CWA Memo: navigable waterways by Eva Conner
For a body of water to fall under the jurisdiction of the Clean Water Act (CWA), it must be a navigable water of the United States. The Supreme Court has found in multiple cases that the term navigable waters, as used in the CWA, is broader than the traditional definition. The traditional definition of navigable waters required that the water either be navigable in fact, or susceptible of being rendered navigable.
1 However, for the purposes of the CWA, the Supreme Court has developed a separate definition.
The Supreme Court has examined the term navigable waters, as used by the CWA, only a couple times. The first case was U.S. v. Riverside Bayview Homes, Inc.
, 474 U.S. 121 (1985), which found that wetlands that directly abutted a navigable creek were navigable for the CWA. The Court noted the Corps’ regulatory conclusion that the wetlands impacted water quality by filtering water, slowing runoff into lakes, and providing a habitant for the wetland species, and upheld it under Chevron deference. However, they also specifically questioned whether or not the Corps’ authority to regulate wetlands would extend to those areas not adjacent to open waters. The second case was Solid Waste Agency of Northern Cook
County v. U.S. Army Corps of Engineers , 531 U.S. 159 (2001), (“SWANCC”), where the Corps tried to claim regulatory authority under the CWA (meaning the water must be termed navigable) over a series of isolated ponds and mudflats that were being used to store solid waste. The Court held that the ponds were not navigable, and in doing so, developed the “significant nexus” test that is still used today. The court stated that the difference between SWANCC and Riverside Bayview was a significant nexus between wetlands and navigable waters, which they found lacking in the isolated ponds in SWANCC. The latest case to define navigable waters was Rapanos v. U.S.
In Rapanos v. U.S.
, 547 U.S. 714 (2006), developer John Rapanos discharged fill material onto 54 acres of wetlands. The wetlands in question were not near traditional navigable waters, but did lie close to
1 See Rapanos v. US, 547 U.S. 715, 731 (2006), citing The Daniel Ball, 77 U.S. 557, 563 (1870).

ditches that eventually emptied into navigable waterways of the United States. The Army Corps of
Engineers sued, claiming that the wetlands constituted navigable waters of the United States, which would make them subject to the CWA and mean that Rapanos should have obtained permits for the backfilling. However, in the Rapanos opinion, the Supreme Court only made the issue more confusing than it had been before. The opinion had no majority, but instead had a four justice plurality, a four justice dissent, and Justice Kennedy’s concurrence, which agreed mostly with the dissent in reasoning while agreeing with the plurality in result.
The plurality, written by Justice Scalia, took a very narrow view of navigable waters under the
CWA. It defined navigable waters as waterways which both 1) are “relatively permanent, standing or continuously flowing, bodies of water” and 2) “only those wetlands with a continuous surface connection” to other regulated waterways. Scalia stated that protection would not be lost, but that instead the Corps would just have to regulate non-navigable waterways as point sources themselves. The dissent by Justice Stevens deferred to the Corps of Engineers, finding that their regulatory decisions should be followed, especially when those decisions supported the purpose of the CWA.
Justice Kennedy’s concurrence also agreed that there should be a broad definition of navigable waters under the CWA, and supported regulation of all waterways where contamination would have downstream effects. He followed the SWANCC “significant nexus” test, explaining that wetlands should be regulated where “either alone or in combination with similarly situated lands in the region, [they] significantly affect the chemical, physical, and biological integrity” of other waterways that are clearly navigable. Kennedy also stated that waters should not be regulated when their effect on other waters was
“speculative or insubstantial,” and believed that the test he proposed should be applied by the Corps on a case-by-case basis. However, Kennedy was unconvinced that the wetlands in Rapanos actually would impact water quality downstream, and so he joined the plurality. Kennedy did, however, explicitly reject the plurality’s reasoning as being “without support in the language and purposes of the CWA or in our cases interpreting it.”

Only one Fifth Circuit case has significantly discussed the Rapanos opinion. In U.S. v. Lucas , 516
F.3d 316 (5th Cir. 2008), the Fifth Circuit addressed the issue of whether waste discharge from septic systems into wetlands was a violation of the CWA. In Lucas , the wetlands had flowing open water along the edges with strong flow and high velocity, as well as open water on the edges that the court concluded made it difficult to determine where the water ended and the wetlands began. The court did not pick to follow either the plurality or the concurrence, but instead found that the wetlands in question met both tests, eliminating the need to determine which test the Fifth Circuit would follow. However, they did address the plurality opinion first and in more detail.
Other circuits have set out more definitive rules. In U.S. v. Gerke , 464 F.3d 723 (7th Cir. 2006), the Seventh Circuit issued a short judgment addressing solely whether Scalia’s plurality or Kennedy’s concurrence should be followed by their courts. They concluded that the controlling law was Kennedy’s concurrence, since it is the “narrowest ground to which a majority of the Justices would have assented if forced to choose.” The First Circuit questioned whether or not Kennedy’s opinion was the one that really met that standard, and instead determined Rapanos attaches if either the plurality or concurrence are met.
U.S. v. Johnson , 467 F.3d 56 (1st Cir. 2006). In Northern California River Watch v. City of Healdsburg ,
496 F.3d 993, 999-1000 (9th Cir. 2007), the Ninth Circuit followed Gerke and found that Justice
Kennedy’s concurrence was the controlling opinion on the issue.
The jurisprudence seems to indicate that one may use either Scalia’s plurality or Kennedy’s concurrence to prove that waters are navigable. That is positive for the Caernarvon diversion case. In order to make the CWA apply, the waters of Caernarvon must meet on of the tests. Caernarvon flows via a diversion canal from the Mississippi River into the Big Mar, which then is connected to Lake Lery through Bayou Mandeville. Lake Lery is connected to the Gulf of Mexico via a series of lakes, canals, and bayous. It is undisputed that the Mississippi River and the Gulf of Mexico are navigable waterways, and both Big Mar and Lake Lery and likely navigable in the traditional sense due to their connections to the River and the Gulf.

To meet the test of Kennedy’s concurrence, it must just be shown that there is a significant nexus between the wetlands and other navigable waterways, defined as a showing that “either alone or in combination with similarly situated lands in the region, [they] significantly affect the chemical, physical, and biological integrity” of other waterways that are clearly navigable. Caernarvon clearly meets that test in multiple ways: first, it’s connection to the Mississippi, second, through its connection to Big Mar and
Lake Lery, and third, through its indirect but close connection to the Gulf of Mexico.
The tougher test to meet will be the plurality’s, where the diversion must be shown to be both 1) a relatively permanent, standing or continuously flowing, body of water and 2) a wetland with a continuous surface connection to other regulated waterways. Even under that test, Caernarvon is almost certainly navigable. First, the diversion canal is almost always flowing, and even when it is not, both it and Big
Mar are standing water. Second, there is a continuous surface connection to Big Mar, Lake Lery, the
Mississippi River, and the Gulf of Mexico. Even under the test where it must be hard to tell where the wetlands end and the open water begins, just a glance at the map will show that the Gulf of Mexico encroaches steadily into the area of wetlands impacted by the diversion. Therefore, under both the concurrence and the plurality, the Caernarvon diversion is a navigable waterway and thus covered by the
CWA.