The Obama administration has found itself in a public brawl with farmers over a proposed rule that would more precisely define what land the Clean Water Act regulates.

A diverse group of business interests, including mining companies and developers, even golf courses, also oppose the rule the administration issued this spring, but the farm lobby, led by the American Farm Bureau Federation, has taken the most public role in trying to persuade Congress to stop the regulation from taking effect.

The other sectors “are more than happy to have the Farm Bureau be the loudest voice,” said Jon Devine, a senior attorney with the Natural Resources Defense Council.

“The irony is that agriculture is the least regulated sector of discharges that I can think of under the Clean Water Act. It enjoys exemptions that many industries would be very happy to have.”

Thirty-five House Democrats, mostly from rural districts, joined Republicans Tuesday in passing a bill sponsored by Steve Southerland II, R-Fla., that would kill the rule and make it nearly impossible for the administration to propose an alternative. The 262-152 margin isn’t veto proof, but the vote sets up a battle over the issue in the next Congress, when Republicans could be in control of the Senate. Two fiscal 2015 appropriations bills pending in the House include riders to block the rule from being finalized.

“We’re shouting pretty loud right now. I don’t regret it,” said Don Parrish, a policy analyst for the Farm Bureau that mounted a “Ditch the Rule” lobbying campaign against the proposed regulation. The title refers to the Farm Bureau’s contention that the rule would significantly expand the Environmental Protection Agency’s jurisdiction regulation of ordinary landscape features, such as ditches, that might hold water. The Farm Bureau and allies in the livestock industry also are working to stir up grass-roots opposition to the rule by posting interactive maps that purportedly allow landowners to tell what parts of their land would be newly regulated.

The rule, issued this spring by the EPA and the Army Corps of Engineers, responded to a pair of Supreme Court rulings that left unanswered questions about what constitutes “waters of the United States” that are subject to regulation under the Clean Water Act (PL 95-217). Administration officials say decisions on jurisdiction are now often made on a case-by-case basis, and vary by region. They had to act to clarify the law’s jurisdiction, they say, because Congress hadn’t.

The law, enacted 42 years ago to clean up polluted waterways, required states to set water standards. It contains various sections restricting the discharge of sewage and industrial waste, the application of pesticides and earthmoving operations.

Along with releasing the proposed rule, the agencies also joined the Department of Agriculture in immediately implementing a separate interpretive rule that defines 56 agricultural and conservation practices that would be exempted from having to apply for Section 404 permits for activities that involve what’s considered dredged or fill material. Mines and construction projects typically require such approvals.

The administration says the proposed rule would provide certainty to landowners about what gullies, ditches, ponds and wetlands are under the law’s jurisdiction because they have a “significant nexus” with rivers downstream. The rule would increase the amount of land the agencies currently regulate by 3 percent, or 1,500 acres, according to the economic analysis.

In speeches and documents, EPA officials have countered what they say are absurd accusations that the rule would extend the pollution law’s reach to “puddles on your lawn.”

The rule was pitched as a way to assure farmers they wouldn’t face any new regulation — but if the idea was to head off an attack from the farm lobby, it didn’t work. EPA Administrator Gina McCarthy was caught by surprise, she said, when farm groups objected that the interpretive rule would effectively require them to comply with what have been voluntary standards for everything from building terraces and fences to managing forage crops.

Environmentalists and sporting groups aren’t happy with the list either, saying there are practices that shouldn’t be included. They have also complained they weren’t consulted before it was released.

Some conservationists also don’t think the proposed rule goes far enough in defining what’s covered by the Clean Water Act. Ducks Unlimited, which works to protect waterfowl habitat for the benefit of hunters, says the rule would leave wetlands in the Dakotas unprotected if they aren’t in a flood plain or near a river.

EPA officials extended the comment period on the proposed rule until Oct. 20 and have suggested in various public appearances that both the proposed rule and interpretive rule are likely to be revised. A top agency official conceded to a corn growers group in July that the proposed rule had created “bona fide, bona fide confusion.”

Still, the pressure on the agency hasn’t abated.

The National Farmers Union, a smaller Farm Bureau rival that has traditionally leaned more Democratic, initially supported the proposed rule, but later demanded the agency clarify what it’s supposed to cover. In a letter to McCarthy, the NFU said the proposed rule “has created less clarity, not more as was intended.” Failing to address the “confusion and anxiety” around the issue “will lead to more resentment in rural America,” the group warned.

The top Democrat on the House Agriculture Committee, Collin C. Peterson of Minnesota, expressed confidence that the rule won’t get finalized for some time, and not before it’s overhauled by the administration.

“They clearly don’t understand how this works in the real world,” said Peterson, one of the 35 Democrats who voted for Southerland’s bill. “If they don’t re-write it we’re going to have to try to re-write it for them. “