San Joaquin Valley Conveyance Study

California Department of Water Resources (DWR) | November 24th, 2025

This San Joaquin Valley Conveyance Study analyzes water conveyance needs in the San Joaquin Valley (Figure ES-1). The purpose of this study is to: •Describe the impa

This San Joaquin Valley Conveyance Study analyzes water conveyance needs in the San Joaquin Valley (Figure ES-1). The purpose of this study is to: •Describe the impacts of subsidence on San Joaquin Valley conveyance facilities. •Evaluate the need for improved or expanded conveyance facilities throughout the San Joaquin Valley.  

Second Report of Recharge Parties Pursuant to RWQCB Resolution No. R8-2008-0019 Cooperative Agreement to Protect Water Quality and Encourage the Conjunctive Uses of Imported Water in the Santa Ana River Basin, Yucaipa and San Timoteo Management Zones

San Bernardino Valley Municipal Water District | July 18th, 2012

The importation of water (i.e., State Water Project (SWP) water, Colorado River water, and imported groundwater) to groundwater basins within the Santa Ana River Region

The importation of water (i.e., State Water Project (SWP) water, Colorado River water, and imported groundwater) to groundwater basins within the Santa Ana River Region is necessary to meet increasing demand. However, long-term conjunctive use of water within the Region could affect groundwater quality. As such, the California Regional Water Quality Control Board Santa Ana Region (RWQCB) is requiring that groundwater quality be managed to meet the water quality objectives for total dissolved solids (TDS) and nitrogen (i.e., Salinity Objectives) regulated in the 1995 Water Quality Control Plan for the Santa Ana River Basin (Basin Plan). On January 22, 2004, the RWQCB adopted Resolution No. R8-2004-0001, incorporating an updated TDS and nitrogen management plan that includes revised groundwater subbasin boundaries; revised TDS and nitrate-nitrogen water quality objectives for groundwater; revised TDS and nitrogen waste load allocations; and revised reach designations, TDS and nitrogen objectives and beneficial uses for specific surface waters. On May 19, 2006, the RWQCB considered a resolution and order that would have adopted general waste discharge requirements for the recharge of imported water to the Santa Ana River Basin. Based on input from stakeholders, it was decided by the RWQCB that the feasibility of a cooperative program should be investigated that would achieve the objectives of and obviate the adoption of the draft resolution and order under consideration. On January 18, 2008, the RWQCB adopted Resolution No. R8-2008-0019 authorizing a “Cooperative Agreement to Protect Water Quality and Encourage the Conjunctive Use of Imported Water in the Santa Ana River Basin.” The purpose of the cooperative agreement is to allow the participating parties to “…monitor and improve water quality objectives within the Santa Ana River Region in a manner that is consistent with the needs of the inhabitants of the Region for a reliable supply of water.” (Cooperative Agreement, 2008). The following Parties have entered into this cooperative agreement: California Regional Water Quality Control Board, Santa Ana Region, City of Corona, City of Riverside, City of San Bernardino Municipal Water Department, Eastern Municipal Water District, Elsinore Valley Municipal Water District, Orange County Water District, San Bernardino Valley Municipal Water District (Valley District), San Gorgonio Pass Water Agency, and Western Municipal Water District of Riverside County (Western).  

Selected Techniques for Monitoring Water Movement Through Unsaturated Alluvium During Managed Aquifer Recharge

U.S. Geological Survey (USGS) | October 21st, 2016

Managed aquifer recharge is used to augment natural recharge to aquifers. It can be used to replenish aquifers depleted by pumping or to store water during wetter years f

Managed aquifer recharge is used to augment natural recharge to aquifers. It can be used to replenish aquifers depleted by pumping or to store water during wetter years for withdrawal during drier years. Infiltration from ponds is a commonly used, inexpensive approach for managed aquifer recharge. At some managed aquifer recharge sites, the time when infiltrated water arrives at the water table is not always clearly shown by water-level data (fig. 1). As part of site characterization and operation, it can be desirable to track downward movement of infiltrated water through the unsaturated zone to identify when it arrives at the water table.

Sensing the ups and downs of Las Vegas: InSAR reveals structuralcontrol of land subsidence and aquifer‐system deformation

Geological Society of America (GSA) | June 1st, 1999

Land subsidence in Las Vegas, Nevada, United States, between April 1992 and December 1997 was measured using spaceborne interferometric synthetic aperture radar. The deta

Land subsidence in Las Vegas, Nevada, United States, between April 1992 and December 1997 was measured using spaceborne interferometric synthetic aperture radar. The detailed deformation maps clearly show that the spatial extent of subsidence is controlled by geologic structures (faults) and sediment composition (clay thickness). The maximum detected subsidence during the 5.75 yr period is 19 cm. Comparison with leveling data indicates that the subsidence rates declined during the past decade as a result of rising ground-water levels brought about by a net reduction in ground-water extraction. Temporal analysis also detects seasonal subsidence and uplift patterns, which provide information about the elastic and inelastic properties of the aquifer system and their spatial variability.

Short-lived pause in Central California subsidence after heavy winter precipitation of 2017

American Association for the Advancement of Science (AAAS) | August 29th, 2018

The Tulare Basin in Central California is a site of intensive agricultural activity and extraction of groundwater, with pronounced ground subsidence and degradation of wa

The Tulare Basin in Central California is a site of intensive agricultural activity and extraction of groundwater, with pronounced ground subsidence and degradation of water resources over the past century. Spatially extensive observations of ground displacements from satellite-based remote sensing allow us to infer the response of the aquifer system to changes in usage and to marked recharge events such as the heavy winter rainfall in 2017. Radar imagery from the Sentinel-1a/b satellites (November 2014 to October 2017) illuminates secular and seasonal trends modulated by changes in withdrawal rates and the magnitude of winter precipitation. Despite the increased precipitation in early 2017 that led to a marked decrease, or in some areas, reversal, of subsidence rates, subsidence returned to rates observed during the drought within a matter of months.

Short‐lived pause in Central California subsidence after heavy winter precipitation of 2017

American Association for the Advancement of Science (AAAS) | August 29th, 2018

The Tulare Basin in Central California is a site of intensive agricultural activity and extraction of groundwater, with pronounced ground subsidence and degrada

The Tulare Basin in Central California is a site of intensive agricultural activity and extraction of groundwater, with pronounced ground subsidence and degradation of water resources over the past century. Spatially extensive observations of ground displacements from satellite-based remote sensing allow us to infer the response of the aquifer system to changes in usage and to marked recharge events such as the heavy winter rainfall in 2017. Radar imagery from the Sentinel-1a/b satellites (November 2014 to October 2017) illuminates secular and seasonal trends modulated by changes in withdrawal rates and the magnitude of winter precipitation. Despite the increased precipitation in early 2017 that led to a marked decrease, or in some areas, reversal, of subsidence rates, subsidence returned to rates observed during the drought within a matter of months.

Simulation of Ground-water Flow in the Mojave River Basin, California

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

Simulation of Ground-Water/Surface-Water Flow in the Santa Clara–Calleguas Ground-Water Basin, Ventura County, California

U.S. Geological Survey (USGS) | July 15th, 2003

Ground-water is the main source of water in the Santa Clara–Calleguas ground-water basin that covers about 310 square miles in Ventura County, California. A steady incr

Ground-water is the main source of water in the Santa Clara–Calleguas ground-water basin that covers about 310 square miles in Ventura County, California. A steady increase in the demand for surface- and ground-water resources since the late 1800s has resulted in streamflow depletion and ground-water overdraft. This steady increase in water use has resulted in seawater intrusion, inter-aquifer flow, land subsidence, and ground-water contamination. 

Simulation of the Impacts of Spring Diversions on Streamflow in the Strawberry Creek Watershed, San Bernardino County, California, Using an Integrated Hydrological Model

U.S. Geological Survey (USGS) | July 27th, 2026

The Strawberry Creek watershed, in the San Bernardino Mountains of southern California, features a group of natural springs known as Arrowhead Springs that have been augm

The Strawberry Creek watershed, in the San Bernardino Mountains of southern California, features a group of natural springs known as Arrowhead Springs that have been augmented with diversions in the form of sub-horizontal borings and tunnels. Understanding the effects of these structures on streamflow through groundwater capture is crucial for managing surface-water resources in this watershed. In this study, we constructed the Strawberry Creek integrated hydrological model to increase this understanding. The Strawberry Creek integrated hydrological model is an integrated surface runoff and groundwater model, GSFLOW to simulate surface runoff and infiltration and groundwater flow. The model has 263 rows and 176 columns in each of its three layers. The model area includes the Strawberry Creek and four adjacent watersheds. The precipitation- runoff modeling system was calibrated using two streamflow gaging stations, and the groundwater and surface-water flow model was calibrated to the reported spring diversion discharge and a sparse number of groundwater- level measurements. The Strawberry Creek integrated hydrological model was run with and without diversions active, and simulated streamflow was compared, indicating that in the headwaters of Strawberry Creek, about 35 percent of the diversion flow was captured from base flow.

Simulation of Water-Management Alternatives in the Mojave River Ground-Water Basin, California

U.S. Geological Survey (USGS) | July 1st, 2002