GRACE Groundwater Drought Index: Evaluation of California Central Valley groundwater drought

Remote Sensing of Environment (Elsevier) | July 3rd, 2017

Quantitative approaches to assess the complexity of groundwater drought are hindered by the lack of direct observations of groundwater over space and time. Here,

Quantitative approaches to assess the complexity of groundwater drought are hindered by the lack of direct observations of groundwater over space and time. Here, we present an approach to evaluate groundwater drought occurrence based on observations from NASA's Gravity Recovery and Climate Experiment (GRACE) satellite mission. Normalized GRACE-derived groundwater storage deviations are shown to quantify groundwater storage deficits during the GRACE record, which we define as the GRACE Groundwater Drought Index (GGDI). As a case study, GGDI is applied over the Central Valley of California, a regional aquifer undergoing intensive human activities and subject to significant drought periods during the GRACE record. Relations between GGDI and other hydrological drought indices highlight our ability to capture drought delays unique to groundwater drought. Further, GGDI captures characteristics of groundwater drought that occur as a result of complex human activities and natural changes, thus presenting a framework to assess multi-driver groundwater drought characteristics.

GRACE satellite observations reveal the severity of recent water over-consumption in the United States

Nature Portfolio (Springer Nature) | August 18th, 2017

Changes in the climate and population growth will critically impact the future supply and demand of water, leading to large uncertainties for sustainable resour

Changes in the climate and population growth will critically impact the future supply and demand of water, leading to large uncertainties for sustainable resource management. In the absence of on-the-ground measurements to provide spatially continuous, high-resolution information on water supplies, satellite observations can provide essential insight. Here, we develop a technique using observations from the Gravity Recovery and Climate Experiment (GRACE) satellite to evaluate the sustainability of surface water and groundwater use over the continental United States. We determine the annual total water availability for 2003–2015 using the annual variability in GRACE-derived total water storage for 18 major watersheds. The long-term sustainable water quantity available to humans is calculated by subtracting an annual estimate of the water needed to maintain local ecosystems, and the resulting water volumes are compared to reported consumptive water use to determine a sustainability fraction. We find over-consumption is highest in the southwest US, where increasing stress trends were observed in all five basins and annual consumptive use exceeded 100% availability twice in the Lower Colorado basin during 2003–2015. By providing a coarse-scale evaluation of sustainable water use from satellite and ground observations, the established framework serves as a blueprint for future large-scale water resource monitoring.

Grassland Groundwater Sustainability Agency Groundwater Sustainability Plan

Grassland Groundwater Sustainability Agency (GGSA) | January 17th, 2020

*Cover gives draft date of December but consulting engineer signature is for 1/17/2020

*Cover gives draft date of December but consulting engineer signature is for 1/17/2020

Grassland Groundwater Sustainability Agency Revised Groundwater Sustainability Plan

Grassland Groundwater Sustainability Agency (GGSA) | July 8th, 2022

This GSP, including the Common Chapter, has been revised (changes are shown in Appendix G) to address items of concern raised by DWR in its initial “Incomplete” Deter

This GSP, including the Common Chapter, has been revised (changes are shown in Appendix G) to address items of concern raised by DWR in its initial “Incomplete” Determination Letter dated January 21, 2022. Every effort was made to ensure that this revised GSP and the revised Common Chapter are consistent. In the event of an inconsistency, the revised Common Chapter controls. The Grassland Plan Area will continue to be sustainable by maintaining the historically balanced groundwater system in order to avoid causing significant and unreasonable undesirable impacts to beneficial users of groundwater as they relate to the six sustainability indicators. The Plan Area participants are committed to continued coordination with neighboring GSP areas and neighboring subbasins in order to aid in the localized and statewide groundwater sustainability goals as defined by each GSP and Subbasin. Due to size, this file has been divided. Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7

Gravelley Ford Water District Groundwater Sustainability Plan

Gravelly Ford Water District (GFWD) | August 12th, 2019

Gravelly Ford Water District Groundwater Sustainability Plan

Gravelly Ford Water District (GFWD) | June 28th, 2022

This Plan is for the Gravelly Ford Groundwater Sustainability Area, one of seven components of the Madera Subbasin. It encompasses approximately 8,500 acres; its boundari

This Plan is for the Gravelly Ford Groundwater Sustainability Area, one of seven components of the Madera Subbasin. It encompasses approximately 8,500 acres; its boundaries are coterminous with those of the Gravelly Ford Water District (District). Grape vineyards, nut tree groves, and on-farm rural residences are the only land uses in the Area. The District has from the beginning bee’n a conjunctive use operation with the import of surface water for both recharge and irrigation. The management of this operation has been to utilize the maximum amount of available surface waters prior to using groundwater for the production of crops.

Greater Kaweah Groundwater Sustainability Agency 2022 First Amended Groundwater Susteainability Plan

Greater Kaweah Groundwater Sustainability Agency (GKGSA) | July 20th, 2022

Due to size, this file has been divided. Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7, Part 8, Part 9, Part 10

Due to size, this file has been divided. Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7, Part 8, Part 9, Part 10

Greenhouse gas emissions from US irrigation pumping and implications for climate-smart irrigation policy

Nature Portfolio (Springer Nature) | January 23rd, 2024

Ground water and climate change

Nature Portfolio (Springer Nature) | November 25th, 2012

As the world's largest distributed store of fresh water, ground water plays a central part in sustaining ecosystems and enabling human adaptation to climate variability a

As the world's largest distributed store of fresh water, ground water plays a central part in sustaining ecosystems and enabling human adaptation to climate variability and change. The strategic importance of ground water for global water and food security will probably intensify under climate change as more frequent and intense climate extremes (droughts and floods) increase variability in precipitation, soil moisture and surface water. Here we critically review recent research assessing the impacts of climate on ground water through natural and human-induced processes as well as through groundwater-driven feedbacks on the climate system. Furthermore, we examine the possible opportunities and challenges of using and sustaining groundwater resources in climate adaptation strategies, and highlight the lack of groundwater observations, which, at present, limits our understanding of the dynamic relationship between ground water and climate.

Ground Water Flow in a Desert Basin: Challenges of Simulating Transport of Dissolved Chromium

National Groundwater Association (NGWA) | December 13th, 2005

A large chromium plume that evolved from chromium releases in a valley near the Mojave River was studied to understand the processes controlling fate and migration of chr

A large chromium plume that evolved from chromium releases in a valley near the Mojave River was studied to understand the processes controlling fate and migration of chromium in ground water and used as a tracer to study the dynamics of a basin and range ground water system. The valley that was studied is naturally arid with high evapotranspiration such that essentially no precipitation infiltrates to the water table. The dominant natural hydrogeologic processes are recharge to the ground water system from the Mojave River during the infrequent episodes when there is flow in the river, and ground water flow toward a playa lake where the ground water evaporates. Agricultural pumping in the valley from the mid‐1930s to the 1970s significantly altered ground water flow conditions by decreasing water levels in the valley by more than 20 m. This pumping declined significantly as a result of dewatering of the aquifer, and water levels have since recovered modestly. The ground water system was modeled using MODFLOW, and chromium transport was simulated using MT3D. Several innovative modifications were made to these modeling programs to simulate important processes in this ground water system. Modifications to MODFLOW include developing a new well package that estimates pumping rates from irrigation wells at each time step based on available drawdown. MT3D was modified to account for mass trapped above the water table when the water table declines beneath nonirrigated areas and to redistribute mass to the system when water levels rise.