Time-varying land subsidence detected by radar altimetry: California, Taiwan and north China

Nature Portfolio (Springer Nature) | June 21st, 2016

Contemporary applications of radar altimetry include sea-level rise, ocean circulation, marine gravity, and icesheet elevation change. Unlike InSAR and GNSS, which are wi

Contemporary applications of radar altimetry include sea-level rise, ocean circulation, marine gravity, and icesheet elevation change. Unlike InSAR and GNSS, which are widely used to map surface deformation, altimetry is neither reliant on highly temporally-correlated ground features nor as limited by the available spatial coverage, and can provide long-term temporal subsidence monitoring capability. Here we use multi-mission radar altimetry with an approximately 23 year data-span to quantify land subsidence in cropland areas. Subsidence rates from TOPEX/POSEIDON, JASON-1, ENVISAT, and JASON-2 during 1992–2015 show time-varying trends with respect to displacement over time in California’s San Joaquin Valley and central Taiwan, possibly related to changes in land use, climatic conditions (drought) and regulatory measures affecting groundwater use. Near Hanford, California, subsidence rates reach 18 cm yr with a cumulative subsidence of 206 cm, which potentially could adversely affect operations of the planned California High-Speed Rail. The maximum subsidence rate in central Taiwan is 8 cm yr. Radar altimetry also reveals time-varying subsidence in the North China Plain consistent with the declines of groundwater storage and existing water infrastructure detected by the Gravity Recovery and Climate Experiment (GRACE) satellites, with rates reaching 20 cm yr and cumulative subsidence as much as 155 cm.

Tri-County Water Authority Groundwater Sustainability Plan

Tri-County Water Authority | December 18th, 2019

Tulare Lake Fact Sheet

California State Water Resources Control Board (SWRCB) | October 12th, 2023

Tulare Lake Subbasin Groundwater Sustainability Plan

Kings County Farm Bureau | January 29th, 2020

Tulare Lake Subbasin Probationary Hearing Draft Report

California State Water Resources Control Board (SWRCB) | October 12th, 2023

The State Water Board recognizes that significant efforts were made by local public agencies in the Tulare Lake Subbasin since the passage of SGMA to form groundwater sus

The State Water Board recognizes that significant efforts were made by local public agencies in the Tulare Lake Subbasin since the passage of SGMA to form groundwater sustainability agencies (GSAs) and then develop detailed technical and other information supporting the adoption and implementation of a groundwater sustainability plan (GSP) for the subbasin. Despite those efforts, in January of 2022, DWR reviewed the GSP to determine if it met SGMA’s requirements and found it to be incomplete. Following revisions made by the GSAs in the subbasin, DWR reevaluated the GSP in March of 2023, determined it to be inadequate, and referred the subbasin to the State Water Board, as required by SGMA. Consistent with SGMA, the State Water Board may now consider whether to designate the Tulare Lake Subbasin as a “probationary basin,” a term that is used in SGMA to describe the first stage of state intervention. Click here for Appendix to the report.

Tulare Lake Subbasin Probationary Hearing Draft Staff Report, Appendix A Summary Table of Proposed Deficiencies and Potential Actions to Address Deficiencies

California State Water Resources Control Board (SWRCB) | October 12th, 2023

Click here to see the main related draft report.

Click here to see the main related draft report.

Tulare Lake Subbasin Probationary Hearing Final Staff Report

California State Water Resources Control Board (SWRCB)nia | March 29th, 2024

State Water Board staff have identified specific deficiencies in the Tulare Lake Subbasin 2022 GSP and have outlined potential corrective actions to address those specifi

State Water Board staff have identified specific deficiencies in the Tulare Lake Subbasin 2022 GSP and have outlined potential corrective actions to address those specific deficiencies. The Final Staff Report also incorporates deficiencies identified by DWR’s determination. Deficiencies that have been identified within the GSP relate to: * Chronic lowering of groundwater levels with insufficient management criteria. * Continued land subsidence (sinking). * Further degradation of groundwater quality.

Tule Subbasin Probationary Hearing Final Staff Report

California State Water Resources Control Board (SWRCB) | August 30th, 2024

Board staff identified specific deficiencies in the Tule Subbasin 2022 GSPs and outlined potential corrective actions to address those specific deficiencies. • Chron

Board staff identified specific deficiencies in the Tule Subbasin 2022 GSPs and outlined potential corrective actions to address those specific deficiencies. • Chronic lowering of groundwater levels with insufficient management criteria. • Continued land subsidence (sinking). • Further degradation of groundwater quality. • Depletions of interconnected surface water.

Uplift and seismicity driven by groundwater depletion in central California

Nature Portfolio (Springer Nature) | May 14th, 2014

Groundwater use in California’s San Joaquin Valley exceeds replenishment of the aquifer, leading to substantial diminution of this resource and rapid subsidence of the

Groundwater use in California’s San Joaquin Valley exceeds replenishment of the aquifer, leading to substantial diminution of this resource and rapid subsidence of the valley floor. The volume of groundwater lost over the past century and a half also represents a substantial reduction in mass and a large-scale unburdening of the lithosphere, with significant but unexplored potential impacts on crustal deformation and seismicity. Here we use vertical global positioning system measurements to show that a broad zone of rock uplift of up to 1–3 mm per year surrounds the southern San Joaquin Valley. The observed uplift matches well with predicted flexure from a simple elastic model of current rates of water-storage loss, most of which is caused by groundwater depletion. The height of the adjacent central Coast Ranges and the Sierra Nevada is strongly seasonal and peaks during the dry late summer and autumn, out of phase with uplift of the valley floor during wetter months. Our results suggest that long-term and late-summer flexural uplift of the Coast Ranges reduce the effective normal stress resolved on the San Andreas Fault. This process brings the fault closer to failure, thereby providing a viable mechanism for observed seasonality in microseismicity at Parkfield and potentially affecting long-term seismicity rates for fault systems adjacent to the valley. We also infer that the observed contemporary uplift of the southern Sierra Nevada previously attributed to tectonic or mantle-derived forces is partly a consequence of human-caused groundwater depletion.

Upper San Gabriel Valley Municipal Water District v. City of Alhambra et al

Superior Court of California, County of Los Angeles | June 21st, 2012

Background note from An Evaluation of California’s Adjudicated Groundwater Basins by Langridge et al, (UC Davis) 2016 The Main San Gabriel Basin is one of the larges

Background note from An Evaluation of California’s Adjudicated Groundwater Basins by Langridge et al, (UC Davis) 2016 The Main San Gabriel Basin is one of the largest groundwater basins in southern California, providing residents of the greater San Gabriel Valley with about 240,000 AF per year. It is geographically situated in the south-easterly portion of Los Angeles County and bounded on the north by the San Gabriel Mountains, on the northwest by Raymond Basin, on the southeast by Puente Basin, and on the south by the Central Basin. The adjudication of the basin was deemed necessary by water producers to streamline administration, reduce overdraft, and adhere to the Long Beach Judgment and Puente Narrows Agreements, and the adjudication was relatively amenable. One of the most significant concerns in the basin is water quality, with four areas of the valley containing Superfund sites. The 1973 Judgment included water quality as one of the Watermaster’s responsibilities, and since the mid-1980s the Watermaster has coordinated with regulatory agencies to have groundwater remediation facilities constructed, permitted and operated to protect and enhance the groundwater supplies. The 1992 Judgment amendment explicitly required coordination with EPA for a federal cleanup of the Superfund sites.