Sierra Valley Subbasin Groundwater Sustainability Plan

Sierra Valley Groundwater Management District | January 18th, 2022

This Groundwater Sustainability Plan (GSP) was developed by the Sierra Valley Groundwater Management District (SVGMD) and Plumas County, the Groundwater Sustainability Ag

This Groundwater Sustainability Plan (GSP) was developed by the Sierra Valley Groundwater Management District (SVGMD) and Plumas County, the Groundwater Sustainability Agencies (GSAs) for the Sierra Valley Groundwater Basin (SV Subbasin). Due to size, this file has been divided into five parts. Part 1, Part 2, Part 3, Part 4, Part 5

Simulation of groundwater and surface-water resources of the San Antonio Creek Valley watershed, Santa Barbara County, California

U.S. Geological Survey (USGS) | February 1st, 2022

In the San Antonio Creek Valley watershed (SACVW), western Santa Barbara County, California, groundwater is the primary source of water for agricultural irrigation, the t

In the San Antonio Creek Valley watershed (SACVW), western Santa Barbara County, California, groundwater is the primary source of water for agricultural irrigation, the town of Los Alamos, and supplemental water to Vandenberg Space Force Base (VSFB). Groundwater pumpage has increased since the 1970s as non-irrigated agricultural land has been converted to irrigated land and as local pumping for municipal use has increased. This increase in groundwater use has resulted in declining groundwater levels, adjustments in surface-water flows and species habitats, and changes in water quality. Water managers are addressing the challenges of meeting this increased demand while maintaining sustainable groundwater supplies. To address these challenges, Santa Barbara County Water Agency, Vandenberg Space Force Base (VSFB), and the U.S. Geological Survey (USGS) undertook a cooperative study to characterize the integrated hydrologic system of the SACVW and develop tools to better understand and manage the groundwater system. The objectives of this study were to improve the understanding of the integrated hydrologic system and incorporate the understanding into an integrated groundwater and surface-water flow model that can be used to help manage the water resources in the SACVW. The San Antonio Creek integrated model (SACIM) was developed using the USGS coupled groundwater and surface-water flow model to simulate the hydrologic system of the SACVW and provide annual and average water budgets for 1948–2018 water years. Results from the SACIM indicated that between 1948 and 2018, total groundwater from storage (storage depletion) for the period was 453,300 acre-feet (acre-ft). Agricultural pumpage was the largest discharge and accounted for a total of 1,020,000 acre-ft of groundwater. Increased pumpage since the mid-1980s (of which agricultural pumpage is the primary component) is tied to an increased rate of storage depletion and reduced rates of groundwater evapotranspiration and surface leakage (groundwater discharge to the surface and soil zone). The increased pumpage also reduced subsurface inflow to Barka Slough, resulting in a decline in upward flow through the underlying hydrogeologic units and surface leakage. In addition to quantifying historical changes in the integrated hydrologic system, the SACIM is a tool than can be used by water managers to evaluate the effects of different climatic and hydrologic conditions and management strategies.

Solano Subbasin Groundwater Sustainability Plan

Solano Subbasin GSA Collaborative | November 30th, 2021

The Sustainable Groundwater Management Act (SGMA) encourages groundwater management at the local level. Local entities are responsible for forming Groundwater Sustainabil

The Sustainable Groundwater Management Act (SGMA) encourages groundwater management at the local level. Local entities are responsible for forming Groundwater Sustainability Agencies (GSAs) to develop and implement Groundwater Sustainability Plans (GSPs) to guide sustainable management of groundwater basins or subbasins identified as high or medium priority by the State. Five GSAs in the Solano Subbasin organized to form the Solano Collaborative to develop a single GSP for the Subbasin: Solano Subbasin GSA, Solano Irrigation District GSA, City of Vacaville GSA, Northern Delta GSA, and Sacramento County GSA. The Solano Collaborative together with five other GSAs have adopted the Solano Subbasin Groundwater Sustainability Plan.

Solar Energy and Groundwater in the San Joaquin Valley

Public Policy Institute of California (PPIC) | October 26th, 2022

The Sustainable Groundwater Management Act (SGMA) requires groundwater users to bring their basins into balance over the next two decades. In the San Joaquin Valley, this

The Sustainable Groundwater Management Act (SGMA) requires groundwater users to bring their basins into balance over the next two decades. In the San Joaquin Valley, this will likely mean taking more than 500,000 acres of agricultural land out of intensive irrigated production. Local and regional economies could be stressed as a result, with some regular employment opportunities in agriculture disappearing and public revenues declining if lands are not put to new uses. As landowners and newly formed groundwater agencies tackle the groundwater deficits in their areas, utility-scale solar development—already an attractive option for landowners owning property with or without water rights—could offer an opportunity to keep lands that exit irrigated production economically productive. Moreover, development could provide multiple benefits by helping to supplement habitat and mitigate dust generation on transitioning lands. However, the expansion of solar hinges on whether state-level energy system planning processes—in conjunction with local land use planning—can address the transmission challenges that threaten the region’s promise as a solar power hub.

Sonoma Valley Groundwater Sustainability Plan

Sonoma Water | January 29th, 2022

South American Subbasin Groundwater Sustainability Plan

Sacramento County | October 29th, 2021

Groundwater management in the South American Subbasin (SASb) has been occurring for decades. Stable groundwater conditions in terms of groundwater levels, storage volume

Groundwater management in the South American Subbasin (SASb) has been occurring for decades. Stable groundwater conditions in terms of groundwater levels, storage volume, and interconnected surface waters have been achieved due to a variety of historically implemented projects and management actions. To ensure continued sustainable conditions allowing for future groundwater use to the benefit of all users in the SASb over the next 50-years, with climate change considered, a groundwater sustainability plan (GSP) has been developed and will be implemented to achieve the sustainability goal for the basin in the next 20 years. Due to size, this file has been divided into eight parts. Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7, Part 8

South Kings Groundwater Sustainability Agency Groundwater Sustainability Plan

South Kings Groundwater Sustainability Agency | December 19th, 2019

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).

Spring 2017 Groundwater Level Data Summary

California Department of Water Resources (DWR) | October 3rd, 2022

This document presents a summary of fall 2017 groundwater level data available in the DWR groundwater level database as of February 21, 2018 and includes a discussion of

This document presents a summary of fall 2017 groundwater level data available in the DWR groundwater level database as of February 21, 2018 and includes a discussion of fall 2017, data coverage and groundwater level trends. Statewide precipitation data come from the U.S. Climate Divisional Database, which has data from January 1895 to the present.

Statement of Findings regarding the Approval of the Ukiah Valley Basin Groundwater Sustainability Plan

California Department of Water Resources (DWR) | July 27th, 2023