Kavanaugh, J., concurring in judgment
text of the statute, as well as 45 years of consistent agency practice and this Court’s precedents, I respectfully disagree with the Court’s decision to interpret “waters of the United States” to include only adjoining wetlands and not adjacent wetlands.
IV
The difference between “adjacent” and “adjoining” in this context is not merely semantic or academic. The Court’s rewriting of “adjacent” to mean “adjoining” will matter a great deal in the real world. In particular, the Court’s new and overly narrow test may leave long-regulated and long-accepted-to-be-regulable wetlands suddenly beyond the scope of the agencies’ regulatory authority, with negative consequences for waters of the United States. For example, the Mississippi River features an extensive levee system to prevent flooding. Under the Court’s “continuous surface connection” test, the presence of those levees (the equivalent of a dike) would seemingly preclude Clean Water Act coverage of adjacent wetlands on the other side of the levees, even though the adjacent wetlands are often an important part of the flood-control project. See Brief for Respondents 30. Likewise, federal protection of the Chesapeake Bay might be less effective if fill can be dumped into wetlands that are adjacent to (but not adjoining) the bay and its covered tributaries. See id., at 35. Those are just two of many examples of how the Court’s overly narrow view of the Clean Water Act will have concrete impact.
As those examples reveal, there is a good reason why Congress covered not only adjoining wetlands but also adjacent wetlands. Because of the movement of water between adjacent wetlands and other waters, pollutants in wetlands often end up in adjacent rivers, lakes, and other waters. Natural barriers such as berms and dunes do not block all water flow and are in fact evidence of a regular connection between a water and a wetland. 85 Fed. Reg.
