A sweeping new report from the Natural Resources Defense Council (NRDC) reveals that tens of millions of acres of U.S. wetlands have lost critical federal protections in the wake of the Supreme Court’s controversial 2023 decision in Sackett v. EPA. The decision, which drastically narrows the scope of the Clean Water Act (CWA), leaves wetlands and streams across the country at heightened risk of pollution, destruction, and degradation, according to the NRDC’s Mapping Destruction: Using GIS Modeling to Show the Disastrous Impacts of Sackett v. EPA on America’s Wetlands report.
Using advanced Geographic Information System (GIS) modeling, the NRDC assessed the potential impact of the Sackett ruling under multiple legal interpretations. Even in the most conservative scenario, the findings are alarming: over 19 million acres of wetlands—an area roughly the size of South Carolina—are now projected to be left unprotected. In the worst-case interpretation, the number climbs to more than 70 million acres, or 84 percent of previously protected wetlands.
“Our analysis confirms that the Supreme Court has gutted the Clean Water Act’s ability to protect our wetlands, exposing communities to increased flooding, worsening water pollution, and threatening habitats that sustain wildlife and local economies,” said Jon Devine, director, freshwater ecosystems, at NRDC (Natural Resources Defense Council). “It also shows that if the Trump administration adopts interpretations of the case favored by polluters, the destruction will be far worse.”
Wetlands, which serve as natural buffers against flooding, filters for clean water, and essential habitats for wildlife, are among the ecosystems hardest hit by the Sackett decision. Under the Court’s ruling, only wetlands with a continuous surface connection to a “relatively permanent” body of water remain federally protected—an interpretation environmental experts say ignores decades of scientific understanding about hydrology and ecological interdependence.
NRDC’s GIS analysis shows that:
- At least 19 million acres of wetlands, or 60 percent of the wetlands modeled, lose protection under the least restrictive legal reading.
- Up to 70 million acres, or 84 percent of previously protected wetlands, would be unprotected under the most restrictive interpretation.
- Nonperennial streams, which do not flow year-round but supply critical drinking water and flood protection, are also at risk. If only perennial streams remain protected, over 8 million miles of streams could fall outside the Clean Water Act’s scope.
These findings are particularly troubling for frontline communities that already bear the brunt of environmental injustice. Many of the areas expected to be hardest hit are home to residents facing compounding challenges from pollution, flood risk, and limited infrastructure.
For over 50 years, the Clean Water Act has served as the foundation of American water protection, helping to preserve drinking water, wildlife habitats, and recreational waters. The Sackett v. EPA decision, however, marks a radical reinterpretation of the law, shifting regulatory focus away from the smaller waterways and wetlands that play an outsized role in the health of entire ecosystems.
The NRDC report warns that the damage could intensify if future administrations adopt the ruling’s most extreme interpretations, which are favored by industry groups seeking to limit regulatory oversight. In fact, the U.S. Environmental Protection Agency has already signaled its intent to roll back further protections in line with the ruling.
Ecological and economic costs
The loss of wetland protections carries steep environmental and economic consequences. Wetlands store carbon, reduce flood risks, recharge groundwater supplies, and support a staggering array of biodiversity. Although they cover just 5 percent of the U.S. landscape, wetlands are home to nearly half of all federally listed threatened and endangered species. They also support recreational activities and natural industries worth billions of dollars annually.
Non-perennial streams, often dismissed due to their seasonal nature, play a vital role in maintaining water quality and ecosystem health downstream. According to the NRDC report, these waterways supply drinking water to more than 117 million Americans and are crucial in nutrient cycling, sediment transport, and flood management.
Yet, many of these critical systems are now legally unprotected and more vulnerable than ever to destruction for development, agriculture, and industrial expansion.
While the Sackett decision has already reshaped the regulatory landscape, the NRDC argues that state governments and Congress still have tools to restore protections. The report underscores the urgent need for states to step up where federal protections have fallen short—and for lawmakers to consider legislative reforms that reestablish strong, science-based protections for the nation’s waters.
