Bruce Howarth’s last day on the job at Alpaugh Irrigation District is April Fool’s Day, but one thing he doesn’t joke about is his admiration for the district and its landowners. “It’s the best job I’ve ever had,” he said. “I love working with farmers.” Howarth is retiring today after 12 years at the helm of the tiny district, which was founded in 1915 and covers about 10,000 acres on the far southwestern edge of Tulare County.  … Stepping in to fill the position is Mike Battles, who previously worked at Lower Tule River and Pixley irrigation districts. … Howarth said he will never forget the two thorniest issues of his tenure: high speed rail line; and the Sustainable Groundwater Management Act (SGMA).