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subsidence

Friant Water Authority

A section of the the Friant-Kern Canal in Tulare County is sinking so much that it's lost about 60 percent of its flow.

Doug DeFlitch with the Friant Water Authority says the canal that helps irrigate a million acres of farmland has sunk two to three feet in some places over about a 25 mile area. The original design capacity in the area is about 4,000 cubic feet per second and he says it’s dropped to 1,600 cfs. 

Ezra David Romero / Valley Public Radio

A new map released by NASA earlier this year shows that large portions of California are sinking. The worst of it is in the San Joaquin Valley. One of the main reasons is the over pumping of groundwater, especially in the last five years of drought.

All that sinking and all the snow melting in the Sierra has Central Valley water managers like Dustin Fuller worried.

USGS

California’s prolonged drought is once again causing the valley in sink. Groundwater pumping to keep water flowing and plants growing is resulting in the valley floor to settling and sinking in what is known as subsidence. As the water is pulled out the ground underneath fills the space and settles. In some places, the land is subsiding as much as a foot a year.

  Hydrologist Jim Borcher says the Valley has experienced sinking before, but now it is back.

California Drought: NASA Says Land Sinking Faster In San Joaquin Valley

Aug 19, 2015
Credit www.usbr.gov

A new report from NASA shows the San Joaquin Valley is sinking much faster than ever before. Ed Joyce reports from Sacramento.

With reduced surface water available because of the drought, more groundwater is pumped.

As the underground aquifers are tapped, land surfaces sink. 

While subsidence in California isn't new, the report from NASA's Jet Propulsion Laboratory says the rate has accelerated.

www.usbr.gov

The U.S. Geological Survey released a study today showing that large groundwater withdrawals are causing land in California’s Central Valley to sink. A 1,200 square mile area is sinking up to a foot a year in some places. The situation has become so serious that it’s threatening flood control and water deliveries. The proposed high speed rail system will also have deal with the changing terrain. But Amy Quinton reports from Sacramento, finding a solution won’t be easy.