“If you look at a watershed, particularly in the Southwest, you have all these tributaries and ephemeral streams that are linked together like capillaries,” Mr. Gillespie said. “And the Trump rule hurt all of us, because we are all downstream from those waters. The Trump rule was very extreme in eliminating protections on waters.”
Farming and construction groups are weighing an appeal.
“This ruling casts uncertainty over farmers and ranchers across the country and threatens the progress they’ve made to responsibly manage water and natural resources,” said Zippy Duvall, president of the American Farm Bureau Federation. “We are reviewing the ruling to determine our next course of action.”
Kerry Lynch, a spokeswoman for the National Stone, Sand and Gravel Association, said her group was disappointed by the ruling and was “evaluating the court’s decision at this time.”
The Trump rule was a revision of an earlier rule promulgated by the Obama administration in 2015, known as Waters of the United States. That rule used the authority of the 1972 Clean Water Act to protect about 60 percent of the nation’s waterways, including large bodies of water such as the Chesapeake Bay, the Mississippi River and the Puget Sound, as well as smaller headwaters, wetlands, seasonal streams and streams that run temporarily underground.
Mr. Trump repealed the policy in 2019, calling it “one of the most ridiculous regulations of all” and claiming that his repeal caused farmers to weep in gratitude. One year later, the E.P.A. finalized his replacement policy, known as the Navigable Waters Protection Rule, which removed protections for more than half the nation’s wetlands and hundreds of thousands of miles of upland streams by narrowing the definition of what constitutes a “water of the United States” that merits federal protection.
With both the Trump and Obama rules off the books, the nation’s waters are now protected by a 1986 rule, which environmentalists, farmers and developers alike have bemoaned as so contradictory and poorly written that it resulted in thousands of legal disputes over water pollution that dragged on for years.
“It was horribly confusing,” Mark Ryan, a former E.P.A. lawyer, said. “It required a very complicated, time-consuming process” to determine whether bodies of water qualified for federal protection from pollution.
This summer, Michael S. Regan, the E.P.A. administrator, announced plans to begin crafting a new water protection rule that could be completed by next year.