WASHINGTON — A divided Supreme Court today upheld the broad power of federal environmental regulators to protect most wetlands from development, even in areas that are dry much of the year.
The decision by five justices dashed the hopes of private property advocates who believed that the more conservative court was ready to sharply cut back the reach of the Clean Water Act.
At issue was an estimated 300 million acres of sometimes swampy ground that includes half of Alaska and an area as large in California. Since the 1970s, the Army Corps of Engineers has said the owners of this land may not fill it or drain it without a permit.
Last year, the court voted to take up a property rights challenge to the broad reach of federal authority. It was brought on behalf of John Rapanos, a Michigan developer who was fined heavily after he had filled in wetlands on three farm fields that were about 20 miles from Lake Huron. After a heavy rain, water from these fields flowed into a drainage ditch, and from there to a tiny stream.
Rapanos acknowledged that federal authorities could prevent the pollution of "navigable" rivers, bays and lakes, but he maintained that they could not exercise control over inland wetlands like those on his fields.
Chief Justice John G. Roberts Jr. and Justice Samuel A. Alito Jr., both new to the court in the past year, agreed with Rapanos and joined an opinion by Justice Antonin Scalia. They argued that only wetlands that were connected to steadily flowing streams came under federal protection, an opinion that Justice Clarence Thomas also accepted.
This opinion would have stripped away federal protection from most wetlands that are well inland and nearly all those in the West because their streambeds are dry most of the year.
Justice Anthony M. Kennedy, a native of Sacramento, balked and wrote a separate opinion that essentially upheld the broad reach of the law. He cited the Los Angeles River and other streams in the West that send "torrents thundering" downstream, but only for short periods of the year.
Kennedy said Scalia's opinion was "unduly dismissive" of the importance of wetlands and was "inconsistent with the text, structure and purpose" of the Clean Water Act. This measure was passed a few years after an oil slick on the Cuyahoga River in Cleveland caught fire in 1969, an embarrassment that focused the nation's attention on polluted water.
Afterward, Congress sought to clean up the "waters of the United States" by giving federal regulators broad authority to stop pollution at its source. A few years later, the Army Corps of Engineers said wetlands helped filter pollution from water and lessen the impact of flooding.
Kennedy said federal authority did not extend to isolated wetlands whose filling would have no effect on "downstream water quality." However, if environmental regulators could show that dredging or filling a wetland could "significantly affect" the waters downstream, they could protect it from development.
Until today, federal regulators — including the Bush administration — said wetlands were under federal jurisdiction if a single drop of water could flow from them to the sea. Lower federal courts for Michigan upheld the government's fine of Rapanos based on that theory.
Kennedy voted with his conservative colleagues to overturn the trial court's initial ruling and give the court an opportunity to reconsider the issue. As guidance, he also said there appeared to be evidence that filling the fields on Rapanos' land had an effect on downstream waters.
He described his view of the law as being closer to the interpretation of the court's four liberals — who said they would have upheld without question the broad reach of the Clean Water Act — than that of the four conservatives.
The court's 4-1-4 split left activists on both sides of the issue a bit unsure about the future.
Several environmentalists expressed relief. "Today, five justices of the Supreme Court wrote or joined opinions that support broad protection of rivers, streams and wetlands," said Doug Kendall, executive director of the Community Rights Counsel.
The National Resources Defense Council said it was pleased the court "rejected an attempt by the court's conservative wing to dramatically roll back" a key environmental measure. But it also said the outcome "muddies the water" because it will force more legal battles over which wetlands are protected.
The Pacific Legal Foundation, which represented Rapanos, said it was pleased the court had "rejected unlimited federal control" of wetlands.
"It is not the role of the federal government to micromanage every pond, puddle and ditch in our country," said Reed Hopper, a lawyer for the foundation.