Climate change adds twist to river restoration

The best hope for cold-water chinook salmon to survive global warming may be near sweltering Fresno, Calif. -- in the San Joaquin River, where salmon have been extinct for 60 years.

That's the latest twist in the long-running debate over restoring the San Joaquin, a project that will begin in less than 18 months.

Farmers, forced by legal settlement to give up irrigation water for the project, are skeptical about the claim. They see global warming as a reason to reconsider the half-billion-dollar restoration. Warmer conditions will kill the restored fish runs, they say.

But fishery experts say San Joaquin salmon would tolerate climate warming better than salmon in cooler places, such as Northern California.

The reason: The highest of the High Sierra would continue to provide the cold water that salmon must have to survive in the San Joaquin. Northern California has the lower end of the Sierra and, scientists predict, eventually won't have much of a snowpack, eliminating a lot of cold water.

"The restored San Joaquin may be an important place for the survival of salmon in the next century," said fishery biologist Peter Moyle of the University of California-Davis.

The back-and-forth over restoring the river has been unfolding for decades, with debate focused mostly on a troubled, 149-mile section of the San Joaquin between Fresno and its confluence with the Merced River.

Global warming came into the picture last year when a report from a worldwide panel of experts said about 40 percent of the salmon habitat in the Pacific Northwest could be lost during climate change.

If the San Joaquin is revived, as is planned over the next decade, it would have the southernmost salmon fishery in North America.

And the San Joaquin Valley is expected to warm up faster than the Pacific Northwest or Northern California.

This prompts some farmers to question the wisdom of trying to return salmon to the San Joaquin.

"Does it really make sense to spend this money and restore salmon down here?" asked Chowchilla-area farmer Kole Upton.

But Moyle, an authority on California's native fish, said it is a very good idea for spring-run salmon. The fish will move up the river from the ocean in spring and spend summer in deep, cool ponds near Friant Dam before spawning during fall.

The release of cold snowmelt from Millerton Lake in summer should keep the ponds cool enough for salmon even as the climate warms up, Moyle said.

The undercurrent of this discussion is political, as it has been all along.

Farmers agreed in 2006 to cooperate in the restoration only because they were losing a marathon lawsuit over the issue. They remain worried about the $2.5 billion agriculture economy that the river helped to create on the Valley's east side.

Now, they're committed to give up an average of 19 percent of their river water each year to reconnect the San Joaquin with the Sacramento-San Joaquin River Delta.

Some of the water losses will begin next year. The first salmon are supposed to be in the river by the end of 2012.

Congress continues to work on a bill to fund about $500 million of the restoration. Much of the money is needed to rebuild the river channel for better flows that will help fish.

Farm officials have long doubted whether salmon could be restored on the San Joaquin. General manager Doug Welch of the Chowchilla Water District was involved in river studies several years ago. He said the restored salmon runs may not live long enough to experience global warming later in the century.

"The temperature will not be suitable for salmon," he said. "It will just get too warm when you get downstream."

Knowing there is a gloomy forecast for cold-water fish, such as salmon and steelhead, the restoration now looks like an even worse investment to many farmers.

But they don't speak publicly about it, saying privately that they fear they will trigger a movement to dissolve the 2006 settlement.

They do not want to see a federal judge decide how much water they must give up.

Upton, a Chowchilla district board member and a former negotiator in the settlement, has lost faith in the agreement. He does not fear the prospect of going back to court. Global warming plays a part in his thinking.

"I'm very concerned about investing in bringing back these fish if we're just going to lose them later on," Upton said. "As a society, we need to consider the best way to invest this money. That's something we need to talk about."

(Distributed by Scripps Howard News Service, www.scrippsnews.com.)