San Luis Obispo County and a coalition of environmental groups are fighting over the appropriate amount of water to release from Lopez Dam to support an endangered fish without jeopardizing the drinking water supply. In December, U.S. District Court Judge Sherilyn Peace Garnett ordered the county to release more water from Lopez Dam to support steelhead trout migration through Arroyo Grande Creek. The county appealed the decision, arguing that the court-ordered water release schedule would drain Lopez Lake during a drought — preventing the county from delivering drinking water to South County.