within the Subbasin to be dedicated to beneficial uses of water in a manner designed to achieve the sustainability goals and to protect against undesirable results.
8.1.2.1.8. Estimated Costs and Funding Plan
The Voluntary Conservation and/or Land Fallowing program is in preliminary stages of discussion and possible consideration. Therefore, no costs have been estimated for its development and implementation. Such costs would be developed, should the Modesto Subbasin GSAs decide to pursue a program in the future. Separately, multiple funding programs exist as a potential source of revenue for individual landowners looking at options for land repurposing, including (EDF, 2021):
• Mitigation or Conservation Banks
• Conservation Easements
• Solar Rentals
• Grazing Leases
• Converting to Low Water Intensity Crops
• Federal and State Grant Funding Programs
8.1.2.1.9. Management of Groundwater Extractions and Recharge This MA encourages the conservation of water; this will be applicable during both drought and non-drought conditions.
8.1.2.2. Conservation Practices (Management Action 6)
8.1.2.2.1. Management Action Description
This MA would create a program to support the use of conservation practices in both urban and agricultural sectors.
Urban water suppliers are already obligated to consider demand reduction and conservation efforts during dry periods. These demand MAs are described in their respective Urban Water Management Plans (UWMPs). These include:
• City of Modesto Urban Water Management Plan (West Yost Associates, 2016b) o https://www.modestogov.com/860/Urban-Water-Management-Plan • Modesto Irrigation District Urban Water Management Plan (West Yost Associates, 2021)
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-19
Revised July 2024
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o https://wuedata.water.ca.gov/public/uwmp_attachments/2173444449/R% 20-%20418%20-%20City%20of%20Modesto_MID%20-
%20Final%202020%20UWMP%20%20-%2006-23-21.pdf
• City of Riverbank Urban Water Management Plan (KSN Inc, 2016) o https://www.riverbank.org/610/Urban-Water-Management-Plan-WSCP • City of Oakdale Urban Water Management Plan (MCR Engineering, 2015) o https://cadwr.app.box.com/s/hg3k8bc9vuka689jkh1x4f9i1n58ey9a/file/521 558561581
• City of Waterford (covered under City of Modesto 2015 UWMP) In addition, SB 606 and AB 1668, both signed into law in May 2018, are laws that introduce conservation mandates that will cap indoor residential use and set a target for efficient outdoor landscape irrigation based on local climate and size of landscaped areas. Urban water suppliers will be required to report on progress to meeting urban water use objectives beginning in 2023 and comply with them beginning in 2028.
In addition to meeting urban water use objectives, this MA could include changing standards for storm drainage so that storm flows do not discharge straight to a river, creek, or canal, as contemplated by the City of Modesto as a potential Group 3 Project. This would help increase the sustainability footprint of the City of Modesto as it grows. Currently approximately 36% of the City of Modesto area drains to a river or canal, while approximately 64% is captured for local recharge. If the City of Modesto adopts new Storm Drain Standards, 100% of runoff from newly developed areas would reach a retention system and contribute to recharge.
Agricultural water suppliers serving more than 25,000 irrigated acres must adopt an Agricultural Water Management Plan (AWMP) that include reports on the implementation status of specific Efficient Water Management Practices required by the Water Conservation Act of 2009 (SB X7-7). Agencies that have developed AWMPs include:
• Modesto Irrigation District Agricultural Water Management Plan o https://www.mid.org/water/awmp/default.html
• Oakdale Irrigation District Agricultural Water Management Plan o https://wuedata.water.ca.gov/public/awmp_attachments/3350354850/OID %202020%20AWMP%20FINAL%20210323.pdf
The Modesto Subbasin GSAs may choose to evaluate the existing UWMPs and AWMPs in the Subbasin and either expand upon minimum requirements to increase the impact of such programs or implement similar conservation practice programs in other areas of the Subbasin that may not be covered under an UWMP or AWMP.
Notably, conservation practices must be considered in the greater context of the Subbasin water budget, especially at the nexus between on-farm water use and groundwater sustainability. In areas where groundwater is the primary or sole water supply, conservation #25..
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-20
Revised July 2024
TODD GROUNDWATER
practices that reduce water demand may also reduce groundwater consumption, but conservation practices may also have unintended consequences that impede water conservation and sustainable groundwater management. Some of these consequences directly result from irrigation efficiency improvements: applying less water to an area and reducing the gap between irrigation and consumptive use also reduces deep percolation and seepage to the groundwater system. Other consequences may stem from behavioral responses and changes in irrigation resulting from these technologies and policies. If less water can be used to produce the same amount of a crop product, growers may be inclined to use the same amount of water and produce more (Lankford, et al., 2020). Additional considerations on the promises, pitfalls, and paradoxes of irrigation efficiency in water management planning are described by Lankford et al. (2020).
Further details on any expansion of the Conservation Practices program are preliminary as of the time of publishing and would need to be developed and refined further during GSP implementation.
8.1.2.2.2. Public Noticing
The Modesto Subbasin GSAs anticipates that public outreach and education on the potential structure of the Conservation Practices program, as well as feasible monitoring and enforcement mechanisms, would be necessary to enable a successful program. Outreach may include public notices, meetings, potential website presence and email announcements. Initial program implementation would likely focus on voluntary compliance while the GSAs or GSAs member agencies consider the necessary elements to begin enforcing the program potentially by 2027 (five years after adopting and submitting the GSP). This date is contingent upon monitoring results and achievement of Interim Milestones.
8.1.2.2.3. Permitting and Regulatory Process
Development of a Conservation Practices program is not a Project as defined by the California Environmental Quality Act (CEQA) and National Environmental Policy Act (NEPA) and would therefore not trigger either.
8.1.2.2.4. Expected Benefits
Benefits to Sustainability Indicators
Sustainability indicators benefitting from Conservation Practices include:
• Chronic lowering of groundwater levels – By reducing groundwater demand, this MA would reduce pumping and pumping-related contributions to chronic lowering of groundwater levels.
• Reduction of groundwater storage – Reduced pumping throughout the Subbasin contributes to a smaller rate of reduction in groundwater storage. • Degraded water quality – This MA does not address this sustainability indicator. • Land subsidence – Depending on the location of Conservation Practices, reduced pumping stress on local aquifer(s) may reduce the potential for subsidence. #25..
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-21
Revised July 2024
TODD GROUNDWATER
• Depletion of interconnected surface water – Reduced pumping would reduce the potential for negative impacts to surface water flows associated with lowering groundwater levels.
Benefits to Disadvantaged Communities
Benefits to disadvantaged communities overlap with the benefits described above for sustainability indicators. Depending on how they are structured, urban conservation programs may also provide a financial benefit to individual users who reduce their water consumption, either via a lower water bill or reduced demand on a domestic well.
Volumetric Benefits to Subbasin Groundwater System
The volumetric benefit to the groundwater system will depend on the extent to which a Conservation Practices program is implemented and will be further studied if a program is developed by the GSAs.
8.1.2.2.5. Implementation Criteria, Status, and Plan
The implementation timeline has yet to be determined but will be provided in GSP Annual Reports and five-year updates when known. Any future changes in implementation would be communicated with the public and other agencies and would be documented in GSP Annual Reports and five-year updates.
8.1.2.2.6. Water Source and Reliability
This MA does not rely on the supplies from outside the Subbasin because it is a planning effort that will result in conservation benefits. It will support overall supply reliability by reducing groundwater demand in the Subbasin and moving the Subbasin towards sustainability.
8.1.2.2.7. Legal Authority
The Modesto Subbasin GSAs have the authority to develop a Conservation Practices program and may perform implementation and enforcement of practices via implementation of fees for noncompliance or through metering or other methods to quantify groundwater use. Mechanisms for enforcement would be outlined in the Conservation Practices program once developed and are expected to be enforced by the Modesto Subbasin GSAs and/or member agencies.
8.1.2.2.8. Estimated Costs and Funding Plan
Costs for UWMP and AWMP report preparation and submittals are ongoing for urban and agricultural water suppliers, respectively. Any future costs related to additional programming or program enforcement have yet to be developed.
8.1.2.2.9. Management of Groundwater Extractions and Recharge This MA encourages the conservation of water; this will be applicable during both wet and dry conditions.
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-22
Revised July 2024
TODD GROUNDWATER
8.1.3. Dry Well Mitigation (Management Action 7)
This MA will develop and implement a well mitigation program to address and mitigate impacts from groundwater level declines that may occur when water levels drop below the MTs.
Management Action Description
This Dry Well Mitigation Program provides mitigation measures for water supply wells that have experienced adverse impacts due to declining groundwater levels, as described in Section 6.3.3.1. It will cover eligible mitigation claims accrued after January 31, 2022, the date the original GSP was adopted. This program will specify mitigation measures, organization of the program, estimated costs and means of funding. As stated in the Resolution, this program will be developed and implemented no later than January 31, 2026, and will continue into perpetuity unless otherwise directed by the STRGBA GSA.
Dry Well Mitigation Program Measures
This Dry Well Mitigation Program will describe potential short-term and long-term measures to mitigate impacts to domestic wells. Mitigation measures may include, but are not limited to:
• Short-term emergency solutions, such as delivery of bottled water and/or water tanks. (Considered only for temporary mitigation while other actions are in progress.)
• Setting well pump at deeper depths, replacement of well pump, well rehabilitation or replacement of wells (including abandonment of existing wells). • Connection to a public water system.
Long-term management actions and projects may include, but are not limited to:
• Reduction of groundwater demand around communities reliant on groundwater for drinking water, e.g., create buffer zones for drinking water users. • Support for managed aquifer recharge near affected communities.
Development of the Dry Well Mitigation Program
The Dry Well Mitigation Program will be developed with potential elements including:
• One or more committees to develop and implement the program on behalf of the
STRGBA GSA,
• A fund to support dry well mitigation and implementation of the program, • Public outreach to publicize this program,
• Definition of eligibility criteria to guide well owners in considering a claims application for mitigation, such as well failure or diminished well yield due to groundwater levels declining below MTs,
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Revised July 2024
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• Definition of an application process, including application submittal, review and investigation of an application, decision-making, reporting, and agreements for approved applications.
8.1.3.1. Public Notice
Public outreach and notice will be included in the Dry Well Mitigation Program. In addition, it is anticipated that the program plan will be circulated for public comment prior to being finalized, although final approval of the plan will be made by STRGBA GSA.
8.1.3.2. Permitting and Regulatory Process
Permitting and other regulatory compliance issues will be identified as the program is developed, consistent with CWC §10726.4 (a) (3 & 4).
8.1.3.3. Expected Benefits
Benefits to Sustainability Indicators
This Management Action provides a program for direct mitigation of impacts to domestic wells during early years of GSP implementation.
Benefits to Disadvantaged Communities
The Dry Well Mitigation Program provides significant direct benefits to disadvantaged communities who rely on groundwater and supply wells and additional potential benefits for other sustainability indicators (see analyses in Section 6.3.3.2).
Volumetric Benefits to Subbasin Groundwater System
The Dry Well Mitigation Program provides benefits to users of the groundwater basin storage who rely on reliability of groundwater and supply wells.
8.1.3.4. Implementation Criteria, Status, and Plan
These components are described in Section 8.1.3. The Dry Well Mitigation Program will be developed and implemented no later than January 31, 2026, and will continue into perpetuity unless otherwise directed by the STRGBA GSA.
8.1.3.5. Water Source and Reliability
This program provides mitigation measures for domestic water supply wells that have experienced adverse impacts due to declining groundwater levels occurring after January 31, 2022, the date of adoption of the Joint GSP. It supports reliable access to groundwater in response to eligible claims at the discretion of the STRGBA GSA.
8.1.3.6. Legal Authority
Legal authority for implementation of this action is provided by STRGBA GSA Resolution No. 2024-XX.
8.1.3.7. Estimated Costs and Funding Plan
As stated in the Resolution, the GSA is establishing baseline funding amounting to $300,000 no later than January 31, 2026.
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STRGBA GSA/Tuolumne GSA 8-24
Revised July 2024
TODD GROUNDWATER
8.1.3.8. Management of Groundwater Extractions and Recharge This program involves mitigation for well failures or diminished well yields of existing domestic water supply wells. It is not intended to provide a net increase beyond original well yield. Accordingly, no long-term net increase in groundwater extractions is planned as part of this program. Long-term management actions and projects associated with this program may include support for managed aquifer recharge or in lieu recharge near impacted wells or areas vulnerable to wells going dry.
8.2. PROJECTS OVERVIEW
This section describes the Projects that are in place, planned, or may be considered for implementation in the Subbasin. In accordance with 23 CCR §354.44, Projects were developed to help achieve and maintain the Subbasin sustainability goal by 2042 and avoid undesirable results over the GSP planning and implementation horizon. Broadly, Projects provide tools that can be used to achieve and maintain groundwater sustainability.
Projects were developed to be aligned with State grant program preferences and the Governor’s Water Action Plan. Projects, where possible, were designed to provide benefits to surface water users, groundwater users, and disadvantaged communities (DACs) and embrace innovation and new technologies. The GSP prioritizes Projects that contain multibenefit approaches to address multiple needs and expand the utilization of natural infrastructure, including the Subbasin itself for storage and the natural waterways and floodplains as recharge areas. Projects that are located in targeted areas to achieve maximum recharge results and address water level decline are a point of emphasis for the Subbasin to achieve its sustainability goal. Additionally, the PMAs prioritize coordination among users, STRBGA GSA member agencies, and neighboring basins to improve the region's groundwater conditions while achieving sustainability.
Projects were identified in the Modesto Subbasin through a several-month process involving the STRGBA GSA Technical Advisory Committee. Project information was provided by the STRGBA GSA and compiled into a draft list. The initial set of projects was reviewed further, and a final list of 13 possible projects was identified for inclusion in the GSP. The project types presented in the GSP include direct and in-lieu recharge, water recycling, and improvements to metering infrastructure. Projects are classified into three categories based on project status:
• Group 1 – Projects that are in place and will continue to be implemented and expanded upon by specific participating agencies within the Subbasin to support groundwater management and GSP implementation.
• Group 2 – Projects that are still in the development phase but are anticipated to be implemented shortly after adoption of the GSP. Group 2 Projects are expected to greatly contribute to achieving the Subbasin’s sustainability goal and continue supporting GSP implementation efforts. Project statuses and implementation schedules are presented in Sections 8.2.2 and 8.2.3 of the GSP. #25..
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Revised July 2024
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• Supplemental Projects – Projects which have been identified for consideration in the Subbasin for future GSA activities. Supplemental Projects are not currently planned for implementation; however, the GSAs will continue assessing their feasibility to support local goals. Should these Projects be implemented, they would support Group 1 and Group 2 Projects’ benefits in attainment of SMCs and support the sustainability goal.
Group 1 and Group 2 Projects are summarized in Section 8.3: Projects Developed for Implementation. These Projects were analyzed as part of scenarios using the C2VSimTM model to estimate their benefit to the groundwater system over the projected planning period. The results of the model scenarios are discussed in Section 8.5: Plan for Achieving Sustainability.
Supplemental Projects are summarized in Section 8.4: Supplemental Projects. These Projects are currently not evaluated in detail and are described at a more general level, reflecting their conceptual nature and planning status. Additional feasibility studies and details for these Projects may be developed in the future and their progress will be reported in Annual Reports and Periodic Evaluations should they be implemented.
The Projects identified in this section will be either directly funded and implemented by the Project Proponent or will be subject to grant funding requests through state and federal funding opportunities. Project proponents are listed in Table 8-2.
Each Project proponent will manage the permitting and oversee implementation for their own Projects. Inclusion of Projects in this GSP does not forego any obligations regarding individual Project implementation under local, state, or federal regulatory programs. While the GSAs do have an obligation to oversee progress towards groundwater sustainability, they are not the primary regulator of land use, water quality, or environmental Project compliance. It is the responsibility of the Project-implementing agencies to ensure that they are collaborating with outside trustees and regulatory agencies to ensure the Projects are in compliance with all applicable laws and permitting requirements.
The GSAs will collaborate with Project proponents and partners to track progress and support Project implementation. The implementation of PMAs will be enhanced by the development of policies and guidance by the GSAs that consider applicable SMCs and establish PMA-specific monitoring and reporting frameworks to facilitate adaptive management. GSP implementation will include guidelines and protocols to coordinate implementation of Projects in such a way that sustainability is achieved through coordinated efforts between the GSAs, Project proponents and sponsors, and other stakeholders.
Table 8-2 shows the Projects within their respective groups. This represents an initial list of Projects; additional Projects may be added during GSP implementation, with updates included in Annual Reports and the Periodic Evaluations. Detailed descriptions of each Project are provided in Sections 8.3 [Projects Developed for Near-Term Implementation (Groups 1 and 2)] and Section 8.4 [Supplemental Projects]. #25..
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Revised July 2024
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Table 8-2: List of Projects
Number Proponent(s) Project Name Primary Mechanism(s)1 Partner(s) Group Included in
Modeling
Scenario
Urban Projects
1 City of
Modesto
Growth Realization of Surface Water
Treatment Plant Phase II
In-Lieu Groundwater
Recharge N/A 1 Baseline
2 City of
Modesto
Advanced Metering Infrastructure
Project (AMI) Conservation N/A 1 ×
3 City of
Modesto
Storm Drain Cross Connection Removal
Project Stormwater Capture N/A 2 ×
4 City of
Waterford
Project 3: Waterford/Hickman Surface
Water Pump Station and Storage Tank
In-Lieu Groundwater
Recharge
City of
Modesto,
MID
2 ×
In-Lieu & Direct Recharge Projects
5 Non-District
East Areas
Modesto Irrigation District In-lieu and
Direct Recharge Project
Direct and In-Lieu
Groundwater Recharge Modesto ID 2 ×
6 NDE Areas Oakdale Irrigation District In-lieu and
Direct Recharge Project
Direct and In-Lieu
Groundwater Recharge OID 2 ×
Flood Mitigation Projects
7 NDE Areas Tuolumne River Flood Mitigation and
Direct Recharge Project
Direct Groundwater
Recharge Modesto ID 2 ×
8 NDE Areas Dry Creek Flood Mitigation and Direct
Recharge Project
Direct Groundwater
Recharge
Stanislaus
County 2 ×
Supplemental Projects
9 NDE Areas Stanislaus River Flood Mitigation and
Direct Recharge Project
Direct Groundwater
Recharge
Stanislaus
County 3
10 City of
Modesto
Retention System Standards
Specifications Update Groundwater Recharge N/A 3
11 NDE Areas Recharge Ponds Groundwater Recharge N/A 3
12 City of Oakdale OID Irrigation and Recharge to Benefit City of Oakdale
Direct or In-Lieu
Groundwater Recharge N/A 3
13 MID MID Flood-MAR Projects Direct Groundwater
Recharge N/A 3
These Projects are considered as potential projects to support the GSP implementation. They are currently considered as alternative options and are not directly analyzed in this Chapter.
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-27
Revised July 2024
TODD GROUNDWATER
8.3. PROJECTS DEVELOPED FOR NEAR-TERM IMPLEMENTATION (GROUPS 1 AND 2) This section describes the Projects that were developed for near-term implementation in the Subbasin and are categorized by proponent. This includes all Group 1 and 2 Projects identified in Table 8-2. These Projects are either:
• Currently in place and will continue to be implemented by specific participating agencies with future expansions planned, or
• Currently planned and will be implemented or started by specific participating agencies in the next five years.
The Projects developed for near-term implementation were modeled in the C2VSimTM to estimate their potential benefit to the groundwater system over the projected future water budget period. Applicable assumptions used to model each Project are described in each Project description. The results of these model scenarios are discussed in Section 8.5: Plan for Achieving Sustainability. C2VSimTM modeling results of Group 1 and Group 2 Projects indicate that Projects developed for near-term implementation are expected to be sufficient in the Subbasin for reaching its sustainability goal. However, the GSAs understand that assumptions used in modeling may differ from actual conditions. As a result, the GSAs have begun developing Management Actions that will be implemented to arrest groundwater level declines by 2027 and raise groundwater levels after 2027. These Management Actions currently under development are presented in Section 8.1: Management Actions.
Table 8-3 lists all Group 1 and Group 2 Projects described in the subsections that follow.
Each Project description is organized to address the applicable regulatory requirements:
• Project Description: 23 CCR §354.44(b)
• Public Noticing: 23 CCR §354.44(b)(1)(B)
• Permitting and Regulatory Process: 23 CCR §354.44(b)(3) • Expected Benefits: 23 CCR §354.44(b)(4), §354.44(b)(5) • Implementation Criteria, Status, and Plan: 23 CCR §354.44(b)(1)(A); §354.44(b)(4); §354.44(b)(6)
• Water Source and Reliability: 23 CCR §354.44(b)(6)
• Legal Authority: 23 CCR §354.44(b)(7)
• Estimated Costs and Funding Plan: 23 CCR §354.44(b)(8) • Management of Groundwater Extractions and Recharge: 23 CCR §354.44(b)(9) Summary of Criteria for Project Implementation (23 CCR §354.44(b)(1)(A)) As described above, the Group 1 and Group 2 Projects presented in this section are either currently in place or are planned to be initiated within five years. Projects that are currently in place will continue to be implemented over the 2042 Plan horizon. #25..
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-28
Revised July 2024
TODD GROUNDWATER
Table 8-3: Projects Developed for Near-Term Implementation Location (Proponent) Project Name Primary Mechanism(s)1 City of Modesto
Project 1: Growth Realization of
Surface Water Treatment Plant
Phase II
In-Lieu Recharge
Project 2: Advanced Metering
Infrastructure Project (AMI) Water Conservation
Project 3: Storm Drain Cross
Connection Removal Project Stormwater Capture
City of Waterford
Project 4: Waterford/Hickman
Surface Water Pump Station and
Storage Tank
Water Conservation
NDE Areas
Project 5: Modesto Irrigation
District In-lieu and Direct Recharge
Project
In-lieu and Direct
Recharge Project
Project 6: Oakdale Irrigation District
In-lieu and Direct Recharge Project
In-lieu and Direct
Recharge Project
Project 7: Tuolumne River Flood
Mitigation and Direct Recharge
Project
Flood control and Direct
Recharge Project
Project 8: Dry Creek Flood
Mitigation and Direct Recharge
Project
Flood control and Direct
Recharge Project
1The primary mechanism of the Project as conceptualized, although during implementation Projects may be used for multiple functions to support groundwater sustainability and beneficial users.
8.3.1. Urban and Municipal Projects
Projects developed for implementation by urban and municipal proponents in the Modesto Subbasin are summarized in the sections below.
8.3.1.1. Growth Realization of Surface Water Treatment Plant Phase II (Project 1)
8.3.1.1.1. Project Description
The Growth Realization of Surface Water Treatment Plant Phase II project (Project) continues the water purchase agreement between Modesto Irrigation District (MID) and the City of Modesto to meet urban demands. It utilizes the expansion from Phase II of the Modesto Regional Water Treatment Plant (MRWTP).
The Modesto Irrigation District operates the MRWTP to treat surface water for use within the City of Modesto and has been expanding its capacity to meet growing and future water demands from its customers. The Initial Phase (first phase) of the MRWTP Project included the construction of a 30 million-gallon per day (mgd) surface water treatment plant, two 5- million-gallon (MG) terminal storage tanks and associated pumping facility. The pump #25..
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station delivered water into the MID transmission system for distribution into either the Del Este or City of Modesto water distribution systems through several MID turnouts. The City of Modesto now owns the Del Este water system.
The Expansion Phase of the MRWTP Project (Phase II) included the construction of a new parallel treatment process consisting of low-pressure membranes, ozone disinfection system, a dissolved air flotation thickener and a new Supervisory Control and Data Acquisition (SCADA) system. The total capacity available at the MRWTP with the completion of the MRWTP Phase II Expansion Project is 60 mgd with a maximum annual supply of up to 67,200 AFY.
The City of Modesto currently operates its treatment and conveyance systems at capacity and has not been able to utilize any additional surface water supply. However, recently the City of Modesto has taken several steps to increase its infrastructural optimization, particularly its water utilization and storage. Some of these steps include: (1) the submittal of a conceptual grant application to modify up to four recharge basins to dilute aquifer contaminants, increase aquifer storage, and improve water quality, and (2) hiring an outside consultant to study system optimization and (3) investigate the feasibility of integrating additional surface water supply for recharge in wet years.
8.3.1.1.2. Public Noticing
The public and other agencies will be notified of the planned or ongoing implementation of Project activities through the outreach and communication channels identified in the GSP and during updates presented at regularly scheduled STRGBA GSA meetings. Noticing will occur as potential activities are being considered for implementation, and as ongoing and planned activities are implemented. Noticing will inform the public and other agencies that the proponent is considering related to the Project and will provide a description of the actions that will be taken.
Public and/or inter-agency noticing may be facilitated through STRGBA GSA meetings and/or local agency meetings, associated website(s), inter-basin coordination meetings, other public meetings hosted by the GSAs, Annual Reports and Periodic Evaluations, public scoping meetings, and/or applicable permitting notification processes.
8.3.1.1.3. Permitting and Regulatory Process
This Project includes the continued transfer of water purchased between MID and the City of Modesto, therefore, permitting and regulatory requirements have already been completed. Future permitting and regulatory processes, if needed to continue or expand Project activities, will be managed through MID and the City of Modesto.
8.3.1.1.4. Expected Benefits
Benefits to Sustainability Indicators
Utilization of purchased water for urban water demands is expected to offset groundwater pumping demands through in-lieu groundwater recharge benefits to the Subbasin. The sustainability indicators expected to benefit from this Project are groundwater levels, #25..
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groundwater storage, land subsidence, and interconnected surface water. Project benefits to sustainability indicators will be evaluated through monitoring groundwater levels within the GSP's representative monitoring network.
Benefits to Disadvantaged Communities
Water supplied through this Project directly benefits areas within the City of Modesto’s water service areas within the Subbasin, most of which are classified as DACs. By supplementing and diversifying their drinking water supply, this Project will provide an alternate drinking water source and operational flexibility to remove or blend production wells with treated surface water to comply with safe drinking water regulations and meeting MCLs. The additional surface water supply will also reduce groundwater pumping and increase groundwater levels near the communities which can reduce pumping costs and potentially mitigate some groundwater quality concerns. Additionally, benefits to groundwater conditions in the Subbasin are also expected to benefit all local DACs, SDACs (Severely Disadvantaged Communities), and EDAs (Economically Distressed Areas).
Volumetric Benefits to the Subbasin Groundwater System
The expected yield of the benefits from the Project was estimated by simulations performed in the C2VSimTM model. General information and assumptions used to simulate this Project are summarized in the Implementation section below. Additional information is provided in Section 8.5: Plan for Achieving Sustainability.
This Project has provided an estimated additional 10 mgd (11,200 AFY) starting in 2016 and continuing at 10 mgd through 2020, and then is anticipated to gradually increase to an additional 30 mgd (33,600 AFY) by 2050.
Evaluation of benefits will be based on analysis of without-Project and with-Project measurements supported by modeling. Measured parameters will include surface water deliveries and groundwater levels. Modeling will be done with the C2VSimTM model used in developing the GSP.
8.3.1.1.5. Implementation Criteria, Status, and Strategy Implementation Strategy and Timeline
This Project is being implemented by the City of Modesto and MID and provides 10 mgd and will eventually increase to 30 mgd. This Project includes the expansion of current water transfers between MID and the City of Modesto. Updates on the status and continuation of this agreement and Project will be provided in Annual Reports and Periodic Evaluations.
Implementation Assumptions for Modeling
Impacts to the Subbasin from the Project were already captured in the Projected Conditions Baseline and thus no additional changes were needed to simulate this Project in the modeling scenarios. Baseline conditions include both the expansion of the City of Modesto’s footprint and the resulting increase of surface water available for urban use. #25..
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8.3.1.1.6. Water Source and Reliability
This Project would use water from MID to supplement water for the City of Modesto for urban demands. The Project has provided an estimated additional 10 mgd (11,200 AFY) starting in 2016 and continuing at 10 mgd through 2020, and then is anticipated to gradually increase to an additional 30 mgd (33,600 AFY) by 2050. These assumptions are included in the model development. Volumetric groundwater benefits will be reported in Annual Reports and Periodic Evaluations.
8.3.1.1.7. Legal Authority
The GSAs, Districts, and Project proponents have the authority to plan and implement Projects through consultation with applicable governing agencies. MID has the authority to construct and continue to operate its water treatment plant and to continue to transfer water to the City of Modesto.
8.3.1.1.8. Estimated Costs and Funding Plan
The Project is a continuation of water transfers from MID to the City of Modesto. Because an agreement and water transfers have already commenced, the estimated costs of this Project are low and include agreement/coordination costs and yearly costs. Infrastructure for this Project has already been constructed and additional infrastructure is not required.
The ongoing capital cost for this Project is $4.1M annually, which will increase to $8.3M in FY 2024 when payment towards the principal balance begins. The City of Modesto has been utilizing the Water Fund as a funding source to cover Project costs as part of Project development and continuation. Other funding sources, such as grants (e.g., Prop 1, Prop 68m, NRCS), fees, local cost share, and loans, may be pursued in the future if needed.
8.3.1.1.9. Management of Groundwater Extractions and Recharge Per 23 CCR § 354.44(b)(9), all PMAs developed for implementation are targeted to maintain the balance of groundwater extractions and recharge to help ensure that lowering of groundwater levels or depletion of supply during periods of drought is offset by increases in groundwater levels and storage in other years.
In-lieu recharge benefits of this Project are expected to increase the use and recharge of available surface water supplies during wetter years, helping to offset potential increases in groundwater pumping during drought when surface water supplies are limited.
8.3.1.2. Advanced Metering Infrastructure Project (AMI) (Project 2) The Advanced Metering Infrastructure (AMI) Project (Project) involves the installation of AMI throughout the City of Modesto. The City of Modesto is in the initial stages of installing AMI smart meters to support water reduction goals. Smart meters will assist the City of Modesto in notifying residents of leaking pipes and helping to reduce overall domestic water consumption through improved and direct consumer data.
8.3.1.2.1. Project Description
The City of Modesto is in progress of upgrading 75,000 meters to AMI smart meters to support water reduction goals. Smart meters will assist the City of Modesto in providing #25..
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analytical tools to manage water usage better such as identifying potential leaks sooner and providing customers with more usable and user-friendly data to manage their water usage.
8.3.1.2.2. Public Noticing
Public and/or inter-agency noticing may be facilitated through STRGBA GSA meetings and/or local agency meetings, associated website(s), inter-basin coordination meetings, other public meetings hosted by the GSAs, Annual Reports and Periodic Evaluations, public scoping meetings, and/or applicable permitting notification processes.
8.3.1.2.3. Permitting and Regulatory Process
Required permitting and regulatory review will be Project-specific and initiated through consultation with applicable governing agencies. Governing agencies for which consultation will be initiated may include, but are not limited to: DWR, SWRCB, CDFW, Flood Board, Regional Water Boards, USFWS, NMFS, LAFCO, County of Stanislaus, and CARB.
8.3.1.2.4. Expected Benefits
Benefits to Sustainability Indicators
The sustainability indicators expected to benefit from the Project are groundwater levels, groundwater storage, land subsidence, and interconnected surface water.
Benefits to Disadvantaged Communities
This Project would apply to and benefit all water customers served by the City of Modesto, most of which are considered a DAC or SDAC.
Volumetric Benefits to the Subbasin Groundwater System
The Project is currently in development and AMI is actively being installed throughout the Project area. As a result, the expected yield of this Project has not been determined.
Volumetric benefits will be reported in Annual Reports and Periodic Evaluations. However, the Project is expected to reduce water use in the City of Modesto to meet future water use mandates and conservation goals.
Evaluation of benefits will be based on analysis of without-Project and with-Project effects on the SGMA sustainability indicators. Project is evaluated as part of C2VSimTM modeling scenarios used to assess the benefits and impacts on the Subbasin.
8.3.1.2.5. Implementation Criteria, Status, and Strategy Implementation Strategy and Timeline
This Project would install AMI smart meters to support water reduction goals by helping the City of Modesto obtain the analytical tools to manage water usage better. The planning phase was completed between 2022 and 2023. Installation activities began in 2024 and Project completion is anticipated in 2026.
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Implementation Assumptions for Modeling
The Project was modeled in the C2VSimTM model. Additional information on Project-related modeling is described in Section 8.5: Plan for Achieving Sustainability.
The following information and assumptions were used to simulate implementation of the Project:
• Modeled as part of scenario of ongoing conservation efforts within the City of Modesto. Simulated change includes the reduction of urban water demand from 228 gallons per person per day (GPCD) (2015 City of Modesto UWMP) to 175 GPCD (2020 City of Modesto UWMP) (West Yost Associates, 2016 & 2021).
8.3.1.2.6. Water Source and Reliability
This Project would not directly use a water source but would help to manage and enhance use of existing water City of Modesto supplies.
8.3.1.2.7. Legal Authority
The GSAs, Districts, and Project proponents have the authority to plan and implement Projects.
8.3.1.2.8. Estimated Costs and Funding Plan
The anticipated cost of this Project is estimated to be $20 million. Any updates or changes to the estimated costs will be reported in Annual Reports and Periodic Evaluations. Funding for planning and development of the Project was sourced through the City of Modesto’s Water Fund. The Project proponent will identify funding sources to cover ongoing development and implementation costs as part of Project development. These may include additional funding through the Water Fund, grants, fees, loans, and other sources.
8.3.1.2.9. Management of Groundwater Extractions and Recharge AMI does not rely on a water source (e.g., no groundwater extraction or recharge is involved), but the Project would help manage and enhance use of existing City of Modesto water supplies.
8.3.1.3. Storm Drain Cross Connection Removal Project (Project 3)
8.3.1.3.1. Project Description
The Storm Drain Cross Connection Removal Project (Project) captures, treats, and infiltrates stormwater within the City of Modesto. The Project components use low impact development (LID) techniques including bio-retention planters, infiltration trenches, and underground retention basins within city parks for groundwater recharge. Additional benefits include the reduction of stormwater flows to the City of Modesto’s wastewater treatment plant and sanitary sewer overflows, reduction of localized flooding, and improved water quality within Dry Creek and the Lower Tuolumne River. Each project component is located in areas with no positive storm drainage systems within the City of Modesto's jurisdiction. The Project components are a cost effective and LID alternative to constructing #25..
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detention basins in undeveloped portions of the city and constructing miles of storm drains.
This Project also includes the removal of failed dry wells and storm to sanitary sewer cross connections. The Project components, status, and expected recharge benefits are included in Table 8-4.
Table 8-4: Storm Drain Cross Connection Removal Project Components, Status, and Expected Recharge Benefit
Component Status
Expected
Recharge Benefit
Garrison Park Completed 12 AFY
Roosevelt Park Completed 29 AFY
JM Pike Park Construction 53 AFY
Catherine Everett Park Planning/Construction
(2026 completion)
29 AFY
Other Planning 125 AFY
Removal of failed dry wells
and storm to sanitary
sewer cross connection
In Progress N/A
8.3.1.3.2. Public Noticing
The public and other agencies will be notified of the planned or ongoing implementation of Project activities through the outreach and communication channels identified in the GSP, during the preparation process of the PEIR (if applicable), and during updates presented at regularly scheduled STRGBA GSA meetings. Noticing will occur as potential activities are being considered for implementation, and as ongoing and planned activities are implemented. Noticing will inform the public and other agencies that the proponent is considering modifications to the Project and will provide a description of the actions that will be taken.
Public and/or inter-agency noticing may be facilitated through STRGBA GSA meetings and/or local agency meetings, associated website(s), inter-basin coordination meetings, other public meetings hosted by the GSAs, Annual Reports and Periodic Evaluations, public scoping meetings, and/or applicable permitting notification processes.
8.3.1.3.3. Permitting and Regulatory Process
Required permitting and regulatory review is being initiated as necessary through consultation with applicable governing agencies. Governing agencies that may be consulted for this Project include, but are not limited to: DWR, SWRCB, the California Department of Fish and Wildlife (CDFW), the Central Valley Flood Protection Board (Flood Board), Regional Water Boards, the United States Bureau of Reclamation (Reclamation or USBR), the United States Army Corps of Engineers (USACE), the United States Fish and Wildlife Service (USFWS), the National Marine Fisheries Service (NMFS), Local Agency Formation #25..
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Commissions (LAFCo), the County of Stanislaus and/or Tuolumne, and the California Air Resources Board (CARB).
8.3.1.3.4. Expected Benefits
Benefits to Sustainability Indicators
Stormwater flows going to sanitary sewer systems will be disconnected and rerouted to provide direct groundwater recharge. Sustainability indicators expected to benefit from this Project are groundwater levels, groundwater storage, land subsidence, and interconnected surface water. All benefits to sustainability indicators will be evaluated through groundwater monitoring at nearby monitoring sites as identified in Section 7.1 of the GSP.
Benefits to Disadvantaged Communities
The Storm Drain Cross Connection Removal Project is expected to provide direct recharge in and around the City of Modesto. Most communities in the Modesto Subbasin are classified as DACs, SDACs, or EDAs (according to 2018 census data, evaluated by place, tract, and block group). Depending on which specific parcels receive surface water deliveries, this Project may directly benefit specific DACs in this area. In addition, maintenance or improvement of groundwater levels will help to protect beneficial groundwater use by rural domestic wells from potential adverse impacts related to chronic groundwater level decline. Benefits to groundwater conditions in the Subbasin are also expected to benefit all DACs, SDACs, and EDAs.
Volumetric Benefits to the Subbasin Groundwater System
The expected yield of the Project was estimated by simulations run in the C2VSimTM model.
General information and assumptions used to simulate this Project are summarized in the following section. Additional information is provided in Section 8.5: Plan for Achieving Sustainability.
On average across all years, the Project is expected to provide approximately 248 AFY of recharge benefit to the Subbasin.
Evaluation of benefits will be based on analysis of without-Project and with-Project measurements supported by modeling. Measured parameters will include surface water deliveries and groundwater levels. Modeling may be done with the C2VSimTM model used for GSP development to evaluate volumetric benefits.
8.3.1.3.5. Implementation Criteria, Status, and Strategy Implementation Strategy and Timeline
This Project consists of several different components of a larger program which has relied on the success of previous grant funds. For the components included in this Project, work is already in progress. The JM Pike Park component is currently under construction. Overall, the final storm to sewer cross connection removals for the program are estimated to be completed in 2061.
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Implementation Assumptions for Modeling
The Storm Drian Cross Connection Removal Project has been modeled in the C2VSimTM model. Additional information about Project-related modeling is described in Section 8.5:
Plan for Achieving Sustainability.
The following general information and assumptions were used to simulate implementation of the Project:
• Volume of water: 41 AFY were provided during the first 10 years of simulation, 70 AFY during the following 5 years of simulation, and 248 AFY for the rest of the simulation, distributed evenly between the months of October and April. The annual average during the 50-year simulation period would be 189 AFY. • The total volume would be provided as direct recharge.
8.3.1.3.6. Water Source and Reliability
This Project would utilize flows that become available from disconnecting storm drain flows going to sanitary sewer systems and redirecting them for groundwater recharge.
Stormwater flows are more dependent on precipitation events. It is anticipated that annual contributions from this project will collect approximately 12 AF from Garrison Park, 29 AF from Roosevelt Park, 53 AF from JM Pike Park, 29 AF from Catherine Everett, and an additional 125 AF from other areas. Changes to water source availability will be identified as the Project is evaluated further. This information will be reported in Annual Reports and Periodic Evaluations.
8.3.1.3.7. Legal Authority
The GSAs, Districts, and Project proponents have the authority to plan and implement Projects. Required permitting and regulatory review will be Project-specific and initiated through consultation with applicable governing agencies. Governing agencies for which consultation will be initiated may include, but is not limited to: DWR, SWRCB, CDFW, Flood Board, Regional Water Boards, USFWS, NMFS, LAFCO, Stanislaus County, and CARB.
8.3.1.3.8. Estimated Costs and Funding Plan
Potential costs of this Project include construction or improvements to new or existing recharge basin and alteration of current stormwater and sewer system connections. The estimated cost for this Project is $40 million for all components. Funding for Project development was sourced through the City of Modesto’s Sewer Fund and grant funding. The City of Modesto will continue utilizing the Sewer Fund during Project development and implementation and will also identify additional funding sources to cover Project costs as part of development. These may include grants (e.g., Prop 1, Prop 68, NRCS), fees, local cost share, loans and other sources.
8.3.1.3.9. Management of Groundwater Extractions and Recharge Per 23 CCR § 354.44(b)(9), all PMAs developed for implementation are expected to maintain the balance of groundwater extractions and recharge to ensure that lowering of #25..
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groundwater levels or depletion of supply during periods of drought is offset by increases in groundwater levels and storage in other years.
8.3.1.4. Surface Water Pump Station and Storage Tank (Project 4)
8.3.1.4.1. Project Description
The Surface Water Pump Station and Storage Tank project (Project entails connecting the City of Waterford’s water supply system to MID’s water treatment plant and potable surface water supply system. The Project includes several components, described in order of the flow of the surface water. Surface water will be diverted from MID’s distribution network at a pipeline turn-out located at the corner of Tim Bell and Vineyard Road, northeast of the City of Waterford. The surface water will be piped into a one-million-gallon storage tank that will be constructed at this intersection. A pump station at this location and transmission line will also be constructed that transports the water to Yosemite Boulevard in the City of Waterford. This Project involves water supply agreements between Modesto Irrigation District, the City of Modesto, and the City of Waterford, the details of which are currently being negotiated.
Another component of this Project entails combining the City of Waterford’s distribution network and providing water to the disadvantaged community of Hickman by 2023. While Hickman is in the Turlock Subbasin, supplying surface water to the community would support the Modesto Subbasin’s sustainability goals of mitigating stream depletions along the Tuolumne River and protecting domestic wells by reinforcing groundwater levels along the Subbasin boundary.
8.3.1.4.2. Public Noticing
The public and other agencies will be notified of the planned or ongoing implementation of Project activities through the outreach and communication channels identified in the GSP, during the preparation process of the PEIR (if applicable), and during updates presented at regularly scheduled STRGBA GSA meetings. Noticing will occur as potential activities are being considered for implementation, and as ongoing and planned activities are implemented. Noticing will inform the public and other agencies that the proponent is considering modifications to the Project and will provide a description of the actions that will be taken.
Public and/or inter-agency noticing may be facilitated through STRGBA GSA meetings and/or local agency meetings, associated website(s), inter-basin coordination meetings, other public meetings hosted by the GSAs, Annual Reports and Periodic Evaluations, public scoping meetings, and/or applicable permitting notification processes.
8.3.1.4.3. Permitting and Regulatory Process
Required permitting and regulatory review would be initiated through consultation with applicable governing agencies. Governing agencies for which consultation will be initiated may include, but are not limited to: DWR, SWRCB, CDFW, Flood Board, Regional Water Boards, USFWS, NMFS, LAFCO, Counties of Stanislaus and/or Tuolumne, and CARB. Specific #25..
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permitting and regulatory processes that may potentially affect the construction of Projectrelated infrastructure include, but are not limited to:
• USACE Section 404 Permits (potential exemption under Section 404(f)(1)(C) of Clean Water Act)
• Regional Water Quality Control Board Section 401 Water Quality Certification (not required if exempt from USACE Section 404)
• SWRCB Construction General Permit and Storm Water Pollution Prevention Plan (SWPPP)
• State Historic Preservation Office (SHPO) and National Historic Preservation Act (NHPA) Section 106 Coordination
• CEQA Environmental Review Process
• California Endangered Species Act (CESA) Consultation • Endangered Species Act (ESA) Compliance
• National Environmental Policy Act (NEPA) Compliance (expected to require either an Environmental Impact Report and Negative Declaration or Mitigated Negative Declaration)
8.3.1.4.4. Expected Benefits
Benefits to Sustainability Indicators
Utilization of surface water for urban water demands in Waterford and Hickman is expected to offset groundwater pumping demands, with in-lieu groundwater recharge benefits to the Subbasin. Because Waterford and Hickman use a combined system, Hickman (which lies in the Turlock Subbasin) will also benefit. Benefits in this area are seen in Tuolumne River stream conditions and will further protect domestic wells in both the Modesto and Turlock Subbasins. The sustainability indicators expected to benefit from this project are groundwater levels, groundwater storage, land subsidence, and interconnected surface water. All benefits to sustainability indicators in the Subbasin will be evaluated through groundwater monitoring at nearby monitoring sites, identified in the GSP.
Benefits to Disadvantaged Communities
The Waterford/Hickman Surface Water Pump Station and Storage Tank Project directly benefits Waterford and Hickman, both classified as DACs, by supplementing and diversifying their drinking water supply. This Project will provide an alternate drinking water source in case of infrastructure or contamination concerns with the communities’ groundwater production wells. The additional surface water supply will also reduce groundwater pumping and increase groundwater levels near the communities which can reduce pumping costs, decrease the likelihood of dewatering domestic wells, and potentially mitigate some groundwater quality concerns. Additionally, benefits to groundwater conditions in the Subbasin are also expected to benefit all DACs, SDACs, and EDAs in the Modesto Subbasin. #25..
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Volumetric Benefits to the Subbasin Groundwater System
The expected yield of the Waterford/Hickman Surface Water Pump Station and Storage Tank was estimated through simulations in the C2VSimTM model. General information and assumptions used to simulate this Project are summarized in the Implementation section below. Additional information is provided in Section 8.5: Plan for Achieving Sustainability.
It is assumed that MID will provide 900 AFY to Waterford and Hickman, except for critical years which will provide a partial allotment (approximately 750 AFY in critical years).
Evaluation of benefits will be based on analysis of without-Project and with-Project measurements supported by modeling. Measured parameters will include surface water deliveries and groundwater levels. Modeling will be done with the C2VSimTM model used for GSP development.
8.3.1.4.5. Implementation Criteria, Status, and Strategy Implementation Strategy and Timeline
The Waterford/Hickman Surface Water Pump Station and Storage Tank will be implemented by the City of Waterford. Waterford will oversee the Project financing and funding, permitting, and construction. The Project will require an agreement(s) between MID and the City of Modesto to purchase treated surface water. Negotiations are underway but have not been concluded. Once negotiations are finalized and financing is secured, then design and subsequent construction will begin. This Project is currently in the early conceptual stage.
Thus, the start and completion dates for this Project have yet to be determined and will be provided in GSP Annual Reports and Periodic Evaluations when known. Once the Project construction is complete, it is expected that MID would provide 900 AFY to Waterford and Hickman in all water years except critical years which will provide a partial allocation.
Implementation Assumptions for Modeling
The Waterford/Hickman Surface Water Pump Station and Storage Tank has been modeled in the C2VSimTM model. Additional information about Project-related modeling is described in Section 8.5: Plan for Achieving Sustainability.
The following general information and assumptions were used to simulate implementation of the Project:
• Estimated volume of surface water deliveries: Proportional to the MID irrigation water allotment based on water year type, not to exceed 900 AFY. The surface water deliveries are distributed throughout the months proportional to monthly urban demands.
• Area receiving surface water deliveries: Surface water is delivered to the jurisdictional extent of the Hickman and Waterford communities, consistent with the extent in the historical C2VSimTM model. Surface water is distributed between Waterford and Hickman proportionally to simulated demands of each community. #25..
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• Water source: It is assumed that all surface water is diverted from MID’s distribution system, with no adjustment to modeled MID diversions, spillage, and seepage. • Groundwater pumping: It is assumed that groundwater production is reduced by the volume of surface water deliveries which is distributed evenly among all wells in Waterford and Hickman.
8.3.1.4.6. Water Source and Reliability
The Waterford/Hickman Surface Water Pump Station and Storage Tank will use water diverted from MID’s surface water distribution network. MID has existing water rights on the Tuolumne River and existing storage and conveyance facilities that afford secure surface water supplies. Surface water is expected to be available for this Project in all hydrologic years, proportional to MID irrigation allotment, while still meeting the demand of existing MID customers.
8.3.1.4.7. Legal Authority
The GSAs, Districts, and Project proponents have the authority to plan and implement Projects through consultation with applicable governing agencies. MID and the City of Modesto have the authority to sell surface water to the City of Waterford.
8.3.1.4.8. Estimated Costs and Funding Plan
Costs of this Project include right of way purchase, environmental permitting, design, construction, and Project management costs. The estimated cost is approximately $8.5 million. However, this Project is currently in the early conceptual stage and a more refined cost can be reported in GSP Annual Reports and Periodic Evaluations when known. It is anticipated that the City of Waterford would identify grant funding sources to cover Project costs as part of development.
8.3.1.4.9. Management of Groundwater Extractions and Recharge Per 23 CCR § 354.44(b)(9), all PMAs developed for implementation are expected to maintain the balance of groundwater extractions and recharge to ensure that lowering of groundwater levels or depletion of supply during periods of drought is offset by increases in groundwater levels and storage in other years.
In-lieu recharge benefits from this Project are expected to increase the use and recharge of available surface water supplies, helping to offset any potential increases in groundwater pumping during drought when surface water supplies are limited.
8.3.2. In-Lieu & Direct Recharge Projects
8.3.2.1. Modesto Irrigation District In-Lieu and Direct Recharge Project (Project 5)
8.3.2.1.1. Project Description
The Modesto Irrigation District In-Lieu and Direct Recharge Project (Project), also known as the Long-Term Groundwater Replenishment Program (GRP), is intended to be a cooperative long-term Project between MID and the non-district east (NDE) landowners. The purpose of #25..
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this Project is to allow MID to facilitate recharge for NDE landowners during times and conditions that will not impact MID’s existing agricultural and urban customers. The Project would be operated separately but coordinated with the Oakdale Irrigation District In-lieu and Direct Recharge Project, which shares a similar goal of facilitating groundwater sustainability in the NDE areas.
Developed agriculture in the NDE areas of the Subbasin is estimated to be approximately 36,000 acres, of which approximately 30,000 acres are permanent crops such as deciduous fruits and nuts. With limited exception, the entire NDE area is solely reliant on groundwater from the Subbasin. This Project involves the delivery of approximately 60,000 AF of surface water from the Tuolumne River in Wet and Above Normal water years (WYs). Deliveries would be supplied through a number of new points of diversions on MID’s existing irrigation conveyance infrastructure and subsequent conveyance through newly constructed private irrigation conveyance infrastructure. Water supply would be provided to NDE during the growing season in the form of in-lieu and direct recharge. Historically (1972-2020), Wet and Above Normal WYs have occurred approximately 47% of the time within the Subbasin.
Under the current Final Environmental Impact Statement for the relicensing of Don Pedro Reservoir, there is estimated to be approximately 1,500,000 AF of surface water in Wet WYs and 620,000 AF of surface water in Above Normal WYs in the Tuolumne River. These water volumes exceed what is necessary to meet existing customer demands (all Tuolumne River Partners) and the recommended instream flow obligations. As a result, 60,000 AF of Tuolumne River surface water to applicable NDE areas amounts to approximately 4% and 10% of available surface water supply for Wet and Above Normal WYs, respectively. Project operation is intended to make surface water delivery available to applicable NDE areas in Above Normal and Wet WYs.
8.3.2.1.2. Public Noticing
The public and other agencies will be notified of the planned or ongoing implementation of Project activities through the outreach and communication channels identified in the GSP, during the preparation process of the PEIR (if applicable), and during updates presented at regularly scheduled STRGBA GSA meetings. Noticing will occur as potential activities are being considered for implementation, and as ongoing and planned activities are implemented. Noticing will inform the public and other agencies that the proponent is considering or will be implementing the Project and will provide a description of the actions that will be taken.
During the development of the Revised GSP, MID has held multiple meetings and workshops to promote the program:
• Landowner Meeting held March 4, 2024, at MID Downtown Office • Landowner Meeting held March 5, 2024, at Waterford Council Chambers • Long-term Groundwater Replenishment Program Workshop held April 23, 2024, at MID Downtown Office
• Long-term Groundwater Replenishment Program Workshop held April 24, 2024, at Waterford Council Chambers
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-42
Revised July 2024
TODD GROUNDWATER
Additionally, MID has promoted the program at STRGBA meetings and Stanislaus County meetings, as well as issued social media notifications and postcard fliers.
Additional public and/or inter-agency noticing may be facilitated through STRGBA GSA meetings and/or local agency meetings, associated website(s), inter-basin coordination meetings, other public meetings hosted by the GSAs, Annual Reports and Periodic Evaluations, public scoping meetings, and/or applicable permitting notification processes.
8.3.2.1.3. Permitting and Regulatory Process
Required permitting and regulatory review would be initiated as necessary through consultation with applicable governing agencies. Surface water would be diverted for this Project by MID through existing pre- and post-1914 water rights. Governing agencies that may be consulted for this Project include but are not limited to the State Water Resources Control Board (SWRCB), Stanislaus and/or Tuolumne Counties of Stanislaus and/or Tuolumne, and DWR.
If necessary for field flooding, the Project proponent will obtain land grading permits from the Stanislaus and/or Tuolumne Counties. Environmental review under CEQA may also be required for the Projects.
8.3.2.1.4. Expected Benefits
Benefits to Sustainability Indicators
Surface water deliveries during the non-irrigation season are expected to provide direct recharge to the Subbasin. For fields that are irrigated using groundwater, surface water deliveries during the irrigation season are expected to offset groundwater demand and provide in-lieu groundwater recharge benefits. In both cases, the sustainability indicators expected to benefit from this Project are groundwater levels, groundwater storage, land subsidence, and interconnected surface water. All benefits to sustainability indicators in the Subbasin will be evaluated through groundwater monitoring at nearby monitoring sites, identified in the GSP.
Benefits to Disadvantaged Communities
The MID In-Lieu and Direct Recharge Project is expected to provide direct or in-lieu recharge for use in the NDE area. Most communities in the Subbasin, particularly in the NDE area, are classified as DACs, SDACs, or EDAs (according to 2018 census data, evaluated by place, tract, and block group). Depending on which specific parcels receive surface water deliveries, this Project may directly benefit certain DACs in this area. In addition, maintenance or improvement of groundwater levels will help to protect beneficial groundwater use by rural domestic wells from potential adverse impacts related to groundwater level decline.
Benefits to groundwater conditions in the Subbasin are also expected to benefit all DACs, SDACs, and EDAs.
Volumetric Benefits to the Subbasin Groundwater System
The expected yield of the Project was estimated through simulations in the C2VSimTM model. General information and assumptions used to simulate this project are summarized #25..
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-43
Revised July 2024
TODD GROUNDWATER
in the following section. Additional information is provided in Section 8.5: Plan for Achieving Sustainability.
On average across all years, the MID In-Lieu and Direct Recharge Project is expected to provide an annual benefit of 28,800 AFY to the Subbasin. These benefits would accrue in years with Wet or Above Normal hydrologic conditions when sufficient water is expected to be available for on-farm recharge (approximately 47 percent of years historically). In Above Normal and Wet WYs, approximately 60,000 AFY of groundwater recharge is expected to be supplied.
Evaluation of benefits will be based on analysis of without-Project and with-Project measurements supported by modeling. Measured parameters will include surface water deliveries and groundwater levels. Modeling will be done with the C2VSimTM model used for GSP development.
8.3.2.1.5. Implementation Criteria, Status, and Strategy Implementation Strategy and Timeline
The Project involves the delivery of surface water from the Tuolumne River in Wet and Above Normal WYs through a limited number of new points of diversions on MID’s existing irrigation conveyance infrastructure and subsequent conveyance through existing and newly constructed private irrigation conveyance infrastructure for in-lieu and direct recharge during the growing season. Modeling results indicate that that most of the surface water made available will be used to meet agricultural demand during the irrigation season throughout the NDE area. This in-lieu use is intended to reduce the pumping needed in this area of the Subbasin in Wet and Above Normal WYs.
On January 23, 2024, the MID Board of Directors approved the implementation of the GRP and adopted an Addendum to the Modesto Irrigation District Comprehensive Water Resources Management Plan Final Programmatic Environmental Impact Report which incorporated the Long-term Groundwater Replenishment Program. Project activities, such as surface water deliveries, are anticipated to begin January 2024.
The GRP is planned to be expanded to parcels outside of the MID Service Boundary but within the Modesto Subbasin following adoption of the Revised GSP. Project updates will be provided in Annual Reports and Periodic Evaluations.
Implementation Assumptions for Modeling
The MID In-lieu and Direct Recharge Project has been modeled in the C2VSimTM model.
Additional information about Project-related modeling is described in Section 8.5: Plan for Achieving Sustainability.
The following general information and assumptions were used to simulate implementation of the Project:
#25..
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-44
Revised July 2024
TODD GROUNDWATER
• Volume of water: 60,000 AFY were provided during Wet and Above Normal WYs, distributed in the months following the demand distribution. During the 50-year simulation period, the average annual water supply from this Project would be 28,800 AFY.
• One third of the total volume would be provided as direct recharge and the remainder would be delivered as in-lieu recharge.
• The location of the in-lieu and direct recharge would be within the NDE area, located near existing MID conveyance facilities and those parcels with low/medium infrastructure requirements.
8.3.2.1.6. Water Source and Reliability
The Project involves the delivery of approximately 60,000 AF of surface water from the Tuolumne River in Wet and Above Normal WYs. Under the current Final Environmental Impact Statement for the relicensing of Don Pedro Reservoir, there is estimated to be approximately 1,500,000 AF of surface water in Wet WYs and 620,000 AF of surface water in Above Normal WYs in the Tuolumne River above and beyond that necessary to meeting existing customer demands (all Tuolumne River Partners) and the recommended instream flow obligations. As a result, 60,000 AF of Tuolumne River surface water to applicable NDE areas amounts to approximately 4% and 10% of available surface water supply respectively, for Wet and Above Normal WYs.
8.3.2.1.7. Legal Authority
The GSAs, Districts, and Project proponents have the authority to plan and implement Projects through consultation with applicable governing agencies. MID has the authority to contract with and provide deliveries to parcels in the NDE area, and individual irrigators have the authority to apply surface water to their fields for on-farm recharge.
8.3.2.1.8. Estimated Costs and Funding Plan
Potential costs of this Project may include coordination and administration, financial, or other incentives to encourage on-farm recharge, field preparation to enhance flooding, and other potential on-field monitoring equipment. Costs per site may vary depending on changes in Project implementation and incentives. Slightly higher costs per site would likely be incurred in the first year an irrigator participates, as more coordination and site preparation may be required. The total costs of the Project will vary over time, depending on the number of sites receiving water, the extent to which irrigators require coordination and support, and any applicable Project incentives.
This Project is currently in the early conceptual stage. Thus, the anticipated costs contained herein are planning level costs and subject to change. However, high-level initial estimates are on the order of $53,340,000 – $75,000,000 of new conveyance infrastructure. Most costs are anticipated to be borne by the NDE participants; however, member agencies of the STRGBA GSA may identify funding sources to cover Project costs as part of development.
These may include grants (e.g., Prop 1, Prop 68, NRCS, others), fees, and loans. Participating #25..
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-45
Revised July 2024
TODD GROUNDWATER
NDE landowners are ultimately responsible for payment and installation of their private conveyance systems and the volumetric rate of MID surface water deliveries.
8.3.2.1.9. Management of Groundwater Extractions and Recharge Per 23 CCR § 354.44(b)(9), all PMAs developed for implementation are targeted to maintain the balance of groundwater extractions and recharge to help ensure that lowering of groundwater levels or depletion of supply during periods of drought is offset by increases in groundwater levels and storage in other years.
In-lieu recharge benefits of this Project are expected to increase the use and recharge of available surface water supplies during wetter years, helping to offset potential increases in groundwater pumping during drought when surface water supplies are limited.
8.3.2.2. Oakdale Irrigation District In-lieu and Direct Recharge Project (Project 6)
8.3.2.2.1. Project Description
The Oakdale Irrigation District In-lieu and Direct Recharge Project (Project) is intended to be a cooperative long-term Project between OID and the NDE east landowners. The purpose of this Project is to allow OID to facilitate recharge for NDE landowners during times and conditions that will not impact OID’s existing agricultural customers. The Project is separate from but similar to the Modesto Irrigation District In-Lieu and Direct Recharge Project and shares a similar goal of facilitating groundwater sustainability in the NDE areas. Coordination between the two Districts is ongoing and these Projects may be operated in tandem, utilizing the MID-OID interconnected distribution systems to potentially work together and convey water to the NDE or others from OID.
Developed agriculture in the NDE areas of the Subbasin is estimated to be approximately 36,000 acres, of which approximately 30,000 acres are permanent crops such as deciduous fruits and nuts. With limited exception, the NDE area is solely reliant on groundwater from the Subbasin. The Project is anticipated to provide approximately 20,000 AF of surface water from the Stanislaus River in all WYs except Critically Dry WYs. Deliveries would be supplied through several existing and new points of diversions on OID’s existing irrigation conveyance infrastructure and subsequent conveyance through newly constructed infrastructure. Water supply benefits would be provided to NDE between March 1st and September 31st in the form of in-lieu and direct recharge. Some direct recharge is expected to occur as canal or reservoir seepage in the expanded conveyance network. The Project will not deliver water supply to the NDE between October 1st- March 1st The OID Board of Directors would consider and define the volume of water (if any) available to this Project on an annual basis outside of the Project’s scope (Critically Dry WYs). Significant progress has been made with this Project since the adoption of the 2022 Modesto Subbasin GSP. The 10- Year out-of-District Water Sales Program (10-Year Program) began in 2023 and includes 4,882 irrigated acres in the Modesto Subbasin within the NDE. Under the 10-Year Program, participating landowners are required to purchase a minimum of 1.5 acre-feet per irrigated acre during each year that surplus surface water is available from OID. The landowners also have the opportunity to purchase and use additional surplus surface water throughout the #25..
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-46
Revised July 2024
TODD GROUNDWATER
irrigation season if available. Under the 10-Year Program, a minimum of 7,300 acre-feet will be purchased each year that out-of-District water is available.
The Paulsell Lateral Expansion (Paulsell Expansion) has been approved by OID and will be funded at least in part with $14.4M of SGMA Implementation Grant funding that was awarded to OID in October 2023. Working in sync with the 10-Year Program, the Paulsell Expansion will rehabilitate, automate, and expand the Paulsell Lateral, largely within the existing right of way, to accommodate an additional 150 cfs, allowing OID to deliver up to 20,000 AFY of available surface water for in-lieu and direct recharge. Infrastructure improvements will also provide further in-lieu recharge benefits by improving irrigation service to in-District lands served by OID, but that have resorted in part to pumping groundwater to supplement irrigation due to service issues on the Paulsell Lateral. In total, the Paulsell Expansion is expected to provide in-lieu and direct recharge benefits across 11,000 irrigated acres in the Subbasin.
Historically (2010-2019), OID diverts between approximately 165,000 AF to 246,000 AF, with an overall average of approximately 208,000 AF. Given OID’s existing surface water rights of 300,000 AF from the Stanislaus River and its overall average system inflows, the surface water deliveries estimated from this Project amounts to approximately 22% of the total available surface water supply. As a result, this Project provides the opportunity for OID to meet a portion of the NDE area needs.
Voluntary transfers of water have provided a basis for funding improvements to the OID distribution system under the District’s Water Resources Plan. As water is conserved and transferred, OID receives revenue and implements additional improvements, resulting in additional water conservation. More information on OID’s WRP implementation to date can be found in Section 8 of OID’s AWMP. Both the OID WRP and AWMP are available for reference on OID’s website (www.oakdaleirrigation.com). OID has participated in numerous water transfers in the past and continues to seek opportunities for mutually beneficial temporary transfer agreements with water users (agricultural, urban, and others) outside of the District.
8.3.2.2.2. Public Noticing
The public and other agencies will continue to be notified of the planned or ongoing implementation of project activities through the outreach and communication channels identified in the GSP, during the preparation process of the PEIR (if applicable), and during updates presented at regularly scheduled STRGBA GSA meetings. Noticing will occur as potential activities are being considered for implementation, and as ongoing and planned activities are implemented. Noticing will inform the public and other agencies that the proponent is considering or will be implementing the project and will provide a description of the actions that will be taken.
Public and/or inter-agency noticing may be facilitated through STRGBA GSA meetings and/or local agency meetings, associated website(s), inter-basin coordination meetings, other public meetings hosted by the GSAs, Annual Reports and Periodic Evaluations, public scoping meetings, and/or applicable permitting notification processes. #25..
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-47
Revised July 2024
TODD GROUNDWATER
Review and approval of both the 10-Year Program and the Paulsell Expansion has occurred at public OID Board of Directors meetings. Numerous presentations of both the 10-Year Program and the Paulsell Expansion have occurred at other Board meetings, workshops, and venues. Landowners impacted by the Paulsell Expansion and those participating in the 10- Year Program continue to be updated by OID staff about project progress on a regular basis.
8.3.2.2.3. Permitting and Regulatory Process
Required permitting and regulatory review would be initiated as necessary through consultation with applicable governing agencies. Surface water would be diverted through this Project by OID via existing water rights. Governing agencies that may be consulted for this Project include but are not limited to the State Water Resources Control Board (SWRCB), Stanislaus and/or Tuolumne Counties, USBR, and DWR.
If necessary, the Project proponent will obtain any applicable permits from the Tuolumne and/or Stanislaus Counties. Recharge projects and construction or expansion of conveyance facilities may also require an environmental review process under CEQA. CEQA review has been completed for both the 10-Year Program and the Paulsell Expansion.
8.3.2.2.4. Expected Benefits
Benefits to Sustainability Indicators
For fields that are irrigated using groundwater, surface water deliveries during the irrigation season are expected to offset groundwater demand and provide in-lieu groundwater recharge benefits. Some additional recharge is anticipated to occur from canal and reservoir seepage in the expanded conveyance network. The sustainability indicators expected to benefit from this Project are groundwater levels, groundwater storage, land subsidence, and interconnected surface water. All benefits to sustainability indicators in the Subbasin will be evaluated through groundwater monitoring at nearby monitoring sites, identified in the GSP.
Benefits to Disadvantaged Communities
The Oakdale Irrigation District In-Lieu and Direct Recharge Project is expected to provide direct and in-lieu recharge for parcels in the NDE area. Several communities in the Subbasin, including the NDE area, are classified as DACs, SDACs, or EDAs (according to 2018 census data, evaluated by place, tract, and block group). Depending on which specific parcels receive surface water deliveries, this Project may directly benefit specific DACs in this area.
In addition, maintenance or improvement of groundwater levels will help to protect beneficial groundwater use by rural domestic wells from potential adverse impacts related to groundwater level decline. Benefits to groundwater conditions in the Subbasin are also expected to benefit all DACs, SDACs, and EDAs.
Volumetric Benefits to the Subbasin Groundwater System
The expected yield of the Project was estimated through simulations using the C2VSimTM model. General information and assumptions used to simulate this Project are summarized in the following section. Additional information is provided in Section 8.5: Plan for Achieving Sustainability.
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-48
Revised July 2024
TODD GROUNDWATER
On average across all years, the Project is expected to provide approximately 14,400 AFY of recharge benefit to the Subbasin. These benefits would accrue in all hydrologic conditions except for Critically Dry WYs (approximately 72 percent of years historically). In nonCritically Dry WYs, approximately 20,000 AFY of groundwater recharge is expected to occur.
Evaluation of benefits will be based on analysis of without-Project and with-Project measurements supported by modeling. Measured parameters will include surface water deliveries, groundwater levels, and other parameters to be determined. Modeling has been done with the C2VSimTM model used for GSP development and will continue to be analyzed during plan implementation.
8.3.2.2.5. Implementation Criteria, Status, and Strategy Implementation Strategy and Timeline
The Project involves the delivery of surface water from the Stanislaus River in Wet, Above Normal, Below Normal and Dry WYs through a limited number of existing and new points of diversions off OID’s existing irrigation conveyance infrastructure and subsequent newly constructed private irrigation conveyance infrastructure for in-lieu and direct recharge during the growing season. The 10-Year Program has entered its second year and the 10- Year term ends in 2032, at which time the OID Board of Directors may decide to extend the program at the request of the participants for another 10-Year term. New turnouts for participants without existing service connections have been installed on the OID canals and it is expected that those landowners will have their private conveyance systems connected no later than the start of the 2025 irrigation season.
Construction of the Paulsell Expansion is proposed to start in Fall 2024 with completion by Spring 2026.
Implementation Assumptions for Modeling
The OID In-Lieu and Direct Recharge Project has been modeled in the C2VSimTM model.
Additional information about Project-related modeling is described in Section 8.5: Plan for Achieving Sustainability.
The following general information and assumptions were used to simulate implementation of the Project:
• Volume of water: Up to 20,000 AFY of water was made available in all years except critically dry hydrologic year types. Surface water deliveries were made within the irrigation season, distributed based on agricultural demand. The annual average water supply during the 50-year simulation period would be approximately 14,400 AFY.
• The location of the in-lieu and direct recharge would be within the NDE area, located near existing OID conveyance facilities and those parcels with low/med infrastructure requirements.
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Modesto Subbasin GSP
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Revised July 2024
TODD GROUNDWATER
8.3.2.2.6. Water Source and Reliability
The Project anticipates the delivery of approximately 20,000 AF of surface water from the Stanislaus River in all WYs except Critically Dry WYs. Historically (2010-2019), OID diverts between approximately 165,000 AF to 246,000 AF, with an overall average of approximately 208,000 AF. Given OID’s existing surface water rights of up to 300,00 AF from the Stanislaus and its overall average system inflows, the surface water deliveries expected from this Project amounts to approximately 22% of the total available surface water. As a result, this Project provides the opportunity for OID to meet a portion of the NDE area needs.
8.3.2.2.7. Legal Authority
The GSAs, Districts, and Project proponents have the authority to plan and implement Projects through consultation with applicable governing agencies. OID has the authority to contract with and provide deliveries to NDE landowners; individual irrigators have the authority to apply surface water to their fields for in-lieu recharge.
8.3.2.2.8. Estimated Costs and Funding Plan
Potential costs of this Project include coordination and administration, permitting, CEQA analysis, construction or expansion of conveyance facilities, and financial or other incentives to encourage in-lieu use. Costs per site may vary depending on proximity to OID conveyance facilities and changes in Project implementation or incentives. The total costs of the Project will vary over time depending on how many NDE landowners participate, the amount of construction necessary, the volumetric rate of OID surface water deliveries, and the extent to which irrigators require coordination and support.
Costs related to the new turnout construction, CEQA process, and private irrigation infrastructure for the 10-Year Program have been borne by the program participants.
The participating NDE landowners will also be responsible for maintenance costs of the turnout, flowmeter, and appurtenances as well as the volumetric rate of OID surface water deliveries. The volumetric price of out-of-District surface water began at $200 per acre-foot during the first year of the 10-Year Program and is subject to a rate increase of 3% each year thereafter.
The estimated cost of design and construction of all three phases of the Paulsell Expansion was $18.6M. OID received $14.4M in funding under a DWR SGMA Implementation Grant for the design of all three phases and the construction of the first phase of the Paulsell Expansion. The first phase includes most of the major construction components (tunnels, siphons, control structures), and will provide a significant improvement to the level of irrigation service. OID or NDE stakeholder groups may pursue future grant funding opportunities to complete construction of the final two phases of the Paulsell Expansion.
8.3.2.2.9. Management of Groundwater Extractions and Recharge Per 23 CCR § 354.44(b)(9), all PMAs developed for implementation are targeted to maintain the balance of groundwater extractions and recharge to help ensure that lowering of groundwater levels or depletion of supply during periods of drought is offset by increases in groundwater levels and storage in other years.
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-50
Revised July 2024
TODD GROUNDWATER
In-lieu recharge benefits of this Project are expected to increase the use and recharge of available surface water supplies during wetter years, helping to offset potential increases in groundwater pumping during drought when surface water supplies are limited.
8.3.3. Flood Mitigation Projects
8.3.3.1. Tuolumne River Flood Mitigation and Direct Recharge Project (Project 7)
8.3.3.1.1. Project Description
The Tuolumne River Flood Mitigation and Direct Recharge Project (Project) is intended to be a cooperative long-term Project between MID and the NDE landowners and is designed to be implemented with no impacts to MID’s existing agricultural and urban customers.
Currently developed agriculture in the NDE areas of the Subbasin is estimated to be approximately 36,000 acres, of which approximately 30,000 acres is deciduous fruits and nuts (permanent crops). With limited exception, the entire NDE area is solely reliant on groundwater from the Modesto subbasin. The Project differs from the Modesto Irrigation District In-lieu and Direct Recharge Project, namely from a timing perspective, and involves the delivery of approximately 20,000 AF of surface water from the Tuolumne River in Wet and Above Normal WYs during the non-growing season. Historically (1972-2020), Wet and Above Normal WYs have occurred approximately 47% of the time on the Tuolumne River. In addition to measurable benefits to groundwater resources within the Subbasin, this Project is intended to mitigate flood releases from Don Pedro Reservoir during the winter months whereby reducing impacts on the lower Tuolumne River (City of Modesto and growers near the confluence of the lower Tuolumne River and the San Joaquin River), the San Joaquin River and the Delta. Under the current Final Environmental Impact Statement for the relicensing of Don Pedro Reservoir, there is estimated to be approximately 1,500,000 AF of surface water in Wet WYs and 620,000 AF of surface water in Above Normal WYs in the Tuolumne River. These water volumes exceed what is necessary to meet existing customer demands (all Tuolumne River Partners) and the recommended instream flow obligations. As a result, 20,000 AF of Tuolumne River surface water to applicable NDE areas during the nongrowing season amounts to approximately 1% and 3% of available surface water supply respectively, for Wet and Above Normal WYs. New licenses for diversions/water rights may be required for this Project.
8.3.3.1.2. Public Noticing
The public and other agencies will be notified of the planned or ongoing implementation of Project activities through the outreach and communication channels identified in the GSP, during the preparation process of the PEIR (if applicable), and during updates presented at regularly scheduled STRGBA GSA meetings. Noticing will occur as potential activities are being considered for implementation, and as ongoing and planned activities are implemented. Noticing will inform the public and other agencies that the proponent is considering or will be implementing the Project and will provide a description of the actions that will be taken.
Public and/or inter-agency noticing may be facilitated through STRGBA GSA meetings and/or local agency meetings, associated website(s), inter-basin coordination meetings, other #25..
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-51
Revised July 2024
TODD GROUNDWATER
public meetings hosted by the GSAs, Annual Reports and Periodic Evaluations, public scoping meetings, and/or applicable permitting notification processes.
8.3.3.1.3. Permitting and Regulatory Process
Required permitting and regulatory review would be initiated as necessary through consultation with applicable governing agencies. Surface water would be diverted through this project by MID via existing water rights. Governing agencies that may be consulted for this Project include but are not limited to the State Water Resources Control Board (SWRCB), Stanislaus and/or Tuolumne Counties, USBR, and DWR.
If necessary, Project proponents will obtain any applicable permits from the Tuolumne and Stanislaus Counties. Recharge projects and construction or expansion of conveyance facilities may also require an environmental review process under CEQA.
8.3.3.1.4. Expected Benefits
Benefits to Sustainability Indicators
Surface water deliveries during the non-irrigation season are expected to provide direct groundwater recharge to the Subbasin. For fields that are irrigated using groundwater, surface water deliveries during the irrigation season are expected to offset groundwater demand and provide groundwater recharge benefits. In both cases, the sustainability indicators expected to benefit from this Project are groundwater levels, groundwater storage, land subsidence, and interconnected surface water. All benefits to sustainability indicators in the Subbasin will be evaluated through groundwater monitoring at nearby monitoring sites, identified in the GSP.
Benefits to Disadvantaged Communities
The Tuolumne River flood mitigation and direct recharge Project is expected to provide direct recharge for NDE landowners area. Most communities in the Subbasin, particularly the NDE area, are classified as DACs, SDACs, or EDAs (according to 2018 census data, evaluated by place, tract, and block group). Depending on which specific parcels receive surface water deliveries, this Project may directly benefit specific DACs in this area. In addition, maintenance or improvement of groundwater levels will help to protect beneficial groundwater use by rural domestic wells from potential adverse impacts related to groundwater level decline. Benefits to groundwater conditions in the Subbasin are also expected to benefit all DACs, SDACs, and EDAs.
Volumetric Benefits to the Subbasin Groundwater System
The expected yield of the Tuolumne River Flood Mitigation and Direct Recharge Project was estimated through simulations using the C2VSimTM model. General information and assumptions used to simulate this Project are summarized in the following section below.
Additional information is provided in Section 8.5: Plan for Achieving Sustainability.
On average across all years, the project is expected to provide approximately 9,600 AFY of recharge benefit to the Subbasin. These benefits would accrue in years with Wet or Above Normal hydrologic conditions when sufficient water is expected to be available for on-farm #25..
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-52
Revised July 2024
TODD GROUNDWATER
recharge (approximately 50 percent of years historically). In those years, approximately 20,000 AFY of groundwater recharge is expected to occur.
Evaluation of benefits will be based on analysis of without-project and with-project measurements supported by modeling. Measured parameters will include surface water deliveries, groundwater levels, and other parameters to be determined. Modeling for the Project will be done with the C2VSimTM model used for GSP development.
8.3.3.1.5. Implementation Criteria, Status, and Strategy Implementation Strategy and Timeline
Project involves the delivery of surface water from the Tuolumne River in Wet and Above Normal WYs through a limited number of new points of diversions off MID’s existing irrigation conveyance infrastructure and subsequent conveyance through newly constructed private irrigation conveyance infrastructure for direct recharge during the growing season. It is expected that fields with non-permanent crops, permeable soils, and existing flood irrigation infrastructure will be most suitable for Project participation.
The Project is planned for discussion with the MID Water Advisory Committee to determine if an implementation plan will be prepared and recommended to Board of Directors for approval. Thus, the start and completion dates for this Project have yet to be determined and will be provided in Annual Reports and Periodic Evaluations.
However, once Project implementation begins, it is expected that MID would deliver surface water during wet and above normal hydrologic years (approximately 50 percent of years historically) when sufficient water is available for field flooding and on-farm recharge. MID would deliver surface water to participating fields, and irrigators would use that water to flood their fields for recharge. Subsequent analysis of projected water availability, actual annual application rates, and extent of participating lands will be necessary as Project development continues and implementation begins.
Implementation Assumptions for Modeling
The Tuolumne River Flood Mitigation Direct Recharge Project has been modeled in the C2VSimTM model. Additional information about project-related modeling is described in Section 8.5: Plan for Achieving Sustainability.
The following general information and assumptions were used to simulate implementation of the Project:
• Volume of water: 20,000 AFY were provided during Wet and Above Normal years, distributed between the months of January and February for direct recharge. The annual average during the 50-year simulation period would be 9,600 AFY.
8.3.3.1.6. Water Source and Reliability
The Project involves the delivery of approximately 20,000 AF of surface water from the Tuolumne River in Wet and Above Normal WYs through a limited number of new points of #25..
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diversions off MID’s existing irrigation conveyance infrastructure and subsequent conveyance through newly constructed private irrigation conveyance infrastructure for and direct recharge during the non-growing season. Historically (1972-2020), Wet and Above Normal WYs have occurred approximately 47% of the time on the Tuolumne River. Under the current Final Environmental Impact Statement for the relicensing of Don Pedro Reservoir, there is estimated to be approximately 1,500,000 AF of surface water in Wet WYs and 620,000 AF of surface water in Above Normal WYs in the Tuolumne River above and beyond that necessary to meeting existing customer demands (all Tuolumne River Partners) and the recommended instream flow obligations. As a result, 20,000 AF of Tuolumne River surface water to applicable NDE areas during the non-growing season amounts to approximately 1% and 3% of available surface water supply respectively, for Wet and Above Normal WYs. New licenses for diversions/water rights may be required for this project.
8.3.3.1.7. Legal Authority
The GSAs, Districts, and individual Project proponents have the authority to plan and implement projects through consultation with applicable governing agencies. MID has the authority to contract with and provide deliveries to NDE landowners, and individual irrigators have the authority to apply surface water to their fields for on-farm recharge.
8.3.3.1.8. Estimated Costs and Funding Plan
Potential costs for this Project include coordination and administration, financial, or other incentives to encourage on-farm recharge, field preparation to enhance flooding, and other potential on-field monitoring equipment. Costs per site may vary depending on changes in Project implementation and incentives. Slightly higher costs per site would likely be incurred in the first year an irrigator participates, as more coordination and site preparation may be required. The total costs of the Project will vary over time, depending on the number of sites receiving water, the extent to which irrigators require coordination and support, and any applicable Project incentives.
This Project is currently in the early conceptual stage. Thus, the anticipated costs have yet to be determined and will be reported in GSP Annual Reports and Five-Year Assessment Reports when known. This project shares the same infrastructural development as the Modesto Irrigation District In-Lieu and Direct Recharge Project (Project 5). However, if implemented without Project 5, high-level initial estimates are on the order of $53,340,000 – $75,000,000 of new conveyance infrastructure. It is anticipated that STRGBA GSA member agencies and/or NDE landowners would identify funding sources to cover Project costs as part of Project development. These may include grants (e.g., Prop 1, Prop 68, NRCS, others), fees, and loans.
8.3.3.1.9. Management of Groundwater Extractions and Recharge Per 23 CCR § 354.44(b)(9), all PMAs developed for implementation are targeted to maintain the balance of groundwater extractions and recharge to help ensure that lowering of groundwater levels or depletion of supply during periods of drought is offset by increases in groundwater levels and storage in other years.
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-54
Revised July 2024
TODD GROUNDWATER
Recharge benefits of this Project are expected to increase the use and recharge of available surface water supplies during wetter years, helping to offset potential increases in groundwater pumping during drought when surface water supplies are limited.
8.3.3.2. Dry Creek Flood Mitigation and Direct Recharge Project (Project 8)
8.3.3.2.1. Project Description
The Dry Creek Flood Mitigation and Direct Recharge Project (Project) is intended to be a cooperative long-term Project implemented by the NDE landowners and is designed to be constructed and managed in a way to prevent negative impacts to downstream users.
Currently developed agriculture in the NDE areas is estimated to be approximately 36,000 acres, of which approximately 30,000 acres are deciduous fruits and nuts. With limited exception, the entire NDE area is solely reliant on groundwater from the Modesto Subbasin.
The Project involves the delivery of approximately 5,400 AF of surface water from Dry Creek through a limited number of new and/or existing points of diversions off Dry Creek and subsequent conveyance through new and/or existing private irrigation conveyance infrastructure for direct recharge during the non-growing season. The volume of water associated with this Project was derived from previous work done on behalf of Stanislaus County and is representative of only a fraction of modeled results for a 2-year storm event in the lower reaches of Dry Creek. As a result, both the frequency and volume of water available are conservative estimates. In addition to measurable benefits to groundwater resources within the Modesto subbasin, this Project is intended to mitigate flood flows in Dry Creek whereby reducing impacts on the lower Tuolumne River (City of Modesto and growers near the confluence of the lower Tuolumne River and the San Joaquin River), the San Joaquin River and the Delta. New licenses for diversions/water rights may be required for this project.
8.3.3.2.2. Public Noticing
The public and other agencies will be notified of the planned or ongoing implementation of Project activities through the outreach and communication channels identified in the GSP, during the preparation process of the PEIR (if applicable), and during updates presented at regularly scheduled STRGBA GSA meetings. Noticing will occur as potential activities are being considered for implementation, and as ongoing and planned activities are implemented. Noticing will inform the public and other agencies that the proponent is considering or will be implementing the Project and will provide a description of the actions that will be taken.
Public and/or inter-agency noticing may be facilitated through STRGBA GSA meetings and/or local agency meetings, associated website(s), inter-basin coordination meetings, other public meetings hosted by the GSAs, Annual reports and Periodic Evaluations, public scoping meetings, and/or applicable permitting notification processes.
8.3.3.2.3. Permitting and Regulatory Process
Required permitting and regulatory review would be initiated as necessary through consultation with applicable governing agencies. Surface water would be diverted through this project by MID via existing water rights. Governing agencies that may be consulted for #25..
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-55
Revised July 2024
TODD GROUNDWATER
this project include but are not limited to the State Water Resources Control Board (SWRCB), Stanislaus and/or Tuolumne Counties, USBR, and DWR.
If necessary, Project proponents will obtain any applicable permits from the Tuolumne and Stanislaus Counties. Recharge projects and construction or expansion of conveyance facilities may also require an environmental review process under CEQA.
8.3.3.2.4. Expected Benefits
Benefits to Sustainability Indicators
Surface water deliveries from storm events during the non-irrigation season are expected to provide direct groundwater recharge to the Subbasin. The sustainability indicators expected to benefit from this project are groundwater levels, groundwater storage, land subsidence, and interconnected surface water. All benefits to sustainability indicators in the Subbasin will be evaluated through groundwater monitoring at nearby monitoring sites, identified in the GSP.
Benefits to Disadvantaged Communities
The Dry Creek Flood Mitigation and Direct Recharge Project is expected to provide direct recharge for NDE landowners area. Most communities in the Subbasin, including the NDE area, are classified as DACs, SDACs, or EDAs (according to 2018 census data, evaluated by place, tract, and block group). Depending on which specific parcels receive surface water deliveries, this Project may directly benefit specific DACs in this area. In addition, maintenance or improvement of groundwater levels will help to protect beneficial groundwater use by rural domestic wells from potential adverse impacts related to chronic groundwater level decline. Benefits to groundwater conditions in the Subbasin are also expected to benefit all DACs, SDACs, and EDAs.
Volumetric Benefits to the Subbasin Groundwater System
The expected yield of the Dry Creek Flood Mitigation and Direct Recharge Project was estimated through simulations in the C2VSimTM model. General information and assumptions used to simulate this Project are summarized in the following section.
Additional information is provided in Section 8.5: Plan for Achieving Sustainability.
On average across all years, the Project is expected to provide approximately 5,400 AFY of recharge benefit to the Subbasin.
Evaluation of benefits will be based on analysis of without-project and with-project measurements supported by modeling. Measured parameters will include surface water deliveries, groundwater levels, and other parameters to be determined. Modeling will be done with the C2VSimTM model used for GSP development.
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-56
Revised July 2024
TODD GROUNDWATER
8.3.3.2.5. Implementation Criteria, Status, and Strategy Implementation Strategy and Timeline
The Project anticipates the delivery of approximately 5,400 AF of surface water from Dry Creek through a limited number of new and/or existing points of diversions off Dry Creek and subsequent conveyance through new and/or existing private irrigation conveyance infrastructure for direct recharge during the non-growing season. At the initiation of this Project and on an ongoing basis, the GSAs and/or NDE landowners plan to identify fields that are most suitable for groundwater recharge. It is expected that fields with nonpermanent crops, permeable soils, and existing flood irrigation infrastructure will be most suitable for Project participation.
This Project is currently in the early conceptual stage. Thus, the start and completion dates for this Project have yet to be determined and will be provided in Annual Reports and Periodic Evaluations.
However, once Project implementation begins, it is expected that storm water would be available for diversion during wet and above normal hydrologic years (approximately 50 percent of years historically) when sufficient water is available for field flooding and on-farm recharge. Subsequent analysis of projected water availability, actual annual application rates, and extent of participating lands will be necessary as Project development continues and implementation begins.
Implementation Assumptions for Modeling
The Dry Creek Flood Mitigation Direct Recharge Project has been modeled in the C2VSimTM. Additional information about project-related modeling is described in Section
8.5: Plan for Achieving Sustainability.
The following general information and assumptions were used to simulate implementation of the project:
• Volume of water: 5,400 AFY were diverted during all years, distributed evenly in the months of January and February. The annual average during the 50-year simulation period would be 5,400 AFY.
• The total volume would be applied as direct recharge over the aquifer.
8.3.3.2.6. Water Source and Reliability
The Project involves the diversion and application of approximately 5,400 AF of surface water from Dry Creek through a limited number of new and/or existing points of diversions off Dry Creek and subsequent conveyance through new and/or existing private irrigation conveyance infrastructure for direct recharge during the non-growing season. The volume of water associated with this Project was derived from previous work done on behalf of Stanislaus County and is representative of only a fraction of modelled results for a 2-year storm event in the lower reaches of Dry Creek. As a result, both the frequency and volume of water available are conservative estimates. In addition to measurable benefits to #25..
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-57
Revised July 2024
TODD GROUNDWATER
groundwater resources within the Subbasin, this Project is intended to mitigate flood flows in Dry Creek whereby reducing impacts on the lower Tuolumne River (City of Modesto and growers near the confluence of the lower Tuolumne River and the San Joaquin River), the San Joaquin River and the Delta. New licenses for diversions/water rights may be required for this project.
8.3.3.2.7. Legal Authority
The GSAs and Project proponents have the authority to plan and implement projects through consultation with applicable governing agencies. Individual irrigators have the authority to apply surface water to their fields for on-farm recharge. However, new licenses for diversions/water rights may be required for this Project.
8.3.3.2.8. Estimated Costs and Funding Plan
Potential costs of this Project include coordination and administration, financial, or other incentives to encourage on-farm recharge, field preparation to enhance flooding, and other potential on-field monitoring equipment. Costs per site may vary depending on changes in project implementation and incentives. Slightly higher costs per site would likely be incurred in the first year an irrigator participates, as more coordination and site preparation may be required. The total costs of the Project will vary over time, depending on the number of sites receiving water, the extent to which irrigators require coordination and support, and any applicable Project incentives.
This Project is currently in the early conceptual stage. Thus, the anticipated costs have yet to be determined and will be reported in Annual Reports and Periodic Evaluations. However, high-level initial estimates are on the order of $4,800,600 - $6,750,000 of new conveyance infrastructure. It is anticipated that STRGBA GSA member agencies would identify funding sources to cover Project costs as part of development. These may include grants (e.g., Prop 1, Prop 68, NRCS, others), fees, and loans.
8.3.3.2.9. Management of Groundwater Extractions and Recharge Per 23 CCR § 354.44(b)(9), all PMAs developed for implementation are targeted to maintain the balance of groundwater extractions and recharge to help ensure that lowering of groundwater levels or depletion of supply during periods of drought is offset by increases in groundwater levels and storage in other years.
Recharge benefits of this project are expected to increase the use and recharge of available surface water supplies during wetter years, helping to offset potential increases in groundwater pumping during drought when surface water supplies are limited.
8.4. SUPPLEMENTAL PROJECTS
This section describes Projects that may be implemented in the Subbasin to support local goals and future GSA activities (Supplemental Projects, Table 8-3). Group 3 projects are not currently planned for implementation; however, the GSAs will continue assessing their feasibility to support sustainable groundwater management. Regardless, should these projects be implemented, the projects would provide benefits in contributing to the #25..
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-58
Revised July 2024
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attainment of SMCs and the sustainability goal. Group 3 projects are in the early conceptual or planning stages at this time, with no specific implementation timeline established.
Summary of Criteria for Project Implementation (23 CCR §354.44(b)(1)(A)) As described above, the Projects described in this section are still in the early conceptual or planning stages. The GSAs will continue evaluating the feasibility for implementing these projects in the future. Additional projects may be added to this list as they are identified and reported through Annual Reports and Periodic Evaluations of the GSP.
In addition, there are projects that have been considered in the past as part of the Integrated Regional Water Management Planning (IRWMP) and are included in the East Stanislaus IRWMP project database1
. These projects are considered as potential projects to support the groundwater sustainability in the Subbasin but are currently considered as alternative options and are not directly analyzed in this Chapter.
8.4.1. Stanislaus River Flood Mitigation and Direct Recharge Project (Project 9) The Stanislaus River Flood Mitigation and Direct Recharge Project (Project) is proposed by the NDE landowners to be a cooperative long-term Project with OID and is designed to be implemented with no impacts to OID’s existing agricultural customers. The project differs from the Oakdale Irrigation District In-lieu and Direct Recharge Project, namely from a timing perspective, and involves the delivery of approximately 5,000 AF of surface water from the Stanislaus River in Wet WYs through a limited number of new points of diversion off OID’s existing irrigation conveyance infrastructure and subsequent newly constructed private irrigation conveyance infrastructure for direct recharge during the non-growing season. Storage in New Melones is approximately 2.5 times what the watershed yields on an average annual basis and as a result, the magnitude and frequency (5,000 AF and Wet WYs) of this Project has been limited. Nonetheless, this Project is intended to mitigate flood releases from New Melones Reservoir during the winter months whereby reducing impacts on the lower Stanislaus River (growers along the lower Stanislaus River), the San Joaquin River and the Delta. This Project may require the acquisition of a right to divert flood flows and supplemental groundwater storage application, as well as agreements with multiple agencies potentially including but not limited to, UBSR, OID, and the SWRCB for the revised operation of existing storage facilities, water diversion and rights on the Stanislaus River.
Further analysis, consultation, and review is anticipated prior to any determination of water availability and utilization for the project. Additional considerations may include the terms and negotiations of a new water rights permit/license. Historical operations of New Melones Reservoir and future water supply availability also have the potential to change significantly if the Lower San Joaquin River flow objectives proposed in the Bay-Delta Plan amendments and Final SED are implemented.
1 http://www.eaststanirwm.org/projects/
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Revised July 2024
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A summary of the Project is provided in Table 8-5.
Table 8-5: Stanislaus River Flood Mitigation and Direct Recharge Project: Summary (23 CCR §354.44(b))
Item in GSP
Regulations Description
Implementation
Strategy and Criteria
(§354.44(b)(1)(A);
§354.44(b)(6))
Utilizing the conveyance infrastructure provided by the OID In-lieu and Direct Recharge Project, this Project would provide approximately 5,000 AF of surface water from the Stanislaus River in Wet WYs. The Project is intended to mitigate flood releases from New Melones Reservoir during the winter months whereby reducing impacts on the lower Stanislaus River, the San Joaquin River, and the Delta. The Project is currently in the conceptual stage and will continue to be evaluated by the GSAs and NDE landowners.
Timeline and
Implementation
Status
(§354.44(b)(4))
Project start and completion dates have not been determined. Updates to Project activities will be provided in Annual Reports and Periodic Evaluations. Benefits are expected to accrue in wet hydrologic year types when flood water is available for use, potentially beginning the first year of Project implementation.
Public Noticing
(§354.44(b)(1)(B))
Public and/or inter-agency noticing may be facilitated through STRGBA GSA meetings and/or local agency meetings, associated website(s), interbasin coordination meetings, other public meetings hosted by the GSAs, Annual Reports and Periodic Evaluations, public scoping meetings, and/or applicable permitting notification processes.
Water Source &
Reliability
(§354.44(b)(6))
The Project would use available flood water from the Stanislaus River.
The precise reliability of available water would be identified when the Project has been evaluated and developed for implementation. This information will be reported in Annual Reports and Periodic Evaluations.
Legal Authority,
Permitting and
Regulatory Processes,
(§354.44(b)(3);
§354.44(b)(7))
Required permitting and regulatory review will be Project-specific and initiated through consultation with applicable governing agencies.
Governing agencies for which consultation will be initiated will be identified during Project evaluation.
Benefits and benefit
evaluation
methodology
(§354.44(b)(5))
The sustainability indicators expected to benefit would be determined during Project evaluation. Conceptually, groundwater levels, groundwater storage, land subsidence, and interconnected surface water would benefit from this project.
The expected groundwater benefits from the Project are not yet known and will be determined during project evaluation. Evaluation of benefits will be based on analysis of without- project and with-project effects on sustainability indicators. Each Project may be evaluated as part of a scenario and the C2VSimTM would be used to assess the benefits and impacts on the subbasin sustainability.
Costs
(§354.44(b)(8))
The anticipated costs of this Project will be determined during its evaluation. The Project proponent would identify funding sources to cover costs as part of Project development. These may include grants, fees, loans, and other assessments.
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Modesto Subbasin GSP
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Revised July 2024
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8.4.2. Retention System Standards Specifications Update (Project 10) The Retention System Standards Specifications Update Project (Project) would aim to change standards for future storm drains so that the drains would not discharge straight to rivers, creeks, or canals but rather to retention systems. This would increase the sustainability footprint of the City of Modesto through future growth. Approximately 36 percent of the surface area in the City of Modesto drains to surface water, with approximately 64 percent draining and contributing to local recharge. If the City of Modesto adopts new storm drain standards, 100 percent of runoff from newly developed areas would reach a retention system with an approximate runoff coefficient of 0.7 and an average rainfall of 12.14 inches per year.
A summary of the Project is provided in Table 8-6.
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Modesto Subbasin GSP
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Revised July 2024
TODD GROUNDWATER
Table 8-6: Retention System Standards Specifications Update: Summary (23 CCR §354.44(b))
Item in GSP
Regulations Description
Implementation
Strategy and Criteria
(§354.44(b)(1)(A);
§354.44(b)(6))
The Project would aim to change standards for future storm drains so that the drains would not discharge straight to rivers, creeks, or canals but rather to retention systems. The Project is currently in the conceptual stage and is being evaluated by the GSAs.
Timeline and
Implementation
Status
(§354.44(b)(4))
Project start and completion dates have not been determined. Updates on Project activities will be provided in Annual Reports and Periodic Evaluations. Benefits are expected to accrue in all years and potentially beginning the first year of implementation.
Public Noticing
(§354.44(b)(1)(B))
Public and/or inter-agency noticing may be facilitated through STRGBA GSA meetings and/or local agency meetings, associated website(s), interbasin coordination meetings, other public meetings hosted by the GSAs, Annual Reports and Periodic Evaluations, public scoping meetings, and/or applicable permitting notification processes.
Water Source &
Reliability
(§354.44(b)(6))
This Project would use urban storm runoff flows from the City of Modesto. This Project is currently in the early conceptual stage. The precise reliability of available water would be identified when the Project has been evaluated and selected and developed for implementation. This information will be reported in Annual Reports and Periodic Evaluations.
Legal Authority,
Permitting and
Regulatory Processes
(§354.44(b)(3);
§354.44(b)(7))
Required permitting and regulatory review will be project-specific and initiated through consultation with applicable governing agencies.
Governing agencies for which consultation will be initiated will be identified during Project evaluation.
Benefits and Benefit
Evaluation
Methodology
(§354.44(b)(5))
The sustainability indicators expected to benefit would be determined during Project evaluation. Conceptually, groundwater levels, groundwater storage, land subsidence, and interconnected surface water would benefit from this Project.
The expected groundwater benefits from the project are not yet known and will be determined during project evaluation. Evaluation of benefits will be based on analysis of without- project and with-project effects on sustainability indicators. Each Project may be evaluated as part of a scenario and the C2VSimTM would be used to assess the benefits and impacts on the subbasin sustainability.
Costs
(§354.44(b)(8))
The anticipated costs of this Project will be determined during its evaluation. The project proponent would identify funding sources to cover costs as part of Project development. These sources may include grants, fees, loans, and other assessments.
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Revised July 2024
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8.4.3. Recharge Ponds Constructed by Non-District East Landowners (Project 11) The Recharge Ponds Constructed by Non-District East Landowners Project (Project) would capture wintertime runoff from the Dry Creek Watershed by constructing detention basins.
It is anticipated the basins would be constructed by NDE Landowners. NDE participants have identified five reservoirs for direct diversion and off-stream storage through an existing water right on Dry Creek. Diversions would originate from a facility on Dry Creek, which was constructed and fully operational by February 2021, to the reservoirs for storage. Stored water would then be used during the growing season in-lieu of groundwater while also providing direct recharge benefits. Conveyance infrastructure from the diversion facility to the proposed reservoirs and receiving irrigated acreage was completed in April 2024. The Project is currently in the conceptual phase. Project scope, implementation schedule, groundwater benefits, and costs will be evaluated further and presented in Annual Reports and Periodic Evaluations.
A summary of the Project is provided in Table 8-7.
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Modesto Subbasin GSP
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Revised July 2024
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Table 8-7: Recharge Ponds Constructed by Non-District East Landowners: Summary (23 CCR §354.44(b))
Item in GSP
Regulations Description
Implementation
Strategy and Criteria
(§354.44(b)(1)(A);
§354.44(b)(6))
This Project would capture wintertime runoff from the Dry Creek Watershed by constructing detention basins. It is anticipated the basins would be constructed by NDE Landowners.
The project is currently in the conceptual stage and is being evaluated by the GSAs.
Timeline and
Implementation Status
(§354.44(b)(4))
Project start and completion dates have not been determined. Updates on Project activities will be provided in Annual Reports and Periodic Evaluations. Benefits are expected to accrue during the winter months beginning the first year of implementation.
Public Noticing
(§354.44(b)(1)(B))
Public and/or inter-agency noticing may be facilitated through STRGBA GSA meetings and/or local agency meetings, associated website(s), inter-basin coordination meetings, other public meetings hosted by the GSAs, Annual Reports and Periodic Evaluations, public scoping meetings, and/or applicable permitting notification processes.
Water Source &
Reliability
(§354.44(b)(6))
This project would use water from the Dry Creek Watershed. This Project is currently in the early conceptual stage. The precise reliability of available water would be identified when the project has been evaluated and selected and developed for implementation. This information will be reported in Annual Reports and Periodic Evaluations.
Legal Authority,
Permitting and
Regulatory Processes
(§354.44(b)(3);
§354.44(b)(7))
Required permitting and regulatory review will be project-specific and initiated through consultation with applicable governing agencies.
Governing agencies for which consultation will be initiated will be identified during project evaluation.
Benefits and Benefit
Evaluation
Methodology
(§354.44(b)(5))
The sustainability indicators expected to benefit would be determined during project evaluation. Conceptually, groundwater levels, groundwater storage, land subsidence, and interconnected surface water would benefit from this project.
The expected groundwater benefits from the project are not yet known and will be determined during project evaluation. Evaluation of benefits will be based on analysis of without- project and with-project effects on sustainability indicators. Each Project may be evaluated as part of a scenario and the C2VSimTM would be used to assess the benefits and impacts on the subbasin sustainability.
Costs
(§354.44(b)(8))
The anticipated costs of this project will be determined during its evaluation. The project proponent would identify funding sources to cover costs as part of project development. These sources may include grants, fees, loans, and other assessments.
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-64
Revised July 2024
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8.4.4. OID Irrigation and Recharge to Benefit City of Oakdale (Project 12) The OID Irrigation and Recharge to Benefit City of Oakdale Project (Project) proposes to utilize surface water from OID to irrigate the City of Oakdale’s parks. The first phase of this Project was constructed at two City of Oakdale parks to assess the costs and benefits for implementation of additional components. The two parks involved in the initial phase are located near an existing OID conveyance system. Surface water for irrigation is being provided for City of Oakdale use during the irrigation, starting as early as March 1st and ending no later than October 31st each year. Anticipated yield from the Project is approximately 50 AF per year. Pending results from the initial phase of the Project, expanded implementation of this Project in cooperation with OID may be subsequently considered by the City of Oakdale.
A summary of the Project is provided in Table 8-8.
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-65
Revised July 2024
TODD GROUNDWATER
Table 8-8: OID Irrigation and Recharge to Benefit City of Oakdale Summary (23 CCR §354.44(b))
Item in GSP Regulations Description
Implementation Strategy
and Criteria
(§354.44(b)(1)(A);
§354.44(b)(6))
This Project aims to reduce City of Oakdale groundwater pumping by providing OID surface water for irrigation of City parks.
Construction of the first phase of implementation has been completed. The City of Oakdale may decide to pursue expansion in the future if the first phase is successful and additional strategies are needed to reach sustainability.
Timeline and
Implementation Status
(§354.44(b)(4))
Construction of the first phase of the Project was completed by the summer of 2023. Updated Project results will be provided in GSP Annual Reports and Five-Year Assessment Reports. Benefits are expected to accrue in all hydrologic year types provided OID’s surface water allocation is sufficient, potentially beginning the first year of Project implementation.
Public Noticing
(§354.44(b)(1)(B))
Public and/or inter-agency noticing may be facilitated through STRGBA GSA meetings and/or local agency meetings, associated website(s), inter-basin coordination meetings, other public meetings hosted by the GSAs, Annual Reports and Periodic Evaluations, public scoping meetings, and/or applicable permitting notification processes.
Water Source &
Reliability
(§354.44(b)(6))
The City of Oakdale remains within the OID boundary and thus is entitled to receive OID surface water when it is available.
Legal Authority,
Permitting and
Regulatory Processes
(§354.44(b)(3);
§354.44(b)(7))
The Districts, Cities, and Project proponents have the authority to plan and implement projects. Required permitting and regulatory review will be project-specific and initiated through consultation with applicable governing agencies. Governing agencies for which consultation will be initiated will be identified during project evaluation.
Benefits and Benefit
Evaluation Methodology
(§354.44(b)(5))
The sustainability indicators expected to benefit are groundwater levels, groundwater storage, land subsidence, and interconnected surface water.
This first phase of the Project has been constructed. The anticipated yield of this Project is approximately 50 AF per year; results will be reported in Annual Reports and Periodic Evaluations once available.
Evaluation of benefits will be based on analysis of without-project and with-project impacts on the sustainability indicators. The project may be evaluated as part of a scenario and the C2VSimTM would be used to assess the benefits and impacts on the Subbasin.
Costs
(§354.44(b)(8))
This first phase of the project cost approximately $250,000. Costs of any future expansion have not been determined. The project proponent would identify funding sources to cover project costs as part of project development. These may include grants, fees, loans, and other assessments.
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-66
Revised July 2024
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8.4.5. MID Flood-MAR Projects (Project 13)
The MID Flood-MAR Projects (Project) would support the development of flood managed aquifer recharge (Flood-MAR) activities in locations in MID boundaries where storm flows are available, or where existing surface water facilities can be utilized to direct and control surface water for various beneficial uses. Components of this Project would be developed privately or as coordinated efforts. Necessary infrastructure would be installed to connect existing delivery systems to Flood-MAR activities. The Project is still conceptual and undergoing evaluation, however, the next steps would likely include a feasibility analysis and design.
A summary of the Project is provided in Table 8-9.
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-67
Revised July 2024
TODD GROUNDWATER
Table 8-9: MID Flood-MAR Projects Summary (23 CCR §354.44(b)) Item in GSP Regulations Description
Implementation Strategy
and Criteria
(§354.44(b)(1)(A);
§354.44(b)(6))
This Project would support the development Flood-MAR activities in locations in MID where storm flows are available, or where existing surface water facilities can be utilized to direct and control stormwater for various beneficial uses.
Timeline and
Implementation Status
(§354.44(b)(4))
Project start and completion dates have not been determined.
Updates on project activities will be provided in Annual Reports and Periodic Evaluations.
Benefits would be expected to accrue in Wet and Above Normal WYs when flood water is available for use.
Public Noticing
(§354.44(b)(1)(B))
Public and/or inter-agency noticing may be facilitated through STRGBA GSA meetings and/or local agency meetings, associated website(s), inter-basin coordination meetings, other public meetings hosted by the GSAs, Annual Reports and Periodic Evaluations, public scoping meetings, and/or applicable permitting notification processes.
Water Source &
Reliability
(§354.44(b)(6))
This Project would use water from storm flows or other excess flow.
This Project is currently in the early conceptual stage. The precise reliability of available water would be identified when the project has been evaluated and selected and developed for implementation. This information will be reported in Annual Reports and Periodic Evaluations.
Legal Authority,
Permitting and
Regulatory Processes
(§354.44(b)(3);
§354.44(b)(7))
Required permitting and regulatory review will be project-specific and initiated through consultation with applicable governing agencies.
Governing agencies for which consultation will be initiated will be identified during project evaluation.
Benefits and Benefit
Evaluation Methodology
(§354.44(b)(5))
The sustainability indicators expected to benefit would be determined during project evaluation. Conceptually, groundwater levels, groundwater storage, land subsidence, and interconnected surface water would benefit from this project.
The expected groundwater benefits from the project are not yet known and will be determined during project evaluation. Evaluation of benefits will be based on analysis of without- project and with-project effects on sustainability indicators. Each Project may be evaluated as part of a scenario and the C2VSimTM would be used to assess the benefits and impacts on the subbasin sustainability.
Costs
(§354.44(b)(8))
The anticipated costs of this project will be determined during its evaluation. The project proponent would identify funding sources to cover costs as part of project development. These sources may include grants, fees, loans, and other assessments.
#25..
- 2093 -
Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-68
Revised July 2024
TODD GROUNDWATER
8.5. PLAN FOR ACHIEVING SUSTAINABILITY
8.5.1. Integrated Modeling Scenarios
To evaluate the effects of PMAs in meeting the sustainability goals of the Modesto Subbasin, Group 1 and 2 Projects have been analyzed using the C2VSimTM model.
C2VSimTM is a fully integrated surface and groundwater flow model capable of analyzing the effects of the PMAs on the land surface, stream, and groundwater systems of the Modesto Subbasin. The C2VSimTM model is used to develop the GSP’s water budget estimates for historical, current, and projected conditions, as well as Subbasin groundwater levels, streamflow, and interconnected surface water bodies under historical, baseline, and various Project conditions. It is understood that the projections of future groundwater conditions using the C2VSimTM model are based on the current understanding of the Subbasin, which can be further refined as more information becomes available. The 50-year projection of groundwater conditions using C2VSimTM is based on assumptions that has uncertainties in hydrologic and climatic conditions, agricultural crop mix and patterns, irrigation practices, population growth patterns and urban development trends, and land use plans, and environmental regulations. However, the C2VSimTM is currently the best available analysis tool to assist in evaluation of Project benefits and impacts, not in an absolute sense, but in a relative scale.
The analysis below evaluates the proposed projects relative to the C2VSimTM Projected Conditions Baseline. The results of this analysis are then compared to MTs to estimate the approximate amount of additional net demand reduction that will be needed to meet the sustainability goal of the Subbasin. The Projected Conditions Baseline applies the projected water supply and demand conditions under the 50-year hydrologic period of WYs 1969- 2018. A total of seven (7) Group 1 and 2 Projects were grouped into two (2) scenarios based on their use-sector and Project type. Table 8-10 shows a matrix of the simulated projects and their respective scenarios. Each of these projects are described in detail in Section 8.2, with modeling assumptions outlined in Section 5 for each Project. #25..
- 2094 -
Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-69
Revised July 2024
TODD GROUNDWATER
Table 8-10: Projects Analyzed Using C2VSimTM Model
Urban and Municipal Projects Scenario 1 Scenario 2
1 Growth Realization of Surface Water Treatment Plant
Phase II Baseline Baseline
2 Municipal Conservations Projects X X
3 Storm Drain Cross Connection Removal Project X X
4 Surface Water Supply Project X X
In-lieu Supply or Recharge Projects
5 MID to Out-of-District Lands In-lieu and Direct Recharge Project X
6 OID to Out-of-District Lands In-lieu and Direct Recharge Project X
Flood Mitigation Projects
7 Tuolumne River Flood Mitigation Direct Recharge Project X 8 Dry Creek Flood Mitigation Direct Recharge Project X
Scenario 1: Urban and Municipal Surface Water Supply
Scenario 1 includes the three urban and municipal projects as proposed by their respective agencies. These projects, shown in Table 8-11 total an average net-recharge of 13,700 AFY over the 50-year simulation period. Impacts to the subbasin were simulated by reducing the urban demand in the City of Modesto, providing surface water supplies to the City of Waterford, and incorporating additional recharge facilities throughout the City of Modesto.
Table 8-11 below summarizes the individual and cumulative impacts of each Project within this scenario.
#25..
- 2095 -
Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-70
Revised July 2024
TODD GROUNDWATER
Table 8-11: Scenario 1 Project Summary
Project Direct
Recharge
In-Lieu
Recharge
Demand
Reduction
Urban and Municipal Projects
Municipal Conservation Projects1 12,800
Storm Drain Cross Connection Removal
Project 200
City of Waterford Surface Water Supply
Project1 700
All Urban and Municipal Projects 200 700 12,800
All Scenario 1 Projects 200 700 12,800
Notes: All Units are in acre-feet 1 The City of Modesto Conservation Projects and the City of Waterford Surface Water Supply Project include beneficiaries in both the Turlock and Modesto Subbasin. The volumes in this table represent an estimated fraction of the effective contribution to the Modesto Subbasin Scenario 1 projects are expected to reduce net groundwater pumping in the Subbasin by 13,700 AFY. The net benefit to groundwater storage is to reduce the projected average annual groundwater storage deficit from 11,000 AFY under the Baseline conditions to 9,500 AFY with these projects, resulting in a net savings of 1,500 AFY of groundwater in storage.
Details are shown in Table 8-13 and Figure 8-1.
Principally, Scenario 1 projects were implemented to mitigate lowering groundwater levels, depletions of interconnected surface water systems, and potential subsidence near the urban centers within the Modesto Subbasin. Section 8.5.2 presents the simulated groundwater conditions under both the projected conditions baseline and each of the PMA scenarios.
Scenario 1 is anticipated to be implemented in conjunction with multiple other agriculturally based projects to further improve and project aquifer conditions. See the descriptions of the following scenario for information on the cumulative impacts to the system.
Scenario 2: In-Lieu Supply Recharge and Flood Mitigation Projects Scenario 2 builds on the benefits of Scenario 1 to incorporate the agriculturally based in-lieu and direct recharge projects. The addition of the projects to this scenario increases the net simulated contribution to the groundwater system from an average of 13,700 AF to 71,900 AFY. The four proposed projects include
1. The MID to Out-of-District Lands In-lieu and Direct Recharge Project, providing up to 60,000 AF of in-lieu recharge in Wet and Above Normal years, or an average annual contribution of 28,800 over the 50-year simulation period. #25..
- 2096 -
Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-71
Revised July 2024
TODD GROUNDWATER
2. The OID to Out-of-District Lands In-lieu and Direct Recharge Project, providing up to 20,000 AFY of in-lieu recharge in all non-critically dry years, providing an average of 14,400 across the planning horizon.
3. The Tuolumne River Flood Mitigation Direct Recharge Project, providing 20,000 AFY of direct recharge in Wet and Above Normal years (9,600 AFY in the 50-year simulation average),
4. The Dry Creek Flood Mitigation Direct Recharge Project, providing 5,400 AFY of direct recharge in all year types.
Table 8-12 below summarizes the individual and cumulative impacts of each Project within this scenario.
Table 8-12: Scenario 2 Project Summary
Project Direct
Recharge
In-Lieu
Recharge
Demand
Reduction
Urban and Municipal Projects
Municipal Conservation Projects1 12,800
Storm Drain Cross Connection Removal Project 200
City of Waterford Surface Water Supply
Project1 700
All Urban and Municipal Projects 200 700 12,800
In-lieu Supply and Direct Recharge Projects
MID to Out-of-District Lands In-lieu and Direct
Recharge Project 9,600 19,200
OID to Out-of-District Lands In-lieu and Direct
Recharge Project 1,400 13,000
All In-lieu Supply or Recharge Projects 11,000 32,200 0 Flood Mitigation Projects
Tuolumne River Flood Mitigation Direct
Recharge Project 9,600
Dry Creek Flood Mitigation Direct Recharge
Project 5,400
All In-lieu Supply or Recharge Projects 15,000 0 0
All Scenario 2 Projects 26,200 32,900 12,800
Notes: All Units are in acre-feet 1 The City of Modesto Conservation Projects and the City of Waterford Surface Water Supply Project include beneficiaries in both the Turlock and Modesto Subbasin. The volumes in this table represent an estimated fraction of the effective contribution to the Modesto Subbasin #25..
- 2097 -
Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-72
Revised July 2024
TODD GROUNDWATER
Scenario 2 projects are expected to reduce groundwater pumping in the subbasin by 44,400 AFY. The net benefit to groundwater storage projected is to reduce the average annual groundwater storage deficit from 11,000 AFY under the Baseline conditions to an average annual positive change in storage of 1,400 AFY with these projects, resulting in a net savings of 12,400 AFY of groundwater in storage. Details are shown in Table 8-13 and Figure 8-1.
Analysis of conditions under Scenario 2 show that under Project buildout, sustainability goals as defined by the Minimum Thresholds (MTs) outlined in Chapter 6, Sustainable Management Criteria, can be met without demand management. Section 8.5.2 below shows how Scenarios 1 and 2 effect groundwater levels at representative monitoring locations throughout the subbasin relative to the simulated minimum thresholds.
While simulated conditions meet sustainability metrics in the long-term, the Modesto Subbasin acknowledges that these scenarios assume immediate implementation of the projects and MAs listed above. In the near-term, sustainability of the Modesto Subbasin relies on the NDE area to actively pursue the development of these projects and understands that interim MAs, including the potential for demand reduction, may be necessary to meet SMCs.
Figure 8-1: Scenario 1-2 Cumulative Change in Storage
#25..
- 2098 -
Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-73
Revised July 2024
TODD GROUNDWATER
Figure 8-2: Scenario 2 Groundwater Budget
Table 8-13: Scenarios 1-2 Groundwater Budgets
Baseline Scenario 1
Urban & Municipal
Scenario 2
In-lieu and Direct
Recharge Projects
Deep Percolation 234,900 230,100 235,800
Canal, Res., & Direct
Recharge 47,300 47,500 73,500
Net Stream Seepage 24,300 18,800 -4,100
Inflow from Foothills 9,300 9,300 9,300
Net Subsurface Flow -5,900 -7,600 -36,500
Groundwater Pumping 321,000 307,600 276,600
Groundwater Storage
Deficit 11,000 9,500 -1,400
8.5.2. Representative Hydrographs Scenarios 1-2
Figure 8-3 shows the location of the representative monitoring wells that were used in the development and calibration of the Modesto Subbasin in C2VSimTM. As representative wells of simulated conditions, these wells were used to evaluate the performance of the PMAs in each of the different scenarios.
#25..
- 2099 -
Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-74
Revised July 2024
TODD GROUNDWATER
Figure 8-3: Modesto Subbasin Representative Wells
Chapter 6: Sustainable Management Criteria describes thresholds for representative monitoring network wells that protect the Subbasin from experiencing Undesirable Results from the chronic lowering of groundwater levels (SMC1), and depletions of interconnected surface water systems (SMC6). Chapter 6 defines Undesirable Results such that at no more than 33% of the representative monitoring wells shall exceed the 2015-low for a period longer than 3 consecutive years. Under Scenario 2, SGMA compliance was predicted to be met throughout the simulation period. As shown in the figures below, simulated groundwater levels occasionally drop below the MT, but do not exceed the combination of drought-time spatial and temporal limitations.
Note, the twelve wells listed below (Figure 8-5 though Figure 8-16) are not inclusive of all monitoring locations, rather this subset was included as they are considered representative of RMS throughout the Subbasin. Locations of these example representative hydrographs are shown in Figure 8-4 below.
#25..
- 2100 -
Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-75
Revised July 2024
TODD GROUNDWATER
Figure 8-4: SMC1 Example Hydrographs
Figure 8-5: SMC1 Hydrograph C2VSimTM 01
#25..
- 2101 -
Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-76
Revised July 2024
TODD GROUNDWATER
Figure 8-6: SMC1 Hydrograph C2VSimTM 07
Figure 8-7: SMC1 Hydrograph C2VSimTM 11
#25..
- 2102 -
Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-77
Revised July 2024
TODD GROUNDWATER
Figure 8-8: SMC1 Hydrograph C2VSimTM 19
Figure 8-9: SMC1 Hydrograph C2VSimTM 24
#25..
- 2103 -
Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-78
Revised July 2024
TODD GROUNDWATER
Figure 8-10: SMC1 Hydrograph C2VSimTM 34
Figure 8-11: SMC1 Hydrograph C2VSimTM 45
#25..
- 2104 -
Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-79
Revised July 2024
TODD GROUNDWATER
Figure 8-12: SMC1 Hydrograph C2VSimTM 48
Figure 8-13: SMC1 Hydrograph C2VSimTM 52
#25..
- 2105 -
Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-80
Revised July 2024
TODD GROUNDWATER
Figure 8-14: SMC1 Hydrograph C2VSimTM 54
Figure 8-15: SMC1 Hydrograph C2VSimTM 64
#25..
- 2106 -
Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 8-81
Revised July 2024
TODD GROUNDWATER
Figure 8-16: SMC1 Hydrograph C2VSimTM 65
#25..
- 2107 -
Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 9-1
Revised July 2024
TODD GROUNDWATER
9. IMPLEMENTATION PLAN
9.1. PLAN IMPLEMENTATION
Implementation of this GSP includes implementation of the projects and MAs included in Chapter 8, as well as the following:
• Modesto Subbasin GSAs administration and management
• Implementing the monitoring program
• Implementation of Projects and Management Actions
• Developing Annual Reports
• Developing Periodic Evaluations
This chapter also describes the contents of both the annual and periodic evaluations that must be provided to the California Department of Water Resources (DWR) as required by Sustainable Groundwater Management Act (SGMA) regulations.
9.1.1. Implementation Schedule
Figure 9-1 illustrates the GSP’s implementation schedule. Included in the chart are activities necessary for ongoing GSP monitoring and updates, as well as tentative schedules for projects and MAs. Additional details about the activities included in the schedule are provided in these activities’ respective sections of this GSP. #25..
- 2108 -
Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 9-2
Revised July 2024
TODD GROUNDWATER
Figure 9-1: Implementation Estimated Schedule1,2
# Project/Management Action Name
20232024202520262027202820292030203120322033203420352036203720382039204020412042 Beyond
Urban and Municipal Projects
1 Growth Realization of Surface Water Treatment Plant Phase II
2 Advanced Metering Infrastructure (AMI) Project
3 Storm Drain Cross Connection Removal Project3
4 Surface Water Supply Project
In-Lieu & Direct Recharge Projects
5 MID to Out-of-District Lands In-lieu and Direct Recharge Project
6 OID to Out-of-District Lands In-lieu and Direct Recharge Project
Flood Mitigation Projects
7 Tuolumne River Flood Mitigation Direct Recharge Project 8 Dry Creek Flood Mitigation Direct Recharge Project
Management Actions
1 Groundwater Allocation and Pumping Management Program 2 Groundwater Extraction and Surface Water Reporting
Program
3 Groundwater Extraction Fee
4 Groundwater Pumping Credit Market and Trading Program 5 Voluntary Conservation and/or Land Fallowing
6 Conservation Practices
7 Dry Well Mitigation Program
PMA development and design period Project construction PMA operation 1 Supplemental projects (Projects 9 through 13) and are not included because they do not currently have a definite schedule. 2 In accordance with the resolution, a schedule for management actions 1 through 6 will be developed no later than January 31, 2026, and implemented no later than January 31, 2027. The dry well mitigation program (management action 7) will be developed and implemented no later than January 31, 2026.
3 The Storm Drain Cross Connection Removal Project has multiple phases and components that will be developed over time and therefore portions are in development/design, construction, or are completed simultaneously. #25..
- 2109 -
Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 9-3
Revised July 2024
TODD GROUNDWATER
9.2. IMPLEMENTATION COSTS BUDGETS AND FUNDING SOURCES
The operation of the Modesto Subbasin GSAs and GSP implementation will incur costs, which will require funding. The five primary activities that will incur costs are listed here.
Table 9-1 summarizes these activities and their estimated costs. These estimates will be refined during GSP implementation as more information becomes available. • Implementing the GSP
• Implementing GSP-related Projects and Management Actions • Operations of the GSAs
• Developing Annual Reports
• Developing Periodic Evaluations
9.2.1. GSP Implementation and Funding
Costs associated with GSP implementation and operation of the GSAs could include the following:
• Modesto Subbasin GSAs administration and legal support: Overall program management and coordination activities, and legal services • Stakeholder Engagement: GSAs board meetings, Technical Advisory (TAC) meetings, general GSA meetings, and public workshops as needed.
• Outreach: Email communications, newsletters, and website management • GSP implementation program management: Program management and oversight of project and management action implementation, including coordination among GSAs Boards, staff and stakeholders, coordination of GSAs implementation technical activities, oversight and management of the GSAs consultants and subconsultants, budget tracking, schedule management, and quality assurance/quality control of project implementation activities, and integrating and maintaining a live projects and management actions list
• Monitoring: Data collection, filling data gaps, improvements and/or enhancements to DMS
#25..
- 2110 -
Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 9-4
Revised July 2024
TODD GROUNDWATER
Table 9-1: Modesto Subbasin GSAs and GSP Implementation Budgets Activity Estimated Annualized Budget a
GSP Implementation and GSA Management
Administration and Legal Support for the GSAs $35,000
Stakeholder and Board Engagement $3,000
Outreach $5,000
GSP Implementation Program Management $25,000
Monitoring Program, including Data Management $15,000
Annual Reporting $100,000
Periodic Evaluations (total cost estimated to be $500,000, $100,000 annually) $100,000 Data Gap Analysis TBD
Projects and Management Actions
Project 1: Growth Realization of Surface Water Treatment Plant Phase II $93,190,000 Project 2: Advanced Metering Infrastructure Project (AMI) $20,000,000 Project 3: Storm Drain Cross Connection Removal Project $40,000,000 Project 4: Waterford/Hickman Surface Water Pump Station and Storage Tank $8,500,000 Project 5: Modesto Irrigation District In-lieu and Direct Recharge Project $53,340,000 - $75,000,000 Project 6: Oakdale Irrigation District In-lieu and Direct Recharge Project $17,780,000 - $25,000,000 Project 7: Tuolumne River Flood Mitigation and Direct Recharge Project See Project 5 above b Project 8: Dry Creek Flood Mitigation and Direct Recharge Project $4,800,600 - $6,750,000 Project 9: Stanislaus River Flood Mitigation and Direct Recharge Project To be developed during evaluation Project 10: Retention System Standards Specifications Update To be developed during evaluation Project 11: Recharge Ponds To be developed during evaluation Project 12: OID Irrigation and Recharge to Benefit City of Oakdale To be developed during evaluation Project 13: Modesto Irrigation District Flood-MAR Projects To be developed during evaluation MA 1: Groundwater Allocation Program To be determined during evaluation MA 2: Groundwater Extraction and Surface Water Accounting Reporting Program To be determined during evaluation MA 3: Groundwater Extraction Fee To be determined during evaluation MA 4: Groundwater Pumping Credit Market and Trading Program To be determined during evaluation MA 5: Voluntary Conservation and/or Land Fallowing To be determined during evaluation MA 6: Conservation Practices To be determined during evaluation MA 7: Dry Well Mitigation Program Baseline fund: $300,000 a Estimates are rounded and based on full implementation years (FY 2023 through FY 2042). Different costs may be incurred in FY 2022 as GSP implementation begins and during each 5-year update cycle. b Projects 5 and 7 use the same infrastructure for surface water conveyance. #25..
- 2111 -
Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 9-5
Revised July 2024
TODD GROUNDWATER
Implementation of this GSP is projected to run between $250,000 and $350,000 per year, and projects totaling between $237,610,600 - $268,440,000. The GSAs have adopted a resolution committing to the development of MAs and a Well Mitigation Program. The GSAs anticipate having the policies and regulations, estimated future costs and funding sources for MAs and the Well Mitigation Program identified by January 31, 2026.
Development of this GSP was funded through a Proposition 1 Sustainable Groundwater Planning Grant. Operation of the GSAs is fully funded through contributions from GSAs member agencies. Although ongoing operation of the GSAs is anticipated to include contributions from its member agencies, which are ultimately funded through customer fees or other public funds, additional funding may be required to implement the GSP. Of the implementation activities in the GSP, only project implementation is likely to be eligible for grant or loan funding; funding through grants or loans have varying levels of certainty. As such, the GSAs will develop a financing plan that may include one or more of the following financing approaches:
• Pumping Fees: Pumping fees would implement a charge for pumping that would be used to fund GSP implementation activities. In the absence of other sources of funding (i.e., grants, loans, or combined with assessments) fees could range between $10 and $100 per AF per year. To meet the funding needs of the GSP, fees would be lower when pumping is higher, such as current pumping levels, and higher when pumping is lower, such as when sustainable pumping levels are achieved.
Although this funding approach would meet the financial needs of the GSP and GSAs, it may discourage pumping reductions due to cost. The financing plan developed by the GSAs would evaluate how to balance the need for funding with encouraging pumpers to commit to compliance with desired groundwater pumping reduction goals.
• Assessments: Assessments would charge a fee based on land areas. There are two methods for implementing an assessment based on acreage. The first option would assess a fee for all acres in the Subbasin outside of those in federal lands, which would cost approximately $5 to $10 per acre per year. This option would not distinguish between land use types. The second option would be to assess a fee only on irrigated acres. Based on current irrigated acreage, the assessment would be $10 to $50 per acre per year. Similar to the pumping fee approach, assessment based on irrigated acreage could affect agricultural operations and contribute to land use conversions, which could affect the assessment amount or ability to fully fund GSP implementation.
• Combination of fees and assessments: This approach would combine pumping fees and assessments to moderate the effects of either approach on the economy in the Basin. This approach would likely include an assessment that would apply to all acres in the Basin, rather than just to irrigated acreage. It would be coupled with a pumping fee to account for those properties that use more water than others. #25..
- 2112 -
Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 9-6
Revised July 2024
TODD GROUNDWATER
During development of a financing plan, the GSAs would also determine whether to apply fees across the Subbasin as a whole or just within certain Management Areas. Prior to implementing any fee or assessment program, the GSAs would complete a rate assessment study and other analysis consistent with the requirements of Proposition 218.
The GSAs member agencies will pursue grants and loans to help pay for project costs to the extent possible. If grants or loans are secured for project implementation, potential pumping fees and assessments may be adjusted to align with operating costs of the GSAs and ongoing GSP implementation activities. A potential hurdle to the utilization of state grant funding is that delays in payment by the state can cause hardships for disadvantaged communities. Therefore, it would be appropriate to expedite payments associated with grant funding by DWR.
9.2.2. Projects and Management Actions
Costs for the Projects and MAs are described in Chapter 8: Projects and Management Actions of this GSP. Financing of the projects and MAs would vary depending on the activity.
Potential financing options for projects and MAs are provided in Table 9-2, though other financing may be pursued as opportunities arise or as appropriate. #25..
- 2113 -
Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 9-7
Revised July 2024
TODD GROUNDWATER
Table 9-2: Financing Options for Proposed Projects, Management Actions, and Adaptive Management Strategies Project/Activity Responsible Entity Potential Financing Options Projects
Project 1: Growth Realization of Surface Water Treatment Plant Phase II City of Modesto/MID City of Modesto Operating CostsGrants and Loans Project 2: Advanced Metering Infrastructure Project (AMI) City of Modesto City of Modesto Operating Costs Grants and Loans
Project 3: Storm Drain Cross Connection Removal Project City of Modesto City of Modesto Operating Costs Grants and Loans
Project 4: Waterford/Hickman Surface Water Pump
Station and Storage Tank City of Waterford City of Waterford Operating Costs Project 5: Modesto Irrigation District In-lieu and Direct Recharge Project NDE Areas Grants and LoansParticipating NDE landowners Project 6: Oakdale Irrigation District In-lieu and Direct Recharge Project NDE Areas Grants and LoansParticipating NDE landowners Project 7: Tuolumne River Flood Mitigation and Direct
Recharge Project NDE Areas Grants and Loans Participating NDE landowners Project 8: Dry Creek Flood Mitigation and Direct Recharge Project Stanislaus County/NDE Areas Grants and LoansParticipating NDE landowners Project 9: Stanislaus River Flood Mitigation and Direct Recharge Project NDE Areas Grants and LoansParticipating NDE landowners Project 10: Retention System Standards Specifications
Update City of Modesto Grants and LoansCity of Modesto Operating Costs Project 11: Recharge Ponds NDE Areas Grants and Loans
Participating NDE landowners
Project 12: OID Irrigation and Recharge to Benefit City of Oakdale OID/City of Oakdale Grants and LoansCity of Oakdale Operating Costs Project 13: Modesto Irrigation District Flood-MAR Projects MID Grants and Loans MID Operating Costs
Management Actions
MA 1: Groundwater Allocation Program GSAs
Grants and Loans
GSA Operating Funds
GSA Member Agencies
MA 2: Groundwater Extraction and Surface Water
Accounting Reporting Program GSAs
Grants and Loans
GSA Operating Funds
GSA Member Agencies
MA 3: Groundwater Extraction Fee GSAs
Grants and Loans
GSA Operating Funds
GSA Member Agencies
MA 4: Groundwater Pumping Credit Market and Trading
Program GSAs
Grants and Loans
GSA Operating Funds
GSA Member Agencies
MA 5: Voluntary Conservation and/or Land Fallowing GSAs Grants and Loans
GSA Operating Funds
GSA Member Agencies
MA 6: Conservation Practices GSAs
Grants and Loans
GSA Operating Funds
GSA Member Agencies
MA 7: Dry Well Mitigation Program GSAs GSA Operating Funds GSA Member Agencies
#25..
- 2114 -
Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 9-8
Revised July 2024
TODD GROUNDWATER
9.3. ANNUAL REPORTS
Annual reports must be submitted by April 1 of each year following GSP adoption per California Code of Regulations. Annual reports must include three key sections as follows:
• General Information
• Basin Conditions
• Plan Implementation Progress
An outline of what information will be provided in each of these sections in the annual report is included below. Annual reporting will be completed in a manner and format consistent with Section 356.2 of the SGMA regulations. As annual reporting continues, it is possible that this outline will change to reflect Subbasin conditions, priorities of the GSAs, and applicable requirements.
9.3.1. General Information
General information will include an executive summary that highlights the key content of the annual report. As part of the executive summary, this section will include a description of the sustainability goals, provide a description of GSP projects and their progress as well as an annually updated implementation schedule and map of the Subbasin. Key components as required by SGMA regulations include:
• Executive Summary
• Map of the Basin
9.3.2. Basin Conditions
Basin conditions will describe the current groundwater conditions and monitoring results.
This section will include an evaluation of how conditions have changed in the Subbasin over the previous year and compare groundwater data for the year to historical groundwater data. Pumping data, effects of project implementation (e.g., recharge data, conservation, if applicable), surface water flows, total water use, and groundwater in storage will be included. Key components as required by SGMA regulations include:
• Groundwater elevation data from the monitoring network • Hydrographs of elevation data
• Groundwater extraction data
• Surface water supply data
• Total water use data
• Change in groundwater in storage, including maps
#25..
- 2115 -
Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 9-9
Revised July 2024
TODD GROUNDWATER
9.3.3. Plan Implementation Progress
Progress toward successful plan implementation would be included in the annual report.
This section of the annual report would describe the progress made toward achieving interim milestones as well as implementation of projects and MAs. Key components as required by SGMA regulations include:
• Plan implementation progress
• Sustainability progress
This section may include updates to the projects and management actions list, as new project ideas are presented or existing projects are phased out, completed, or found not to be feasible.
9.4. PERIODIC EVALUATION
SGMA requires evaluation GSPs regarding their progress toward meeting approved sustainability goals at least every five years. SGMA also requires developing a written assessment and submitting this assessment to DWR. An evaluation must also be made whenever the GSP is amended. A description of the information that will be included in the periodic evaluation is provided below and would be prepared in a manner consistent with Section 356.4 of the SGMA regulations.
9.4.1. Sustainability Evaluation
This section will contain a description of current groundwater conditions for each applicable sustainability indicator and will include a discussion of overall Subbasin sustainability.
Progress toward achieving interim milestones and measurable objectives will be included, along with an evaluation of groundwater elevations (i.e., those being used as direct or proxy measures for the sustainability indicators) in relation to minimum thresholds. If any of the adaptative management triggers are found to be met during this evaluation, a plan for implementing adaptive management described in the GSP would be included.
9.4.2. Plan Implementation Progress
This section will describe the status of project and management action implementation, and report on whether any adaptive management action triggers had been activated since the previous periodic evaluation. An updated project implementation schedule will be included, along with any new projects that were developed to support the goals of the GSP and a description of any projects that are no longer included in the GSP. The benefits of projects that have been implemented will be included, and updates on projects and MAs that are underway at the time of the periodic evaluation will be reported. #25..
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9.4.3. Reconsideration of GSP Elements
Part of the periodic evaluation will include a reconsideration of GSP elements. As additional monitoring data are collected during GSP implementation, land uses and community characteristics change over time, and GSP projects and management actions are implemented, it may become necessary to revise the GSP. This section of the periodic evaluation will reconsider the Basin setting, management areas, undesirable results, minimum thresholds, and measurable objectives. If appropriate, the periodic evaluation will recommend revisions to the GSP. Revisions would be informed by the outcomes of the monitoring network, and changes in the Basin, including changes to groundwater uses or supplies and outcomes of project implementation.
9.4.4. Monitoring Network Description
A description of the monitoring network will be provided in the periodic evaluation. Data gaps, or areas of the Subbasin that are not monitored in a manner commensurate with the requirements of Sections 352.4 and 354.34(c) of the SGMA regulations will be identified. An assessment of the monitoring network’s function will also be provided, along with an analysis of data collected to date. If data gaps are identified, the GSP will be revised to include a program for addressing these data gaps, along with an implementation schedule for addressing gaps and how the GSAs will incorporate updated data into the GSP.
9.4.5. New Information
New information that becomes available after the previous evaluation or GSP amendment would be described and evaluated. If the new information warrants a change to the GSP, this would also be included.
9.4.6. Regulations or Ordinances
The periodic evaluation will include a summary of the regulations or ordinances related to the GSP that have been implemented by DWR since the previous report, and address how these may require updates to the GSP.
9.4.7. Legal or Enforcement Actions
Enforcement or legal actions taken by the GSAs or its member agencies in relation to the GSP will be summarized in this section along with how such actions support sustainability in the Subbasin.
9.4.8. Plan Amendments
A description of amendments to the GSP will be provided in the periodic evaluation, including adopted amendments, recommended amendments for future updates, and amendments that are underway during development of the periodic evaluation. #25..
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9.4.9. Coordination
The Modesto Subbasin GSAs will continue to work collaboratively to ensure implementation of the GSP to reach sustainability in the Subbasin by 2042. The GSAs will also coordinate with neighboring Subbasins including Eastern San Joaquin, Turlock, Delta-Mendota, and Tracy as needed, or any other land use agencies or entities for project implementation. This section of the periodic evaluation will describe coordination activities between these entities, such as meetings, joint projects, or data collection efforts.
9.5. DATA GAP ANALYSIS
As documented in Table 3-7, data gaps have been identified that would support sustainable groundwater management. Those data gaps include improved monitoring and analysis for the Western Lower Principal Aquifer, Eastern Principal Aquifer, interconnected surface water, and GDEs. In addition, the analysis in Section 2.3.3 identified data gaps for domestic wells. Each of these data gaps are described in the sections below.
9.5.1. Improvements to Monitoring Network
The current GSP monitoring network described in Chapter 7 meets monitoring objectives for initial tracking and evaluation of sustainable groundwater management criteria in each principal aquifer across the Subbasin. Nonetheless, there are data and knowledge gaps that could improve local monitoring and management. Monitoring improvements targeted for early GSP implementation are summarized below. These improvements will be made over time based on priorities and funding. As mentioned above, a comprehensive assessment of the monitoring network will be conducted as part of the periodic evaluation.
9.5.1.1. Western Lower Principal Aquifer
As noted in Table 3-7, an insufficient number of monitoring wells are screened solely in the Western Lower Principal Aquifer to monitor groundwater levels and flow. Figure 7-2 shows the five existing monitoring sites for this aquifer and illustrates the need for additional wells in the west. As noted on the figure, these wells support monitoring for chronic lowering of groundwater levels, reduction of groundwater in storage, and land subsidence. Additional wells would provide better coverage for development and tracking of sustainable management criteria and development of groundwater elevation contour maps. In turn, these improvements would allow better protection against future land subsidence, assist with water budgets and model calibration, and provide a better understanding of groundwater quality data in the Subbasin.
As part of this process, the GSAs will prioritize unmonitored areas of the aquifer and identify district-owned or other available lands where new monitoring wells might be sited in the future. To expedite collection of key data in the short-term, GSAs will explore the use of existing, properly screened wells from cooperative private well owners. If available, the GSAs would use grant funding for additional monitoring well installations in the future. Two of the existing five monitoring sites were recently installed with a Sustainable Groundwater Management grant funded by Proposition 68.
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9.5.1.2. Eastern Principal Aquifer
As noted in Table 3-7 and described in Section 7.1.1, the Eastern Principal Aquifer in the Non-District East Management Area represents a critical data gap for both historical and current data on groundwater levels and flow. As documented throughout the technical analyses in Chapters 3, 5, and 6, groundwater in this area has had the largest rates of decline and continuing overdraft – conditions that have the greatest potential to lead to undesirable results.
Proposition 68 provided an opportunity to install additional monitoring wells in this area to provide more information on local groundwater conditions. However, existing wells are insufficient for development and tracking of sustainable management criteria in key areas of the Non-District East Management Area. It is anticipated that new wells will be installed as part of project implementation by the Non-District East Management Area. Grant funding will be used for these new wells, as available.
In addition to new monitoring wells, there are data gaps with respect to the existing agricultural wells that need to be better understood. Construction and extraction data from active irrigation wells in this area are unknown. Using available well records and working directly with Non-District East Management Area landowners, the GSAs will work to fill these data gaps, providing more accurate assessments of groundwater conditions in the future. These new data will be incorporated into the water budget analyses as available, which will be provided in annual reports (see Section 9.3).
9.5.1.3. Interconnected Surface Water
As indicated in Table 3-7 and illustrated on Figure 7-5, data gaps exist for monitoring and management of interconnected surface water along the Subbasin river boundaries. The Proposition 68 grant provided the opportunity to install five new wells along the Tuolumne and Stanislaus rivers to support GSP monitoring of interconnected surface water. However, given the long river boundaries and other priorities for monitoring, the current network is incomplete. Since the GSP was submitted in 2022, the GSAs have completed an analysis and have identified potential locations of new monitoring wells along the rivers. The GSAs may seek future grant opportunities to provide funding for the additional wells. Additional wells would also assist with monitoring GDEs.
GSAs in the neighboring subbasins, including the Eastern San Joaquin, Turlock and DeltaMendota subbasins, are currently planning additional wells along the shared river boundaries of the Stanislaus, Tuolumne, and San Joaquin rivers. Consistent with the Modesto Subbasin Sustainability Goal, the GSAs will coordinate with neighboring GSAs to site and install wells that are capable of generating useful data for the shared surface water resources.
9.5.2. Analyses of Groundwater Dependent Ecosystems
The dataset of Natural Communities Commonly Associated with Groundwater (NCCAG) provided by DWR were published after the GSP work plan and grant application had been completed. As such, it was difficult to include anything more than a high-level screening of #25..
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potential GDEs in the initial GSP using periods of high and low groundwater elevations (Section 3.2.8). Following this screening, more than 70 percent of the original NCCAG polygons were retained as potential GDEs for future analyses.
As explained in Section 3.2.8, Moore Biological Consultants reviewed the potential GDEs within Mapes Ranch, a private property near the San Joaquin River. Using both a desktop study and field survey, Moore Biological Consultants concluded that 56 potential GDE polygons within Mapes Ranch are not GDEs. Given this, there may be more potential GDEs in the Subbasin that are not actually GDEs.
Because of the large number of potential GDE polygons, it was unreasonable to incorporate field surveys for all of these areas in the initial GSP assessment. As noted in Section 6.8, MTs were set at 2015 levels along the interconnected surface water to be protective of the GDEs along the rivers (where most of the potential GDE polygons occur). Monitoring data will be used to consider potential impacts on GDEs and shared publicly in annual reports.
In addition, the GSAs will continue to investigate potential GDEs and conduct additional analyses going forward. As an initial step, the GSAs will seek technical consultants with expertise to assist in developing a plan for additional GDE analyses.
9.5.3. Domestic Well Data
During the analysis of impacts to domestic wells, it was determined that significant data gaps exist. As noted in Table 6-2 (Section 6.3.1.1), 159 domestic wells failed during 2015- 2017 drought conditions (see also Figures 2-15 and 6-1). However, recent records of well permits also indicate that many of the failed wells appear to have since been replaced.
Although more than 3,000 domestic wells are included in the DWR Well Completion Report database, hundreds of those lack either completion date, construction data or complete location information and there is no indication of which wells have since been destroyed or taken offline. In addition, the well use is not documented for many additional wells in the DWR database, which could represent unknown domestic wells.
The technical team worked with the GSA representative from the City of Modesto to test the DWR database in a rural neighborhood outside of the city where domestic wells are known to be located. Even in that small area, many wells could not be correlated to DWR data and/or did not have construction or other key data in the DWR dataset.
Although production from these wells is likely to be de minimis (less than 2 AFY/well) as defined by SGMA, it would be helpful to better understand the number, location, and status of domestic wells. As part of GSP implementation, GSAs will consider how best to improve domestic well datasets. Areas where domestic wells are concentrated or vulnerable to declining water levels will be prioritized (see Figures 2-14, 2-17, and 6-1). An additional resource for domestic well data includes the Nitrate Control Program (NCP), where ongoing monitoring for nitrate and other constituents is focused on domestic wells (see Sections
2.4.4, 6.6.2.1.1, 6.6.2.2, and 7.1.4); access to well data will be coordinated through the Valley Water Collaborative, which is implementing the NCP in the Modesto Subbasin. #25..
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Outreach and well registration activities being applied in other subbasins will also be considered for the Modesto Subbasin.
9.6. CLOSING
The GSP implementation activities are designed to identify and document steps for successful implementation. Collectively, the sustainable management criteria, monitoring networks, and projects and management actions are anticipated to achieve the Modesto Subbasin sustainability goal. Although it is recognized that more information and actions will be needed over time, the GSAs will incorporate an adaptive management approach to prioritize activities based on best available information and document those activities and data through continued outreach and annual reporting.
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Revised July 2024
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https://www.nature.com/articles/s41467-018-04475-3.pdf.
Soil Survey Staff, 2003, Soil Service Geographic Database(SSURGO), Natural Resources Conservation Service, United States Department of Agriculture, Web Soil Survey, https://websoilsurvey.nrcs.usda.gov/.
State Water Resources Control Board, State of California (SWRCB), 2017, Groundwater Information Sheet – Tetrachloroethylene (PCE), Division of Water Quality, GAMA Program, 8 p., https://www.waterboards.ca.gov/water_issues/programs/gama/docs/coc_pce.pdf.
State Water Resources Control Board, State of California (SWRCB), 2018, Order WQ 2018- 002, In the Matter of Review of Waste Discharge Requirements General Order No. R5-2012- 0116 for Growers Within the Eastern San Joaquin River Watershed that are Members of the Third-Party Group, Issued by the California Regional Water Quality Control Board, Central Valley Region, SWRC/OCC Files A-2239(a)-(c),
https://www.waterboards.ca.gov/board_decisions/adopted_orders/water_quality/2018/wq o2018_0002_with_data_fig1_2_appendix_a.pdf.
State Water Resources Control Board, State of California (SWRCB), 2019, 1,2,3- Trichloropropane,
https://www.waterboards.ca.gov/drinking_water/certlic/drinkingwater/123TCP.html.
State Water Resources Control Board, State of California (SWRCB), 2021, GeoTracker Online Database, https://geotracker.waterboards.ca.gov/.
Stollenwerk, K.G., 2003, Geochemical processes controlling transport of arsenic in groundwater, a review of adsorption, in Welch, A.H., and Stollenwerk, K.G., eds., Arsenic in groundwater—geochemistry and occurrence: Boston, Kluwer Academic Publishers, 488 p., https://pubs.er.usgs.gov/publication/70198531.
The Nature Conservancy, 2018, Groundwater Dependent Ecosystems under the Sustainable Groundwater Management Act, Guidance for Preparing Groundwater Sustainability Plans, January, https://www.scienceforconservation.org/assets/downloads/GDEsUnderSGMA.pdf.
The Nature Conservancy (TNC), 2019, Identifying GDEs under SGMA, Best Practices for using the NC Dataset, July.
Todd Groundwater (Todd), 2016, Groundwater Characterization and Recharge Study, June. #25..
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 10-8
Revised July 2024
TODD GROUNDWATER
Towill, Inc. (Towill), 2021, InSAR Data Accuracy for California Groundwater Basins, CGPS Data Comparative Analysis, January 2015 to October 2020, https://data.cnra.ca.gov/dataset/tre-altamira-insar-subsidence/resource/a1949b59-2435- 4e5d-bb29-7a8d432454f5
Viers, J.H., Liptzin, D., Rosenstock, T.S., Jensen, V.B., Hollander, A.D., McNally, A., King, A.M., Kourakos, G., Lopez, E.M., De La Mora, N., Fryjoff-Hung, A., Dzurella, K.N., Canada, H.E., Laybourne, S., McKenney, C., Darby, J., Quinn, J.F. & Harter, T., 2012, Nitrogen Sources and Loading to Groundwater, Technical Report 2 in: Addressing Nitrate in California’s Drinking Water with a Focus on Tulare Lake Basin and Salinas Valley Groundwater, Report for the State Water Resources Control Board Report to the Legislature, Center for Watershed Sciences, University of California, Davis, July,
https://ucanr.edu/sites/groundwaternitrate/files/139110.pdf.
Wagner, D.L., Bortugno, E.J., and McJunking, R.D., 1991, Geologic Map of the San FranciscoSan Jose Quadrangle, California, 1:250,000, https://ngmdb.usgs.gov/Prodesc/proddesc_519.htm.
Waterford Planning Department, 2007, City of Waterford General Plan Update Vision 2025, June 21, https://www.cityofwaterford.org/v5/wp-content/uploads/2018/07/General-PlanFinal.pdf.
Welch, A.H., Oremland, R.S., Davis, J.A., and Watkins, S.A., 2006, Arsenic in groundwater—A review of current knowledge and relation to the CALFED solution area with recommendations for needed research: San Francisco Estuary and Watershed Science, v. 4, no. 2, Article 4, 32 p, https://escholarship.org/uc/item/8342704q.
Welch, A.H., Westjohn, D.B., Helsel, D.R., and Wanty, R.B., 2000, Arsenic in ground water of the United States—Occurrence and geochemistry: Ground Water, v. 38, no. 4, p. 589–604.
West Yost Associates, 2011, City of Modesto & Modesto Irrigation District Joint 2010 Urban Water Management Plan, May, https://www.mid.org/water/uwmp/uwdp.html.
West Yost Associates, 2016a, City of Modesto 2015 Urban Water Management Plan, June, https://www.modestogov.com/DocumentCenter/View/4608/City-of-Modesto-Final-2015- UWMP-PDF.
West Yost Associates, 2016b, City of Turlock 2015 Urban Water Management Plan, June, https://www.cityofturlock.org/_pdf/files/2015UWMP-PublicDraft.pdf.
West Yost Associates, 2021, Joint 2020 Urban Water Management Plan, City of Modesto 2020 & Modesto Irrigation District, June,
https://www.mid.org/water/uwmp/uwmp_2020/R418CityofModestoMIDFinal2020UWMP1 11021.pdf.
#25..
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Modesto Subbasin GSP
STRGBA GSA/Tuolumne GSA 10-9
Revised July 2024
TODD GROUNDWATER
Woodard & Curran (W&C) and Provost & Pritchard (P&P), 2019, Northern and Central DeltaMendota Regions, Groundwater Sustainability Plan, November, http://sldmwa.org/NDCP_Temporary/DM_NorthCentral_Adopted_GSP.pdf.
Woodard & Curran (W&C), 2019, Merced Groundwater Subbasin Groundwater Sustainability Plan, November, http://mercedsgma.org/assets/pdf/gsp-sections/MercedSubbasin-GSP-no-appendices_2019-11-12.pdf.
WRIME, 2007, Recharge Characterization for Stanislaus and Tuolumne Rivers Groundwater Basin Association, Memorandum, May 2.
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Revised July 2024
Groundwater
Sustainability Plan
Appendices
Modesto Subbasin
Stanislaus and Tuolumne Rivers
Groundwater Basin Association (STRGBA)
Groundwater Sustainability Agency
&
County of Tuolumne
Groundwater Sustainability Agency
#25..
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Appendix A
Notice of Intent to Prepare a GSP
#25..
- 2132 -
Stanislaus and Tuolumne Rivers Groundwater Basin Association Groundwater Sustainability Agency
1231 11th Street ● Modesto, CA 95354
Phone: (209) 526-7564 ● Fax: (209) 526-7352
E-mail: [email protected]
March 14, 2018
Mr. Trevor Joseph
California Department of Water Resources
901 P Street, Room 201
P.O. Box 942836
Sacramento, CA 94236-0001
Re: Stanislaus and Tuolumne Rivers Groundwater Basin Association Groundwater Sustainability Agency - Notification of Intent to Develop a Groundwater Sustainability Plan
Dear Mr. Joseph,
Pursuant to California Water Code Section 10727.8 and California Code of Regulations, Title 23, Section 353.6, the Stanislaus and Tuolumne Rivers Groundwater Basin Association Groundwater Sustainability Agency (STRGBA GSA) hereby notifies the Department of Water Resources (DWR) of its intent to develop a Groundwater Sustainability Plan (GSP) for the Modesto Sub-basin (Sub-basin) in cooperation with other Groundwater Sustainability Agencies within the Sub-basin. The action of the STRGBA GSA authorizing the submission of this initial notification is attached.
The public may participate in the development of the GSP for the Sub-basin by attending the STRGBA GSA’s monthly meetings held at the Modesto Irrigation District’s offices – 1231 11th Street, Modesto, California 95354. A schedule of upcoming meetings, meeting agendas, meeting minutes and information on the GSP development process are available on the STRGBA GSA website at: www.strgba.org.
The STRGBA GSA looks forward to working collaboratively with the public and DWR staff to develop and implement the GSP for the Sub-basin. Should you have any questions or concerns regarding the information noted herein, please feel free to contact me at (209) 526-7564.
Sincerely,
John B. Davids, P.E.
STRGBA GSA Coordinator
Enclosure: STRGBA GSA February 14, 2018 Meeting Minutes #25..
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Stanislaus and Tuolumne Rivers Groundwater Basin Association Groundwater Sustainability Agency
1231 11th Street ● Modesto, CA 95354
Phone: (209) 526-7564 ● Fax: (209) 526-7352
E-mail: [email protected]
cc: Administration Files
Stanislaus County Board of Supervisors
City of Modesto City Council
City of Oakdale City Council
City of Riverbank City Council
City of Waterford City Council
Modesto Irrigation District Board of Directors
Oakdale Irrigation District Board of Directors
#25..
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Attachment B
STRGBA Member Resolutions and Proofs of Publication of Notice #25..
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TUESDAY JANUARY 10 2017 Cov 5A
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MOD0002471855-01
NOTICE OF
PUBLIC HEARING
Notice is hereby given that, pursuant to Water Code section 10723, Modesto Irrigation District (MID) will hold a public hearing during a special meeting on January 24, 2017, at Modesto Irrigation District Board Room, 1231 11th Street, Modesto, to determine whether MID will authorize the execution of the MEMORANDUM OF
UNDERSTANDING FORMING THE STANISLAUS AND TUOLUMNE
RIVERS GROUNDWATER BASIN ASSOCIATION GROUNDWATER
SUSTAINABILITY AGENCY and participate in the Stanislaus and Tuolumne Rivers Groundwater Basin Association (STRGBA) election to become a groundwater sustainability agency for the Modesto Groundwater Sub-Basin.
Written comments may be submitted to MID at Attn: John Davids, P.O. Box 4060, Modesto, CA 95352.
During the hearing, MID will allow oral comments and will receive additional written comments until the STRGBA elects to be a groundwater sustainability agency.
1231 11th Street | P.O. Box 4060 | Modesto, CA
www.mid.org
Public Hearing: Groundwater Sustainability Agency
Location: MID Board Room
1231 11th Street, Modesto
Date: January 24, 2017
Time: 9 a.m.
Phone: 209.526.7360
Local media
partners:
TEXT A TIP TO 274637 INCLUDE TIP704 IN YOUR MESSAGE. TIPS CAN BE SUBMITTED VIA WEBSITE @ www.stancrimetips.org Call or visit www.stancrimetips.org today. All tips are anonymous! 405
CAPTURES
January 10
th
, 2017
Crimes profiled are investigated by Law Enforcement in Stanislaus County. Crime Stoppers is a non profit agency and does not investigate the tips.
ANONYMOUS TIP HOTLINE 24 HOURS A DAY: 1-866-602-7463*TEXT AN ANONYMOUS TIP TO 274637 INCLUDE “TIP 704” IN YOUR MESSAGE • ANONYMOUS TIPS CAN BE SUBMITTED VIA WEBSITE @ www.stancrimetips.org
Gabriel Gomez has a warrant out for his arrest from Modesto Police for Human Trafficking charges.
Gomez is last known to live in the Stockton area. If you have any information regarding him or his whereabouts please contact Crime Stoppers.
Human Trafficking
Larceny/Theft
MOD0002867526-01
Name: Gomez, Gabriel
Sex: Male
Age: 19
DOB: 04/16/1997
Modesto Police Department
On December 20, 2016 this suspect stole items from
Kohl’s. When the suspect was confronted outside by Loss Prevention Officers the suspect took off running to a black 90’s model four door car. The Loss Prevention Officers chased and when the suspect got into the car the suspect threatened and gestured that he had a gun. The suspect then took off with the clothing. If you know the identity or whereabouts of this suspect please contact Crime Stoppers.
cast shows it peaking at
just under 52 feet
Wednesday, then receding through Saturday.
Turlock Irrigation District
records showed it flowing
at 5,693 cubic feet per
second midmorning Monday.
Dry Creek, notorious
for flooding, has stayed to
its banks this season. But
American Legion Post 74,
located at 1001 S. Santa
Cruz Ave., just north of
Legion Park on the Tuolumne, is taking no
chances. The threat of
flooding led the veterans
service organization to
move most of its equipment out of the building
and into storage. Consequently, its monthly dinner, scheduled for Tuesday, and monthly breakfast, scheduled for Sunday, have been canceled.
In the January 1997
flooding, “the small hall
was completely submerged and the large hall
was flooded all the way to
the roof,” said Becky
Crow, Post 74 adjutant.
“In light of that, we
thought it was prudent to
get as much out as we
could, given the weather
forecast by Saturday
morning.”
In advance of the storm
that moved through the
region Saturday through
Monday, the weather
service issued a forecast
saying Modesto could get
3 to 4 inches of rain. But
according to Modesto
Irrigation District measurements, 0.79 inches
fell downtown Saturday,
0.77 Sunday and 0.18 in
the early hours Monday.
The bull’s eye of the
storm tracked farther
north than expected,
Clapp said.
This next storm will be
maybe two-thirds the
strength of the last, he
said. The weather service
forecast says Sonora can
expect 2 to 3 inches of
precipitation, and Yosemite 3 to 4 inches.
The service’s snow
forecast through Wednesday is broken down by
routes. Along Highway 4,
Arnold could get 6 to 8
inches, and Bear Valley 48
to 60. Along Highway
108, Twain Harte could
get 3 to 4 inches, Mi-Wuk
Village 8 to 12, and Strawberry, 36 to 48. And on
Highway 120, the area of
Big Oak Flat Road is looking at 8 to 12 inches.
Wind could be a big
issue in this storm. The
weather service says
strong winds from the
south could bring gusts of
50 mph or more in lower
elevations, 65 mph or
more at higher elevations.
It warns the gusts could
lead to falling trees and
branches, downed power
lines and moderate-size
power failures. Again,
though, Clapp said the
strongest winds are likely
to be felt north of Modesto, in Stockton and Sacramento.
To report a power failure to MID, call
209-526-8222, day or
night. To report one to
Turlock Irrigation District,
call the 24-hour service
line at 209-883-8301.
Tuesday will bring a 90
percent chance of rain,
the weather services says,
with thunderstorms also
possible after 4 p.m. The
high should be near 56
degrees. The chance of
precipitation Tuesday
night rises to 100 percent,
again with up to half an
inch possible.
On Wednesday, there’s
a 40 percent chance of
showers, mainly before 4
p.m. Otherwise, the day
should be partly sunny,
with a high near 56. The
chance of rain Wednesday
night is 60 percent –
mainly after 10 p.m.
There’s a 50 percent
chance of showers Thursday, which otherwise will
be partly sunny, with a
high near 53.
Deke Farrow:
209-578-2327
CHRISTOPHER WINTERFELDT [email protected]
Water rushed through Dry Creek while staying within its banks in Kewin Park at the La Loma Avenue overpass on Monday in Modesto.
. . .....................................................
Flood watch
vs. warning
Flood warning: Take
action! A flood warning is
issued when the hazardous
weather event is imminent
or already happening. A
flood warning is issued
when flooding is imminent
or occurring.
Flood watch: Be prepared.
A flood watch is issued
when conditions are
favorable for a specific
hazardous weather event
to occur. A flood watch is
issued when conditions are
favorable for flooding. It
does not mean flooding
will occur, but it is possible.
Source: National Weather Service
. .....................................................
FROM PAGE 1A
STORM
North Grove Trail, Tealdi
suggested people check in
at parks.ca.gov.
For more, visit the Facebook pages of Calaveras
Big Trees State Park and
the Calaveras Big Trees
Association.
The Sacramento Bee and
news services contributed to
this report.
Deke Farrow:
209-578-2327
Tree in Yosemite National
Park was carved, the owners of the North Grove
responded by doing the
same. The Pioneer Cabin
Tree was chosen because
of its wide base – about 22
feet in diameter. It had
the widest trunk in the
park’s North Grove, said
California State Parks
Supervising Ranger Tony
Tealdi. It also was chosen
because its trunk already
had a hole from fire damage, Tealdi said. The sequoias don’t heal themselves after damage like that, they send all their
nutrients to the treetop,
he said.
The tree reportedly fell
about 2 p.m. Sunday.
Though the park was
open, there were no witnesses to it, Tealdi said.
People working in the
visitors center didn’t hear
or feel a thing when the
giant toppled, he said.
Park docent Jim Allday of
Arnold was taking a walk
on the trail and made the
discovery.
The tree fell onto the
trail, and because the
wood of sequoias easily
splits, the top shattered as
it hit the ground, Tealdi
said. There’s no estimate
on how tall the roughly
2,000-year-old tree was.
The tree did not snap
where the tunnel was
carved, but rather uprooted. The North Grove trail
is closed as environmental
scientists assess the tree,
Tealdi said. The trail will
be rerouted because the
Pioneer Cabin Tree will
be left where it lies.
“You have to look at the
life cycle of these trees,”
he said. “... At this point in
time, the next part of its
life cycle is on the ground,
as a habitat for animals
and insects. It’s still a
producing factor in nature
– it also helps with greenhouse gases.”
The park remains open
with about 25 campsites
available. It got nearly 8
inches of rain over the
weekend, Tealdi said, and
about 6 inches of snow
already on the ground is
melting with the rainfall.
There is standing water
throughout the trail.
The Pioneer Cabin
Tree’s shallow root system, combined with the
inundation from the rain,
likely contributed to its
fall.
The loss of the tree has
made news internationally. Tealdi said he’s received calls from Russian media and the BBC. “It’s
a sad day, and we’ve seen
goosebumps thinking
about that tree that went
down,” Tealdi said, “but it
is part of the life cycle.”
For updates on the
DEKE FARROW [email protected]
Visitors to Calaveras Big Trees State Park in Arnold stand in the tunnel of the Pioneer Cabin Tree on Dec. 29.
FROM PAGE 1A
TREE
homes for foster youth,”
Olsen said. “Group homes
are going away. We want
to make sure every foster
child has a nurturing,
loving home.”
By pushing through a
2015 bill, the former legislator played a key role in
ending a tax inequity that
caused the county to lose
an estimated $72 million
over 35 years. The county
now keeps an extra $6
million a year, and Olsen
wants to use some of that
as seed money for projects
developed by Focus on
Prevention.
The county’s 10-year
prevention initiative aims
to tackle problems with
homelessness, family dysfunction, troubled youths
and crime recidivism.
While serving on the
Modesto council, Olsen
often grilled staff members
about the costs of projects
and government administration. She vowed to emphasize fiscal accountability as a county leader.
Olsen raised some eyebrows when she waited
until late in the filing
period last year to announce she would run for
District 1 supervisor.
Within a half-hour of
announcing her candidacy, O’Brien announced he
would not run and endorsed Olsen, creating the
impression of an easy
transition from one Republican to another. A
filing period extension left
only four days for others
to decide whether to challenge Olsen, a well-funded political veteran, and no one did.
Olsen defended her
timing, saying she didn’t
have much advance notice
that O’Brien was going to
step down. “When I announced I was not going
to run for state Senate, I
thought I was going to
take a break from public
service” and devote time
to family life, she said.
Olsen will stay involved
with state politics as the
recently appointed vice
chairwoman of the California Republican Party.
She said her party responsibilities will require her
attendance at three weekend conventions in the
next two years, and “beyond that the schedule is
up to me,” she said.
Olsen planned to fly
Monday night to San Diego to speak with Republicans there and then return to Modesto for the
county’s swearing-in ceremony Tuesday morning.
“The goal is to elect more
Republicans to improve
the quality of life in California,” Olsen said. “Oneparty dominance is not good for any state in our
nation.”
Ken Carlson: 209-578-2321
FROM PAGE 1A
SUPERVISOR
‘‘
WE NEED TO
OPERATE WITH
GOOD DATA AND
SOUND SCIENCE
WHEN WE ARE
MAKING
DECISIONS ON
WATER
MANAGEMENT.
Kristin Olsen
#25..
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4A TUESDAY JANUARY 17 2017 Local MODBEE.COM
MODESTO
What: Modesto Kiwanis meeting
When: Tuesday, 11:30 a.m.
Where: Famiglia Bistro, 2501 McHenry Ave.
Info: The Modesto Kiwanis invites the public to its weekly lunch meeting. This week’s special guest is Nancy Salmeron, who will discuss personnel development and entrepreneurship. Lunch is $15; reservation is needed. Seating is limited. For more information or to make a reservation, contact Anthony at 209-985-3473 or
[email protected].
What: Modesto Parkinson’s Support Group
When: Wednesday, 1:30 to 3:30 p.m.
Where: Trinity Presbyterian Church, 1600 Carver Road
Info: The Modesto Parkinson’s Support Group will be holding its monthly meeting for caregivers and those with the Parkinson’s disease.
What: Latino Emergency Council meeting
When: Friday, 8:15 to 9:15 a.m.
Where: El Concilio Community Center, 1314 H St.
Info: The El Concilio Community Center invites the public to its monthly morning meeting. The guest is Modesto Irrigation District spokeswoman Melissa Williams. She will discuss the impact the weather has had on the Modesto area. The meeting is free to attend; come early, because seating is limited. For more information, contact Dale Butler 209-613-1058.
TURLOCK
What: Turlock Chamber of Commerce mixer
When: Tuesday, 5 to 7 p.m.
Where: VaraniSmile Dentistry, 527 E. Olive Ave.
Info: Join the Turlock Chamber of Commerce and VaraniSmile Dentistry in an evening of networking with the community. The event is free to attend. For more information, call 209-632-2221 or visit www.turlockchamber.com.
Send Region items to Region, The Modesto Bee, P.O. Box 5256, Modesto 95352; call 209-578-2330; fax 209-578-2207; or email [email protected].
25 YEARS AGO: Increased evening and weekend bus service was on top of the list for Stanislaus County. At a meeting where bus riders voiced their concerns, the Stanislaus Area Association of Governments also considered increased service for the disabled.
The hearing was a small step in securing an estimated $8.2 million in transportation funds for the following year. The suggestions from the public included the use of international symbols to make transit signs more understandable to the illiterate and those who don’t speak English.
AROUND THE REGION
We want to make sure the
information in this paper
is accurate. Please call
mistakes to our attention,
so we may correct them.
Local News .........578-2330
City Desk.............578-2327
Work & Money...578-2343
Features ...............578-2312
Sports .................578-2300
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Las Vegas is home to world-class entertainment and incredible stage shows. It is possible to see world-famous stars perform almost every day of the week. If you are a fan of magic, you can see David Copperfield perform. Don’t miss Cirque du Soleil, which is world-famous for its breathtaking performances. Artists like Celine Dion, Elton John and Rod Stewart thrill audiences night after night. Staying on the Las Vegas Strip is like no other vacation in the world.
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NOTICE OF
PUBLIC HEARING
Notice is hereby given that, pursuant to Water Code section 10723, Modesto Irrigation District (MID) will hold a public hearing during a special meeting on January 24, 2017, at Modesto Irrigation District Board Room, 1231 11th Street, Modesto, to determine whether MID will authorize the execution of the MEMORANDUM OF
UNDERSTANDING FORMING THE STANISLAUS AND TUOLUMNE
RIVERS GROUNDWATER BASIN ASSOCIATION GROUNDWATER
SUSTAINABILITY AGENCY and participate in the Stanislaus and Tuolumne Rivers Groundwater Basin Association (STRGBA) election to become a groundwater sustainability agency for the Modesto Groundwater Sub-Basin.
Written comments may be submitted to MID at Attn: John Davids, P.O. Box 4060, Modesto, CA 95352.
During the hearing, MID will allow oral comments and will receive additional written comments until the STRGBA elects to be a groundwater sustainability agency.
1231 11th Street | P.O. Box 4060 | Modesto, CA
www.mid.org
Public Hearing: Groundwater Sustainability Agency
Location: MID Board Room
1231 11th Street, Modesto
Date: January 24, 2017
Time: 9 a.m.
Phone: 209.526.7360
OLD ICE-MAKING PLANT IN RIVERBANK BURNS AGAIN
Stanislaus Consolidated Fire Protection District crews spent about an hour battling a small blaze at a one-time ice-making plant in Riverbank early Monday. “It wasn’t much of a fire, just hard to access,” Battalion Chief Eric DeHart said of the blaze in the 5800 block of Terminal Avenue. Because the report of the fire at the vacant site went out as a commercial structure fire, it drew a large response: five engines and two trucks. But two to three crews were released from the scene almost immediately, DeHart said. The fire was reported about 12:40 a.m. The mostly concrete building burned in the mid-’90s and a couple of times since, DeHart said. The building is attractive to transients seeking shelter. Earlier fires caused the roof to collapse, which created lean-tos, of sorts, which offer protection from the outside elements, he said. Without knowing for sure, DeHart said, this blaze likely was a warming fire that got out of control. No one was found at the scene and there are no known injuries. Crews did what they could from the ground, then put up ladders and used hoses from above. They battled the fire from outside because entering the collapsed interior would have put firefighters at risk. The building once served as an ice-making facility for the Burlington Northern Santa Fe Railway. The railroad has a switchyard adjacent to the plant.
TURLOCK MAN ARRESTED IN ROAD-RAGE INCIDENT
A Turlock man was arrested on suspicion of making criminal threats Sunday afternoon after Tuolumne County sheriff’s deputies responded to a reported road-rage incident near the Dodge Ridge ski area. The road in the area was backed up and many cars were passing illegally, the Sheriff’s Office said in a post on Facebook.
Tony Alahverdi was trying to pass, but another motorist was in the way, the post said. Alahverdi, 36, pointed a firearm and threatened to kill the motorist, the Sheriff’s Office said. The driver spotted the 2016 gray Toyota Tundra pickup near Dodge Ridge lodge and gave the Sheriff’s Office its description and license plate number. The California Highway Patrol located and stopped the truck after Alahverdi left the area. Deputies arrived, searched the truck and found a handgun. Alahverdi was taken to the Tuolumne County jail.
LAW & ORDER
T
he third annual
Valley Hackathon
– a 24-hour competition for programmers – will be held Friday in downtown Modesto.
More than 100 programmers are expected to
turn out, competing in
teams of one to four
participants to build a
software project in just a
day. Each will be judged
by a panel on how complete, viable, aesthetically
pleasing and technical it
is.
Competitors can register right up until check-in
begins at 5 p.m. Friday. As
of Monday, there were 81
participants.
The top 10 teams will
present their hacks in the
event’s finals. Prejudging
will take place during the
final hour of the programming time.
The event was begun to
harness interest and talent
in technology within the
Central Valley, but has
grown to draw entrants
from as far away as the
Bay Area, Sacramento and
Fresno, organizers say.
Participation in the Valley
Hackathon has increased
from 22 participants in
2015 to 63 last year.
“The Central Valley’s
economy is seeing a big
shift right now,” said
David White, chief executive officer of Opportunity Stanislaus, one of the event’s sponsoring organizations, in a news release.
“We see hackathons as a
sort of pipeline for talent
in the technology sector
and believe that events
like the Valley Hackathon
will be instrumental in
creating connections for
this community, as well as
nurturing the innovative
ideas such an event creates. This is a fun event in
and of itself but it’s also a
piece in the larger puzzle
that is a local revolution of
sorts.”
Other sponsors include
Inventaweb, the Alliance
Small Business Development Center, Oportun
and California Community Colleges.
The free event draws
some amazing talent,
organizers say, but the
hackathon also is for beginning programmers and
designers. The minimum
age to compete is 18.
“Though 24 hours is not
a ton of time, we have
been very impressed by
the complexity of the
projects,” said Phillip Lan,
Valley Hackathon organizer and head of business
development for Hearst
Digital. “We’ve seen
everything from a program designed to sample
soil moisture to software
that scanned movie reviews to create viewing
suggestions to users based
on their current mood, so
competitors will want to
be sure their project is
both inventive and interesting.”
The winning teams will
walk away with more than
$5,000 in prize money
Other draws include
chair massages, free
meals, snacks and energy
drinks and a Lego competition with its own separate kitty.
This year’s hackathon
has a “Star Wars” theme
and a prize for the best
team “Star Wars” cosplay.
The event will be at
Redeemer Church, at 820
H St. Check-in is at 5 p.m.,
orientation at 6, and the
competition begins at
6:30. To learn more, visit
www.valleyhackathon.
com.
Hackathon returns
to test programmers
Bee Staff Reports
Rain is expected to
return to the Modesto
area Wednesday afternoon and could stick
around beyond the weekend, according to the
National Weather Service.
After patchy fog in the
morning, Tuesday should
be mostly sunny, with a
high near 54. Clouds will
gather in the night.
Wednesday brings an
80 percent chance of rain,
mainly after 4 p.m., and
the high is expected to be
near 58. The chance of
rain increases to 90 percent Wednesday night.
There’s a 60 percent
chance of showers Thursday, which otherwise will
be mostly cloudy, with a
high near 57. Rain is likely
Thursday night, the
weather service predicts.
Weather service meteorologists say Friday also
will bring rain, and a high
near 54.
There’s a chance of
showers Saturday, and
rain is likely Sunday. The
high both days is expected
to be near 54.
The first storm system
passing through will be
Wednesday and Thursday. Modesto is expected
to receive 1 to 2 inches of
rain, while Sonora and
Yosemite National Park
could get 2 to 3 inches.
Snow levels Wednesday
should be at 5,000 to
6,000 feet, lowering to
3,000 to 4,000 feet
Thursday. The weather
service says Tioga Pass
could get 18 to 24 inches
of snow, while the Sonora,
Ebbetts and Carson passes
all could see 24 to 30
inches.
The second system
should bring its heaviest
precipitation Friday, with
lingering showers Saturday. No estimate of
amounts for Modesto and
Sonora has been provided
by the weather service.
Snow level will be down
to 3,000 feet Friday,
lowering to perhaps 2,000
feet by Saturday morning
and during a third storm
system expected to be
here Sunday through
Monday.
“None of these storms
appear to be as strong or
wet as last week’s
storms,” the weather
service said in a report
issued Monday morning.
“However, with soils still
saturated and rivers and
streams still running high,
any additional rainfall will
bring localized flooding
concerns.”
For updates on conditions and problems locally, follow the Stanislaus County Office of Emergency Services at
StanEmergency on Facebook and Twitter.
More rain and snow
in the forecast for
Valley, foothills
Bee Staff Reports
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Attachment C
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Appendix B
Adoption of GSP
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AGENDA REPORT
STRGBA GSA Strgba Gsa Agenda Report Gsp Adoption Resolution 2022-03_FinalDraft
D R A F T
RESOLUTION NO. 2022-03
RESOLUTION ADOPTING THE MODESTO SUBBASIN
GROUNDWATER SUSTAINABILITY PLAN (GSP) AND
AUTHORIZING THE STRGBA GSA PLAN MANAGER
TO SUBMIT THE GSP TO DWR BY JANUARY 31, 2022.
WHEREAS, in April 1994, the City of Modesto, Modesto Irrigation District, City of Oakdale, Oakdale Irrigation District, City of Riverbank, and County of Stanislaus executed a Memorandum of Understanding to form the Stanislaus and Tuolumne Rivers Groundwater Basin Association (STRBGA) for the purpose of coordinating planning and groundwater management activities in the Modesto Subbasin;; and
WHEREAS, in July 2015, the Memorandum of Understanding was amended to include the City of Waterford as a member agency of STRGBA; and
WHEREAS, in August 2014, the California Legislature passed, and in September 2014 the Governor signed, legislation creating the Sustainable Groundwater Management Act (SGMA) “to provide local groundwater sustainability agencies with the authority and technical and financial assistance necessary to sustainably manage groundwater” (Wat. Code, § 10720, (d)); and
WHEREAS, SGMA requires sustainable management through the development of groundwater sustainability plans (“GSP”), which can be a single plan developed by one or more groundwater sustainability agency (“GSA”) or multiple coordinated plans within a basin or subbasin (Wat.
Code, § 10727); and
WHEREAS, SGMA requires a GSA to manage groundwater in all basins designated by the Department of Water Resources (“DWR") as a medium or high priority, including the Modesto Subbasin (designated basin number 5-022.02); and
WHEREAS, the STRGBA GSA was formed on February 16, 2017, for the purpose of sustainably managing groundwater in the Modesto Subbasin, within its jurisdictional boundaries, pursuant to the requirements of SGMA; and
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AGENDA REPORT
STRGBA GSA Strgba Gsa Agenda Report Gsp Adoption Resolution 2022-03_FinalDraft WHEREAS, the STRGBA GSA has the authority to draft, adopt, and implement a GSP (Wat. Code, § 10725 et seq.); and
WHEREAS, the STRGBA GSA submitted an Initial Notification to DWR to jointly develop a GSP for the Modesto Subbasin on February 28, 2017; and
WHEREAS, the STRGBA GSA has coordinated with the Tuolumne County GSA to develop a single, coordinated GSP for the Modesto Subbasin; and
WHEREAS, on August 10, 2021 the STRGBA GSA released the Notice of Intent to Adopt the GSP to cities and counties in the plan area pursuant to Water Code section 10728.4 WHEREAS, the STRGBA GSA and Tuolumne County GSA developed the draft Modesto Subbasin GSP and released the draft Modesto Subbasin GSP chapters for public review and comment; and
WHEREAS, the STRGBA GSA and Tuolumne County GSA reviewed and responded to comments on the Modesto Subbasin GSP; and
WHEREAS, all seven STRGBA GSA member agencies have held public hearings, adopted the draft GSP and authorized the Plan Manager to submit the final GSP to DWR; and WHEREAS, the final Modesto Subbasin GSP is incorporated in its entirety by reference hereto this resolution.
NOW, THEREFORE, THE GOVERNING BODY OF THE STANISLAUS AND TUOLUMNE RIVERS
GROUNDWATER BASIN ASSOCIATION GROUNDWATER SUSTAINABILITY AGENCY DOES HEREBY
ADOPT THE MODESTO SUBBASIN GROUNDWATER SUSTAINABILITY PLAN AND AUTHORIZES THE
STRGBA GSA PLAN MANAGER TO SUBMIT THE MODESTO SUBBASIN GSP TO DWR BY JANUARY 31, 2022.
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AGENDA REPORT
Subject: Modesto Subbasin Groundwater Sustainability Plan Recommended
Action:
Resolution adopting the Modesto Subbasin Groundwater Sustainability Plan (GSP) and authorizing the STRGBA GSA Plan Manager to submit the GSP to DWR by January 31, 2022.
Background and
Discussion:
In April 1994, the Modesto Irrigation District along with Oakdale Irrigation District, Stanislaus County and the Cities of Modesto, Oakdale, and Riverbank executed a Memorandum of Understanding to form the Stanislaus and Tuolumne Rivers Groundwater Basin Association (STRBGA) for the purpose of coordinating planning and groundwater management activities in the Modesto Subbasin. In July 2015, the Memorandum of Understanding was amended to include the City of Waterford as a member agency of STRGBA.
In August 2014, the California Legislature passed, and in September 2014 the Governor signed, legislation creating the Sustainable Groundwater Management Act (SGMA) “to provide local groundwater sustainability agencies with the authority and technical and financial assistance necessary to sustainably manage groundwater” (Wat. Code, § 10720, (d)). SGMA requires sustainable management through the development of groundwater sustainability plans (GSP), which can be a single plan developed by one or more groundwater sustainability agency (GSA) or multiple coordinated plans within a basin or subbasin (Wat. Code, § 10727). SGMA also requires a GSA to manage groundwater in all basins designated by the Department of Water Resources (DWR) as a medium or high priority, including the Modesto Subbasin (designated basin number 5-022.02).
The STRGBA GSA was formed on February 16, 2017, for the purpose of sustainably managing groundwater in the Modesto Subbasin, within its jurisdictional boundaries, pursuant to the requirements of SGMA. The STRGBA GSA also has the authority to draft, adopt, and implement a GSP (Wat. Code, § 10725 et seq.).
On February 28, 2017, the STRGBA GSA submitted an Initial Notification to DWR to jointly develop a GSP for the Modesto Subbasin along with Tuolumne County GSA. The STRGBA GSA has since then worked with the Tuolumne County GSA to develop a single, coordinated GSP for the Modesto Subbasin.
On August 10, 2021 the STRGBA GSA released the Notice of Intent to Adopt the GSP to cities and counties in the plan area pursuant to Water Code section 10728.4.
On November 15, 2021, the STRGBA GSA and Tuolumne County GSA released the completed draft of the Modesto Subbasin GSP for public review and comment. The STRGBA GSA and Tuolumne County GSA have subsequently GSA Meeting Date: January 31, 2022
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AGENDA REPORT
STRGBA GSA Strgba Gsa Agenda Report Gsp Adoption Resolution 2022-03_FinalDraft received, reviewed, and incorporated public comments into the final document where appropriate.
All seven STRGBA GSA member agencies (MID, OID, Stanislaus County, Cities of Modesto, Oakdale, Riverbank, and Waterford) have held public hearings, adopted the draft GSP and authorized the Plan Manager to submit the final GSP to DWR by January 31, 2022. The final Modesto Subbasin GSP will be incorporated in its entirety by reference hereto this resolution.
Alternatives, Pros
and Cons of Each
Alternative:
1. Do Nothing – Cons: Does not comply with State law, not eligible for DWR grant funding, liable for costs associated with DWR engagement of 3rd party to prepare plan; Pros: No staff time or consultant costs.
2. Approve GSP – Cons: Staff time and consultant costs; Pros: Complies with State law, eligible for DWR grant funding, demonstrates unified long-term water resource planning with other STRGBA GSA member agencies..
Concurrence: The GSP has been prepared in accordance with the requirements of the Sustainable Groundwater Management Act of 2014, and Water Code, § 10727.
All seven STRGBA GSA member agencies have adopted the final draft of the GSP.
Fiscal Impact: In July 2018, the STRGBA GSA member agencies entered into a cost share agreement for the preparation of the GSP for the Modesto Subbasin. In August 2017, City awarded a contract to Todd Groundwater to prepare the GSP for a total cost of $1,616,226 inclusive of a 10% contingency.
Subsequently, the City of Modesto applied for and was awarded a $1,000,000 grant from DWR to help defray the plan preparation costs. The seven STRGBA GSA member agencies along with the Tuolumne County GSA agreed to each pay approximately 12.5% (1/8) of the unfunded balance, or $77,028, to cover their share of the GSP development.
Recommendation: Resolution adopting the Modesto Subbasin Groundwater Sustainability Plan (GSP) and authorizing the STRGBA GSA Plan Manager to submit the GSP to DWR by January 31, 2022.
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AGENDA REPORT
STRGBA GSA Strgba Gsa Agenda Report Gsp Adoption Resolution 2022-03_FinalDraft Attachments: Supporting documents attached:
Resolution Presentation Other supporting docs None attached Note: Original contracts and agreements are housed in the GSA Secretary’s Office, phone (209) 526-7360.
Presenter GSA Chairman
Gordon Enas, P.E. Eric Thorburn, P.E.
Date Signed Date Signed
Eric Thorburn
1/25/22 1/25/22
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12/14/2021/Utilities/MAlvarez/Item 26 1 2021-512
MODESTO CITY COUNCIL
RESOLUTION NO. 2021-512
RESOLUTION APPROVING THE ADOPTION OF THE MODESTO SUBBASIN
GROUNDWATER SUSTAINABILITY PLAN AND AUTHORIZING THE
STANISLAUS AND TUOLUMNE RIVERS GROUNDWATER SUSTAINABILITY
ASSOCIATION GROUNDWATER SUSTAINABILITY AGENCY TO SUBMIT THE
MODESTO SUBBASIN GROUNDWATER SUSTAINABILITY PLAN TO THE
DEPARTMENT OF WATER RESOURCES
WHEREAS, in September of 2014, Governor Edmund G. Brown signed into law the Sustainable Groundwater Management Act of 2014 (SGMA), which changed groundwater management in California. SGMA is a comprehensive package of legislation that sets the framework for statewide sustainable groundwater management and declares that such authority be given to local public agencies that have either water supply, land use authority, or both, and
WHEREAS, SGMA requires the formation of Groundwater Sustainability Agencies (GSAs) made up of local public agencies, and
WHEREAS, GSAs are the local agencies responsible for the development and implementation of the Groundwater Sustainability Plans (GSPs), ultimately aimed at ensuring groundwater sustainability over a 20-year implementation period, and WHEREAS, the City of Modesto overlies the Modesto Subbasin and the Turlock Subbasin, which are designated as high priority, non-critically overdrafted groundwater basins by the State. The regulatory deadline for the completion of the GSPs for the Modesto Subbasin and Turlock Subbasin is January 31, 2022, and WHEREAS, on January 24, 2017, by Resolution No. 2017-30, Council authorized a Groundwater Sustainability Agency Memorandum of Understanding with the Stanislaus and Tuolumne Rivers Groundwater Basin Association (STRGBA) member agencies and approved the formation of the Stanislaus and Tuolumne Rivers #25..
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12/14/2021/Utilities/MAlvarez/Item 26 2 2021-512
Groundwater Basin Association Groundwater Sustainability Agency (STRGBA GSA).
The STRGBA GSA was officially formed on February 16, 2017. The STRGBA GSA is a partnership consisting of the cities of Modesto, Oakdale, Riverbank and Waterford; the Oakdale Irrigation District, Modesto Irrigation District and Stanislaus County, and WHEREAS, due to the structure of the Memorandum of Understanding governing the administration of the STRGBA GSA, all member agencies must approve and adopt the Modesto Subbasin GSP by their respective governing bodies. All member agencies of the STRGBA GSA and the Tuolumne County GSA, will be taking action to approve and adopt the Modesto Subbasin GSP, and
WHEREAS, this proposed action is in compliance with State legislation known as the “Sustainable Groundwater Management Act” which mandates the adoption of a Groundwater Sustainability Plan for groundwater basins categorized as high priority, but not in a condition of critical overdraft, by January 31, 2022, and WHEREAS, failure to adopt such GSP would result in the groundwater resources of the basin being subject to regulation by the State of California Water Resources Control Board.
NOW, THEREFORE, BE IT RESOLVED by the Council of the City of Modesto that it hereby approves the adoption of the Modesto Subbasin Groundwater Sustainability Plan and authorizes the Stanislaus and Tuolumne Rivers Groundwater Sustainability Association Groundwater Sustainability Agency to submit the Modesto Subbasin Groundwater Sustainability Plan to the Department of Water Resources. #25..
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RESOLUTION 2021-64
WATERFORD CITY COUNCIL
RESOLUTION #2021-64
RESOLUTION ADOPTING THE MODESTO SUBBASIN GROUNDWATER SUSTAINABILITY
PLAN AND AUTHORIZING THE SUBMISSION TO THE DEPARTMENT OF WATER
RESOURCES
WHEREAS, in April 1994, the City of Modesto, Modesto Irrigation District, City of Oakdale, Oakdale Irrigation District, City of Riverbank, and County of Stanislaus executed a Memorandum of Understanding to form the Stanislaus and Tuolumne Rivers Groundwater Basin Association (“STRBGA”) for the purpose of coordinating planning and groundwater management activities in the Modesto Subbasin; and
WHEREAS, in July 2015, the Memorandum of Understanding was amended to include the City of Waterford as a member agency of STRGBA; and
WHEREAS, in August 2014, the California Legislature passed, and in September 2014 the Governor signed, legislation creating the Sustainable Groundwater Management Act (“SGMA”) “to provide local groundwater sustainability agencies with the authority and technical and financial assistance necessary to sustainably manage groundwater” (Wat. Code, § 10720, (d)); and
WHEREAS, SGMA requires sustainable management through the development of groundwater sustainability plans (“GSP”), which can be a single plan developed by one or more groundwater sustainability agency (“GSA”) or multiple coordinated plans within a basin or subbasin (Wat.
Code, § 10727); and
WHEREAS, SGMA requires a GSA to manage groundwater in all basins designated by the Department of Water Resources (“DWR") as a medium or high priority, including the Modesto Subbasin (designated basin number 5-022.02); and
WHEREAS, the STRGBA GSA was formed on February 16, 2017, for the purpose of sustainably managing groundwater in the Modesto Subbasin, within its jurisdictional boundaries, pursuant to the requirements of SGMA; and
WHEREAS, the STRGBA GSA has the authority to draft, adopt, and implement a GSP (Wat.
Code, § 10725 et seq.); and
WHEREAS, the STRGBA GSA submitted an Initial Notification to DWR to jointly develop a GSP for the Modesto Subbasin on February 28, 2017; and
WHEREAS, the STRGBA GSA has coordinated with the Tuolumne County GSA to develop a single, coordinated GSP for the Modesto Subbasin; and
WHEREAS, on August 10, 2021 the STRGBA GSA released the Notice of Intent to Adopt the GSP to cities and counties in the plan area pursuant to Water Code section 10728.4; and WHEREAS, the STRGBA GSA and Tuolumne County GSA developed the draft Modesto Subbasin GSP and released the draft Modesto Subbasin GSP chapters for public review and comment; and
WHEREAS, the STRGBA GSA and Tuolumne County GSA reviewed and will respond to comments on the Modesto Subbasin GSP; and
WHEREAS, the final staff version of the Modesto Subbasin GSP was presented to the Waterford City Council on December 16, 2021; and
DocuSign Envelope ID: 24CD477A-D363-4E96-8357-F277DF3AE4B5 #25..
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RESOLUTION 2021-64
WHEREAS, the City of Waterford understands its staff and consultant team will finalize the GSP by making non-substantive revisions to the final Modesto Subbasin GSP presented on December 16, 2021; and
WHEREAS, the final Modesto Subbasin GSP will be incorporated in its entirety by reference hereto this resolution.
NOW, THEREFORE, BE IT RESOLVED that the City Council of the City of Waterford hereby finds as follows:
1. The City of Waterford hereby approves and adopts the final staff version of the Modesto Subbasin GSP.
2. The City of Waterford authorizes the Modesto Subbasin Plan Manager and consultants to take such actions as may be reasonably necessary to:
a. finalize the staff version of the Modesto Subbasin GSP, barring any substantive changes to the document;
b. submit the final Modesto Subbasin GSP to DWR by January 31, 2022; or c. implement the purpose of this Resolution.
The foregoing Resolution was passed and adopted by the City Council of the City of Waterford, County of Stanislaus, State of California, at a regular meeting thereof held on December 16, 2021, by the following vote:
AYES: Aldaco, Kitchens, Talbott
NOES: None
ABSTAIN: None
ABSENT: Ewing, Hilton
City of Waterford,
Jose Aldaco, Mayor
ATTEST:
Patricia Krause, CMC, City Clerk
APPROVED AS TO FORM:
Corbett J. Browning, City Attorney
DocuSign Envelope ID: 24CD477A-D363-4E96-8357-F277DF3AE4B5 #25..
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THE BOARD OF SUPERVISORS OF THE COUNTY OF STANISLAUS
AGENDA ITEM
DEPT: Environmental Resources BOARD AGENDA:6.B.2
AGENDA DATE: August 31, 2021
CONSENT:
CEO CONCURRENCE: YES 4/5 Vote Required: No
SUBJECT:
Approval to Set a Public Hearing on December 7, 2021, at the 9:00 a.m. Meeting to Consider Adoption of the Modesto Groundwater Subbasin Groundwater Sustainability Plan
STAFF RECOMMENDATION:
1. Set a public hearing on December 7, 2021, at the 9:00 a.m. meeting for consideration of adoption of the Modesto Groundwater Subbasin Groundwater Sustainability Plan.
DISCUSSION:
In September of 2014, Governor Edmund G. Brown signed into law the Sustainable Groundwater Management Act of 2014 (SGMA), which changed the landscape of groundwater management in California. SGMA is a comprehensive package of legislation that sets the framework for statewide sustainable groundwater management and declares that such authority be given to local public agencies that have either water supply or land use authority, or both.
SGMA requires, among many other items, the formation of Groundwater Sustainability Agency‘s (GSAs) made up of local public agencies. SGMA empowers these GSAs to use a number of management tools to achieve “sustainability” in the affected groundwater basins, including authorities required in order to manage groundwater in a sustainable manner. GSAs are the local agencies responsible for the development and implementation of the Groundwater Sustainability Plans (GSPs), ultimately aimed at ensuring groundwater sustainability over a 20 year implementation period. GSPs are focused on the development and implementation of long-term groundwater sustainability programs, plans and practices over a 50 year planning horizon.
There are four groundwater subbasins underlying Stanislaus County, in whole or in part.
These basins include the following:
1. Eastern San Joaquin Groundwater Subbasin
2. Modesto Groundwater Subbasin
3. Turlock Groundwater Subbasin
4. Delta-Mendota Groundwater Subbasin
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