…. Southern California has done a great job saving water — so good a job that it’s now facing a budget deficit. The Metropolitan Water District, the state’s largest water supplier, is considering double-digit rate increases after its 19 million customers saved so much water over the past two years that sales dropped to their lowest levels since the 1970s. … The problem has been building for decades but became urgent over the past two years when water sales came in 11 and then 24 percent less than forecast. At the same time, inflation drove up costs. While the district has chosen to dip into its reserves in the past to avoid large rate increases, Met General Manager Adel Hagekhalil argued that’s not enough anymore in light of increasing extreme weather swings.