Concentrations for total dissolved solids, arsenic, boron, fluoride, and nitrite-nitrate for wells sampled in the Mojave Water Agency Management Area

U.S. Geological Survey (USGS) | July 1st, 2001

Concentrations for total dissolved solids, arsenic, boron, fluoride, and nitrite-nitrate for wells sampled in the Mojave Water Agency Management Area, California, 1991-97

U.S. Geological Survey (USGS) | January 31st, 2001

Conceptual Model of the Great Basin Carbonate and Alluvial Aquifer System

U.S. Geological Survey (USGS) | September 20th, 2011

Conceptual Model Review of Napa Valley Groundwater Model

Napa County | November 15th, 2010

The purpose of this technical memorandum is to provide a general review of the Napa Valley Groundwater model (groundwater model) produced by DHI Water & Environment (

The purpose of this technical memorandum is to provide a general review of the Napa Valley Groundwater model (groundwater model) produced by DHI Water & Environment (DHI) as part of the 2005 Napa County Baseline Data Report (2005 BDR) (Jones & Stokes et al., 2005). This memorandum is not intended to be a full peer-review in which model code, input/output files, and output results would be analyzed. Opinions stated herein are based solely on a review of the 2006 Final BDR Technical Appendix (DHI, 2006a), which presents the model code, model construction, calibration, and application of modeling efforts introduced in Chapters 15, 16, and 17 of the BDR. Further information on the groundwater model was reviewed from the 2005 BDR and a 2007 technical memorandum Modeling Analysis in Support of Vineyard Development Scenarios Evaluation (DHI, 2007) in which the groundwater model was updated/expanded and applied in evaluating various vineyard development scenarios. The scope of Luhdorff & Scalmanini, Consulting Engineers’ (LSCE) work, described herein, included a review of the conceptual model developed by DHI from which the inputs to the groundwater model were based. In addition, information provided on the model code, construction, and development of the groundwater model and model calibration were also reviewed. The focus of LSCE’s work was to assess whether the information provided in the reviewed documents was complete and whether the model can be used for the stated purpose for which it was developed.

Conduct Airborne Electromagnetic Surveys

California Department of Water Resources (DWR) | July 15th, 2020

Confined Animal Facility Permitting and Reporting Under the Porter-Cologne Water Quality Control Act: An Analysis of Regional Board Activities

Stanford University | February 2nd, 2026

This white paper analyzes reports containing (1) data from 2023 for the five regions with the largest numbers of CAFs in California; and (2) data from 2024 from the regio

This white paper analyzes reports containing (1) data from 2023 for the five regions with the largest numbers of CAFs in California; and (2) data from 2024 from the region with the most CAFs in the state. We identify six central problems with the self-reporting regime: CAFs frequently underreport wastewater production, or fail to report it at all. CAFs frequently underreport manure production. CAFs do not disclose, or inadequately document, where waste goes. Most CAFs fail to report how much waste they apply to their crops. (Those that do typically report significant overapplication.) CAFs frequently fail to account for all nutrients in the waste they produce. Regional Boards do not adequately enforce reporting requirements.

Conjunctive Management and Groundwater Storage (Resource Management Strategy)

California Department of Water Resources (DWR) | July 29th, 2016

Conjunctive management or conjunctive use refers to the coordinated and planned use and management of both surface water and groundwater resources to maximize the availab

Conjunctive management or conjunctive use refers to the coordinated and planned use and management of both surface water and groundwater resources to maximize the availability and reliability of water supplies in a region to meet various management objectives. Surface water and groundwater resources typically differ significantly in their availability, quality, management needs, and development and use costs. Managing both resources together, rather than in isolation, allows water managers to use the advantages of both resources for maximum benefit. Conjunctive management thus involves the efficient use of both resources through the planned and managed operation of a groundwater basin and a surface water storage system combined through a coordinated conveyance infrastructure. Water is stored in the groundwater basin that is planned to be used later by intentionally recharging the basin when excess water supply is available, for example, during years of above-average surface water supply or through the use of recycled water. The necessity and benefit of conjunctive water management are apparent when surface water and groundwater are hydraulically connected. Well-planned conjunctive management that prevents groundwater depletion by maintaining baseflow to streams and support for ecosystem services not only increases the reliability and the overall amount of water supply in a region, but also provides other benefits such as flood management, environmental water use, and water quality improvement.  

Corning Subbasin Groundwater Sustainability Plan

Tehama County Flood Control and Water Conservation District | December 20th, 2021

Preparation of this GSP is the first step for the GSAs to achieve groundwater sustainability in the Corning Subbasin. To evaluate progress toward groundwater sustainabili

Preparation of this GSP is the first step for the GSAs to achieve groundwater sustainability in the Corning Subbasin. To evaluate progress toward groundwater sustainability during implementation, annual reports and 5-year updates to the GSP will be prepared as required by SGMA. The GSAs recognize that sustainability is only possible with support of stakeholders and coordination of local, state, tribal and federal agencies and the managed use of both surface and groundwater resources. While SGMA does not require the Plan to address California’s Public Trust Doctrine, a 2018 California Court of Appeal ruling found that groundwater pumping that reduces the flow or volume of water in a navigable stream (and tributaries that supply navigable streams) may violate the public trust. This Plan recognizes the importance of protecting public trust resources, including fish and wildlife, in the Subbasin’s streams that are connected to groundwater.

County of San Bernardino Hydrology Manual

San Bernardino County | August 1st, 1986

Coupling a spatiotemporally distributed soil water budget with stream-depletion functions to inform stakeholder-driven management of groundwater-dependent ecosystems

Water Resources Research, American Geophysical Union | November 12th, 2013

Groundwater pumping, even if only seasonal, may significantly impact groundwater-dependent ecosystems through increased streamflow depletion, particularly in semiarid and

Groundwater pumping, even if only seasonal, may significantly impact groundwater-dependent ecosystems through increased streamflow depletion, particularly in semiarid and arid regions. The effects are exacerbated, under some conditions, by climate change. In social sciences, the management of groundwater-dependent ecosystems is generally considered a “wicked” problem due to the complexity of affected stakeholder groups, disconnected legal frameworks, and a divergence of policies and science at the cross road between groundwater and surface water, and between ecosystems and water quality. A range of often simplified scientific tools plays an important role in addressing such problems. Here we develop a spatiotemporally distributed soil water budget model that we couple with an analytical model for stream depletion from groundwater pumping to rapidly assess seasonal impacts of groundwater pumping on streamflow during critical low flow periods. We demonstrate the applicability of the tool for the Scott Valley in Northern California, where protected salmon depend on summer streamflow fed by cool groundwater. In this example, simulations suggest that increased recharge in the period immediately preceding the critical low streamflow season, and transfer of groundwater pumping away from the stream are potentially promising tools to address ecosystem concerns, albeit raising difficult infrastructure and water trading issues. In contrast, additional winter recharge at the expense of later spring recharge, whether intentional or driven by climate may reduce summer streamflows. Comparison to existing detailed numerical groundwater model results suggests that the coupled soil water mass balance—stream depletion function approach provides a viable tool for scenario development among stakeholders, to constructively inform the search for potential solutions, and to direct more detailed, complex site-specific feasibility studies. The tool also identifies important field monitoring efforts needed to improve the understanding and quantification of site-specific groundwater-stream interactions.