In late December 2022, the Environmental Protection Agency (“EPA”) released its long-anticipated final rule to redefine the term “waters of the United States” (“WOTUS”) under the Clean Water Act (“CWA”). The term WOTUS is key to implementation of the CWA because only those waters that meet the WOTUS definition fall under CWA jurisdiction. Creating a lasting definition of WOTUS has proven a challenge for EPA. The new rule is EPA’s latest attempt to craft what it refers to as a “durable definition” that is able to satisfy EPA’s CWA responsibilities and withstand judicial review.

Already, lawsuits challenging the latest WOTUS rule have been filed in federal court. Additionally, legislators in both the House and the Senate have initiated Congressional Review Act (“CRA”) proceedings which would allow Congress to consider overturning the new WOTUS rule.


The CWA was established by Congress in 1972 in order to “restore and maintain the chemical, physical, and biological integrity of the Nation’s waters.” 33 U.S.C. § 1251(a). In order to achieve this purpose, the CWA employs a permitting program referred to as the National Pollutant Elimination Discharge System (“NPDES”). Under the CWA, it is illegal to make a discharge of any pollutant from a discernable, concrete source into “navigable waters” without a NPDES permit. 33 U.S.C. § 1342. The term “navigable waters” is defined under the CWA to mean “the waters of the United States, including the territorial seas.” 33 U.S.C. § 1362(7). Congress chose not to define the term “waters of the United States” in the CWA, instead leaving it to EPA to craft a definition.

In the years following the passage of the CWA, EPA initially struggled to craft a WOTUS definition. However, by the 1980s, EPA had adopted a definition of WOTUS that brought six general categories of waterbodies and their “adjacent” wetlands under CWA jurisdiction. This definition of WOTUS would remain in place until 2015, when EPA adopted a new WOTUS definition known as the Clean Water Rule. EPA’s purpose for adopting the Clean Water Rule was to incorporate recent decision from the United States Supreme Court on the limitations of WOTUS. Specifically, the Clean Water Rule attempted to clarify the scope of WOTUS following the Supreme Court decision in Rapanos v. U.S., 547 U.S. 715 (2006), where the Court considered the degree to which wetlands could be included in the WOTUS definition.

In Rapanos, the Supreme Court was asked to consider whether CWA jurisdiction could include wetlands that did not directly “abut” a recognized WOTUS. The case did not result in a majority opinion, but instead produced a four-justice plurality opinion authored by Justice Scalia, and a concurrence authored by Justice Kennedy writing for himself. In the plurality opinion, the justices concluded that the definition of WOTUS should only include those waters that are “relatively permanent, standing, or continuous flowing” such as streams, rivers, and lakes. From there, only the wetlands that shared a continuous surface connection with such waters would fall under CWA jurisdiction. In contrast, Justice Kennedy concluded that wetland jurisdiction under the CWA should be determined on a case-by-case basis, based on whether the wetland possessed a “significant nexus” to a recognized WOTUS. According to Justice Kennedy, a significant nexus exists when a wetland “either alone or in combination with similarly situated lands in the region, significantly affect[s] the chemical, physical, and biological integrity of other covered waters[.]” After the Rapanos decision, courts and EPA tended to apply Justice Kennedy’s significant nexus test either on its own or in conjunction with the plurality opinion.

The 2015 Clean Water Rule was regarded as an expansion of WOTUS beyond the definition adopted in the 1980s. As a result, it was highly controversial, and due to court cases was prevented from going into effect in twenty-eight states. Ultimately, the Clean Water Rule was repealed in 2019. In 2020, EPA once again released a new WOTUS definition. The new definition, known as the Navigable Water Protection Rule (“NWPR”), was the narrowest WOTUS definition EPA had put forth. It limited the definition of WOTUS to four distinct categories of waterbodies. That rule was overturned by a federal judge in 2021. At the time, EPA was already in the process of crafting a new WOTUS rule.

According to EPA, its latest WOTUS definition reinstates the 1980s regulations, with some updates to both tests outlined in Rapanos. The new rule describes five categories of waters that fall under CWA jurisdiction, and includes for the first time definitions for key terms such as “adjacent,” and “significant affect.” The rule was published in the Federal Register on December 30, 2022, and will go into effect on March 20, 2023. An in-depth review of the rule is available here. Importantly, the Supreme Court heard oral argument in a case last fall that has asked the Court to reconsider the scope of wetlands jurisdiction under the CWA. While the Court has yet to issue a decision, it is possible that the holding will affect the 2022 WOTUS rule.

Current Lawsuits

Legal challenges to the new WOTUS rule have already begun. The state of Texas, together with the state of Idaho, and multiple industry groups filed State of Texas v. EPA, No. 3:23-cv-00017 (S.D. Tex.), in January 2023. In February, another coalition of industry groups led by the Kentucky Chamber of Commerce filed Kentucky Chamber of Commerce v. EPA, No. 3:23-cv-00008 (E.D. Ky.). Also in February, a group of 24 states led by West Virginia filed State of West Virginia v. EPA, No. 3:23-cv-00032 (D. N.D.). While the lawsuits raise numerous arguments challenging the 2022 WOTUS rule, there are three primary claims that are present in each.

First, the plaintiffs in each lawsuit claim that the 2022 WOTUS rule is unlawful because the text of the CWA only authorizes jurisdiction for “navigable” waters. According to the plaintiffs, the text of the CWA only permits EPA to regulate “navigable waters,” defined as “waters of the United States.” Because the CWA uses the term “navigable waters” throughout the statute, the plaintiffs argue that navigability must be central to determining the scope of CWA jurisdiction. The term “navigable waters” was defined by the Supreme Court in the landmark decision The Daniel Ball, 77 U.S. 557 (1870). There, the Court concluded that “navigable waters” refers to those waters which can be used as “highways for commerce over which trade and travel are or may be conducted in the customary modes of trade and travel on water.” The plaintiffs in these current lawsuits argue that because the 2022 WOTUS definition would cover waters that cannot be used to facilitate commerce, the definition unlawfully allows EPA to regulate waters that fall beyond the scope of CWA jurisdiction.

The next argument raised by plaintiffs is that the 2022 WOTUS rule violates the Tenth Amendment of the United States Constitution. The Tenth Amendment provides that “[t]he power not delegated to the United States by the Constitution, nor prohibited by it to the States, are reserved to the States respectively, or to the people.” U.S. Const. amend. X. In other words, the Tenth Amendment clarifies that the powers of the federal government are limited to the powers granted in the Constitution, and all other powers are reserved for the states. Because the Constitution does not explicitly grant the federal government power to regulate land and water resources, that power is generally regarded as belonging to the states. Although Congress can authorize the federal government to exercise a power that is traditionally reserved for states through a “clear and manifest” statement, the plaintiffs argue that the phrase “waters of the United States” does not constitute such a statement. Additionally, the plaintiffs note that the CWA was enacted according to Congress’s authority to regulate interstate commerce under Article I, Section 8 of the Constitution. Therefore, the plaintiffs argue that the 2022 WOTUS rule violates the Tenth Amendment by allowing the federal government to regulate water resources beyond the regulation of interstate commerce.

Finally, the plaintiffs in all three lawsuits argue that the 2022 WOTUS rule is invalid because it violates the major questions doctrine. The major questions doctrine has arisen out of case law concerning the scope of agency authority. Specifically, the major questions doctrine arises out of a number of Supreme Court decisions that have held that when an agency takes an action on an issue of major national significance, the action must be founded on clear congressional authorization. To date, the Supreme Court has only referred to the major questions doctrine by name once in a majority opinion. In West Virginia v. EPA, 142 S. Ct. 2587 (2022), the Court explained that under the major questions doctrine, it will reject claims of agency authority when the claim of authority concerns an issue of “vast economic and political significance” that Congress has not clearly empowered the agency to take action on. The Court further explained that clear Congressional authorization is rarely provided through language that is modest, vague, subtle, or ambiguous. In each of the present lawsuits, the plaintiffs argue that the 2022 WOTUS rule violates the major questions doctrine because the rule has vast economic significance by allowing EPA to regulate the development of land and water resources, and Congress did not clearly empower EPA with such authority.

Congressional Challenge

Along with facing judicial challenges, the 2022 WOTUS rule has also been challenged in Congress under the Congressional Review Act (“CRA”). The CRA was adopted by Congress in 1996. It requires all federal agencies to report issuance of rules to Congress, and provides Congress with a process for reviewing and overturning agency rules. The process requires that both houses of Congress approve a resolution of disapproval, which must then by signed by the President, in order to overturn an agency rule. Once a rule is successfully overturned according to the CRA, it is immediately considered invalid and treated as though it had never gone into legal effect. Additionally, if an agency rule is successfully overturned pursuant to the CRA, the agency may not issue a rule that is “substantially the same” as the overturned rule without specific authorization from Congress. The CRA does not specifically define the scope of “substantially the same,” nor does it clarify who should make such a determination.

Legislators in both the House of Representatives and the Senate have introduced a joint resolution to overturn the 2022 WOTUS rule. The resolution introduced by the House passed out of the Transportation Committee in late February, after members voted 30-22 to approve it. The resolution will next go to a vote on the House floor. At the moment, there has been no similar action taken on the joint resolution introduced by the Senate.

Going Forward

All of the challenges to the 2022 WOTUS rule are still in the early stages, and it is currently unclear how courts will rule. It is also unclear how successful the CRA joint resolution will be. To date, around twenty agency regulations have been overturned via the CRA since it was adopted by Congress in 1996. Additionally, the Supreme Court has yet to issue its decision in the case it heard last October, Sackett v. EPA, 8 F.4th 1075 (9th Cir. 2021), cert. granted Jan. 24, 2022, concerning the scope of wetlands jurisdiction under the CWA. It is likely that the Court’s decision will have an impact on legal challenges to the 2022 WOTUS rule, and could possibly require EPA to revisit the WOTUS definition once again. The National Agricultural Law Center will continue to provide updates as legal developments occur.


To read the complaint in State of Texas v. EPA, click here.

To read the complaint in Kentucky Chamber of Commerce v. EPA, click here.

To read the complaint in State of West Virginia v. EPA, click here.

To read the text of the 2022 WOTUS rule, click here.

To read the text of the CWA, click here.

To read the text of the CRA, click here.

For more National Agricultural Law Center resources on the CWA, click here.