Groundwater Flow Model of the East and South Las Posas Sub-Basins – Preliminary Draft Report

Calleguas Municipal Water District (CMWD) | ?

INTERA Incorporated (INTERA) was retained by the Calleguas Municipal Water District (CMWD) to develop a numerical groundwater model of the East Las Posas Management Area

INTERA Incorporated (INTERA) was retained by the Calleguas Municipal Water District (CMWD) to develop a numerical groundwater model of the East Las Posas Management Area (ELPMA), which includes the locally-recognized east and south sub-basins of the Las Posas Valley Basin (LPVB). Groundwater in the ELPMA is found in a multiple-aquifer system characterized by intense faulting and folding, which is known to exert structural controls on groundwater flow and movement. The ELPMA is known to receive recharge from surface water flows in Arroyo Las Posas/Simi that runs east to west along the southern edge of the basin. Flows in the Arroyo have become perennial as a result of discharges from wastewater treatment plants and dewatering wells within and upstream of the ELPMA. Hence, understanding and modeling the surface-water/groundwater interaction along the Arroyo is an important component of the numerical model development. CMWD also owns and operates the Las Posas Basin Aquifer Storage and Recovery (ASR) Project, consisting of eighteen high capacity ASR wells and associated facilities located in the ELPMA that are used to inject and recover potable water purchased from Metropolitan Water District of Southern California (Metropolitan). Basin response to injection/extractions at the ASR well fields and the evaluation of storage capacity of the ASR well field are key considerations for this modeling project. 

Groundwater Management and Safe Drinking Water in the San Joaquin Valley

Water Foundation | June 2nd, 2020

Groundwater Sustainability Assessments: A Review of the Department of Water Resources’ Determinations on Groundwater Sustainability Plans in Critically Overdrafted Basins

Groundwater Leadership Forum (GLF) | August 31st, 2022

Of the 46 GSPs submitted in January 2020, the Department of Water Resources (DWR) determined eight GSPs to be adequate and 34 GSPs to be incomplete. In this paper we eval

Of the 46 GSPs submitted in January 2020, the Department of Water Resources (DWR) determined eight GSPs to be adequate and 34 GSPs to be incomplete. In this paper we evaluate to what extent DWR’s determinations provide oversight on the key issues of drinking water, disadvantaged communities, the environment, stakeholder involvement,and climate change. We summarize the corrective actions that DWR is recommending or requiring, as well as compare DWR’s determinations to the assessment of 31 GSPs that we conducted in 2020. We also reviewed the 11 comment letters submitted by the State Water Resources Control Board (SWRCB), 25 comment letters submitted by the California Department of Fish and Wildlife (CDFW), and seven comment letters submitted by the National Oceanic and Atmospheric Administration’s National Marine Fisheries Service (NMFS) to compare deficiencies identified in GSPs across agencies.

Groundwater Sustainability Plan (GSP) Annotated Outline

California Department of Water Resources (DWR) | December 22nd, 2016

The objective of this Guidance Document is to provide Groundwater Sustainability Agencies (GSAs) and other stakeholders an example Groundwater Sustainability Plan (GSP) A

The objective of this Guidance Document is to provide Groundwater Sustainability Agencies (GSAs) and other stakeholders an example Groundwater Sustainability Plan (GSP) Annotated Outline to aid in GSP development and standardize future reporting. The GSP Annotated Outline is only intended to be a guide. GSAs have the option of using this information as they develop a GSP. The content provided here does not create any new requirements or obligations for the GSA or other stakeholders.

Groundwater Sustainability Plan (GSP) Emergency Regulations Guide

California Department of Water Resources (DWR) | August 3rd, 2016

This guide includes information designed to aid with the understanding the Groundwater Sustainability Plan (GSP) Emergency Regulations (regulations). Written for local ag

This guide includes information designed to aid with the understanding the Groundwater Sustainability Plan (GSP) Emergency Regulations (regulations). Written for local agencies1 and interested parties including stakeholders, this guide is organized to walk the reader through four phases developed to compartmentalize activities necessary or potentially necessary to address GSP regulations or related requirements, beginning with the formation of groundwater sustainability agencies (GSAs) and leading up to implementation of an adopted and State approved GSP or alternative to GSP (Alternative). Therefore, the intent of this guide is to explain the fundamental concepts of the regulations and information directly relevant to the regulations to the reader through four general phases of development and implementation. The regulations provide a descriptive overview of requirements for development and implementation of GSPs, Interagency Agreements, Alternatives, and DWR’s evaluation process. This guide focuses on the requirements for completing GSPs and also presents the timeline for Alternatives that comply with the regulations. Details regarding Alternatives are described in Article 9 of the regulations. This guide does not serve as a substitute for the regulations.

Groundwater Sustainability Plan Antelope Subbasin

Tehama County Flood Control and Water Conservation District | January 31st, 2022

For the full 4,074-page file, go to the Tehama County Flood Control and Water Conservation District or the California Department of Water Resources (DWR).

For the full 4,074-page file, go to the Tehama County Flood Control and Water Conservation District or the California Department of Water Resources (DWR).

Groundwater Sustainability Plan Bedford-Coldwater Basin

Bedford-Coldwater Groundwater Sustainability Authority | November 3rd, 2021

The Sustainable Groundwater Management Act (SGMA) requires local agencies in groundwater basins designated as high- or medium-priority to form Groundwater Sustainabilit

The Sustainable Groundwater Management Act (SGMA) requires local agencies in groundwater basins designated as high- or medium-priority to form Groundwater Sustainability Agencies (GSAs) and develop a Groundwater Sustainability Plan (GSP) to plan for achieving and/or maintaining sustainability within 20 years of implementing the plan. The Bedford-Coldwater Groundwater Subbasin (Basin) has been designated by the California Department of Water Resources (DWR) as very low-priority, so the preparation of a GSP is not required. However, the City of Corona (Corona), Temescal Valley Water District (TVWD), and Elsinore Valley Municipal Water District (EVMWD), the three major water purveyors and groundwater users in the Basin, are committed to protecting and maintaining sustainable groundwater conditions in the Basin into the future. The three agencies signed a Joint Powers Agreement (Agreement) creating a Joint Powers Authority (JPA) and forming the Bedford-Coldwater Groundwater Sustainability Agency (BCGSA). The BCGSA has volunteered to become the GSA for the Bain and prepare and implement this GSP. Due to size, this file had been divided into two parts. Part 1, Part 2

Groundwater Sustainability Plan Bowman Subbasin

Tehama County Flood Control and Water Conservation District | January 31st, 2022

The Bowman Subbasin, which is entirely located within Tehama County, is comprised of approximately 122,500 acres, and relies on an average of approximately 5,200 acre-fe

The Bowman Subbasin, which is entirely located within Tehama County, is comprised of approximately 122,500 acres, and relies on an average of approximately 5,200 acre-feet (AF) of groundwater annually for agriculture (1991-2019), has been identified by the California Department of Water Resources (DWR) as a very low priority subbasin. Under the Sustainable Groundwater Management Act (SGMA) of 2014, high or medium priority subbasins are required to prepare and be managed under a Groundwater Sustainability Plan (GSP, or Plan) by January 31, 2022 (California Water Code (CWC) Section 10720.7(a)(1)). Although the Bowman Subbasin is not designated as a high or medium priority subbasin, the Groundwater Sustainability Agency (GSA) received funding to develop the GSP and is leading its development in conjunction with three other GSPs being developed by the GSA. Due to size, the file has been divided into four parts. Part 1, Part 2, Part 3, Part 4

Groundwater Sustainability Plan Emergency Regulations

California Department of Water Resources (DWR) | July 16th, 2016

These regulations specify the components of groundwater sustainability plans, alternatives to groundwater sustainability plans, and coordination agreements prepared pursu

These regulations specify the components of groundwater sustainability plans, alternatives to groundwater sustainability plans, and coordination agreements prepared pursuant to the Sustainable Groundwater Management Act (Part 2.74 of Division 6 of the Water Code, beginning with Section 10720), and the methods and criteria used by the Department to evaluate those plans, alternatives, and coordination agreements, and information required by the Department to facilitate that evaluation.

Groundwater Sustainability Plan for Big Valley (Lake County) Basin

Lake County Watershed Protection District | January 31st, 2022

The purpose of this Groundwater Sustainability Plan (GSP) is to verify and maintain sustainable groundwater management in the Big Valley Groundwater Basin (Basin Number 5

The purpose of this Groundwater Sustainability Plan (GSP) is to verify and maintain sustainable groundwater management in the Big Valley Groundwater Basin (Basin Number 5-015) by meeting the regulatory requirements set forth in the three-bill legislative package: Assembly Bill (AB) 1739 (Dickinson), Senate Bill (SB) 1168 (Pavley), and SB 1319 (Pavley) collectively known as the Sustainable Groundwater Management Act of 2014 (SGMA). Under SGMA, high- and medium-priority basins not identified as critically overdrafted must develop and submit a GSP to the California Department of Water Resources (DWR) by January 31, 2022. GSPs are prepared and implemented by Groundwater Sustainability Agencies (GSA) that are formed from local agencies or combinations of local agencies as outlined in CWC § 10723, with the goal to reach sustainability within 20 years of implementing the sustainability plans. SGMA defines sustainable groundwater management as “management and use of groundwater in a manner that can be maintained during the planning and implementation horizon without causing undesirable results.” Big Valley Basin was identified as a medium-priority basin by DWR based on components such as population and groundwater use; therefore, it is subject to SGMA. The Big Valley Basin GSP is being developed by the Lake County Watershed Protection District (District), which serves as the sole GSA in the Big Valley Basin. The Big Valley GSA has jurisdiction over most of the region, excluding the portion containing the Big Valley Rancheria which is governed by the Big Valley Band of Pomo Indians of the Big Valley Rancheria, a federally recognized tribe. Due to size, the file is divided into four parts. Part 1, Part 2, Part 3, Part 4 Plan approved by DWR 4/27/23