San Antonio Creek Valley Groundwater Basin Groundwater Sustainability Plan

San Antonio Basin Groundwater Sustainability Agency | December 16th, 2021

The Sustainable Groundwater Management Act (SGMA), effective as of January of 2015, created a new statewide framework for managing California’s groundwater at the loca

The Sustainable Groundwater Management Act (SGMA), effective as of January of 2015, created a new statewide framework for managing California’s groundwater at the local level through the formation of Groundwater Sustainability Agencies (GSAs). SGMA requires the development and implementation of a Groundwater Sustainability Plan (GSP) for each groundwater basin in the state that has been designated as high or medium priority. A GSP presents strategies for maintaining or bringing a groundwater basin into a sustainable condition within the next 20 years. SGMA exempts de minimus pumpers (e.g., individual domestic well owners who extract up to 2 acre-feet per year [AFY]) from most of the SGMA requirements and does not require metering. The San Antonio Basin Groundwater Sustainability Agency (SABGSA) was formed in 2017 for the purpose of sustainably managing groundwater and developing this GSP for the San Antonio Creek Valley Groundwater Basin (Basin). The SABGSA member agencies are the San Antonio Basin Water District and Los Alamos Community Services District. The Basin occupies approximately 123 square miles in western Santa Barbara County (see Figure ES-1). It is bounded on the north by the Casmalia Hills and Solomon Hills, on the east by the San Rafael Mountains and a watershed divide separating the adjoining Santa Ynez River Valley groundwater basin, on the south by the Purisima Hills and Burton Mesa, and the west by the approximate western boundary of Barka Slough. This GSP describes the physical setting of the Basin; quantifies historical, present, and future water budgets; develops quantifiable management objectives that account for the interests of the Basin’s beneficial groundwater uses and users and identifies a group of projects and management actions that will allow the Basin to achieve sustainability within 20 years of plan adoption. This document also includes the list of references and technical studies, documentation of the stakeholder engagement process undertaken in the development of this plan, and several supporting appendices. Due to size, the file has been divided. Part 1, Part 2, Part 3, Part 4, Part 5, Part 6

San Antonio Water Company v. Foothill Irrigation Company, et al

Superior Court of California, County of San Bernardino | July 25th, 1958

From "An Evaluation of California's Adjudicated Groundwater Basins" by Langridge et al: "The Cucamonga Basin is a small groundwater basin located in San Bernardino Co

From "An Evaluation of California's Adjudicated Groundwater Basins" by Langridge et al: "The Cucamonga Basin is a small groundwater basin located in San Bernardino County. In the 1950s, approximately 25 parties, mostly small local water companies and several individual water users, filed an action to adjudicate the rights to the basin’s groundwater and certain surface waters tributary to the basin. The subsequent adjudication resulted in a 1958 Decree that contains some provisions for the metering and recording of water production, inspection of records, prohibitions against new water production, and potential reductions in water production. The court did not appoint an official Watermaster for the basin, and annual reports are not required. Since adjudication, water use in the basin has shifted from primarily agricultural use to primarily municipal use. Today there are three main water agencies — Cucamonga Valley Water District, San Antonio Water Company, and West End Consolidated Water Company — that hold nearly all of the adjudicated rights in the basin and jointly manage the basin pursuant to the 1958 Decree. Studies differ regarding the condition of the basin. A 2007 Metropolitan Water District review indicates that water levels in key wells have decreased about 120 feet and that the basin is experiencing long-term decline. Basin managers point to production data that also shows water production in the basin can trend below the total allocated rights production data."

San Diego Basin Study

U.S. Bureau of Reclamation (USBR) | August 15th, 2017

The purpose of the San Diego Basin Study (Basin Study) is to determine potential climate change impacts on water supplies and demands within the San Diego region and to i

The purpose of the San Diego Basin Study (Basin Study) is to determine potential climate change impacts on water supplies and demands within the San Diego region and to identify how potential adaptation strategies could mitigate supply shortages. The intention of Task 2.3 is to create a computer simulation model to forecast supply and demand imbalances under current and future conditions, and current and future demands under a baseline water system infrastructure in the Study Area. This Interim Report describes the methodologies and findings of this Task. 

San Diego County Ecosystems: Ecological Impacts of Climate Change on a Biodiversity Hotspot

California Energy Commission (CEC) | August 27th, 2018

The diverse ecosystems, habitats, plants, and animals in the San Diego County region will be impacted by climatic shifts in multifold ways due to current and future vari

The diverse ecosystems, habitats, plants, and animals in the San Diego County region will be impacted by climatic shifts in multifold ways due to current and future variability, along with other factors including habitat loss and fragmentation, land use shifts, and changing fire regimes. While home to a major metropolitan area, San Diego County still hosts expanses of native and preserved habitats where management and conservation action could be greatly enhanced through science-based assessments and planning for climate change and increased climate variability. Projections of climate change in the region include warming by 4-9° F on average, and a 15-25% decrease in fall and spring precipitation with an increase in variability resulting in more frequent and intense droughts punctuated by increasingly rare yet extreme precipitation and flooding events. In addition, an increase in fire events and potential lessening of coastal marine influence may also affect San Diego’s ecosystems. Climate warming superimposed upon the pronounced spatially-varying temperature in the San Diego region will likely be associated with range shifts for many species resulting in novel community assemblages and biotic interactions and could create phenological mismatches. More frequent and intense heat waves may disproportionately affect younger age classes and reduce reproductive and survival rates of species sensitive to temperature extremes. With increasingly variable precipitation, drought may occur more frequently due to increased occurrence of dry days and could intensify because of warmer temperatures. Since drought disproportionately affects some species, these projected changes may cause structural changes to ecosystems. Santa Ana winds, occurring during increasingly dry fall months, would create ideal fire conditions. Coastal low clouds and fog along San Diego’s coast buffer this zone from the effects of warming and drying through shading and cooling. Although these marine stratus clouds will remain a presence, future changes in this phenomenon are uncertain. The spatial and temporal scales at which climate variations and change operate must be considered to build resilience into natural systems. Effective conservation actions will need to build on ongoing efforts focused on landscape-scale planning rather than more traditional single-species approaches. To carry this out will require cross-jurisdictional, multidisciplinary collaboration by scientists, policy-makers, planners, land managers, and the broader conservation community, which has a decades-long history of accomplishment in San Diego County.

San Fernando Groundwater Basin Remediation Program

Los Angeles Department of Water & Power (LADWP) | January 1st, 2018

San Francisco Bay California Toxics Rule Priority Pollutant Ambient Water Monitoring Report

San Francisco Estuary Institute (SFEI) | March 2nd, 2017

In 2000, the USEPA published Water Quality Standards; Establishment of Numeric Objectives for Priority Toxic Pollutants for the State of California, commonly known as the

In 2000, the USEPA published Water Quality Standards; Establishment of Numeric Objectives for Priority Toxic Pollutants for the State of California, commonly known as the California Toxics Rule (CTR), which established numeric water quality standards for 126 priority pollutants. Under the Policy for Implementation of Toxics Standards for Inland Surface Waters, Enclosed Bays, and Estuaries of California (also known as the State Implementation Policy, SIP) the San Francisco Bay Regional Water Quality Control Board (SFBRWQCB) is required to establish water quality-based effluent limitations in order to achieve priority pollutant standards. For the purposes of this document “water quality criteria” (WQCs) will be used to refer both to the CTR established numeric criteria for 126 priority pollutants as well as to numeric objectives for 12 of these priority pollutants and tributyltin previously established in the San Francisco Bay Water Quality Control Plan (Basin Plan) and/or the National Toxics Rule. A number of these pollutants previously were or continue to be regularly monitored as part of the Regional Monitoring Program Status and Trends (RMP S&T). The priority pollutants not routinely included in RMP S&T were previously monitored in wet and dry season ambient water sampling in 2002 and 2003. Results of that effort are detailed in a previously issued report: http://www.sfei.org/documents/san-francisco-bay-ambient-monitoring-interim-report Most of the priority pollutants were not detected in that study, or detected at concentrations below their WQC. Among the pollutants that were detected, a number of them were also found at similar concentrations in lab blanks, suggesting they might not have been present (or at least were at lower concentrations) in the ambient environment. Since over a decade had passed since that previous monitoring effort, the RMP embarked on an effort to repeat measurement of these seldom analyzed (non- S&T) contaminants, to ensure conditions have not changed appreciably to present greater risk for any of them.

San Francisco Bay California Toxics Rule Priority Pollutant Ambient Water Monitoring Report

San Francisco Estuary Institute (SFEI) | February 1st, 2017

In 2000, the USEPA published Water Quality Standards; Establishment of Numeric Objectives for Priority Toxic Pollutants for the State of California, commonly known as t

In 2000, the USEPA published Water Quality Standards; Establishment of Numeric Objectives for Priority Toxic Pollutants for the State of California, commonly known as the California Toxics Rule (CTR), which established numeric water quality standards for 126 priority pollutants. Under the Policy for Implementation of Toxics Standards for Inland Surface Waters, Enclosed Bays, and Estuaries of California (also known as the State Implementation Policy, SIP) the San Francisco Bay Regional Water Quality Control Board (SFBRWQCB) is required to establish water quality-based effluent limitations in order to achieve priority pollutant standards. For the purposes of this document “water quality criteria” (WQCs) will be used to refer both to the CTR established numeric criteria for 126 priority pollutants as well as to numeric objectives for 12 of these priority pollutants and tributyltin previously established in the San Francisco Bay Water Quality Control Plan (Basin Plan) and/or the National Toxics Rule. A number of these pollutants previously were or continue to be regularly monitored as part of the Regional Monitoring Program Status and Trends (RMP S&T). The priority pollutants not routinely included in RMP S&T were previously monitored in wet and dry season ambient water sampling in 2002 and 2003. Results of that effort are detailed in a previously issued : Most of the priority pollutants were not detected in that study, or detected at concentrations below their WQC. Among the pollutants that were detected, a number of them were also found at similar concentrations in lab blanks, suggesting they might not have been present (or at least were at lower concentrations) in the ambient environment. Since over a decade had passed since that previous monitoring effort, the RMP embarked on an effort to repeat measurement of these seldom analyzed (non- S&T) contaminants, to ensure conditions have not changed appreciably to present greater risk for any of them.

San Francisco Bay Hydrologic Region Groundwater Update

California Department of Water Resources (DWR) | April 1st, 2015

The primary goal of the San Francisco Bay Hydrologic Region (San Francisco Bay region) groundwater update is to expand information about region-specific groundwater condi

The primary goal of the San Francisco Bay Hydrologic Region (San Francisco Bay region) groundwater update is to expand information about region-specific groundwater conditions for California Water Plan Update 2013 and to guide more informed groundwater management actions and policies. A second goal is to steadily improve the quality of groundwater information in future California Water Plan (CWP) updates to a level that will enable regional water management groups (RWMGs) to accurately evaluate their groundwater resources and implement management strategies that can meet local and regional water resource objectives within the context of broader statewide objectives. The final goal is to identify data gaps and groundwater management challenges that will guide prioritizing of future data collection and funding opportunities relevant to the region. This regional groundwater update is not intended to provide a comprehensive and detailed examination of local groundwater conditions, or be a substitute for local studies and analysis. Nonetheless, where information is readily available, this update does report some aspects of the regional groundwater conditions in greater detail.

San Francisco Bay Interim Model Validation Report

San Francisco Estuary Institute (SFEI) | December 1st, 2017

As part of the Nutrient Management Strategy, a coupled hydrodynamic-biogeochemical model of San Francisco Bay is being developed. The process-based, numerical model will

As part of the Nutrient Management Strategy, a coupled hydrodynamic-biogeochemical model of San Francisco Bay is being developed. The process-based, numerical model will be used to inform nutrient management decisions, by: • improving quantitative understanding of processes that shape current conditions, • forecasting ecosystem response under future scenarios, and • evaluating potential effectiveness of management actions. This report describes the model in its present configuration and the status of its validation. Model development is necessarily an iterative process, with early stages focused on refining the model’s representation of hydrodynamics and transport, and later stages of the effort including increasingly complex representations of biogeochemistry. Present validation efforts focus on assessing model skill with respect to hydrodynamics, salinity and transport. The final report will additionally consider model validation of water quality and biogeochemical processes.

San Francisco Bay Microplastics Project: Science-Supported Solutions and Policy Recommendations

San Francisco Estuary Institute (SFEI) | September 2nd, 2019

Plastics in our waterways and in the ocean, and more specifically microplastics (plastic particles less than 5 mm in size), have gained global attention as a pervasive an

Plastics in our waterways and in the ocean, and more specifically microplastics (plastic particles less than 5 mm in size), have gained global attention as a pervasive and preventable threat to marine ecosystem health. The San Francisco Bay Microplastics Project was designed to provide critical data on microplastics in the Bay Area. The project also engaged multiple stakeholders in both science and policy discussions. Finally, the project was designed to generate scientifically supported regional and statewide policy recommendations for solutions to plastic pollution.