Land Subsidence and Aquifer-System Compaction in the San Jacinto Valley, Riverside County, California

U.S. Geological Survey (USGS) | January 1st, 1976

Land subsidence caused by the East Mesa geothermal field, California, observed using SAR interferometry

American Geophysical Union (AGU) | April 15th, 1997

Interferometric combination of pairs of synthetic aperture radar (SAR) images acquired by the ERS-1 satellite maps the deformation field associated with the activity o

Interferometric combination of pairs of synthetic aperture radar (SAR) images acquired by the ERS-1 satellite maps the deformation field associated with the activity of the East Mesa geothermal plant, located in southern California. SAR interferometry is applied to this flat area without the need of a digital terrain model. Several combinations are used to ascertain the nature of the phenomenon. Short term interferograms reveal surface phase changes on agricultural fields similar to what had been observed previously with SEASAT radar data. Long term (2 years) interferograms allow the study of land subsidence and improve prior knowledge of the displacement field, and agree with existing, sparse levelling data. This example illustrates the power of the interferometric technique for deriving accurate industrial intelligence as well as its potential for legal action, in cases involving environmental damages. *Correction appended

Land Subsidence from Groundwater Use in California

California Water Foundation | April 5th, 2014

Historically, groundwater has been pumped as needed in many areas of the state, often with little regard for the deleterious effects of over pumping. Over pumping is not

Historically, groundwater has been pumped as needed in many areas of the state, often with little regard for the deleterious effects of over pumping. Over pumping is not sustainable in the long-term and can lead to a number of adverse consequences, including water-quality degradation; increased energy costs for groundwater pumping; costs for well deepening or replacement; impacts to nearby rivers and streams; and land subsidence. This report highlights the current and historical impacts of land subsidence in California due to groundwater pumping and makes recommendations for monitoring and assessment. The purpose of this report is to summarize knowledge about the extent and costs of subsidence so that this information can be part of a larger discussion on sustainable groundwater management in California. This report confirms that land subsidence in California is not just an historical occurrence, but that it is an ongoing problem in many regions. The report presents key examples of significant historical subsidence and current active occurrences of subsidence, including the impacts and costs. There is no comprehensive land subsidence monitoring program in California. The information in this report was compiled from individual regional or local studies, which usually were initiated after substantial subsidence impacts had occurred. The most comprehensive evaluation of land subsidence in California occurred between 1955 and 1970, to assist with the construction of the state and federal water projects. Funding for this program ended soon after completion of the state and federal water projects. The lack of comprehensive subsidence monitoring has had costly consequences for the state.

Land Subsidence from Groundwater Use in California (Summary Report)

California Water Foundation | April 5th, 2014

Historically, groundwater has been pumped as needed in many areas of the state, often with little regard for the deleterious effects of over pumping. Over pumping is not

Historically, groundwater has been pumped as needed in many areas of the state, often with little regard for the deleterious effects of over pumping. Over pumping is not sustainable in the long-term and can lead to a number of adverse consequences, including water-quality degradation; increased energy costs for groundwater pumping; costs for well deepening or replacement; impacts to nearby rivers and streams; and land subsidence. This report highlights the current and historical impacts of land subsidence in California due to groundwater pumping and makes recommendations for monitoring and assessment. The purpose of this report is to summarize knowledge about the extent and costs of subsidence so that this information can be part of a larger discussion on sustainable groundwater management in California. This report confirms that land subsidence in California is not just an historical occurrence, but that it is an ongoing problem in many regions. The report presents key examples of significant historical subsidence and current active occurrences of subsidence, including the impacts and costs. There is no comprehensive land subsidence monitoring program in California. The information in this report was compiled from individual regional or local studies, which usually were initiated after substantial subsidence impacts had occurred. The most comprehensive evaluation of land subsidence in California occurred between 1955 and 1970, to assist with the construction of the state and federal water projects. Funding for this program ended soon after completion of the state and federal water projects. The lack of comprehensive subsidence monitoring has had costly consequences for the state.

Land Subsidence in Santa Clara Valley, Alameda, San Mateo, and Santa Clara Counties California

U.S. Geological Survey (USGS) | January 31st, 1971

Land subsidence in the San Joaquin Valley, California, as of 1972

U.S. Geological Survey (USGS) | July 10th, 1975

Land subsidence which began in the mid-1920's due to groundwater overdraft in the San Joaquin Valley has caused widespread concern for the past two decades. Withdrawals

Land subsidence which began in the mid-1920's due to groundwater overdraft in the San Joaquin Valley has caused widespread concern for the past two decades. Withdrawals for irrigation increased from 3 million acre-feet in 1942 to 10 million acre-feet in 1966. Water levels declined at unprecedented rates during the 1950's and early 1960's. Pumping lifts became inordinately high, well casings failed at alarming rates, and differential settlement caused numerous farming and engineering problems. By 1970,5,200 square miles of valley land had been affected, and maximum subsidence exceeded 28 feet. The valley-wide volume of subsidence totaled 15.6 million acre-feet, one-half the initial storage capacity of Lake Mead. This subsidence represents one of the great environmental changes imposed by man. Importation of surface water to the northwestern and eastern areas of overdraft in the valley began in the 1950's and to the much larger western and southern areas in the late 1960's. Canal imports have largely replaced ground-water pumpage in these areas. As of 1973, after three decades of continued declining water levels, many hundreds of irrigation wells are idle and water levels are rising. Throughout much of the valley, artesian pressures are recovering toward their presubsidence levels, and elevations of the subsiding land surface are stabilizing. Basic-data graphs and computer-plotted stress-strain relationships constitute a major part of this report. They are based on 10-13 years of detailed field measurements of both water-level change and compaction collected by the U.S. Geological Survey at 20 selected locations in the San Joaquin Valley. The recharge characteristics of a ground-water reservoir are indicated roughly by the volume ratio, which is subsidence/pumpage. In the Los Banos-Kettleman City area, the values of this ratio range from less than 0.2 near the perimeter to more than 0.6 in the central part of the area. In the corresponding parts of the Arvin-Maricopa area, the ratio ranges from near 0 to more than 0.4.

Land subsidence in the San Joaquin Valley, California, as of 1980

U.S. Geological Survey (USGS) | July 1st, 1984

Land subsidence in the San Joaquin Valley, California, USA, 2007–2014

Copernicus Publications | November 12th, 2015

Land Subsidence in the Santa Clara Valley, California, as of 1982

U.S. Geological Survey (USGS) | July 31st, 1988

Land Subsidence in the Southwestern Mojave Desert, California, 1992–2009

U.S. Geological Survey (USGS) | July 8th, 2017

Groundwater has been the primary source of domestic, agricultural, and municipal water supplies in the southwestern Mojave Desert, California, since the early 1900s. Incr

Groundwater has been the primary source of domestic, agricultural, and municipal water supplies in the southwestern Mojave Desert, California, since the early 1900s. Increased demands on water supplies have caused groundwater-level declines of more than 100 feet (ft) in some areas of this desert (fig. 2 inset) between the 1950s and the 1990s (Stamos and others, 2001; Sneed and others, 2003). These water-level declines have caused the aquifer system to compact, resulting in land subsidence. Differential land subsidence (subsidence occurring at different rates across the landscape) can alter surface drainage routes and damage surface and subsurface infrastructure. For example, fissuring across State Route 247 at Lucerne Lake (fig. 2) has required repairs as has pipeline infrastructure near Troy Lake. Land subsidence within the Mojave River and Morongo Groundwater Basins of the southwestern Mojave Desert has been evaluated using InSAR, ground-based measurements, geology, and analyses of water levels between 1992 and 2009 (years in which InSAR data were collected). The results of the analyses were published in three USGS reports— Sneed and others (2003), Stamos and others (2007), and Solt and Sneed (2014). Results from the latter two reports were integrated with results from other USGS/ MWA cooperative groundwater studies into the broader scoped USGS Mojave Groundwater Resources Web site (http://ca.water.usgs.gov/mojave/). This fact sheet combines the detailed analyses from the three subsidence reports, distills them into a longer-term context, and provides an assessment of options for future monitoring.