Since the new rules came into effect last June, the Army Corps has assessed more than 40,000 wetlands, streams, and other water elements that have potential development impacts. The agency found that only 24% of U.S. environmental laws qualify for protection, said Doug Garman, an Army Corps spokesman in Washington.

Garman said comparable data prior to the rule change was not readily available. However, an online database maintained by the Environmental Protection Agency shows that 42% of the bodies of water and water elements assessed by the Army Corps since August 2015 met the criteria for federal protection under the earlier regulations.

President Joe Biden’s administration has ordered a review of Trump’s rule changes and could reverse them. However, some conservation groups fear this would take too long and hope that Trump’s rollbacks will be lifted by a judge.

“It’s having an impact across the country,” said Kelly Moser, a Southern Environmental Law Center attorney who challenged the rollbacks in the US District Court in South Carolina. “With these types of waters losing their protection, there is no time to lose.”

The Okefenokee National Wildlife Refuge covers nearly 1,630 square kilometers in southeast Georgia and is home to alligators, bald eagles, and other protected species. The swamp’s wildlife, cypress forests, and flooded prairies draw about 600,000 visitors each year, according to the US Fish and Wildlife Service, which manages the refuge.