According to The Associated Press, the regulation is commonly referred to as WOTUS, the “waters of the United States” regulation, which defines what waterways qualify for protection under the Clean Water Act.

The action by the Environmental Protection Agency will reinstate a rule that was in place in 2015 while the administration creates a new rule sometime next year.

In June, the Biden administration publicly stated its intent to redefine the regulations and reinstate protections removed under Trump. Before they could, however, an Arizona federal judge removed Trump’s regulations and reinstated a 1986 standard.

The standard put in place by Arizona’s U.S. District Court Judge Rosemary Marquez was a midpoint between the Trump and Obama administrations, as the Obama administration’s standards protected about 60 percent of waterways in the country.

Marquez said the EPA, by not acting on the regulation sooner, was ignoring its findings in past studies that smaller waterways no longer protected under the Trump-era regulations can impact the health and ecosystem of the larger bodies of water they feed into.

Opponents of larger regulations of the nation’s waterways like home builders, oil and gas developers and farmers say the Obama-era definitions impacted waterways on private property, and could make their jobs more expensive and time-consuming to complete. However, environmental groups say strong federal protections are necessary to protect smaller, more vulnerable waterways from the pollution that could harm wildlife and the environment.

For more reporting from The Associated Press, see below.

The regulation has long been a point of contention among environmental groups, farmers, homebuilders, lawmakers and the courts.

The agency’s action Thursday formalizes steps it already has been taking since the court order.

The Trump-era rule resulted in an estimated 25 percent reduction in the number of streams and wetlands that are afforded federal protection, officials said.

Groups including the National Association of Home Builders and the American Farm Bureau Federation argued that the court should not have removed the Trump rule without deciding on the merits of legal challenges. The judge’s ruling in August “casts uncertainty over farmers and ranchers across the country and threatens the progress they’ve made to responsibly manage water and natural resources,″ the farm bureau said at the time.

An EPA spokesman declined to comment on the legal appeal.

In a statement, EPA Administrator Michael Regan acknowledged the uncertainty that has come to define the water rule. “The only constant with WOTUS has been change, creating a whiplash in how to best protect our waters in communities across America,” he said.

EPA spokesman Nick Conger said Thursday’s proposal included updates that reflect the latest science and Supreme Court rulings. The EPA also said long-standing clean water exemptions for farmers will continue.

Kelly Moser, an attorney for the Southern Environmental Law Center, which has pushed for stricter regulation, said the action shows that this administration is “serious about quickly returning to a mode of protecting the quality of the nation’s waters instead of dismantling them.”

The agencies will accept public comments on the proposal through late January.