SCOTUS Takes Up WOTUS (Again)

By Laura Rabinow

When the Supreme Court of the United States (SCOTUS) returns for the beginning of its new term on October 3rd, it is slated to hear the case of Sackett v. EPA, a case with significant potential to shift water regulations across the United States, for the second time.

At issue in the case is whether or not Michael and Chantell Sackett can develop a private residence on wetlands in Idaho. But, more foundationally, the case takes up the question of which water bodies are and are not subject to protections under the Clean Water Act (CWA).

This case is one of a handful of cases that the Supreme Court has ruled on in the last several decades with respect to the definition of waters of the United States (WOTUS) which is not further defined in the language of the CWA. When the Sackett’s case was first heard by the Supreme Court in 2012, they argued that the underlying jurisdictional determination by the Army Corps was “arbitrary and capricious” (with respect to the Administrative Procedures Act) and that, in essence, the bodies of water at issue were incorrectly determined to be waters of the United States and therefore do not require federal permitting.

The Court ruled in 2012 that, because the resulting order from the EPA constituted a final agency action, the Sacketts could bring a civil suit challenging it, thus remanding the issue back to the lower courts. Those lower courts, however, upheld the EPA’s determination. The US Court of Appeals for the 9th Circuit did so based on Justice Kennedy’s opinion in the split 4-1-4 Supreme Court decision in Rapanos v. United States (2006) which found that “a water or wetland constitutes ‘navigable waters’ under the [Clean Water] Act if it possesses a ‘significant nexus’ to waters that are navigable in fact or that could reasonably be so made,” but that further stated that absent specific regulations, those determinations would need to be made on a case-by-case basis.

…the choice not to define navigable waters… was expressly done with the intention of having the “broadest possible constitutional interpretation.”

What’s at Stake in the New Sackett Case (in 2022)?

The new case brought by the Sacketts challenges whether or not Kennedy’s opinion in Rapanos should be the controlling one. The Supreme Court’s decision to take up the case has been seen as a signal by many legal scholars that it will instead adopt Scalia’s plurality opinion in Rapanos. In that opinion, Scalia outlined two criteria for determining which bodies of water fall under WOTUS: “relatively permanent, standing or continuously flowing bodies of water,” and “only those wetlands with a continuous surface connection to bodies that are ‘waters of the United States’ in their own right.” These criteria would in effect establish a much narrower definition of WOTUS. One that may be at odds with the underlying legislative intent in the CWA. As noted in the Rockefeller Institute’s earlier policy brief, “The Shape of Water Regulations: The Disputed Waters of the United States,” the choice not to define navigable waters, and therein waters of the United States, was expressly done with the intention of having the “broadest possible constitutional interpretation.

Moreover, this narrower set of criteria may be at odds with how wetlands and ephemeral and intermittent streams function ecologically. Wetlands are transitional areas between water bodies and drained (or seemingly dry) land. They typically exist where the water table is at, near, or just above the land’s surface. Commonly referred to as the kidneys of the ecosystem, wetlands provide the crucial function of filtering water as it makes its way to drinking water systems. Ephemeral streams are streams that flow briefly in direct response to precipitation that is nearby. Intermittent streams flow continuously, but for only part of the year, as with a stream that flows in response to snow melt each spring. Ephemeral and intermittent streams often represent the ultimate source of water for streams and other water bodies, comprising nearly 60 percent of all streams in the United States (not counting Alaska). These bodies of water likewise provide critical ecosystem functions and work to replenish and filter drinking water sources. And, according to earlier reports by the EPA, they “provide the same ecological and hydrological functions as perennial streams […] by moving water, nutrients, and sediment throughout the watershed.”

The potential ecological and regulatory impacts of such a ruling could be considerable as evidenced by other recent shifts in the definition of WOTUS. Based on Justice Kennedy’s opinion in 2006, the Obama Administration attempted to clarify CWA regulations in 2015 and expand the definition of WOTUS to be more inclusive of waterbodies like wetlands and ephemeral streams. In 2020, the Trump Administration then instituted a new definition of WOTUS through the Navigable Waters Protection Rule that worked to roll back the 2015 rule. As noted in The Shape of Water Regulations, internal Army Corps documents estimated that defining protected waters as only those with a “continuous surface connection” which are directly adjacent to bodies traditionally understood as navigable waters would mean that 51 percent of mapped wetland acreage in the United States would not fall under CWA regulations. Once more, the impacts of such a decision would be felt unevenly by arid states and those that rely entirely on federal regulations for such protections, like New Mexico. The 2020 Rule issued by the Trump Administration similarly excluded all non-adjacent wetlands and narrowed those intermittent streams (and other water bodies) protected. When that rule was proposed, state officials in New Mexico estimated that 96 percent of the New Mexico’s streams and wetlands could be excluded from regulation.

When [the 2020 Rule] was proposed, state officials in New Mexico estimated that 96 percent of the New Mexico’s streams and wetlands could be excluded from regulation.

What Happens Next?

Since then, under the Biden Administration, vis-à-vis the EPA and U.S. Army Corps, “agencies have halted implementation of the Navigable Waters Protection Rule and are interpreting ‘waters of the United States’ consistent with the pre-2015 regulatory regime until further notice” while it develops a new proposed rule. The Administration has noted that, although it will continue working on the proposed rule, in light of the Supreme Court decision to take up the Sackett’s new case, that rule may not be finished before the Court hands down its decision.

While it is difficult to estimate the full reach and impact of a potential SCOTUS decision on WOTUS—nor can we know what that decision will be at this juncture—if the predictions of legal scholars and observers play out, it is likely that the impact would be both significant and uneven across states with different regulations and geographies. That impact may, however, may be mitigated by the new rule defining WOTUS that the EPA and Army Corps under the Biden Administration have said they will propose. As this case plays out and as that rule is proposed, we will continue to update our analysis.


Laura Rabinow is deputy director of research at the Rockefeller Institute of Government