The Southland’s biggest water agency painted a surprisingly upbeat picture Monday of the region’s water supplies. Although the Southland remains stuck in a severe drought, officials of the Metropolitan Water District of Southern California say they are rebuilding depleted storage reserves with imports from the north. They also dismissed concerns about slipping conservation efforts since state regulators eased urban water savings requirements in June. “I was very pleased that the numbers stayed as high as they did,” said Jeffrey Kightlinger, the district’s general manager.