The U.S. Supreme Court case, Rapanos v. United States (2005), centered around the issue of federal jurisdiction over wetlands under the Clean Water Act (CWA). John A. Rapanos was charged with filling his Michigan wetlands without a permit from the Army Corps of Engineers, violating CWA regulations which protect "navigable waters". The key dispute in this case was whether these isolated wetlands fell under such definition and thus within federal jurisdiction. The court did not reach a majority decision; four justices argued that only permanent bodies of water are covered by CWA while another four contended that it extends to any water body with a significant nexus to navigable waters. Justice Kennedy provided an individual opinion suggesting compromise: non-navigable waters should be regulated if they bear a 'significant nexus' to traditional navigable waters affecting their chemical, physical or biological integrity.

In the dissenting opinion for Rapanos v. United States, Justice John Paul Stevens argued that the majority's decision to narrow the scope of "waters of the United States" under the Clean Water Act was misguided and unsupported by precedent or scientific understanding. He contended that Congress intended a broad interpretation when it passed this legislation in order to protect water quality across state lines effectively. The Justice criticized his colleagues' reliance on dictionary definitions over expert agency interpretations and their dismissal of significant ecological connections between wetlands and navigable waters as mere 'hydrologic connection.' Furthermore, he expressed concern about potential negative environmental impacts resulting from this ruling, which could leave many bodies of water without federal protection against pollution or destruction. Ultimately, Stevens believed that deferring to experts at agencies like EPA would have been more appropriate than reinterpreting statutory language based on non-expert judicial perspectives.