The Biden administration finalized a rule to increase protection for small streams, wetlands and other waterways across the country. The move reverses a Trump-era regulation that federal courts threw out over fear of pollution.

The policy adds definitions to what constitutes “waters of the United States” that are protected by the 1970 Clean Water Act, reestablishing regulations set under the Obama administration. The Trump administration rolled back the regulations.

Republicans warned that the new rule, which the Environmental Protection Agency and the U.S. Army Corps of Engineers signed off on last week, would be overreaching for private property owners because federal protection could apply to minor waterways such as gullies, creeks and ravines.

“This is a step in the wrong direction from the Biden administration, and it infringes on the rights of Montana farmers, ranchers and landowners,” said Sen. Steve Daines, Montana Republican. “This overreaching rule threatens Montana ag and natural resources and is unacceptable.”

The protection was originally rolled back under former President Donald Trump at the urging of farmers, land developers, and the oil and natural gas industry. They argued the federal protection would create environmental obstacles.

Green advocates, meanwhile, said the lack of protection would allow for the destruction of natural habitats, with larger implications for surrounding communities.

U.S. District Court Judge Rosemary Marquez of Arizona, an Obama appointee, in 2021 threw out Mr. Trump’s rule because she said it failed to consider the pollution that small waterways could feed into larger ones. She split the difference and instituted a new rule.

However, the uncertainty over which waterways are protected by the federal government may continue.

A separate case is making its way through the Supreme Court featuring an Idaho couple who have been prevented by the EPA since 2007 from building a home near a lake because the agency says protected wetlands are on their property nearby.

The EPA said its new regulation establishes a “durable definition” that it believes will be able to survive the test of time, including legal challenges.

“The rule returns to a reasonable and familiar framework founded on the pre-[Obama-era] definition with updates to reflect existing Supreme Court decisions, the latest science and the agencies’ technical expertise,” the department said. “It establishes limits that appropriately draw the boundary of waters subject to federal protection.”

Sen. Shelley Moore Capito of West Virginia, the top Republican on the Senate Environment and Public Works Committee, argued the new rule will have the adverse effect and will “move us backwards by making more projects subject to federal permitting requirements and adding more bureaucratic red tape.”