Another article: https://www.scotusblog.com/2023/05/supreme-court-curtails-clean-water-act/

In agreeing that the Sacketts’ lot is a wetland, the U.S. Court of Appeals for the 9th Circuit applied the test outlined by Justice Anthony Kennedy in Rapanos v. United States: whether there is a “significant nexus” between the wetlands and waters that are covered by the CWA, and whether the wetlands “significantly affect” the quality of those waters.

On Thursday the Supreme Court reversed the 9th Circuit’s ruling. Instead, Justice Samuel Alito explained, courts should apply a more stringent test, outlined by four justices (including Alito, Chief Justice John Roberts, and Justice Clarence Thomas) in Rapanos, in which the CWA applies to a particular wetland only if it blends or flows into a neighboring water that is a channel for interstate commerce.