Eastern San Joaquin Valley and other CA drinking water supplies at risk in the next drought

by Amanda Fencl, Rich Pauloo, Alvar Escriva-Bou, Hervé Guillon During the 2012-2016 drought, the state received more than 2,500 domestic well failure reports, the majority of which were in the Central Valley (DWR 2018).
Our submission was driven by open data from public agencies and assessed the vulnerability of domestic wells to failure in the Central Valley.
Which domestic wells will be vulnerable in the next drought?
Due to already low groundwater levels, a simulated a 4-year-long-drought starting in January 2018 would result in more than 4,000 domestic well failures in the Central Valley alone, nearly twice as many well failures compared to 2012-2016.
About 1.5 times more well failures were reported by households in disadvantaged and severely disadvantaged communities (DAC + SDAC together) compared to those at or above the Median Household Income (MHI+).
Results from the spatial model of well failure were used to train an ensemble machine learning classifier on 56 climatic and geologic variables to predict present day well failure across the Central Valley and assess the climatic controls on domestic well failures.
We can’t avoid another drought in California.
Our hope is to show local and state decision-makers what is possible with existing data and methodologies to proactively address drinking water issues in California’s rural communities.
Dr. Hervé Guillon is a Postdoctoral Scholar at the UC Davis Water Resources Management Group and Dr. Alvar Escriva-Bou is a Research Fellow at the Public Policy Institute of California.
Arnold, Escriva-Bou, and Lund (2017) San Joaquin Valley Water Supplies – Unavoidable Variability and Uncertainty.

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