In early January, the U.S. Supreme Court limited the scope of the federal Clean Water Act, effectively telling a federal agency it cannot subjectively expand its mission. Hallelujah. It's about time mission creep got checkmated. In essence, the court told the U.S. Army Corps of Engineers to shut up, pull up stakes and get back on the river. Trouble is, the process took 16 years and $40 million.

The whole thing started in 1985 when 23 Chicago-area towns and villages tried to develop a disposal site for "baled, nonhazardous solid waste"--a garbage dump, in normal terms, and a clean one at that, even by today's rigid standards. The 23 towns formed a single coalition to locate and establish a dump. They found 533 acres that had previously been a sand and gravel mining operation. It had stopped operating in the early 1960s. The pits had filled with water, some a few inches deep, others up to 13 feet.

The group checked with state officials, filed paperwork and bought the property for $5 million. Everything was kosher. Even the U.S. Army Corps of Engineers thought so. The corps said it had no jurisdiction because the site had no wetlands and did not support vegetation "adapted for life in saturated soil conditions."

But then the clean-hands, green-tongue, big-wallet crowd got involved. They'd seen migratory birds on those abandoned gravel pits. The corps got a not-so-subtle nudge. And as we've come to expect, political pressure caused a federal entity to change course. The corps asserted jurisdiction, halted the project and claimed violation of the Clean Water Act.

With the move, the corps ventured into new territory by claiming jurisdiction over select man-made ponds. For cover, they used the Migratory Bird Rule, a 1986 revision of the Clean Water Act extending protection to habitat for migratory birds.

Still, the Chicago suburbanites weren't dissuaded. They proceeded to lay out solutions to keep migratory birds on the property. Their efforts were enough to garner all necessary approvals by local and state officials, even the state conservation department. But not the corps. They stuck to their ducks.

Get a grip, said the suburbanites. "It's an abandoned gravel pit," a mayor said. He was a good interview, describing himself as an environmentalist. "It's not like we're going into some pristine forest--that we're going to rape the environment to bury garbage."

The Supreme Court agreed, nullifying the corps' logic, noting that "we find nothing approaching a clear statement from Congress that it intended [the Clean Water Act] to reach an abandoned sand and gravel pit such as we have here."

If the court had upheld the corps' argument, the impact on agriculture could have been stunning, considering livestock ponds, irrigation ponds, watering troughs and other bodies of water that could have been subject to governmental control.

To their credit, at the last minute public officials turned away pleas from the Sierra Club and the Nature Conservancy to drop the litigation, pleas that came only after environmentalists realized they had overreached. The suit was not about turning back environmental laws, the public officials argued. It was about local control and common sense, they maintained. Sound familiar?

It should. It's agriculture's predicament in a nutshell. Mission creep accounts for the Environmental Protection Agency's new-found prominence in agriculture, in the Fish and Wildlife Service's role in the Missouri River basin. State agencies have the same proclivities. It's about time mission creep was stopped. Governmental agencies should be circumscribed by original intent, not used to further the current majority's popular cause.