Congress enacted the law to `restore and maintain the chemical, physical, and biological integrity of the Nation's waters,' 33 U.S.C. 1251(a), and it pursued that objective by restricting dumping and filling in `navigable waters,' sections 1311(a), 1362(12).???Id. at 779. ???Justice Kennedy concluded that the term ???waters of the United States??? encompasses wetlands and other waters that ???poss