Farmers and rural residents told California regulators they’re concerned about a proposal to increase water flows in the San Joaquin River and its tributaries to protect threatened fish. Native fish populations in the system have been declining for decades.The river system is part of the Sacramento-San Joaquin Delta, which provides water to Central Valley farms and millions of Californians. Regulators say currently up to 70 percent of the water is diverted. J.D. Richey, a Delta fishing guide, says his industry is collapsing.