Mapping Structural Control Through Analysis of Land-Surface Deformation for the Rialto-Colton Groundwater Subbasin, San Bernardino County, California, 1992–2010

U.S. Geological Survey (USGS) | July 29th, 2022

The locations of many faults in and near the Rialto-Colton groundwater subbasin are not precisely known because the spatial density of existing lithologic and hydrologic

The locations of many faults in and near the Rialto-Colton groundwater subbasin are not precisely known because the spatial density of existing lithologic and hydrologic data used to infer the locations of faults can be sparse. The U.S. Geological Survey, in cooperation with the San Bernardino Valley Municipal Water District, analyzed structural control of groundwater flow in and near the Rialto-Colton groundwater subbasin using Interferometric Synthetic Aperture Radar (InSAR) methods. Faults commonly are barriers to groundwater flow, and the high spatial resolution of InSAR imagery can be used to infer the locations of buried faults where groundwater pumping occurs. InSAR results have revealed three areas in and near the Rialto-Colton groundwater subbasin where buried faults are interpreted as groundwater-flow barriers: the northwestern area about 3 miles northwest of the City of Rialto, the San Jacinto fault area west of the City of San Bernardino, and the southeastern area about 2 miles southeast of the City of Colton. The InSAR results were combined with knowledge gained from previous studies to better define the location and extent of faults acting as groundwater-flow barriers. New data about faults acting as groundwater-flow barriers can be incorporated into future conceptual and hydrologic models of the Rialto-Colton groundwater subbasin and provide water managers information to help effectively manage groundwater resources.

Mapping the global threat of land subsidence

American Association for the Advancement of Science (AAAS) | January 1st, 2021

Subsidence, the lowering of Earth's land surface, is a potentially destructive hazard that can be caused by a wide range of natural or anthropogenic triggers but mainly r

Subsidence, the lowering of Earth's land surface, is a potentially destructive hazard that can be caused by a wide range of natural or anthropogenic triggers but mainly results from solid or fluid mobilization underground. Subsidence due to groundwater depletion is a slow and gradual process that develops on large time scales (months to years), producing progressive loss of land elevation (centimeters to decimeters per year) typically over very large areas (tens to thousands of square kilometers) and variably affects urban and agricultural areas worldwide. Subsidence permanently reduces aquifer-system storage capacity, causes earth fissures, damages buildings and civil infrastructure, and increases flood susceptibility and risk. During the next decades, global population and economic growth will continue to increase groundwater demand and accompanying groundwater depletion  and, when exacerbated by droughts, will probably increase land subsidence occurrence and related damages or impacts. To raise awareness and inform decision-making, we evaluate potential global subsidence due to groundwater depletion, a key first step toward formulating effective land-subsidence policies that are lacking in most countries worldwide.

Maps, Models, and Mystery: Interconnected Groundwater and the Public Trust

American Bar Association (ABA) | August 10th, 2019

Walk into the office of any water law practitioner, anywhere, and you might think you made a wrong turn and walked into the office of your local cartographer. We are a p

Walk into the office of any water law practitioner, anywhere, and you might think you made a wrong turn and walked into the office of your local cartographer. We are a profession that depends on, and you might even say reveres, a good map. Rights to water flowing in surface streams are fundamentally defined by geography, and maps have long been a requirement of appropriation and essential evidence of riparian ownership. In turn, injury to a surface water right is determined by physics, as the topography of the land establishes the linear relation of impacts from other diversions, whether it be upstream (cause), or downstream (affected). In homage to these principles, some hydrologists will orient their maps top-to-bottom as upstream to downstream, rather than north to south. In our practice, gravity is our compass. Upending the convenient simplicity of rivers and streams flowing from mountaintop to ocean are alluvial and glacial valleys, in which unconsolidated sediment serve as giant sponges and blocks of fractured rock contain hidden stores of oftentimes ancient waters. Through these geologic features, hidden beneath the surface, water percolates, flows, and moves across the landscape. These subsurface waterbodies interconnect with surface streams and changes in the groundwater basin, whether due to drought or artificial extractions, and influence surface flow on a time scale ranging from minutes to centuries. To understand the relationship with any hope of precision, we need much more than a map; we need a hydrogeologist and a whole lot of data. All of this is by way of introducing two themes of emerging law in California that stand to influence trends beyond the state: (1) the legal relevance of interconnected groundwater to surface flows in protecting instream uses, and (2) recognition in the law of the need to understand and manage these interconnected waters.

Martis Valley Groundwater Basin Sustainable Groundwater Management Act Alternative Submittal

Truckee Donner Public Utility District (TDPUD) | December 22nd, 2016

Maxey-Eakin Methods for Estimating Groundwater Recharge in the Fenner Watershed, Southeastern California

U.S. Department of Energy (DOE) | May 15th, 2000

Recent review comments by the U.S. Geological Survey, Water Resources Division on the Cadiz Groundwater Storage and Dry-Year Supply Program Draft Environmental Planning

Recent review comments by the U.S. Geological Survey, Water Resources Division on the Cadiz Groundwater Storage and Dry-Year Supply Program Draft Environmental Planning Report were accompanied by an independent recharge estimate to the Fenner Basin based on a Maxey-Eakin method. The following report has analyzed WRD's recharge estimates and concludes that those results greatly underestimate annual recharge and lack credibility. Among the reasons outlined are 1) WRDÕs lack of geographic scale and context when analyzing precipitation-elevation data, 2) WRD's use of an uncalibrated Maxey-Eakin model, and 3) WRD's lack of direct observational experience in the eastern Mojave-Fenner Basin region. This report presents a more exhaustive analysis of data, supported by direct field observations, and estimates recharge using a calibrated Maxey-Eakin model. This report concludes that the possible range in annual groundwater replenishment rates to the Fenner Basin are between 7864 acre-ft and 29,185 acre-ft. The lower limit is a worst-case-scenario. This range is consistent with original recharge estimates calculated and presented in the Cadiz Groundwater Storage and Dry-Year Supply Program Draft Environmental Planning Report.

McMullin Area Groundwater Sustainability Agency Groundwater Sustainability Plan

McMullin Area Groundwater Sustainability Agency (MAGSA) | November 6th, 2019

McMullin Area Groundwater Sustainability Agency Groundwater Sustainability Plan (Revised)

McMullin Area Groundwater Sustainability Agency (MAGSA) | July 6th, 2022

Measuring and Interpreting Multilayer Aquifer-System Compactions for a Sustainable Groundwater-System Development

American Geophysical Union (AGU) | March 23rd, 2021

Ever decreasing water resources and climate change have driven the increasing use of groundwater causing land subsidence in many countries. Geodetic sensors such as InSAR

Ever decreasing water resources and climate change have driven the increasing use of groundwater causing land subsidence in many countries. Geodetic sensors such as InSAR, GPS and leveling can detect surface deformation but cannot measure subsurface deformation. A single‐well, single‐depth extensometer can be used to measure subsurface deformation, but it cannot delineate the depths of major compaction and provide insight about the deformation mechanism throughout a complex aquifer system, unless man extensometers at different depths are used. We present a multilayer compaction well (MLCW), installed in a borehole, that uses magnetic rings to detect stratum compaction at 25 depths as deep as 300 m below land surface. Our laboratory and field assessments indicate 1 mm precision and accuracy for one single‐depth magnetic reading. We tested the performance of MLCW by measuring aquifer‐system compaction over the proximal, middle, and distal fans of the Choushui River Alluvial Fan (CRAF) that has long experienced severe land subsidence. The MLCW measurements were used to create time‐depth diagrams of compaction, showing different compaction rates at different layers of aquifers and aquitards to identify the depths of major compactions. The elastic (reversible) and inelastic (irreversible) compactions from MLCW were used in stress‐strain analyses to estimate skeletal specific storages and the safe groundwater levels, below which groundwater extractions have caused irreversible compactions. The hydrogeological parameters derived from MLCW measurements can help governmental agencies to determine effective land‐use and water‐use policies, and ascertain the best strategy for utilizing artificial recharge to prevent land subsidence and achieve sustainable groundwater management.

Measuring Land Subsidence from Space

U.S. Geological Survey (USGS) | April 13th, 2000

Interferometric Synthetic Aperture Radar (InSAR) is a powerful new tool that uses radar signals to measure deformation of the Earth’s crust at an unprecedented level of

Interferometric Synthetic Aperture Radar (InSAR) is a powerful new tool that uses radar signals to measure deformation of the Earth’s crust at an unprecedented level of spatial detail and high degree of measurement resolution. InSAR is now being used by the USGS and others to map and monitor subsidence caused by the compaction of aquifer systems. Geophysical applications of radar interferometry take advantage of the phase component of reflected radar signals to measure apparent changes in the range distance of the land surface (Gabriel and others, 1989; Massonnet and Feigl, 1998). Ordinary radar on a typical Earth-orbiting satellite has a very poor ground resolution of about 3 to 4 miles because of the restricted size of the antenna on the satellite. Synthetic Aperture Radar (SAR) takes advantage of the motion of the spacecraft along its orbital track to mathematically reconstruct (synthesize) an operationally larger antenna and yield high-spatial-resolution imaging capability on the order of hundreds of feet.

Measuring What Matters: Setting Measurable Objectives to Achieve Sustainable Groundwater Management in California

Union of Concerned Scientists | September 1st, 2015

Groundwater supplies between 30 and 50 percent of California’s water supply, depending on precipitation, and represents a storage reservoir that is over three times gre

Groundwater supplies between 30 and 50 percent of California’s water supply, depending on precipitation, and represents a storage reservoir that is over three times greater than available surface water storage. The California Water Action Plan (CNRA, CDFA, and CEPA 2014) identifies groundwater as “a critical bu?er to the impacts of prolonged dry periods and climate change on our water system.” Many groundwater basins have historically experienced significant chronic overdraft and related negative impacts. California’s ongoing drought helped spur the state to enact legislation to strengthen local control and management of groundwater basins. Governor Jerry Brown signed the threebill package (AB 1739, SB 1168, SB 1319), known as the Sustainable Groundwater Management Act (SGMA), into law on September 16, 2014. SGMA represents California’s attempt to regulate groundwater comprehensively for the first time in the state’s history. SGMA, which went into e?ect on January 1, 2015, lays out a process and a timeline for local agencies to achieve sustainable management of groundwater basins (see Box 1). It also provides tools, authorities, and deadlines meant to lead to achievement of the legislation’s purpose. For local agencies involved in implementation, the requirements are significant and are expected to take many years to accomplish. While setting measurable objectives is a new requirement, it is by no means a new concept in natural resource management. This report summarizes the theory and practice of setting measurable objectives for groundwater management, using examples from California and elsewhere. The goal is to begin to develop a shared knowledge base and to identify key features of e?ective measurable objectives.