The Effect of Declining Groundwater Levels on Supply Well Operations

University of California, Davis (UC Davis) | August 15th, 2016

This report explores the impact of droughts on domestic and irrigation well operations. Well completion reports and groundwater depth data obtained from the Department of

This report explores the impact of droughts on domestic and irrigation well operations. Well completion reports and groundwater depth data obtained from the Department of Water Resources were used in the analysis. The percentages of wells in which the top, middle or bottom of the screened interval became exposed above the pumping water level were calculated and implied maintenance or replacement costs were estimated. Increases in pumping costs from greater depths to groundwater were estimated as well. For our case study, we selected a 27 square mile area in Tulare County, where the California Department of Water Resources has determined that groundwater is in a state of critical overdraft and designated the basin as High Priority under the Sustainable Groundwater Management Act. Results indicate that for the 2015 drought, there was significant potential for incurring well maintenance and replacement costs as a result of drought conditions and water levels approaching critical points in the screened intervals. While the assumptions associated with the current method appear to result in overestimation of impacts, the current drought may have resulted in several million dollars in well maintenance and replacement costs. For irrigation wells that remained in operation, increased depths to groundwater would increase overall pumping costs. About $5.31 per acre ($1.7 per acre-foot) were estimated as increased pumping costs in the recent 2012-2015 drought. While these costs are not large on a per acre basis, they may be significant when incurred across large agricultural areas. This proof of concept analysis highlights the value of information on groundwater levels and well constructions for estimating impacts of droughts on long term groundwater pumping capacity and operation. This analysis can be extended for the entire Central Valley in an effort to quantify the impacts of drought and the importance of groundwater management.

The Future of Agriculture in the San Joaquin Valley

Public Policy Institute of California (PPIC) | February 9th, 2023

The Future of Groundwater in California: Lessons in Sustainable Management from Across the West

Environmental Defense Fund (EDF) | January 31st, 2018

The 2014 Sustainable Groundwater Management Act (SGMA) created, for the first time and on an unprecedented scale, a mandate to change how groundwater is managed statewide

The 2014 Sustainable Groundwater Management Act (SGMA) created, for the first time and on an unprecedented scale, a mandate to change how groundwater is managed statewide in California. While enacting SGMA was a tremendous step forward, communities and water districts now face the considerable challenge of creating successful groundwater management programs. This report is aimed at helping California’s water managers, public water agencies, county commissioners, city planners, and others better understand the suite of tools and approaches that can be used to enhance the sustainable management of groundwater. Specifically, we consider four categories of management tools—regulatory, incentive-based, agency supply augmentation and protection, and education and outreach—to evaluate how these tools are being used to address water quantity, water quality, and surface water and groundwater interaction challenges. We present nine comprehensive case studies of groundwater management across the Western United States to highlight how these tools have been used to address those challenges. The case studies represent basins that have a range of water uses— agricultural, municipal, or mixed water use, as well as basins with diverse hydrologic, political and social settings. Effective groundwater management takes time and requires significant resources and commitment on the part of water managers and communities. Each groundwater management program presented in this report relies upon a variety of interdependent tools and actions to meet management goals. The case studies illustrate the importance of building trust, having sufficient data, using a portfolio of management approaches, assuring performance, and access to funding. Given the similarities between the goals of SGMA and those described in the case studies, these themes emerge as crucial to the successful implementation of California’s landmark groundwater legislation.  

The Sustainable Groundwater Management Act challenges the diversity of California farms

California Agriculture (UCANR) | November 16th, 2016

California’s agricultural sector, a major groundwater user, finds itself in the midst of the implementation of the Sustainable Groundwater Management Act (SGMA). The la

California’s agricultural sector, a major groundwater user, finds itself in the midst of the implementation of the Sustainable Groundwater Management Act (SGMA). The law mandates the formation of local groundwater sustainability agencies (GSAs) and adoption of groundwater sustainability plans (GSPs) for all overdrafted groundwater basins across the state by 2020. Each GSA will be unique, with its own governance structures and rules, including the size and composition of the governing board, mechanisms for representing different interests, opportunities for stakeholders to participate, and rules concerning the allocation of pumping “rights” and the use of economic instruments, such as pumping permits, pumping taxes or tiered pricing, to incentivize pumping curtailments (DWR 2016). This new water management landscape may threaten the diversity of the state’s farming operations.

The Sustainable Groundwater Management Act Governance Conference: Research and Practice Synthesis Report 2018

University of California, Davis (UC Davis) | June 8th, 2018

“The Sustainable Groundwater Management Act Governance Conference: Research and Practice,” held at the UC Davis in February 2018, assembled 55 social science research

“The Sustainable Groundwater Management Act Governance Conference: Research and Practice,” held at the UC Davis in February 2018, assembled 55 social science researchers as well as practitioners from across the state to discuss the ongoing implementation of the Sustainable Groundwater Management Act (SGMA). The California Legislature passed SGMA in 2014. SGMA required the formation of new groundwater sustainability agencies (GSAs) by June 2017 in order to develop and implement Groundwater Sustainability Plans (GSPs) for 127 medium- and high-priority groundwater basins by 2020 and 2022. With such a large task at hand, and given the importance of groundwater to California’s public health, environment, and economy, strengthening collaboration across research teams as well as between researchers and practitioners is crucial to increasing the capacity for learning about governance processes and to bridging the science-policy divide in order to support the creation of effective governance institutions. The goals of this report are to synthesize key lessons learned about SGMA at the nexus of research and practice, and to create a roadmap and research agenda going forward. Sharing information and knowledge among research teams enables a comparative perspective that cannot be achieved by one team alone. Furthermore, perspectives from practitioners inform research directions, focus attention on relevant issues and knowledge gaps, and build relationships among the SGMA community for more collaborative applied research. Conference discussions focused on discovering what has been learned in the first three years of SGMA implementation and GSA development, identifying high priority questions for the next stage of GSP development, sharing research methods, and coordinating research activities.

Thousands of domestic and public supply wells face failure despite groundwater sustainability reform in California’s Central Valley

Nature Portfolio (Springer Nature) | September 8th, 2023

Tools for Assessing Groundwater-Surface Water Connectivity Under the Sustainable Groundwater Management Act

Stanford University | February 14th, 2019

In 2014, California enacted the Sustainable Groundwater Management Act (SGMA), which requires local agencies to develop and implement groundwater sustainability plans (G

In 2014, California enacted the Sustainable Groundwater Management Act (SGMA), which requires local agencies to develop and implement groundwater sustainability plans (GSPs) in all groundwater basins designated by the California Department of Water Resources (DWR) as high or medium priority by 2020 or 2022, depending on basin condition. For the first time in California’s history, agencies managing groundwater under SGMA must assess the impacts of groundwater pumping on water supply and surface water flows and avoid “significant and unreasonable adverse impacts on beneficial uses of the surface water.” SGMA’s legal and regulatory requirements pertaining to interconnected surface water – defined in SGMA as, “surface water that is hydraulically connected at any point by a continuous zone to the underlying aquifer and the overlying surface water is not completely depleted.” – represent a significant step forward in recognizing the interconnected nature of surface water and groundwater and for managing this resource accordingly. However, because groundwater-surface water connectivity was not a common management consideration prior to the enactment of SGMA, many basins lack data or models or technical capacity to adequately characterize interconnected surface water (ISW) and evaluate the impacts of groundwater pumping on these systems. Thus, meeting legal and regulatory requirements related to ISW may be hindered by a lack of information about both the location and timing of such waters, as well as the many beneficial uses and users that they support. In March 2018, Water in the West, The University of Victoria, Foundry Spatial, The Nature Conservancy (TNC) and Environmental Defense Fund co-hosted a workshop on tools to assess ISW under SGMA. The workshop, which included a small, select group of hydrologists, water managers, water lawyers, nongovernmental organizations (NGOs) and academia, focused on four main areas: 1) Accounting for beneficial uses and users in GSP development and implementation; 2) Identifying physical or analytical approaches for characterizing, quantifying and monitoring ISW; 3) Using hydrological modeling to assess the effects of groundwater pumping on ISW and streamflow depletions; and 4) Understanding the functionality and use of decision support tools from other jurisdictions This report summarizes key findings from the one-day workshop and a short questionnaire completed by workshop participants during the day. A list of workshop attendees, the workshop agenda and workshop questionnaire can be found in Appendices A-C, respectively.

Tracy Subbasin Groundwater Sustainability Plan

County of San Joaquin GSA | November 1st, 2021

The Tracy Subbasin boundaries follow the Old River on the northwest, the Coastal Range on the southwest and south, and the San Joaquin River on the east. The southeast bo

The Tracy Subbasin boundaries follow the Old River on the northwest, the Coastal Range on the southwest and south, and the San Joaquin River on the east. The southeast boundary of the Subbasin, along the San Joaquin-Stanislaus county line, follows irregular water district boundaries. The Subbasin is almost entirely with San Joaquin County but includes a small triangular portion of Alameda County. About one-half of the Subbasin is a mix of Delta islands (mostly agriculture) and waterways while the other half is comprised of urban and agricultural communities (Non-Delta areas).

Trading Sustainably: Critical Considerations for Local Groundwater Markets Under the Sustainable Groundwater Management Act

University of California, Berkeley (UC Berkeley) | June 1st, 2017

The Sustainable Groundwater Management Act (SGMA), passed in 2014, is changing the way California manages its groundwater resources. SGMA calls for the creation of loc

The Sustainable Groundwater Management Act (SGMA), passed in 2014, is changing the way California manages its groundwater resources. SGMA calls for the creation of local Groundwater Sustainability Agencies (GSAs) and tasks them with developing and implementing Groundwater Sustainability Plans (GSPs) to achieve sustainable groundwater management. SGMA offers GSAs a broad palette of tools to choose from and significant flexibility to tailor their management activities to local conditions and needs. Because it allows GSAs to assign groundwater extraction allocations to pumpers and to authorize transfers of these allocations under certain circumstances, SGMA potentially opens the door for the development of local groundwater markets. In such a market, a willing seller might trade a portion of their groundwater extraction allocation to a willing buyer, allowing the buyer to pump groundwater in the seller’s stead.

Tri-County Water Authority Groundwater Sustainability Plan

Tri-County Water Authority | December 18th, 2019