Water availability and land subsidence in the Central Valley, California, USA

• Published in: Hydrogeology journal Vol. 24; no. 3; pp. 675 - 684
• Main Authors: Faunt, Claudia C., Sneed, Michelle, Traum, Jon, Brandt, Justin T.
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01.05.2016; Springer Nature B.V
• Subjects: Agriculture; Aquatic Pollution; Aquifer management; Aquifers; Availability; Central Valley of California; Compaction; Drought; Earth and Environmental Science; Earth Sciences; flood control; Geology; Geophysics/Geodesy; Groundwater; Groundwater irrigation; Groundwater levels; Groundwater recharge; Groundwater storage; Historic; Hydrogeology; Hydrologic models; Hydrology; Hydrology/Water Resources; Irrigation water; Land subsidence; Land use; land use change; laws and regulations; Legislation; Modelling; monitoring; planning; Pumpage; Subsidence; Surface water; Sustainable use; Valleys; Waste Water Technology; Water availability; Water demand; Water Management; Water Pollution Control; Water Quality/Water Pollution; Water resources management; water table; United States > US; California; INE, USA, California; USA, California, Central Valley; USA, California, San Joaquin Valley; Central Valley of California; Groundwater/surface-water relations; USA; Subsidence; Geohazards; Compaction
• DOI: 10.1007/s10040-015-1339-x
• ISSN: 1431-2174

The Central Valley in California (USA) covers about 52,000 km 2 and is one of the most productive agricultural regions in the world. This agriculture relies heavily on surface-water diversions and groundwater pumpage to meet irrigation water demand. Because the valley is semi-arid and surface-water availability varies substantially, agriculture relies heavily on local groundwater. In the southern two thirds of the valley, the San Joaquin Valley, historic and recent groundwater pumpage has caused significant and extensive drawdowns, aquifer-system compaction and subsidence. During recent drought periods (2007–2009 and 2012-present), groundwater pumping has increased owing to a combination of decreased surface-water availability and land-use changes. Declining groundwater levels, approaching or surpassing historical low levels, have caused accelerated and renewed compaction and subsidence that likely is mostly permanent. The subsidence has caused operational, maintenance, and construction-design problems for water-delivery and flood-control canals in the San Joaquin Valley. Planning for the effects of continued subsidence in the area is important for water agencies. As land use, managed aquifer recharge, and surface-water availability continue to vary, long-term groundwater-level and subsidence monitoring and modelling are critical to understanding the dynamics of historical and continued groundwater use resulting in additional water-level and groundwater storage declines, and associated subsidence. Modeling tools such as the Central Valley Hydrologic Model, can be used in the evaluation of management strategies to mitigate adverse impacts due to subsidence while also optimizing water availability. This knowledge will be critical for successful implementation of recent legislation aimed toward sustainable groundwater use.