The Trump administration is set to continue its dismantling of Obama-era environmental protections for the country’s waterways on Thursday, issuing new rules that remove federal protections for half the nation’s wetlands and hundreds of thousands of small waterways. Trump repealed Obama’s 2015 “Waters of the United States” regulation in September, a set of rules restricting dumping and development that affected the country’s rivers, streams, and wetlands. Now, the Trump administration is finalizing its own set of water rules that will, for the first time in decades, allow for pesticides and fertilizers to be dumped in waterways and open up wetlands to new development.

The Obama water rule was loathed by farmers, a crucial vote bank for Trump in 2020, as well as developers and the fossil fuel industry. It covered 60 percent of American waterways, including large waterways like the Chesapeake Bay or Mississippi River and smaller rivers and streams as well as seasonal waterways. Those protections limited, for example, the pollution runoff from fertilizers and pesticides from nearby farms, the dumping of industrial chemicals by extraction companies, and wanton development on real estate that affected nearby waterways. Golf course developers (like Trump) were vocal opponents of the Obama rule.

“Legal experts say that Mr. Trump’s replacement rule would go further than simply repealing and replacing the 2015 Obama rule—it would also eliminate protections to smaller headwaters that have been implemented for decades under the 1972 Clean Water Act,” according to the New York Times. “That could open millions of acres of pristine wetlands to pollution or destruction, and allow chemicals and other pollutants to be discharged into smaller headland waters that eventually drain into larger water bodies, experts in water management said. Wetlands play key roles in filtering surface water and protecting against floods, while also providing wildlife habitat.”

“I terminated one of the most ridiculous regulations of all: the last administration’s disastrous Waters of the United States rule,” Trump said last week during a speech at the American Farm Bureau Federation’s annual convention in Texas. “That was a rule that basically took your property away from you.”