[1] The case involves developers John A. Rapanos (Midland, Michigan) and June Carabell, whose separate projects were stopped because of the environmental regulations that make up the Clean Water Act.

In the late 1980s, Rapanos prepared 22 acres (8.9 ha) of land for the development of a mall by pulling trees and filling the hole with sand.

Rapanos did not file for a permit when he pulled the trees, but the government claimed that his land was a wetland because it was adjacent to a drainage ditch.

[3] But the United States Environmental Protection Agency has interpreted the term "navigable waterway" broadly, to include areas connected to or linked to waters via tributaries or other similar means.

[10] Next, with representation from the nonprofit public interest law firm Pacific Legal Foundation, Rapanos unsuccessfully sought a rehearing from the Sixth Circuit.

[12] In 2001, a divided Court found that the migratory bird rule could not reach isolated ponds in Solid Waste Agency of Northern Cook County v. Army Corps of Engineers (SWANCC).

Four justices voted to vacate, to strike down the Corps's interpretation of the CWA, and to remand under a new "continuous surface water connection" standard.

[16] Scalia argued the "immense expansion of federal regulation" over "swampy lands" would give the Corps jurisdiction over "half of Alaska and an area the size of California in the lower 48 States.

[19] He also rejected Justice Kennedy's assertion that the same dictionary definition lists floods as an alternative usage, on the grounds that it is "strange to suppose that Congress had waxed Shakespearean."

Quoting the CWA's policy to "protect the primary responsibilities and rights of the States", he argued that the Corps's inferred jurisdiction failed the clear statement rule.

Justice John Paul Stevens wrote that the plurality opinion upset three decades of administrative and congressional practice, but Scalia rejected that argument as "a curious appeal to entrenched Executive error" and also characterized Kennedy's significant nexus test as a "gimmick" to devise "his new statute all on his own" and his reasoning as "turtles all the way down".

[fn 1] But while he agreed that the cases should be vacated and remanded, he believed that a wetland or non-navigable waterbody falls within the scope of the Clean Water Act's jurisdiction if it bears a "significant nexus" to a traditional navigable waterway.

[22] He argued that a nexus exists where the wetland or waterbody, either by itself or in combination with other similar sites, significantly affects the physical, biological, and chemical integrity of the downstream navigable waterway.

Referring to the inconsistencies found by the GAO investigation, Kennedy wrote that he could not share Stevens's trust in the Corps's reasonableness.

Stevens called the Corps's asserted jurisdiction "a quintessential example of the Executive's reasonable interpretation" and argued that Riverside Bayview already "squarely controls" the validity of the regulations.

[31] Justice Breyer wrote separately to note that he believed that Corps CWA authority extended to the very limits of the interstate commerce power.

Roberts observed that the lower courts would likely look to Marks v. United States[20] to guide them in applying the competing Rapanos standards.

"[20] Stevens, writing the principal Rapanos dissent, suggested that lower courts could use either the plurality's or Kennedy's test, as both would command the support of at least five justices.

On October 3, 2022, the court held oral arguments in Sacket v. EPA, and on May 25, 2023, Justice Alito announced an opinion adopting the Rapanos plurality's "continuous surface water connection" test.

[41][42] Citing the confusion created by Rapanos, on June 29, 2015, the Corps and EPA promulgated a new 75-page regulation attempting to clarify the scope of waters of the United States, to take effect on August 28.