Before throngs of TV news cameras in April last year, Gov. Jerry Brown stood on a patch of bare Sierra dirt that should have been covered in snow and told Californians they had to be unified in conserving water.

Noting that his call for voluntary conservation had not resulted in a significant change in habits among urban and suburban residents the previous summer, Brown said that he had no choice but to order urban water providers to collectively reduce water use by 25 percent compared with 2013. “We’re in an historic drought,” Brown said. “And that demands unprecedented action.”