So, You Want a Farm in Westlands Water District

University of California | August 2nd, 1976

Social Disparities in Nitrate-Contaminated Drinking Water in California’s San Joaquin Valley

National Institutes of Health (NIH) | September 1st, 2011

Soil suitability index identifies potential areas for groundwater banking on agricultural lands

California Agriculture (UCANR) | ?

Groundwater pumping chronically exceeds natural recharge in many agricultural regions in California. A common method of recharging groundwater — when surface

Groundwater pumping chronically exceeds natural recharge in many agricultural regions in California. A common method of recharging groundwater — when surface water is available — is to deliberately flood an open area, allowing water to percolate into an aquifer. However, open land suitable for this type of recharge is scarce. Flooding agricultural land during fallow or dormant periods has the potential to increase groundwater recharge substantially, but this approach has not been well studied. Using data on soils, topography and crop type, we developed a spatially explicit index of the suitability for groundwater recharge of land in all agricultural regions in California. We identified 3.6 million acres of agricultural land statewide as having Excellent or Good potential for groundwater recharge. The index provides preliminary guidance about the locations where groundwater recharge on agricultural land is likely to be feasible. A variety of institutional, infrastructure and other issues must also be addressed before this practice can be implemented widely.

Solar and wind energy enhances drought resilience and groundwater sustainability

Nature Portfolio (Springer Nature) | November 6th, 2019

Water scarcity brings tremendous challenges to achieving sustainable development of water resources, food, and energy security, as these sectors are often in co

Water scarcity brings tremendous challenges to achieving sustainable development of water resources, food, and energy security, as these sectors are often in competition, especially during drought. Overcoming these challenges requires balancing trade-offs between sectors and improving resilience to drought impacts. An under-appreciated factor in managing the water-food-energy (WFE) nexus is the increased value of solar and wind energy (SWE). Here we develop a trade-off frontier framework to quantify the water sustainability value of SWE through a case study in California. We identify development pathways that optimize the economic value of water in competition for energy and food production while ensuring sustainable use of groundwater. Our results indicate that in the long term, SWE penetration creates beneficial feedback for the WFE nexus: SWE enhances drought resilience and benefits groundwater sustainability, and in turn, maintaining groundwater at a sustainable level increases the added value of SWE to energy and food production.

Source area management practices as remediation tool to address groundwater nitrate pollution in drinking supply wells

Journal of Contaminant Hydrology (Elsevier) | July 19th, 2019

Nitrate in drinking water may cause serious health problems for consumers. Agricultural activities are known to be the main source of groundwater nitrate contaminating ru

Nitrate in drinking water may cause serious health problems for consumers. Agricultural activities are known to be the main source of groundwater nitrate contaminating rural domestic and urban public water supply wells in farming regions. Management practices have been proposed to reduce the amount of nitrate in groundwater, including improved nutrient management practices and “pump and fertilize” with nitrate-affected irrigation wells. Here, we evaluate the feasibility and long-term impacts of agricultural managed aquifer recharge (Ag-MAR) in the source area of public water supply wells. A numerical model of nitrate fate and transport was developed for the Modesto basin, part of California's Central Valley aquifer system. The basin is representative of semi-arid agricultural regions around the world with a diversity of crop types, overlying an unconsolidated sedimentary aquifer system. A local public supply well in an economically disadvantaged community surrounded by farmland was the focus of this study. Model scenarios implemented include business as usual, alternative low-impact crops, and Ag-MAR in the source area of the public supply well. Alternative nutrient management and recharge practices act as remediation tools in the area between farmland and the public supply well. Improved agricultural source area management practices are shown to be an effective tool to maintain or even enhance groundwater quality in the targeted supply well while remediating ambient groundwater.

South Kings Groundwater Sustainability Agency Groundwater Sustainability Plan

South Kings Groundwater Sustainability Agency | December 19th, 2019

South Kings Groundwater Sustainability Agency Groundwater Sustainability Plan (Revised)

South Kings Groundwater Sustainability Agency | July 13th, 2022

Special Issue: The Sustainable Groundwater Management Act

California Agriculture (UCANR) | March 13th, 2018

This special issue of California Agriculture focuses on the implications of the Sustainable Groundwater Management Act, or SGMA, the package of bills signed into law by C

This special issue of California Agriculture focuses on the implications of the Sustainable Groundwater Management Act, or SGMA, the package of bills signed into law by California Gov. Jerry Brown in September 2014. The legislation puts California on a path to the sustainable management of a resource that accounts for between one-third (in wet years) and two-thirds (in dry years) of the state’s water use. In dry years, statewide overdraft is in the range of 3 to 7 million acre-feet. Some of that is recharged in wet years, but in many basins, including some of the state’s top-producing agricultural regions, the long-term trend has been falling water tables (see groundwater.ucdavis.edu for links to UC video introductions to groundwater in California and SGMA). Sustainable management under the act is defined as the avoidance of “significant and unreasonable” levels of six impacts: (1) lowering of groundwater levels, (2) reduction in groundwater storage, (3) seawater intrusion, (4) water quality degradation, (5) land subsidence and (6) impacts on beneficial uses of interconnected surface waters. Regulation of groundwater in California was long in coming. The state has often been a national leader in environmental policy, for instance on air quality and greenhouse gas emissions. But it was the last state to adopt statewide groundwater regulations (Cannon Leahy 2016). In most basins, groundwater use was unrestricted beyond the basic requirement in the state constitution that all water use be reasonable and beneficial. Of the state’s 515 groundwater basins, SGMA applies to the 127 judged to be high- or medium-priority based on a combination of factors related to current and future groundwater demand and the consequences of overdraft. These 127 basins account for 96% of the state’s groundwater extraction (CASGEM 2018). Twenty-seven of these basins have previously been adjudicated — meaning that they are under a court order to limit overdraft. The act mandated the creation, by June 30, 2017, of a new set of local agencies, groundwater sustainability agencies (GSAs), responsible for complying with SGMA’s directives. To date, 266 groundwater sustainability agencies have been formed, accounting for 378 areas in 141 basins statewide (in many cases there is more than one GSA in a basin; also, GSAs may be formed in low-priority basins even though the law does not require it). The next step is the preparation of groundwater sustainability plans. These plans must put the basin on a path that will lead to sustainable management within 20 years, with interim milestones subject to state review every 5 years. Critically overdrafted basins (map) must submit plans by January 31, 2020; other basins must submit by January 31, 2022. Two state agencies have primary responsibility for supporting the implementation of SGMA. The Department of Water Resources acts as facilitator and evaluator, while the State Water Resources Control Board has an enforcement role, ensuring compliance with the law (see article page 18).

Special Report on Climate Change and Land

UN Intergovernmental Panel on Climate Change (IPCC) | August 7th, 2019

This Special Report on Climate Change and Land1 responds to the Panel decision in 2016 to prepare three Special Reports during the Sixth Assessment cycle, taking

This Special Report on Climate Change and Land1 responds to the Panel decision in 2016 to prepare three Special Reports during the Sixth Assessment cycle, taking account of proposals from governments and observer organizations. This report addresses greenhouse gas (GHG) fluxes in land-based ecosystems , land use and sustainable land management in relation to climate change adaptation and mitigation, desertification, land degradation and food security. This report follows the publication of other recent reports, including the IPCC Special Report on Global Warming of 1.5°C (SR15), the thematic assessment of the Intergovernmental Science Policy Platform on Biodiversity and Ecosystem Services (IPBES) on Land Degradation and Restoration, the IPBES Global Assessment Report on Biodiversity and Ecosystem Services, and the Global Land Outlook of the UN Convention to Combat Desertification (UNCCD). This report provides an updated assessment of the current state of knowledge while striving for coherence and complementarity with other recent reports. This Summary for Policymakers (SPM) is structured in four parts: A) People, land and climate in a warming world; B) Adaptation and mitigation response options; C) Enabling response options; and D) Action in the near-term. Index and Links to Full Report

State Water Project and Central Valley Project Drought Contingency Plan May 1, 2021 – September 30, 2021

California Department of Water Resources (DWR) | May 28th, 2021

This Drought Contingency Plan (Drought Plan) is prepared by the California Department of Water Resources (DWR) and the U.S. Bureau of Reclamation (Reclamation) in an effo

This Drought Contingency Plan (Drought Plan) is prepared by the California Department of Water Resources (DWR) and the U.S. Bureau of Reclamation (Reclamation) in an effort to provide updated information about areas of potential concern given the current dry hydrology of 2021. DWR and Reclamation operate the State Water Project (SWP) and the Central Valley Project (CVP), respectively, to the 2020 Record of Decision (ROD) as analyzed in the 2019 U.S. Fish and Wildlife Service (USFWS) Biological Opinion and 2019 National Marine Fisheries Service (NMFS) Biological Opinion on the Coordinated Long-Term Operation of the Central Valley Project and the State Water Project (Collectively the 2019 Biological Opinions), and DWR also operates the SWP to the 2020 California Department of Fish and Wildlife (CDFW) Incidental Take Permit (ITP). This updated Drought Plan will be submitted by DWR to CDFW in response to Condition 8.21 of CDFW’s ITP. Concurrently, this plan will be shared with the Water Operations Management Team (WOMT) which includes representatives from DWR, Reclamation, USFWS, NMFS, CDFW, and the State Water Resources Control Board (SWRCB) (collectively referred to as Agencies). This report was first drafted in February and subsequently updated in March, April, and May 2021.