Conjunctive Management and Groundwater Storage (Resource Management Strategy)

California Department of Water Resources (DWR) | July 29th, 2016

Conjunctive management or conjunctive use refers to the coordinated and planned use and management of both surface water and groundwater resources to maximize the availab

Conjunctive management or conjunctive use refers to the coordinated and planned use and management of both surface water and groundwater resources to maximize the availability and reliability of water supplies in a region to meet various management objectives. Surface water and groundwater resources typically differ significantly in their availability, quality, management needs, and development and use costs. Managing both resources together, rather than in isolation, allows water managers to use the advantages of both resources for maximum benefit. Conjunctive management thus involves the efficient use of both resources through the planned and managed operation of a groundwater basin and a surface water storage system combined through a coordinated conveyance infrastructure. Water is stored in the groundwater basin that is planned to be used later by intentionally recharging the basin when excess water supply is available, for example, during years of above-average surface water supply or through the use of recycled water. The necessity and benefit of conjunctive water management are apparent when surface water and groundwater are hydraulically connected. Well-planned conjunctive management that prevents groundwater depletion by maintaining baseflow to streams and support for ecosystem services not only increases the reliability and the overall amount of water supply in a region, but also provides other benefits such as flood management, environmental water use, and water quality improvement.  

Conjunctive Water Management Resource Management Strategy

California Department of Water Resources (DWR) | April 29th, 2024

Conjunctive water management, also referred to as conjunctive use, is broadly defined as the coordinated and planned use and management of the different sources of water

Conjunctive water management, also referred to as conjunctive use, is broadly defined as the coordinated and planned use and management of the different sources of water in time and space. It is usually focused on surface water and groundwater resources to maximize the availability and reliability of water supplies in a region to meet various management objectives. It is a holistic approach to water resource management that can increase available water for beneficial uses, allow water agencies greater flexibility in scheduling deliveries, and improve drought resiliency (California Department of Water Resources 2003).

Corning Subbasin Groundwater Sustainability Plan

Tehama County Flood Control and Water Conservation District | December 20th, 2021

Preparation of this GSP is the first step for the GSAs to achieve groundwater sustainability in the Corning Subbasin. To evaluate progress toward groundwater sustainabili

Preparation of this GSP is the first step for the GSAs to achieve groundwater sustainability in the Corning Subbasin. To evaluate progress toward groundwater sustainability during implementation, annual reports and 5-year updates to the GSP will be prepared as required by SGMA. The GSAs recognize that sustainability is only possible with support of stakeholders and coordination of local, state, tribal and federal agencies and the managed use of both surface and groundwater resources. While SGMA does not require the Plan to address California’s Public Trust Doctrine, a 2018 California Court of Appeal ruling found that groundwater pumping that reduces the flow or volume of water in a navigable stream (and tributaries that supply navigable streams) may violate the public trust. This Plan recognizes the importance of protecting public trust resources, including fish and wildlife, in the Subbasin’s streams that are connected to groundwater.

County of San Bernardino Hydrology Manual

San Bernardino County | August 1st, 1986

Coupling a spatiotemporally distributed soil water budget with stream-depletion functions to inform stakeholder-driven management of groundwater-dependent ecosystems

Water Resources Research, American Geophysical Union | November 12th, 2013

Groundwater pumping, even if only seasonal, may significantly impact groundwater-dependent ecosystems through increased streamflow depletion, particularly in semiarid and

Groundwater pumping, even if only seasonal, may significantly impact groundwater-dependent ecosystems through increased streamflow depletion, particularly in semiarid and arid regions. The effects are exacerbated, under some conditions, by climate change. In social sciences, the management of groundwater-dependent ecosystems is generally considered a “wicked” problem due to the complexity of affected stakeholder groups, disconnected legal frameworks, and a divergence of policies and science at the cross road between groundwater and surface water, and between ecosystems and water quality. A range of often simplified scientific tools plays an important role in addressing such problems. Here we develop a spatiotemporally distributed soil water budget model that we couple with an analytical model for stream depletion from groundwater pumping to rapidly assess seasonal impacts of groundwater pumping on streamflow during critical low flow periods. We demonstrate the applicability of the tool for the Scott Valley in Northern California, where protected salmon depend on summer streamflow fed by cool groundwater. In this example, simulations suggest that increased recharge in the period immediately preceding the critical low streamflow season, and transfer of groundwater pumping away from the stream are potentially promising tools to address ecosystem concerns, albeit raising difficult infrastructure and water trading issues. In contrast, additional winter recharge at the expense of later spring recharge, whether intentional or driven by climate may reduce summer streamflows. Comparison to existing detailed numerical groundwater model results suggests that the coupled soil water mass balance—stream depletion function approach provides a viable tool for scenario development among stakeholders, to constructively inform the search for potential solutions, and to direct more detailed, complex site-specific feasibility studies. The tool also identifies important field monitoring efforts needed to improve the understanding and quantification of site-specific groundwater-stream interactions.

Coupling a spatiotemporally distributed soil water budget with stream‐depletion functions to inform stakeholder‐driven management of groundwater‐dependent ecosystems

American Geophysical Union (AGU) | November 12th, 2013

Groundwater pumping, even if only seasonal, may significantly impact groundwater‐dependent ecosystems through increased streamflow depletion, particularly in semiarid a

Groundwater pumping, even if only seasonal, may significantly impact groundwater‐dependent ecosystems through increased streamflow depletion, particularly in semiarid and arid regions. The effects are exacerbated, under some conditions, by climate change. In social sciences, the management of groundwater‐dependent ecosystems is generally considered a “wicked” problem due to the complexity of affected stakeholder groups, disconnected legal frameworks, and a divergence of policies and science at the cross road between groundwater and surface water, and between ecosystems and water quality. A range of often simplified scientific tools plays an important role in addressing such problems. Here we develop a spatiotemporally distributed soil water budget model that we couple with an analytical model for stream depletion from groundwater pumping to rapidly assess seasonal impacts of groundwater pumping on streamflow during critical low flow periods. We demonstrate the applicability of the tool for the Scott Valley in Northern California, where protected salmon depend on summer streamflow fed by cool groundwater. In this example, simulations suggest that increased recharge in the period immediately preceding the critical low streamflow season, and transfer of groundwater pumping away from the stream are potentially promising tools to address ecosystem concerns, albeit raising difficult infrastructure and water trading issues. In contrast, additional winter recharge at the expense of later spring recharge, whether intentional or driven by climate may reduce summer streamflows. Comparison to existing detailed numerical groundwater model results suggests that the coupled soil water mass balance—stream depletion function approach provides a viable tool for scenario development among stakeholders, to constructively inform the search for potential solutions, and to direct more detailed, complex site‐specific feasibility studies. The tool also identifies important field monitoring efforts needed to improve the understanding and quantification of site‐specific groundwater‐stream interactions.

Critical Aquifer Overdraft Accelerates Degradation of Groundwater Quality in California's Central Valley During Drought

American Geophysical Union (AGU) | September 1st, 2021

It has been established that wells are at risk to run dry when groundwater levels decline during drought, but associated impacts to water quality are poorly understood. 

It has been established that wells are at risk to run dry when groundwater levels decline during drought, but associated impacts to water quality are poorly understood. This study examined 30 yr of data from California's Central Valley to find dramatic groundwater-level declines during drought were associated with worsening groundwater quality. This likely happens because increased pumping during drought can draw shallow, contaminated groundwater to depths commonly tapped by public drinking water wells. This is the first study of its kind to show direct linkages between drought and groundwater quality at such a broad spatial scale

Cuyama Basin Groundwater Sustainability Plan

Cuyama Basin Groundwater Sustainability Agency (CBGSA) | December 4th, 2019

Cuyama Valley Groundwater Basin Groundwater Sustainability Plan (Revised)

Cuyama Basin Groundwater Sustainability Agency (CBGSA) | July 6th, 2022

The CBGSA is a joint-powers agency that is comprised of Kern, Santa Barbara, San Luis Obispo and Ventura counties, the Cuyama Community Services District and the Cuyama B

The CBGSA is a joint-powers agency that is comprised of Kern, Santa Barbara, San Luis Obispo and Ventura counties, the Cuyama Community Services District and the Cuyama Basin Water District. The CBGSA is governed by an 11-member Board of Directors, with one representative from Kern, San Luis Obispo and Ventura counties, two representatives from Santa Barbara County, one member from the Cuyama Community Services District, and five members from the Cuyama Basin Water District. Due to file size, this GSP has been divided. Part 1, Part 2, Part 3,, Part 4, Part 5, Part 6, Part 7, Part 8

CV SALTS Prioritization & Optimization Study Year 1 Progress Report

Central Valley Salinity Alternatives for Long-Term Sustainability (CV-SALTS) | March 24th, 2023