New WOTUS Rule to Take Effect June 22, 2020

The final Navigable Waters Protection Rule (“NWPR”) to define “waters of the United States” (WOTUS) issued by the U.S. Environmental Protection Agency and the U.S. Army Corps will be published in the Federal Register on April 21, 2020. The Rule will take effect on June 22, 2020. Once effective, it replaces the rule the agencies published last year, which rescinded the 2015 WOTUS Rule and reinstated the previous definition ( However, litigation over the Rule is likely to ensue, as are questions about how the Rule may apply in specific contexts.

The final NWPR is similar to the proposed rule ( in many respects. Like the proposed rule, the NWPR regulates territorial seas and traditional navigable waters; all tributaries of those waters; lakes, ponds and impoundments of jurisdictional waters; and wetlands adjacent to jurisdictional waters (but not wetlands adjacent to other wetlands). The NWPR also maintains many of the same exemptions as the proposed rule, including for groundwater, ephemeral features, diffuse stormwater runoff, some ditches, converted cropland, artificially irrigated areas, artificial lakes and ponds, stormwater control features, waste treatment systems, etc. Further, like in the proposal, the agencies eliminated the entire category of interstate waters from federal jurisdiction and, in stark contrast to the pre-2015 approach, removed the concept of significant nexus from the analysis entirely.

However, the final NWPR is different from the proposal in several important ways. First, under the final rule, the agencies assert jurisdiction over wetlands separated from jurisdictional waters by a natural berm, bank, dune, or other similar natural feature. The proposal required a sufficient surface water connection.

Second, although the final NWPR purports to exclude ephemeral waters (i.e., waters that only flow in response to precipitation) and ditches, the rule draws in some ephemeral features and non-jurisdictional ditches in its treatment of tributaries and lakes, ponds and impoundments. As defined under both the proposed and final versions, a “tributary” requires an “intermittent” or “perennial” connection, i.e., it must contribute continuous surface flow to a traditional navigable water during certain times in a typical year. However, under the final rule, if the waterway contains a stretch that flows only ephemerally or that runs through a non-jurisdictional ditch, the agencies are declaring federal jurisdiction over the intermittent or perennial stretch on either side.

Likewise, in both the proposed and final rules, the agencies assert jurisdiction over all lakes, ponds and impoundments that contribute surface water flow to traditional navigable waters in a typical year. However, under the final rule, that connection may be through a channelized ephemeral feature or non-jurisdictional ditch. Although the agencies would not claim jurisdiction over that ephemeral stretch or the ditch, the lake, pond or impoundment and any intermittent or perennial flows on either side of those features would be subject to federal regulation.

Critically, similar to the 2015 WOTUS Rule, the agencies are retaining the authority to ascertain the location of intermittent waters, ephemeral features and ditches through remote means, including desktop modeling. In a February 2020 webinar explaining the rule, the agencies reported they will soon publish a beta version of a modeling tool available to the public, which they intend to add clarity to this effort. The agencies will continue to delineate wetlands using their longstanding methods, including the 1987 Corps of Engineers Wetland Delineation Manual and its regional supplements.

KMCL attorneys have been deeply involved in the WOTUS rule developments and litigation and welcome questions about the effect of this final NWPR on specific industries or situations.