IN 1972, the United States Congress passed the historic Clean Water Act to protect federal waters from pollution. Among other provisions, the law subjected the nation's navigable waterways to the stewardship of the US Army Corps of Engineers, requiring those who wished to dump materials into these waters and their tributaries to obtain a Corps permit.Almost 20 years later, the federal government has declared control over millions of acres of private land - without a single act of Congress. Through a series of federal court rulings, an obscure section of the Clean Water Act has become a powerful instrument for regulating "wetlands," whose definition by some estimates covers more than 60 percent of the US. The once-reasonable permit system has become a threat to private property rights. The strange odyssey of the Clean Water Act began in 1975, when a federal court ruled that Section 404 of the law, which protected navigable waters, in fact also covered non-navigable waters including wetlands, although "wetlands" are never mentioned in the Act. Previously, the Corps of Engineers had limited its jurisdiction to traditionally designated navigable waters, which are subject to federal regulation under the Commerce Clause of the Constitution. The new ruling ordered the Corps to enforce the law to the fullest extent permissible under the court's expanded interpretation. On its face, the decision was not unreasonable; in 1972, Congress used a modified definition of navigable waters that was intended to include tributaries of those waters in order to prevent upstream pollution. But instead of merely extending its regulatory powers to such tributaries, the Corps assumed the authority to restrict the use of almost any body of water. Among those areas under its jurisdiction, the Corps listed "interstate wetlands," and "wetlands adjacent" to navigable waters. The Corps also used the Commerce Clause to rationalize its new powers. It now claimed the right to regulate "wetlands ... the use, degradation, or destruction of which could affect interstate or foreign commerce...." Along with the Supreme Court's interpretation of the Commerce Clause to extend over virtually any economic activity, this implicitly removed all limits to the scope of the Corps' enforcement authority. In the following years, the Corps' new regulatory scheme was repeatedly upheld by federal courts, despite its tenuous basis in law. The courts also upheld the Corps' Commerce Clause authority over private wetlands. In 1978 a federal court ruled that salt ponds could be regulated because the salt produced was sold in interstate and foreign commerce. In 1979 a federal court ruled that a wetland adjacent to a lake used by interstate travelers could be regulated, and another court, with mind-bending logic, r uled that a stream could be regulated which flowed into a reservoir whose water was used for agricultural irrigation where the resulting products were sold in interstate commerce. Although the Corps had firmly established jurisdiction over almost all "wetlands," to the chagrin of environmentalists, it took a relatively restrained approach to enforcement. Congress gave the Environmental Protection Agency (EPA) the right to veto any Corps permit, but both agencies restricted their powers to lands that fit the conventional image of a swamp and rarely denied permits. During the 1980s, pressure from environmentalists grew, and in the final years of the Reagan administration, the EPA began to change its policy, vetoing two dozen Corps permits and preventing the construction of a shopping mall. Then, in 1988, George Bush made his now-famous campaign pledge of "no net loss" of US wetlands. Only days after he took office, the administration issued a "wetlands delineation manual" that finally provided the Corps and EPA with strict wetlands definitions: Any land in which mo isture rises to within 18 inches of the surface during at least one week per year would qualify as a wetland. The Corps and EPA had suddenly attained control over vast areas of private land, with almost no basis in law. When William Laffer, a former attorney for the Department of Justice (now at the Heritage Foundation), studied the legal foundations of the federal wetlands program, he was shocked to find that it has no statutory authority at all. "Legislation is supposed to be enacted by Congress and presented to the president before becoming law. However, the Corps and the EPA have actively circumvented the Constitution's requirements," says Laffer. "They have been treating the Clean Water Act as a convenient vehicle by which to provide the wetlands preservation program Congress never enacted." Today, as Congress and the president battle over the definition of wetlands, the disturbing story of the program's origins seems to have been forgotten. But the millions of bewildered property owners whose financial future may hang in the balance should take notice: Government "by the people" can easily disappear in our swampy environmental bureaucracy.