The Trump administration has finalized environmental rules that undo an expansion of environmental protection for U.S. waterways enacted by the Obama administration in 2015.

President Donald Trump began the process with an executive order not long after taking office.

The new rules stand to benefit real estate developers, since it will now be easier to fill in creeks, streams and other small waterways for development. Golf course developers in particular were among the key opponents of the old rules, The New York Times reports, though hardly the only ones.

Farmers and other property owners also objected to the expanded rules, and 28 states sought and received injunctions in various federal courts to block their enforcement, the American Bar Association reports.

At issue is the definition of Waters of the United States under the Clean Water Act. Until 2015, those waters were generally taken to mean rivers, lakes and other major bodies.

The Obama administration directed the Environmental Protection Agency and the Army Corps of Engineers to expand the definition. Under the 2015 interpretation, Waters of the United States also included small tributaries of larger rivers, even ditches in some cases, as well as bodies of water with 1,500 feet of waters covered by the rule, vastly enlarging the waterways under EPA regulation.

The Trump administration directed the EPA and the corps to rewrite the rules again, with a goal of generally going back to the pre-2015 definitions.

Environmental groups criticized the rollback, as did some other organizations, even a few with connections to the real estate industry. The repeal is the first step in rolling back clean water protections on a much larger scale, said Shawn Kelly, president of the American Society of Landscape Architects.

The change in federal policy isn't stopping some states from regulating waters within their borders. Fewer than half the states have wetlands permitting programs, the ABA reports, but some of those are robust, such as in Wisconsin or Minnesota, and last year, California defined wetlands in the state for the purpose of discharging dredge or fill material into them.

Other states are considering further regulatory action. The Arizona Department of Environmental Quality, for example, is reviewing its options for a Waters of Arizona policy.