Northwest of Manteca, where salmon struggle to survive in the San Joaquin River, farmers face challenges of their own.
Last week, growers in the southern Sacramento-San Joaquin Delta told of how their irrigation supplies have been harmed by exports to other parts of California.
They also complained about a new push by state regulators to question their right to use the water flowing through the delta.
"We are under attack, and it is a very serious attack," said John Herrick, a Stockton-based attorney working on behalf of the farmers.
He spoke to a group of Stanislaus County agricultural leaders who headed north on a tour organized by the county Farm Bureau.
It included a stop at the federal pumps that send some of the delta water southward. The pumping has been reduced to protect salmon and other fish, meaning sharp irrigation cutbacks in parts of the western and southern San Joaquin Valley.
About two-thirds of California's water supply flows through the delta, where the San Joaquin and Sacramento rivers join on their way to the Pacific Ocean.
More than a century of water exports have reduced the flows and made the delta vulnerable to salt water intruding from San Francisco Bay.
South delta farmers said their water is especially at risk because the San Joaquin River, already reduced by upstream diversions, does not have enough volume to dilute the salt.
They complained that the state and federal governments have promised more water to other farming regions than the delta is capable of supplying.
"We are suffering because there is not enough water to go around for everybody," said Mike Robinson, a farmer on Roberts Island in the south delta.
Jerry Robinson, another Roberts Island farmer, said the exports are hurting fish, too.
"We are kind of siding with the fish now, because we have so few friends in the delta," he said.
The tour showed how California water politics are not at all simple. It's not just farmer versus environmentalist, but sometimes farmer versus farmer.
Last week, federal water recipients learned that their supplies could be as little as 5 percent of the contracted amount this year.
"Five percent means more lands will be fallowed, more people will be out of work, and more businesses will fail," said a written statement from Tom Birmingham, general manager of the Westlands Water District, west of Fresno.
The delta, where 1,100 miles of levees protect islands made of fertile peat, was one of the first parts of California to be farmed in the 19th century.
Farmers there say their rights take precedence over parts of the state that got delta water much later, including the West Side of Stanislaus County.
The State Water Resources Control Board has ordered several delta farmers to show proof of their rights to draw water from the channels. The agency contends that it is just looking for excessive use, but the farmers see it as an effort to increase exports.
They also criticized the renewed push to build a canal or tunnel for the export water along the east side of the delta. They fear that this plan, once known as the Peripheral Canal, would leave the interior delta channels in even worse shape than today.
They support an alternative that would improve exiting channels so the San Joaquin River could flow better toward the bay and ocean. This would involve locks and other structures that allow better-quality water from the Sacramento River to flow more freely in the delta.
At the export pumping plant, the tour group got a look at efforts to protect salmon, smelt and other fish.
Since the 1950s, this has included the nearby Tracy Fish Collection Facility, designed to keep the critters from being sucked into the pumps. Federal employees capture the fish, load them into tanker trucks and release them several miles upstream on the San Joaquin and Sacramento rivers.
The success rate has dropped because striped bass and other predators have found this site to be easy feeding grounds, said Ron Silva, who helps oversee the effort for the U.S. Bureau of Reclamation.
Silva said the fish could be suffering from urban water pollution and poor ocean conditions, so reduced pumping is not the only answer.
Steve Larsen, an engineer who helps run the pumping plant, said fish continue to have trouble navigating delta channels that sometimes flow backward because of the exports.
"They don't have a GPS," he said. "They have a feeling to go with the flow."
Bee staff writer John Holland can be reached at firstname.lastname@example.org or 578-2385.