He’s sort of working and sort of using up the last of his vacation time, but it’s official that Tom Mosby, Montecito Water District’s general manager, is retiring on November 2. He’s already cleared his desk, he says, but he’ll still be available via email and phone as his staff continues the district’s day-to-day while looking for a replacement. “I’m trying to phase myself out,” said Mosby, 63, who started with the district on November 1, 1990, during the worst of the region’s previous big drought. He was promoted to general manager in 2007. “After these past couple years, I don’t know how to have fun anymore,” he said, referring to the intense job stress associated with conserving and supplying water to a district that — during the worst drought in California history — is 95-percent reliant on surface water. “It’s been a struggle, but we have been successful in purchasing supplemental water.”