WASHINGTON, D.C.: It was the stamp of vindication that private property owners had long awaited in their battle over a key environmental law. In a unanimous decision, the Supreme Court ruled that people who claim to have suffered economic harm may use the Endangered Species Act to file lawsuits accusing the federal government of doing too much to protect some species. The ruling is sure to affect the hundreds of ongoing environmental disputes nationwide. It came as a defeat for the Clinton administration, which until now had been successful in lower court decisions seeking a "one-way" interpretation of the law, in which only environmentalists could use the act to sue for greater protection of wildlife. Justice Antonin Scalia wrote in the court opinion that the Endangered Species Act's citizen-suit provision should allow people to sue the government for overprotection as well. In the 1992 case before the court, cattle ranchers and farmers in Oregon had sued to recover some $75 million in damages after the government cut off water to farms and ranches during a drought to help preserve two endangered species of fish downstream. Farmers watched their crops die, and ranchers were forced to sell cattle they couldn't feed. The case will now head back to the lower court for reconsideration.