Groundwater Sustainability Plan for the Oxnard Subbasin

Fox Canyon Groundwater Management Agency (FCGMA) | December 13th, 2019

The Fox Canyon Groundwater Management Agency (FCGMA, or the Agency) has developed this Groundwater Sustainability Plan (GSP) for the Oxnard Subbasin (Subbasin; DWR Basin

The Fox Canyon Groundwater Management Agency (FCGMA, or the Agency) has developed this Groundwater Sustainability Plan (GSP) for the Oxnard Subbasin (Subbasin; DWR Basin 4-004.02) of the Santa Clara River Valley Groundwater Basin (DWR Basin 4-004), in compliance with the 2014 Sustainable Groundwater Management Act (SGMA; California Water Code, Section 10720 et seq.). The purpose of this GSP is to define the conditions under which the groundwater resources of the entire Oxnard Subbasin, which support agricultural, municipal and industrial, and environmental uses, will be managed sustainably in the future. Historical groundwater production has resulted in seawater intrusion in the five primary aquifers of the Subbasin. These aquifers have been divided into an Upper Aquifer System, which comprises the Oxnard and Mugu Aquifers, and a Lower Aquifer System, which comprises the Hueneme, Fox Canyon, and Grimes Canyon Aquifers. The average rate of groundwater production from the Upper Aquifer System between 2015 and 2017 was approximately 40,000 acre-feet per year (AFY). The average production from the Lower Aquifer System between 2015 and 2017 was approximately 29,000 AFY. Numerical groundwater simulations indicate that if these production rates were carried into the future, seawater intrusion would continue in the Subbasin and the area currently impacted by concentrations of chloride greater than 500 milligrams per liter would grow. The landward extent of this area is referred to as the saline water impact front. Combinations of projects and management actions were explored to estimate the rate of groundwater production that would prevent future expansion of the area of the Subbasin currently impacted by concentrations of chloride greater than 500 milligrams per liter. This rate of groundwater production is referred to as the sustainable yield. With the currently available projects and management actions, the sustainable yield of the Upper Aquifer System, was calculated to be approximately 32,000 AFY, with an uncertainty of ± 4,100 to 6,000 AFY. The sustainable yield of the Lower Aquifer System was calculated to be approximately 7,000 AFY, with an uncertainty of ± 2,300 to 3,600 AFY. Adoption of this GSP represents the first step in achieving groundwater sustainability within the Oxnard Subbasin by 2040, as required by SGMA. Evaluation of this GSP is required at a minimum of every 5 years following submittal to the California Department of Water Resources (DWR). As part of the 5-year evaluation process, the sustainable yield for each aquifer system will be refined and adjusted. These refinements will be based on new data, additional studies undertaken to fill data gaps, and groundwater modeling. Refinements and adjustments will also be made to the minimum threshold water levels developed to avoid undesirable results, the measurable objective water levels that account for the need to continue groundwater production during drought cycles and the associated interim milestones to help gauge progress toward sustainability over the next 20 years. In order to minimize the pumping reductions required to achieve sustainable management of the Subbasin, investment in large-scale projects to increase water supply, provide the infrastructure to redistribute pumping, and/or directly control seawater intrusion should be investigated. Basin optimization studies, groundwater modeling, and project feasibility studies will be conducted over the next 5 years to explore practicable processes and approaches to increasing the sustainable yield of the Oxnard Subbasin.

Groundwater Sustainability Plan for the Pleasant Valley Basin

Fox Canyon Groundwater Management Agency (FCGMA) | December 13th, 2019

The Fox Canyon Groundwater Management Agency (FCGMA, or the Agency) has developed this Groundwater Sustainability Plan (GSP) for the Pleasant Valley Basin (PVB; DWR Basi

The Fox Canyon Groundwater Management Agency (FCGMA, or the Agency) has developed this Groundwater Sustainability Plan (GSP) for the Pleasant Valley Basin (PVB; DWR Basin 4-006), in compliance with the 2014 Sustainable Groundwater Management Act (SGMA) (California Water Code, Section 10720 et seq.). FCGMA is one of three Groundwater Sustainability Agencies (GSAs) in the PVB. The other two GSAs are the Camrosa Water District–Pleasant Valley GSA and the Pleasant Valley Outlying Areas GSA. This GSP is the sole GSP prepared for the PVB, and covers the entire PVB, including all areas of the PVB outside of FCGMA’s jurisdiction. The purpose of this GSP is to define the conditions under which the groundwater resources of the entire PVB, which support agricultural, municipal and industrial, and environmental uses, will be managed sustainably in the future. The PVB shares a boundary and is in hydraulic communication with Oxnard Subbasin (Subbasin; DWR Basin 4-004.02) to the west. The boundary between the PVB and the Oxnard Subbasin is associated with a change in character of recent and older alluvial deposits. In the PVB, these deposits are finer grained and are, in general, less suitable for groundwater production than the coarser-grained sediments of the same age in the Oxnard Subbasin. There is no corresponding change in character in the deeper aquifers, including the Fox Canyon Aquifer, which are continuous across the boundary between the PVB and the Oxnard Subbasin. Groundwater production from wells on either side of the boundary between the PVB and the Oxnard Subbasin influences groundwater elevations and the direction of groundwater flow across this boundary. Historical groundwater production from the PVB and Oxnard Subbasin combined has resulted in seawater intrusion in the aquifers of the Subbasin. In the PVB, the average rate of groundwater production between 2015 and 2017 was approximately 13,200 acre-feet per year (AFY). In 2015, approximately 53% of the production from the Lower Aquifer System, which comprises the Hueneme, Fox Canyon, and Grimes Canyon Aquifers, and 47% of the production from the Upper Aquifer System, which comprises the older alluvium in the PVB, and the Oxnard and Mugu Aquifers in the Oxnard Subbasin. Numerical groundwater simulations indicate that if these production rates were carried into the future, groundwater elevations in the PVB would not recover during multi-year cycles of drought and recovery, and seawater intrusion would continue in the Oxnard Subbasin. The landward extent of the area in the Subbasin currently impacted by concentrations of chloride greater than 500 milligrams per liter is referred to as the “saline water impact front.” Combinations of projects and management actions were explored to estimate the rate of groundwater production that would allow groundwater elevations in the PVB to recover during multi-year cycles of drought and recovery, and prevent future landward migration of the saline water impact front. This rate of groundwater production is referred to as the sustainable yield. With the currently available projects and management actions, the sustainable yield of the PVB was estimated to be approximately 11,600 AFY, with an uncertainty of ± 1,200 AFY. At the upper bound of the uncertainty estimate (12,600 AFY), the estimated sustainable yield of the PVB is 600 AFY lower than the 2015–2017 average production rate. Adoption of this GSP represents the first step in achieving groundwater sustainability within the PVB by 2040, as required by SGMA. Evaluation of this GSP is required at a minimum of every 5 years following submittal to the California Department of Water Resources (DWR). As part of the 5-year evaluation process, the sustainable yield will be refined and adjusted. These refinements will be based on new data, additional studies undertaken to fill data gaps, and groundwater modeling. Refinements and adjustments will also be made to the minimum threshold groundwater levels developed to avoid undesirable results, the measurable objective groundwater levels that account for the need to continue groundwater production during drought cycles and the associated interim milestones to help gauge progress toward sustainability over the next 20 years. In order to minimize the pumping reductions required to achieve sustainable management of the PVB, investment in projects to increase water supply, provide the infrastructure to redistribute pumping, and/or directly control seawater intrusion in the Oxnard Subbasin should be investigated. Inter-basin optimization studies, groundwater modeling, and project feasibility studies are recommended over the next 5 years to explore practicable processes and approaches to increasing the sustainable yield of the PVB. Due to size, this file has been divided. Part 1, Part 2, Part 3, Part 4, Part 5, Part 6

Groundwater Sustainability Plan for the San Jacinto Groundwater Basin

Eastern Municipal Water District | September 30th, 2021

Eastern Municipal Water District (EMWD) has developed this Groundwater Sustainability Plan (GSP) for the San Jacinto Groundwater Basin (SJGB) in compliance with the Sust

Eastern Municipal Water District (EMWD) has developed this Groundwater Sustainability Plan (GSP) for the San Jacinto Groundwater Basin (SJGB) in compliance with the Sustainable Groundwater Management Act (SGMA; California Water Code [CWC], Section 10720 et seq.), which was passed by the California legislature and signed into law in 2014. This GSP has been developed by EMWD as the Groundwater Sustainability Agency (GSA) in accordance with the Department of Water Resources (DWR) GSP Regulations to apply to the entirety of the San Jacinto Groundwater Basin (DWR Basin 8-005) that is not adjudicated. The non-adjudicated part of the SJGB is considered the Plan Area in this GSP. Data from, and conditions in the adjudicated portions of the SJGB have been incorporated into this GSP, as appropriate, for understanding groundwater conditions within the Plan Area (Figure ES-1). The purpose of this GSP is to define the groundwater conditions that will be used to ensure ongoing, long-term, sustainable management of the groundwater resources within the Plan Area. Part 1; Part 2 ; Part 3; Part 4 ; Part 5; Part 6; Part 7  GSP approved by DWR 4/27/23

Groundwater Sustainability Plan for the San Joaquin River Exchange Contractors Groundwater Sustainability Plan (GSP) Group in the Delta-Mendota Subbasin

San Joaquin River Exchange Contractors GSA (SJREC GSA) | December 13th, 2019

Groundwater Sustainability Plan for the San Joaquin River Exchange Contractors GSP Group in the Delta-Mendota Subbasin (5-022.07)

San Joaquin River Exchange Contractors Water Authority (SJRECWA) | June 30th, 2022

The GSP was adopted by the SJREC GSA on December 13, 2019. The GSP has been amended in response to the January 21, 2022 DWR Determination letter to Delta-Mendota Subbasin

The GSP was adopted by the SJREC GSA on December 13, 2019. The GSP has been amended in response to the January 21, 2022 DWR Determination letter to Delta-Mendota Subbasin’s Point of Contact that included evaluation of the San Joaquin River GSA’s Groundwater Sustainability Plan (GSP). The amended plan was adopted by the SJRECGSA Board on July 5, 2022. On March 2nd, 2023, the Department of Water Resources announced decisions for Groundwater Sustainability Plans (GSPs), finding that numerous subbasins were found to be inadequate. One of these subbasins—the Delta-Mendota Subbasin in San Joaquin, Stanislaus, Merced, Fresno, Madera, and San Benito counties—includes a region for which the Exchange Contractors are responsible for developing the GSP. Due to size, this file has been divided. Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7, Part 8

Groundwater Sustainability Plan for the Santa Monica Groundwater Subbasin

Santa Monica Basin Groundwater Sustainability Agency | January 27th, 2022

The Santa Monica Basin Groundwater Sustainability Agency (GSA), which comprises the City of Santa Monica, the City of Los Angeles via its Department of Water and Power (L

The Santa Monica Basin Groundwater Sustainability Agency (GSA), which comprises the City of Santa Monica, the City of Los Angeles via its Department of Water and Power (LADWP), the City of Culver City, the City of Beverly Hills, and the County of Los Angeles, has prepared this Groundwater Sustainability Plan (GSP) for the non-adjudicated portion of the Santa Monica Subbasin (Subbasin) of the Los Angeles Plain Groundwater Basin (DWR Basin 4-011.01). This GSP was prepared in compliance with the 2014 Sustainable Groundwater Management Act (SGMA), which is codified in California Water Code (CWC), Part 2.75 (Sustainable Groundwater Management), §10720 et seq.1 This GSP has been developed in accordance with the Department of Water Resources (DWR) GSP Regulations to apply to the entirety of the Subbasin that is not adjudicated. The purpose of this GSP is to define the groundwater conditions that will be used to ensure the long-term sustainability of groundwater resources for current and future stakeholders through ongoing, proactive stewardship. Long-term sustainability includes: • Maintaining sufficient groundwater in storage to allow for continued groundwater production that meets the operational demands and regulatory commitments of the City of Santa Monica as well as other groundwater producers and stakeholders.• Ensuring groundwater conditions in the Subbasin support sufficient seaward flow of fresh water to prevent significant and unreasonable seawater intrusion in the Silverado aquifer. • Continuing groundwater production at rates and in aquifers that do not impact the ability of groundwater-dependent ecosystems to access groundwater. Due to size, this file has been divided into five parts. Part 1, Part 2, Part 3, Part 4, Part 5

Groundwater Sustainability Plan for the Santa Ynez River Valley Groundwater Basin, Central Management Area

Santa Ynez River Valley Basin Groundwater Sustainability Agency, Central Management Area | January 3rd, 2022

This Groundwater Sustainability Plan (GSP) is prepared in accordance with the 2014 Sustainable Groundwater Management Act (SGMA) and covers the Central Management Area (C

This Groundwater Sustainability Plan (GSP) is prepared in accordance with the 2014 Sustainable Groundwater Management Act (SGMA) and covers the Central Management Area (CMA) of the Santa Ynez River Valley Groundwater Basin (Basin or SYRVGB) located in coastal central California. There is one principal aquifer in the CMA: the Buellton Aquifer which covers the Buellton Upland and the older formations that lie under the Santa Ynez River alluvium near the City of Buellton. The Santa Ynez River is the primary surface water source within the Basin. The underflow of the Santa Ynez River is considered part of the river flow and is managed as surface water pursuant to the administrative authority and jurisdiction of the State Water Resources Control Board (SWRCB) over waters flowing in known and definite channels. The analyses conducted for this GSP indicate that current Basin conditions are sustainable and no undesirable results (defined as significant and unreasonable impacts to sustainability indicators) are occurring. Potential undesirable results have been identified and specific minimum thresholds have been developed to help ensure that undesirable results do not occur under future conditions. Potential project operations and management actions designed to maintain and improve groundwater conditions and sustainability have been identified and are described within this GSP.

Groundwater Sustainability Plan for the White Wolf Basin

White Wolf Groundwater Sustainability Agency | December 15th, 2021

Groundwater Sustainability Plan Greater Kaweah Groundwater Sustainability Agency

Greater Kaweah Groundwater Sustainability Agency (GKGSA) | January 22nd, 2020

Groundwater Sustainability Plan Los Molinos Subbasin

Theama County Flood Control and Water Conservation District | January 31st, 2022

The Los Molinos Subbasin (DWR Subbasin No. 5-021.56) of the Sacramento Valley Groundwater Basin was assigned a medium priority designation by DWR and is required to submi

The Los Molinos Subbasin (DWR Subbasin No. 5-021.56) of the Sacramento Valley Groundwater Basin was assigned a medium priority designation by DWR and is required to submit a GSP. The Tehama County Flood Control and Water Conservation District (Tehama County FCWCD) (District), a local and regional authority, serves as the exclusive GSA for the Los Molinos subbasin.