A federal court ruling ruled last week that four dams on the lower Snake River in southeastern Washington state must comply with the Clean Water Act, a move that enviros hope will give a boost to their fight to breach the dams in order to help restore salmon runs. The ruling stemmed from a lawsuit filed in March 1999 by environmental groups that accused the U.S. Army Corps of Engineers of violating the act by operating dams in a way that raises the river’s temperature and its levels of dissolved oxygen. The judge agreed that the corps must abide by the act and has now given the agency three months to prove that the dams are in compliance. If the court finds that the corps is violating the Clean Water Act, which enviros believe is likely, the corps might have to spend from $460 million to $900 million to make changes to the dams (unless, of course, the dams come down).