Cadiz Inc., which for decades has sought the federal government’s green light to pump groundwater from the Mojave Desert and pipe it to Southern California, has seen the project’s prospects brighten under the Trump administration. In April, a potential backer of the project was nominated by President Donald Trump to a high-ranking Interior Department post. In late March, the department’s Bureau of Land Management rescinded two legal directives the Obama administration used in a 2015 decision to block Cadiz from building the 43-mile pipeline.