San Francisco Chronicle: By growing less thirsty crops and investing in more efficient irrigation technology, California farmers could save billions of gallons of water each year – the equivalent of 3 dams to 20 dams, according to a controversial new report by an influential water policy think tank. In a study to be released Monday, researchers at Oakland’s Pacific Institute say that before Californians take on costly new dam and reservoir projects, state and federal policymakers need to build on existing …