New EDF preliminary analysis estimates millions of acres of wetlands could now be at risk in the wake of 2023 Supreme Court ruling

March 19, 2024
Samantha Tausendschoen, (715) 220-9930,

(March 19, 2024) – New preliminary analysis by Environmental Defense Fund (EDF) reveals that millions of acres of critical wetland habitat are now at risk of losing vital protections in the wake of a 2023 Supreme Court majority opinion (Sackett v EPA) that drastically narrowed the scope of wetlands protected under the Clean Water Act.

Prior to the decision, the Supreme Court and lower courts upheld that wetlands that are connected to federal waterways, including those connected below the surface, such as through groundwater, should be protected. The Supreme Court opinion now states that wetlands must have “a continuous surface connection” to federal waters, an approach that is not grounded in science and establishes tremendous uncertainty as to how this will be interpreted in the long-term.   

EDF scientists have estimated federal protections based on multiple interpretations of the Supreme Court’s decision. Preliminary results show that between 15 and 90 million acres (just smaller than the state of California) of wetlands in the contiguous U.S. may have lost federal protections. The analysis presents a wide range of estimated impacts precisely due to the subjective language in the opinion, the true impact of which will be seen over time. The decision is compounded by the fact that many states have few or no state-level wetlands protections, with 24 states relying entirely on federal protections via the Clean Water Act and therefore potentially leaving wetlands without any protection at all.   

“Wetlands provide important wildlife habitat, clean water and significant flood risk reduction,” said Dr. Adam Gold, a scientist with EDF’s Climate Resilient Coasts and Watersheds program in North Carolina. “Losing the ability at both federal and state levels to manage impacts to wetlands and promote their conservation is bad for communities. This new preliminary analysis demonstrates the uncertainty in federal wetlands protections going forward due to the Supreme Court’s unscientific ruling.” 

Wetlands are pivotal in protecting communities from flooding, our nation’s costliest natural hazard, because they act as natural sponges that slow and absorb floodwaters, reducing downstream damages. With one acre of wetlands storing as much as 1.5 million gallons of flood water, continued loss of wetlands and development in high-risk areas will only exacerbate the impacts of climate change and put more communities at risk of flooding. Wetlands also clean our water and are home to 40% of the world’s species and 75% of commercially harvested fish and shellfish species in the United States.   

EDF is working together with scientists, advocates and policymakers to better quantify, communicate and protect the breadth and value of benefits that wetlands provide. This will require cutting-edge advancements in science and economics, partnerships across a wide spectrum of stakeholders and targeted policy actions.   

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One of the world’s leading international nonprofit organizations, Environmental Defense Fund ( creates transformational solutions to the most serious environmental problems. To do so, EDF links science, economics, law, and innovative private-sector partnerships. With more than 3 million members and offices in the United States, China, Mexico, Indonesia and the European Union, EDF’s scientists, economists, attorneys and policy experts are working in 28 countries to turn our solutions into action. Connect with us on Twitter @EnvDefenseFund