Energy & Environment

How the Supreme Court’s wetlands ruling could impact pollution, flooding

A Great White Heron looks for food in the marsh at Orlando Wetlands Park in Christmas, Florida, on March 1, 2023.

The Supreme Court’s decision to curb federal regulations for wetlands could have far-reaching implications for America’s water.

The ruling is expected to open the nation up to more water pollution, experts say. And not only that: They say it could also make the country more vulnerable to floods.

The court Thursday narrowed the federal government’s authority to regulate wetlands, saying it only has jurisdiction over those that have a “continuous surface connection” with other regulated waters such as lakes or rivers.

In practice, this will mean that wetlands that don’t meet this definition will be open to development, unless they are in a state that has its own requirements. 

“People will no longer need a permit to fill the wetlands,” Mark Ryan, a former Clean Water Act litigation specialist at the Environmental Protection Agency (EPA), told The Hill on Thursday. 


“If you’re a developer and you buy a piece of farmland that had a bunch of wetlands on it that weren’t right next to the river … you could just go out and start filling those wetlands now. You don’t need a permit unless the state requires it,” Ryan said. 

A significant number of wetlands are expected to be impacted by the ruling. 

The Trump administration previously sought to cut back protections for wetlands, making changes an analysis obtained by E&E News found were expected to leave 51 percent of the nation’s wetlands unprotected. 

Sam Sankar, vice president of programs at Earthjustice, said the Supreme Court’s decision narrows the field even further than the Trump rule did, and it is expected to leave more wetlands open to unrestricted dumping and development. 

“The Trump administration’s rule covered more areas than the court’s opinion does,” Sankar said, adding that this means even more wetlands are likely to be affected. 

Scientists say the potential loss of more wetlands as a result of the decision could lead to more water pollution and more floods. 

Gary Lamberti, a professor of aquatic science at the University of Notre Dame, described wetlands as “the kidneys of the landscape.”

“These wetlands are sort of microbial pumps,” he said. “They have their own microbes in them and microbes, bacteria and other types of small organisms are incredibly efficient at removing and detoxifying and then converting some of these nutrients and other contaminants that enter with the water.”

He noted that even if a wetland itself is not directly touching a river or a lake, it may be connected to groundwater that is. 

“That groundwater that then spreads from below that wetland and sort of percolates and infiltrates long distances becomes water supplies,” he said, noting that pollution spread in this way could have particular impacts for rural people who drink well water. 

Curtis Richardson, director of the Duke University Wetland Center, noted that when these natural filters are removed, that can result in high costs to treat the water, which can fall on the taxpayer. 

“Every place we remove them, we’ve ended up having to spend millions of dollars on treatment plants or have polluted water,” he said. 

Wetlands can also prevent flooding, and filling them in could limit their ability to carry out this function. 

“Wetlands basically operate like a sponge,” said Summer Modelfino, strategy director at the American Flood Coalition. 

“During a storm, they can absorb and store huge quantities of water and prevent it from flowing downstream and making flooding worse for communities.”

She pointed to figures from a 2008 study that found coastal wetlands were providing $23.2 billion worth of storm protection services. 

Richardson, meanwhile, pointed to the floods that Houston faced during Hurricane Harvey, saying they were exacerbated by prior wetland removal.

“When Houston was flooded with the last major hurricane, one of the reasons they were in such trouble is the city allowed all the storage wetlands to be filled in and built on, and they had no storage capacity,” he said. 

The issue is also expected to be compounded by climate change, which could exacerbate flooding.

“You’re going to exacerbate flooding because … climate change is contributing to that already.  And by not protecting these wetlands and taking them off the landscape and converting them to agriculture or urban or suburban development, you’re losing these low spots that can hold water during a heavy rain or a big flood event,” said Christopher Craft, director of Indiana University’s Wetlands Laboratory.

Ultimately, how much of an impact the ruling will have on wetlands may depend on what regulations states do or do not have in place 

“There are some states that have robust wetland protection programs in place already that are independent of the Clean Water Act, and so there you may not see much of an impact,” said Royal Gardner, a law professor at Stetson University. 

“However, about half the states don’t have a separate, independent wetland regulatory program, or states depended on using Clean Water Act section 401 … and in those states, that’s where you’re going to see potentially massive losses,” Gardner added.