We’ve been hearing the word “drought” a lot in the last few weeks, with rain 20% to 50% of average on the Central and South Coasts this rainfall season. Much of the focus on how much water we have in our lakes, and how much we are getting from the state water project. But, what gets overlooked is groundwater. In the United States, about 40% of our drinking water comes from wells, and about 50% for agriculture is pumped from underground.
A new global study by some South Coast researchers shows the key resource in many parts of the world is literally being pumped dry. One in five in the study are in danger of growing dry.
Debra Perrone and Scott Jasechko are UC Santa Barbara researchers who have compiled what’s being called one of the most comprehensive looks at the global groundwater situation. They compiled 39 million records of functional wells.
Perrone, with the university’s Environmental Studies Program, says drought years are compounded by things like overdrafting of available underground supplies.
Water experts on the Central and South Coasts say even when we had significant rainfall two years ago, which helped water supply sources like Cachuma Lake, Lake Casitas, and Gibraltar Dam, it didn’t make a big dent in the underground water debt. They say it take several years of heavy rainfall to recharge the underground water basins.
And, wells are a key part of the water mix for communities like Santa Barbara and Ventura.
Jasechko, with the Bren School of Environmental Science and Management, says they thought maybe people would be adding new, deeper wells to address some of the issues. But, he says they found that wasn’t the case.
Among the concerning findings are that in a number of areas, groundwater levels are close to the bottom of wells. The situation could leave people high and dry without the critical resource.
The researchers say while groundwater sustainability is a complex issue, their study helps illustrate a growing crisis, and can also provide data which can help shape policies to address the issue.
They are hoping to expand on their research. which was just published in the journal Science. They want to examine specifics on where water levels are dropping the most, and where the crisis is the most severe.
