Responding to a lawsuit by an Indian tribe, government lawyers said Monday that officials properly approved a 10-square mile solar farm to power San Diego and asked a judge not to stop the project. The Quechan Indian tribe has sued in San Diego federal court to stop the Imperial Valley Solar project, which would provide 709 megawatts to San Diego Gas & Electric if fully built. The tribe said that the environmental reviews of the project didn't fully consider the impact on artifacts and sacred sites. But in a filing with the court, lawyers for the Department of Interior said officials did what was required of them and a judge can't second-guess those decisions unless they were "arbitrary and capricious."