Updated: Aug 27
Years of irrigation have taken toll on San Joaquin Valley
March 23, 2014
Even before the drought, the southern San Joaquin Valley was in big trouble.
Decades of irrigation have leached salts and toxic minerals from the soil that have nowhere to go, threatening crops and wildlife. Aquifers are being drained at an alarming pace. More than 95 percent of the area's native habitat has been destroyed by cultivation or urban expansion, leaving more endangered bird, mammal and other species in the southern San Joaquin than anywhere in the continental U.S.
Federal studies long ago concluded that the only sensible solution is to retire hundreds of thousands of acres of farmland. Some farming interests have reached the same conclusion, even as they publicly blamed an endangered minnow to the north, known as the delta smelt, for the water restrictions that have forced them to fallow their fields.
(L-R) Beau Clark, his dad Mike Clark and Larry Curtsinger sit on their horses and watch as cattle move from one pasture to another on Jack Mitchell's ranch in Alpaugh, CA, Thursday, March 20, 2014. Farmer Jack Mitchell has sold about 2000 acres of his ranch to the Atwell Island Sanctuary which, through the Bureau of Land Management, is turning former farm land in the San Joaquin Valley back to it's natural pre-agriculture state. Michael Short/The Chronicle
The 600,000-acre Westlands Water District, representing farmers on the west side of the valley, has already removed tens of thousands of acres from irrigation and proposed converting damaged cropland to solar farms.
Many experts said if farmers don't retire the land, nature eventually will do it for them.
"We can make the decision now, when we actually have the choice about how to rationally back out of that bad situation and make landowners whole," said Jon Rosenfield, a conservation biologist for the Bay Institute, an environmental group. "Or we can just wait until the worst is upon us, we've driven the species extinct, we've plowed under the last bit of naturalized landscape in the area, and then we're going to retire these lands anyway."
More than a decade ago, Jack Mitchell, now 74, sold 3,000 acres of his irrigated land to federal officials trying to find out whether imperiled farmland could be reclaimed by the native plants, birds, mammals and other wildlife that once thrived in the San Joaquin Valley.
Mitchell's farm was on the site of the old Tulare Lake, once the largest freshwater lake west of the Mississippi, covering 800 square miles and yielding 3-foot trout. It went dry in the early 20th century as farmers began diverting water.
Mitchell had grown cotton and other row crops since his father bought the farm in 1946. But water was getting scarce and expensive, the drainage was terrible, and the government was offering a buyout. "We could see the writing on the wall," Mitchell said.
The experimental plot, called Atwell Island, covers about 8,000 acres in Tulare County. For more than a decade there and at a smaller site to the north in Fresno County called Tranquillity, federal land agents and university scientists experimented with restoring native plants and animals. The program was authorized by the Central Valley Project Improvement Act of 1992, the brainchild of Rep. George Miller, D-Martinez.
No one really knew how to restore old farmland that had been cleared, cultivated and doused in fertilizers and herbicides. The land and hundreds of thousands of acres like it is perched atop an impermeable layer known as the Corcoran clay, trapping irrigation drain water that leaches salt, boron, selenium and other naturally occurring minerals from the soil.
Restoration was difficult and expensive, costing roughly $1,500 an acre. But native plants began to establish, birds arrived in abundance, and mammals started to colonize.
The program will all but close down next year. The government abandoned plans to buy out more farmers and funding has dried up, even as biologists say the need is desperate.
Native shrubs, like this Atriplex Polycarpa are growing well in fields that were sold by local rancher Jack Mitchell to the Atwell Island Sanctuary in Alpaugh, CA, Thursday, March 20, 2014. Farmer Jack Mitchell has sold about 2000 acres of his ranch to the Atwell Island Sanctuary which, through the Bureau of Land Management, is turning former farm land in the San Joaquin Valley back to it's natural pre-agriculture state. Michael Short/The Chronicle
"The sad fact of the matter is that everybody knows the plight of many of these species," said Patrick Kelly, a zoologist at California State University Stanislaus who worked on the plots. Endangered animals and plants found at the sites, he said, range "from the blunt-nosed leopard lizard, a very magnificent large lizard that is only above ground for about six months of the year at most, to the San Joaquin kit fox, one of most beautiful canines in North America, to various species of kangaroo rats and various types of flowers like the California jewel flower."
The drought is taking a terrible toll on all of them, Kelly said, but the main reason for their predicament is "a loss and fragmentation and degradation of habitat."
The San Joaquin Valley is an ancient seabed arid enough to be classified as desert but irrigated by a huge complex of dams and canals. Large swaths of it have serious drainage problems, including more than 1.75 million acres of farmland, according to a 2005 federal report.
Much of the problem land lies on the valley's west side, represented primarily by Westlands. More than half its acreage has been classified as drainage-impaired.
In 2006, the U.S. Fish and Wildlife Service said that despite hundreds of millions of federal dollars spent over two decades, no technological solution had been found to dispose of drain water. Enormous amounts of salt and selenium - toxic to birds, other wildlife and humans at high concentrations - continue to accumulate each year.
Proposals have included a drain to carry the water to the Sacramento-San Joaquin River Delta. It was partly built but was shut down after the drain water killed and deformed thousands of internationally protected migratory birds in a 1983 disaster at the Kesterson National Wildlife Refuge.
Another plan, since scrapped, was to build a giant drain over the coastal range to Morro Bay in San Luis Obispo County. Other plans include concentrating the drain water in thousands of acres of evaporation ponds, which federal officials have warned would pose a lethal threat to wildlife.
The Fish and Wildlife Service concluded that the best solution is to "remove the fundamental underlying source of the problem" by retiring 379,000 acres of land from irrigation.
In 2008, the U.S. Geological Survey warned that within 50 years, 20 million tons of contaminated salt will have to be disposed of. The agency said experimental technologies are "unprecedented and untested at the scale needed" and that the "potential release of selenium-contaminated drainage is massive." The agency concluded that the best solution would be to retire 300,000 acres in the western San Joaquin Valley.