On January 23, 2020, the new “Waters of the United States” (WOTUS) rule was issued by the US Army Corps of Engineers and the Environmental Protection Agency. It becomes effective 60 days from its publication in the Federal Register, which has yet to occur. The new rule defines “WOTUS” to mean territorial seas, traditionally navigable water bodies, tributaries, lakes and ponds, impoundments of jurisdictional waters, and their adjacent wetlands. It affects several Clean Water Act programs, including Section 404 (wetlands), Section 402 (end-of-the-pipe discharges), and Section 311 (oil and hazardous substance spills).

Regulated wetlands are the most controversial area of this new rule. They are often private lands but are heavily regulated. When proposed in 2019, the rule was to be clear enough for landowners to follow. Now, it is not so clear without fieldwork, although it is less complex than the previous (2015) WOTUS rule. Under the new rule, fieldwork is needed in order to make a wetlands or tributary assessment.

The final rule makes several critical changes from its 2019 proposal. The administration seems to be downplaying these changes, but the future field application of the new rule remains to be seen. Noteworthy changes include the following.

Man-made ditches were not to be regulated unless tidal or navigable. Drainage ditches had been used in the past as a regulatory connection between more distant wetlands and navigable waterways. However, the final rule calls ditches “tributaries” if they pass through wetlands and water flows through them. This continues to potentially expand wetlands regulation. (Tributaries under the proposed rule were to be natural only, not man-made.)

Wetlands, to continue to be regulated, had to be “adjacent” to navigable waterways, which the proposal narrowed to meaning abutting or touching. In the final rule, “adjacent” is expanded to include separation by natural or artificial means, e.g., berms and levees, as long as the wetlands are inundated by the waterway in a typical year, e.g., by culverts, gates, or pumps. This again expands regulations to include more wetlands in their entirety, even if the wetlands are separated by a culverted road. The more ditches are called “tributaries,” the more wetlands near tributaries can be federally regulated.

Ephemeral streams were not to be federally regulated, as they were inundated by rainwater only (using model data). However, an ephemeral break in an otherwise regulated intermittent or perennial tributary continues the regulatory jurisdiction. This new rule covers waters upstream, if water still flows downstream through barriers to a waterway, such as culverts, rocks, debris, a subterranean river, etc.

Possibly ephemeral surface waters may be considered regulated as intermittent, if they are seasonally inundated by more than a direct response to precipitation, e.g., indirectly by groundwater table elevation or snowpack melts. This is an expansion.

As regulated waters expand, more land can be federally regulated. We do not say this potential result is as broad as the now-repealed 2015 WOTUS rule, but it is likely broader than the rule proposed in 2019.

Now, all is not so expansive. The final rule rejects the controversial “significant nexus” test from 2015 and the concurring opinion in the Rapanos v. United States case. Instead, it accommodates the plurality and concurring opinion in Rapanos by expanding jurisdiction somewhat. That test, absent massive wetlands and stream data nationally, was actually too difficult for agencies to fulfill their burden on substantial proof of jurisdiction. Also, the final rule expands the Natural Resources Conservation Service-certified “prior converted cropland” exemption from Section 404, which excludes lands farmed since 1985 from 404 regulation if they have not been abandoned from documented cropping, haying, pasturing, or conservation for five years. Interstate waters, groundwater, and isolated waters such as prairie potholes are also excluded, and are left to states and Indian tribes to regulate.

Prior to undertaking projects, the 2020 final rule should be carefully reviewed.