Unexpected Water Source Brings Hope to California—If Managed Correctly

June 27, 2016 | Comments

“It’s not often that you find a ‘water windfall,’ but we just did,” said Robert Jackson, the Michelle and Kevin Douglas Provostial Professor at Stanford University. “There’s far more fresh water and usable water than we expected.”

Jackson co-authored a study published in the journal Proceedings of the National Academy of Science. The findings state that there is three times more water in California’s Central Valley than previously estimated. The article also highlights that there is a great need for groundwater aquifers around the world to be better protected and scientifically analyzed.

While California is an especially drought-stricken area, the findings in this recent study are relevant to all sorts of regions that are experiencing water shortages. Mary Kang, a postdoctoral associate at Stanford School of Earth, Energy and Environmental Sciences, has stated that regions with water shortages that could benefit from the study include Texas, China and Australia.

KERN COUNTY, CA - MAY 6, 2015: Despite the severe drought, this Central California farm has a newly-planted vineyard. The small grape plants are served with an extensive drip irrigation system.

A drip-irrigation vineyard in Kern County. Despite its relatively arid climate, Central California still has a high level of farming activity.

 

Groundwater Supply Increasingly Tapped

About 30 percent of California’s total annual water supply comes from groundwater. During drought, this value jumps to about 60 percent. While groundwater is certainly a vital source, its warehouses of scientific data are still relatively small and outdated.

For instance, in California, the previous estimates on the quantity and quality of groundwater was based on data that was not as reliable as current findings. It was decades old and only extended to a maximum depth of 1,000 ft.

Now, these deep aquifers are increasingly being used to supply fresh water to the state of California and as a result, more scientific efforts are underway to understand just exactly how much water is left.

In this recent study, Jackson and Kang used data from 938 oil and gas pools and more than 35,000 oil and gas wells to better understand California’s aquifer water supply. Across eight counties, both deep and shallow groundwater sources were analyzed for their future supplies.

It was found that when deeper groundwater sources were factored in, the amount of usable groundwater in the Central Valley is over 650 cubic miles (2,700 cubic km) more than previously estimated. This is almost triple of the state’s current estimates.

 

Water Must Be Managed Properly

While California desperately needs new water sources, it is equally important to manage them responsibly. Researchers have many concerns about maintaining the quality and quantity of this aquifer. For example:

  • Tapping these deeper aquifers may cause serious ground subsidence—or a literal sinking of the land. This is already an issue in California’s Central Valley.
  • Deeper aquifers may need further study before installing pumps, as they tend to be higher in salt concentration. This can require more intensive treatment such as desalinization before it can be sent to homes.
  • The fact that it is deeper also means it will likely cost more to pump. Much of the water in this aquifer is 1,000 to 3,000 ft underground, almost three times as deep as some shallower aquifers.
  • Oil and gas drillings are occurring in as much as 30 percent of the sites where the deep groundwater resources are located.

huff post ground subsidence

A man measures land subsidence caused by groundwater depletion at the San Joaquin Valley’s Santa Rita Bridge. (Image courtesy of U.S. Geological Survey.)

Oil and gas are a consistent threat to groundwater supply. For example, it was found that of all the oil and gas activities occurring in Kern County, one in six was occurring directly into fresh water aquifers. Jackson and Kang’s study stresses that there is a serious need to monitor activities such as hydraulic fracturing (fracking).

“What we are saying is that no one is monitoring deep aquifers. No one’s following them through time to see how and if the water quality is changing,” Kang said. “We might need to use this water in a decade, so it’s definitely worth protecting.”

To learn more, visit the Stanford University website.

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