The Nickel Report

On November 17, 2025, the US Environmental Protection Agency and U.S. Department of the Army (together, Agencies) issued a pre-publication notice of proposed rulemaking (NPRM) to update the definition of “waters of the United States” (WOTUS) under the Clean Water Act (CWA) for consistency with the US Supreme Court’s 2023 decision in Sackett v. Environmental Protection Agency.^[1]  

The proposal provides, for the first time, definitions of key terms from Sackett, such as “continuous surface connection” and “relatively permanent” waters and re-establishes new definitions for “tributary,” “ditch,” “prior converted cropland,” and “waste treatment system.” By doing so, this proposed rule would provide some bright lines to landowners as to whether and to what extent they will need a CWA permit to develop or use their land. As a result, this rule will benefit development of energy, infrastructure, and critical minerals projects.

On November 20, 2025, the Agencies published the NPRM in the Federal Register with a 45-day comment period running through January 5, 2026. The Agencies plan to issue a final rule in early 2026.

Background

In Sackett, the Supreme Court held that the CWA extends only to relatively permanent bodies of water connected to traditional navigable waters and wetlands with a continuous surface connection to those waters so that there is no clear demarcation between waters and wetlands.^[2] Wetlands, the Court explained, must be “as a practical matter indistinguishable from waters of the United States.”^[3] In so holding, the Court rejected the “significant nexus” test articulated by Justice Kennedy in Rapanos v. United States^[4] as unsupported by the CWA, adopting instead the Rapanos plurality’s view that “the CWA’s use of ‘waters’ encompasses only those relatively permanent, standing or continuously flowing bodies of water forming geographic[al] features that are described in ordinary parlance as streams, oceans, rivers, and lakes.”^[5]

Prior to Sackett, the Agencies promulgated a final rule interpreting CWA jurisdiction to extend to waters that met either the Rapanos plurality’s “relatively permanent” test or Justice Kennedy’s “significant nexus” test (2023 Rule).^[6] In response to Sackett, the Agencies issued a final rule amending portions of the earlier 2023 Rule that were inconsistent with the Court’s decision, such as the reliance on the “significant nexus” test.^[7] In March 2025, the Agencies issued guidance to provide clarification on the implementation of “continuous surface connection.” This guidance is discussed in more detail in a previous blog post.

The Proposed Rule

The proposal includes revisions to the jurisdictional categories of WOTUS; new definitions for “relatively permanent,” “continuous surface connection,” and other key terms; modifications to certain exclusions; and the addition of an exclusion for groundwater.

Under the proposed rule, WOTUS would include: (1) traditional navigable waters and the territorial seas; (2) most impoundments of “waters of the United States;” (3) relatively permanent tributaries of traditional navigable waters, the territorial seas, and impoundments; (4) wetlands adjacent (i.e., having a continuous surface connection) to traditional navigable waters, impoundments, and tributaries; and (5) lakes and ponds that are relatively permanent and have a continuous surface connection to a traditional navigable water, the territorial seas, or a tributary.

• Interstate Waters. The Agencies propose to remove “interstate waters” as an independent jurisdictional category because it can encompass bodies of water that are not jurisdictional in their own right under Sackett (e., lacking relatively permanent flow). Interstate waters would therefore only be WOTUS if they fall within one of the other jurisdictional categories.
• “Relatively Permanent.” One of the key components to show jurisdiction for tributaries, adjacent wetlands, and lakes and ponds, is the identification of relatively permanent, standing, or continuous flowing bodies of water. The proposed rule defines “relatively permanent” as “standing or continuously flowing bodies of surface water that are standing or continuously flowing year-round or at least during the wet season.” According to the proposal, the phrase “at least during the wet season” encapsulates extended periods of continuous surface water occurring in the same geologic feature every year in response a specific wet season. The Agencies acknowledge and solicit comment on various issues related to implementing the “wet season” concept (g., there could be instances of discontinuity between the presence of surface water and the bounds of a particular wet season). This new definition will require the Agencies to assess the length and timing of expected flow in relation to a particular region’s wet season.^[8]
• “Tributary.” The proposal defines “tributary” as “a body of water with relatively permanent flow, and a bed and banks, that connects to a downstream traditional navigable water or the territorial seas, either directly or through one or more waters or features that convey relatively permanent flow. A tributary does not include a body of water that contributes surface water flow to a downstream jurisdictional water through a feature such as a channelized non-jurisdictional surface water feature, subterranean river, culvert, dam, tunnel, or similar artificial feature, or through a debris pile, boulder field, wetland, or similar natural feature, if such feature does not convey relatively permanent flow.”
• Although tributaries can connect directly to a traditionally navigable water or through other waters or features that have relatively permanent flow, features with non-relatively permanent flow would sever jurisdiction upstream, including flow through non-relatively permanent reaches or streams or wetlands.
• “Continuous Surface Connection” for Wetlands. To be jurisdictional, adjacent wetlands must have a “continuous surface connection” to jurisdictional waters. The Agencies propose “continuous surface connection” to mean “having surface water at least during the wet season^[9] and abutting (e., touching) a jurisdictional water.” This definition would require (1) abutment of a jurisdictional water, and (2) surface water at least during the wet season (regardless of the full delineated scope of the wetland). This differs from the current approach whereby an entire wetland is ‘‘adjacent’’ if any part of the wetland is ‘‘adjacent.’’
• WOTUS Exclusions. The Agencies propose to revise the WOTUS exclusions for waste treatment systems, prior converted cropland, and certain ditches. Additionally, the Agencies propose to add a new exclusion for groundwater.
  • Waste Treatment Systems. The Agencies propose to modify the “waste treatment system” by codifying a definition of “waste treatment system” and deleting redundant language within the exclusion. The Agencies are not proposing to change their longstanding approach to implementing the exclusion. Under the proposal, “waste treatment system” means “all components of a waste treatment system designed to meet the requirements of the Clean Water Act, including lagoons and treatment ponds (such as settling or cooling ponds), designed to either convey or retain, concentrate, settle, reduce, or remove pollutants, either actively or passively, from wastewater prior to discharge (or eliminating any such discharge).”
  • Prior Converted Cropland (PCC). The Agencies propose to modify the PCC exclusion by removing definitional language and codifying a separate definition.^[10] The new definition revives the concepts of “abandonment” and “reversion” from the first Trump administration’s Navigable Waters Protection Rule^[11] (e., the cropland has not been used for or in support of agricultural purposes for a period of greater than five years, and the land has reverted to wetlands). Importantly, even if both abandonment criteria are satisfied, wetlands would be jurisdictional only if they are adjacent to a WOTUS.
  • Ditches. The Agencies propose to modify the exclusion for ditches (including roadside ditches) that are constructed or excavated entirely in dry land. The Agencies propose to define “ditch” as a constructed or excavated channel used to convey water. The proposed revisions mean that the exclusion is no longer flow-based (e., it would exclude ditches if they are excavated entirely in dry land, even if they have relatively permanent flow).
    • Ditches that are constructed or excavated in tributaries, relocate a tributary, or are constructed or excavated in wetlands or other aquatic resources are not considered to be constructed or excavated entirely in dry land. Those features would have to be evaluated to see if they meet the tributary definition.
    • The proposal places the burden of proof on the Agencies to show that a ditch was not constructed or excavated in dry land. When there is not sufficient evidence to support historical construction conditions (i.e., if agencies are not sure whether a ditch was excavated in dry land), the rule would default to non-jurisdictional status.
  • Groundwater. The Agencies propose to explicitly exclude groundwater, including groundwater drained through subsurface drainage systems. This would codify the Agencies’ longstanding interpretation that groundwater is excluded from CWA jurisdiction.
    
    

[1] 598 U.S. 651 (2023).

[2] Id. at 678.

[3] Id.

[4] 547 U.S. 715 (2006).

[5] Sackett, 598 U.S. at 671 (quoting Rapanos, 547 U.S. at 739 (internal quotation marks omitted)).

[6] See Revised Definition of “Waters of the United States,” 88 Fed. Reg. 3,004 (Jan. 18, 2023).

[7] See Revised Definition of “Waters of the United States”; Conforming, 88 Fed. Reg. 61,964 (Sep. 8, 2023).

[8] The timing of a “wet season” varies across the country due to a range of precipitating factors including climate, hydrology, topography, and soil composition.

[9]  According to the proposal, the phrase “having surface water at least during the wet season” is intended “to include wetlands that have at least semipermanent surface hydrology that is persistent surface water hydrology uninterrupted throughout the wet season except in times of extreme drought and would not include wetlands without semipermanent surface hydrology, including wetlands with only saturated soil conditions supported by groundwater.” Pre-publication notice at 110.

[10] “Prior converted cropland means any area that, prior to December 23, 1985, was drained or otherwise manipulated for the purpose, or having the effect, of making production of an agricultural product possible. EPA and the Corps will recognize designations of prior converted cropland made by the Secretary of Agriculture. An area is no longer considered prior converted cropland for purposes of the Clean Water Act when the area is abandoned and has reverted to wetlands, as defined in paragraph (c)(1) of this section. Abandonment occurs when prior converted cropland is not used for, or in support of, agricultural purposes at least once in the immediately preceding five years. For the purposes of the Clean Water Act, the EPA Administrator shall have the final authority to determine whether prior converted cropland has been abandoned.” Pre-publication notice at 185.

[11] 85 Fed. Reg. 22,250 (Apr. 21, 2020).