What’s the Issue?

Federal jurisdiction under the Clean Water Act (CWA) is limited to “Waters of the United States,” or WOTUS for short. WOTUS defines where the federal government can require permits to protect rivers, wetlands, lakes, estuaries, and other waterbodies from pollution under the Clean Water Act. In the 21st century, this definition has undergone a series of alterations by courts and the US Environmental Protection Agency (EPA). In 2001 the Supreme Court ruled that federal jurisdiction did not extend to isolated intrastate waters, invalidating the existing definition of WOTUS used by the EPA and Army Corps of Engineers. Five years later, the Supreme Court, in a case called Rapanos v. United States, decided that traditionally navigable waters and interstate waters with a “significant nexus” to such waters were subject to CWA jurisdiction. In 2015, the EPA issued a new regulatory definition, expanding the definition of WOTUS and extending federal protections. This expansion included numerous wetlands and headwater streams that had previously been excluded, despite their importance to the water quality of the larger waterbodies they flow into.  

Image of hydrologic connections and protections under the Clean Water Act from American Fisheries Society, adapted from a US EPA 2015 graphic.  

This new definition was yet again challenged in federal courts, and was eventually replaced in 2020, with a new rule based on Justice Antonin Scalia’s opinion in Rapanos. This rule removed federal protection from wetlands, headwater streams, and ephemeral streams, all of which can have major impacts on the water quality of larger, unquestionably jurisdictional streams. As a result, this “Navigable Waters Protection Rule” (NWPR) became known as the “Dirty Water Rule.”

In 2021, EPA and the Army Corps of Engineers withdrew the Dirty Water Rule and released a revised definition of WOTUS rule at the end of 2022. This revised definition also came under attack through court rulings.

In May 2023, when ruling in the Sackett v. EPA case, the Supreme Court catastrophically narrowed the scope of the Clean Water Act by drastically reducing wetland protections. On September 8, 2023, EPA published a final rule amending the revised definition to conform to the Court’s decision. Visit our Waters of the US resource page and our blog post about the impact of the Sackett v. EPA decision to learn more.

While federal protections have shifted over the last 20+ years, some states have stepped up and clarified what streams are protected from unpermitted pollution under their own state laws or expanded their state jurisdiction to make sure critical headwater streams are protected. 

Examples of State Policy & Regulations

Lawyers for Good Government’s Wetlands Dashboard provides information on state level water and wetland protections for all 50 states, the District of Columbia, and Puerto Rico. Information for each state includes definitions of “waters of the state” and “wetlands;” relevant regulating agencies protecting these resources; protections for wetlands that already exist in the state; any proposed changes made to wetlands protections as of May 2024; processes for amending existing state law and policy defining state water and wetlands; protections potentially available at the local level, and; if the state offers a model policy for protecting wetlands.

Lessons from the Network

Additional Resources

• Clean Water for All Coalition Report: Sackett v. EPA: The State of Our Waters One Year Later (May 2024)
• Earthjustice State-level analysis of Wetlands and Streams Most in Danger After the U.S. Supreme Court’s Sackett v. EPA Ruling
• Environmental Law Institute’s analysis of states’ ability to fill in regulatory gaps in water protection, Murky Waters Ahead? State Protections for Nonfederal Waters (2022), James McElfish
• EPA supplementary materials published in preparation for the repeal of the Dirty Water Rule includes a list of state actions on jurisdiction after NWPR
• River Network’s Waters of the United States (WOTUS) page tracks the current definition of WOTUS and features relevant news stories
• Clean Water Act Owner’s Manual
• Clean Water Act Training Series – Module 5: Protecting Wetlands, Streams, and Lakes from Dredging and Filling ‐ Section 404
• EPA’s About Waters of the United States webpage
• EPA’s Current Implementation of Waters of the United States webpage
• Harvard’s Environmental and Energy Law Project has a timeline of the controversy over federal jurisdiction
• Earthjustice story map explores the implications of WOTUS’ moving definition
• Redefining Waters of the United States (WOTUS): Recent Developments, Congressional Research Service, July 8, 2022
• The Status and Trends of Wetland Loss and Legal Protection in North Carolina, North Carolina State Extension Publications, 2022
• Trout Unlimited interactive map on the importance of intermittent and ephemeral streams 
• Report: The contribution of headwater streams to biodiversity in river networks Research from the U.S. Forest Service shows that headwater streams are critical to biodiversity. Judy Meyer, U.S. Forest Service, et al.
• Report: The Role of Headwater Streams in Downstream Water Quality Research from  National Institutes of Health found that protecting headwater streams positively impacts downstream water quality. Richard B. Alexander, USGS, et al.

Bolstering CWA Protections Policy Database