President Donald Trump’s administration is moving to slash federal protections for the nation’s wetlands and streams, potentially leaving millions of acres of habitat in Illinois and the Midwest vulnerable to being dug up, filled in or paved over.
At the heart of the proposal announced earlier this week is a new, stricter definition to the long-debated legal term, “Waters of the United States,” the federal guidance that determines which bodies of water are protected under the 1972 Clean Water Act.
The proposal codifies a 2023 Supreme Court decision that limited federal protection to wetlands indistinguishable from larger, relatively permanent bodies of water like streams, rivers and lakes. Effectively, the new definition excludes seasonal streams and wetlands, which remain dry for much of the year.
Environmental Protection Agency Administrator Lee Zeldin defended the move in a statement, arguing it “protects the nation’s navigable waters from pollution, advances cooperative federalism by empowering states, and will result in economic growth across the country.”
Agricultural, chemical and mining industry groups celebrated the EPA’s push to curb federal water regulations, citing regulatory uncertainty that made it hard to do business.
“The Supreme Court clearly ruled several years ago that the government overreached in its interpretation of what fell under federal guidelines,” read a statement from American Farm Bureau Federation President Zippy Duval. “We are still reviewing the entire rule, but we are pleased that it finally addresses those concerns and takes steps to provide much-needed clarity.”
Wetlands are crucial ecosystems that filter drinking water, mitigate flooding and provide habitat for millions of species — roughly 40% of all plants and animals rely on wetlands for some part of their lifecycle.
Losing wetlands is also detrimental to efforts to combat climate change, as they help prevent flooding and store carbon dioxide. Inland wetlands, which account for about 6% of the Earth’s land surface, are estimated to hold about 30% of the world’s soil carbon.
Illinois’ wetlands alone provide $419 million worth of residential flood protection annually, according to the University of Illinois Urbana Champaign.
Nationally, the picture is bleak.
“We’re looking at up to 85% of the country’s wetlands losing their protected status under the Clean Water Act,” said Andrew Wetzler, the Natural Resources Defense Council’s senior vice president for nature.
A 2025 analysis from the nonprofit environmental group found that, at minimum, more than 70 million acres of wetlands are at risk.
Under the current regulations, developers must obtain a permit from the Army Corps of Engineers before destroying a wetland to ensure environmentally responsible practices.
The new regulations will eliminate the need for a federal permit to build over wetlands, allowing developers to act with minimal environmental oversight, according to Weltzer.
Since the Supreme Court decision gutted federal protections for wetlands, states like Colorado have passed their own laws to safeguard their endangered ecosystems. Illinois lawmakers have attempted to introduce similar legislation, but have yet to succeed.
Illinois, once home to more than 8 million acres of wetlands, has already lost about 90% of that terrain to agriculture, development and urbanization.
“The vast majority of Illinois wetlands do not have federal protection,” said Robert Hirschfeld, director of water policy at the Prairie Rivers Network. “The loss of the federal Clean Water Act means it is open season on wetlands.”
A recent study from the University of Illinois Urbana-Champaign found that slashing the wetland protection could endanger the vast majority of the state’s dwindling wetlands.
“We determined that about 72% of Illinois wetlands, which is about 700,000 acres, no longer meet that criteria for continuous surface connection to relatively permanent waters in Illinois,” said Chelsea Peterson, a Ph.D. candidate in wetland ecology at the University of Illinois and a lead author of the study. “So they are not protected by the Clean Water Act.”
That figure could get higher depending on how regulators hash out wetness requirements. “The next best estimate is 90%,” she said.
The EPA has opened a 45-day comment period on the proposed change. Comments are due by Jan. 5.
