Tulare Lake Subbasin Groundwater Sustainability Plan -- Amended

Mid-Kings River Groundwater Sustainability Agency | July 26th, 2022

The Tulare Lake Subbasin submitted a single GSP in January 2020 to the Department of Water Resources (DWR). DWR was required to determine whether the GSP conformed to the

The Tulare Lake Subbasin submitted a single GSP in January 2020 to the Department of Water Resources (DWR). DWR was required to determine whether the GSP conformed to the specific requirements of SGMA. In a letter dated January 28, 2022, DWR determined that that the GSP is incomplete. DWR stated that the GSP was considered incomplete as it “does not define undesirable results or set sustainable management criteria for groundwater levels, subsidence, and water quality in the manner consistent with SGMA and the GSP regulations.” Upon receiving the incomplete determination, the Subbasin had 180 days to address the identified deficiencies and submit a revised GSP by July 27, 2022. The GSAs are submitting this 2022 Amended GSP to address the three deficiencies outlined in the determination letter. The 2022 Amended GSP consists of clean and redline strike out versions of the 2020 GSP and the attached 2022 GSP Addendum. The 2022 GSP Addendum was prepared to specifically address the incomplete determination letter from DWR. Sections of this document have been edited since the original submittal in 2020 and direct the reader to the Addendum for further details. Due to size, this file has been divided. Part 1, Part 2, Part 3, Part 4, Part 5, Part 6

Tulare Lake Subbasin Probationary Hearing Draft Report

California State Water Resources Control Board (SWRCB) | October 12th, 2023

The State Water Board recognizes that significant efforts were made by local public agencies in the Tulare Lake Subbasin since the passage of SGMA to form groundwater sus

The State Water Board recognizes that significant efforts were made by local public agencies in the Tulare Lake Subbasin since the passage of SGMA to form groundwater sustainability agencies (GSAs) and then develop detailed technical and other information supporting the adoption and implementation of a groundwater sustainability plan (GSP) for the subbasin. Despite those efforts, in January of 2022, DWR reviewed the GSP to determine if it met SGMA’s requirements and found it to be incomplete. Following revisions made by the GSAs in the subbasin, DWR reevaluated the GSP in March of 2023, determined it to be inadequate, and referred the subbasin to the State Water Board, as required by SGMA. Consistent with SGMA, the State Water Board may now consider whether to designate the Tulare Lake Subbasin as a “probationary basin,” a term that is used in SGMA to describe the first stage of state intervention. Click here for Appendix to the report.

Tulare Lake Subbasin Probationary Hearing Final Staff Report

California State Water Resources Control Board (SWRCB)nia | March 29th, 2024

State Water Board staff have identified specific deficiencies in the Tulare Lake Subbasin 2022 GSP and have outlined potential corrective actions to address those specifi

State Water Board staff have identified specific deficiencies in the Tulare Lake Subbasin 2022 GSP and have outlined potential corrective actions to address those specific deficiencies. The Final Staff Report also incorporates deficiencies identified by DWR’s determination. Deficiencies that have been identified within the GSP relate to: * Chronic lowering of groundwater levels with insufficient management criteria. * Continued land subsidence (sinking). * Further degradation of groundwater quality.

Tule Subbasin Probationary Hearing Draft Staff Report

California State Water Resources Control Board (SWRCB) | March 1st, 2024

The State Water Board recognizes that local public agencies in the Tule Subbasin significant efforts since the passage of SGMA to form groundwater sustainability agencies

The State Water Board recognizes that local public agencies in the Tule Subbasin significant efforts since the passage of SGMA to form groundwater sustainability agencies (GSAs) and then develop detailed technical and other information supporting the adoption and implementation of six groundwater sustainability plans (GSPs) for the subbasin. Despite those efforts, in January of 2022, DWR reviewed GSPs to determine if the GSPs met SGMA’s requirements and found it to be incomplete. Following revisions made by the GSAs in the subbasin, DWR reevaluated the GSPs in March of 2023, determined the GSPs to be inadequate, and referred the subbasin to the State Water Board, as required by SGMA. Consistent with SGMA, the State Water Board may now consider whether to designate the Tule Subbasin as a “probationary basin,” a term that is used in SGMA to describe a basin in the first stage of state intervention.

Tule Subbasin Probationary Hearing Final Staff Report

California State Water Resources Control Board (SWRCB) | August 30th, 2024

Board staff identified specific deficiencies in the Tule Subbasin 2022 GSPs and outlined potential corrective actions to address those specific deficiencies. • Chron

Board staff identified specific deficiencies in the Tule Subbasin 2022 GSPs and outlined potential corrective actions to address those specific deficiencies. • Chronic lowering of groundwater levels with insufficient management criteria. • Continued land subsidence (sinking). • Further degradation of groundwater quality. • Depletions of interconnected surface water.

Tuolumne Watershed Diversions without Hetch Hetchy Reservoir: Comparison of Interties to Cherry and Don Pedro Reservoirs

Environmental Defense Fund (EDF) | February 14th, 2005

Without storing water in Hetch Hetchy Valley, additional conveyance facilities could allow the San Francisco Public Utilities Commission to divert supplies from storage i

Without storing water in Hetch Hetchy Valley, additional conveyance facilities could allow the San Francisco Public Utilities Commission to divert supplies from storage in other Tuolumne River watershed reservoirs. The most obvious potential locations for additional conveyance are at Don Pedro Reservoir or at Holm Powerplant below Cherry Reservoir. Computer modeling, using a 73 year hydrologic record, indicates that either a Don Pedro Intertie or a Cherry Intertie would allow the SFPUC to deliver more than 95 percent of customer demand without diminishing system reliability. Some additional supplies would be needed in dry years to replace the loss of Hetch Hetchy Reservoir.

Twenty-first Annual Report of the Mojave Basin Area Watermaster

Mojave Basin Area Watermaster | May 1st, 2015

Twenty-first century hydroclimate: A continually changing baseline, with more frequent extremes

National Academy of Sciences (NAS) | March 14th, 2022

Variability in hydroclimate impacts natural and human systems worldwide. In particular, both decadal variability and extreme precipitation events have substantial effect

Variability in hydroclimate impacts natural and human systems worldwide. In particular, both decadal variability and extreme precipitation events have substantial effects and are anticipated to be strongly influenced by climate change. From a practical perspective, these impacts will be felt relative to the continuously evolving background climate. Removing the underlying forced trend is therefore necessary to assess the relative impacts, but to date, the small size of most climate-model ensembles has made it difficult to do this. Here we use an archive of large ensembles run under a high-emissions scenario to determine how decadal “megadrought” and “megapluvial” events—and shorter-term precipitation extremes—will vary relative to that changing baseline. When the trend is retained, mean state changes dominate: In fact, soil moisture changes are so large in some regions that conditions that would be considered a megadrought or pluvial event today are projected to become average. Time-of-emergence calculations suggest that in some regions including Europe and western North America, this shift may have already taken place and could be imminent elsewhere: Emergence of drought/pluvial conditions occurs over 61% of the global land surface (excluding Antarctica) by 2080. Relative to the changing baseline, megadrought-/megapluvial risk either will not change or is slightly reduced. However, the increased frequency and intensity of both extreme wet and dry precipitation events will likely present adaptation challenges beyond anything currently experienced. In many regions, resilience against future hazards will require adapting to an ever-changing “normal,” characterized by unprecedented aridification/wetting punctuated by more severe extremes.

Two-dimensional and three-dimensional digital flow models of the Salinas Valley ground-water basin, California

U.S. Geological Survey (USGS) | November 16th, 1978

The Salinas Valley is a topographic and ground-water basin in central coastal California. The ground-water basin extends from Monterey Bay south­eastward along the Salin

The Salinas Valley is a topographic and ground-water basin in central coastal California. The ground-water basin extends from Monterey Bay south­eastward along the Salinas River to San Arda, a distance of 70 miles, and has a maximum thickness of 2,000 feet. Annual recharge to the ground-water basin, which is derived mostly from the Salinas River, is about 290,000 acre­feet. Annual discharge, which is mostly from pumpage but also includes the consumptive use of ground water by riparian vegetation along the Salinas River, is about 507,000 acre-feet. About 45 percent of the pumpage, or 217,000 acre-feet of water annually, returns to the ground-water system. A group of interacting hydrologic models was developed for the Salinas Valley. These models include the small-stream model, river model, two­dimensional ground-water model, and three-dimensional ground-water model. The small-stream model simulates ground-water recharge from small streams that are tributary to the Salinas River. The river model simulates ground­water recharge from and surface-water discharge in the Salinas River. The two-dimensional and three-dimensional ground-water models simulate hydraulic head in the ground-water basin. The ground-water models were calibrated by comparing water level com­puted by the models to the corresponding measured water level for both steady-state and transient-state simulations. For the steady-state simulation, which was used to calibrate transmissivity for the two-dimensional model and hydraulic conductivity for the three-dimensional model, the median deviation of the model-generated water level from measured water level was 6 and 5 feet for the two-dimensional and three-dimensional models, respectively. For the transient-state simulation, which was used to calibrate storage coefficient for the two-dimensional model and specific storage for the three-dimensional model, the median deviation of the model-generated water level (at the end of a 3-year calibration period) from measured water level was 6 feet for both models.

U.S. Geological Survey Integrated Water Availability Assessment—2010–20, Chapter A

U.S. Geological Survey (USGS) | January 15th, 2025

This is one chapter in a multichapter report that assesses water availability in the United States for water years 2010–20. This work was conducted as part of the fulfi

This is one chapter in a multichapter report that assesses water availability in the United States for water years 2010–20. This work was conducted as part of the fulfillment of the mandates of Subtitle F of the Omnibus Public Land Management Act of 2009 (Public Law 111-11), also known as the SECURE Water Act. As such, this work examines the spatial and temporal distribution of water quantity and quality in surface water and groundwater, as related to human and ecosystem needs and as affected by human and natural influences. Chapter A (this chapter) introduces the National Integrated Water Availability Assessment and provides important background and definitions for how the report characterizes water availability and its components. Chapter A also presents the key findings of Chapters B–F and thus acts as a summary of the entire report. Chapter B (Gorski and others, 2025) is a national assessment of water supply, which is the quantity of water supplied through climatic inputs. Chapter C (Erickson and others, 2025) is a national assessment of water quality, which is the chemical and physical characteristics of water. Chapter D (Medalie and others, 2025) assesses water use including withdrawals and consumptive use in the conterminous United States. Chapter E (Scholl and others, 2025) presents an analysis of factors affecting future water availability under changing climate conditions. The National Integrated Water Availability Assessment culminates with Chapter F (Stets and others, 2025a), which is an integrated assessment of water availability that considers the amount and quality of water coupled with the suitability of that water for specific uses. Together, these six chapters constitute the National Integrated Water Availability Assessment for water years 2010–20.