Following years of discussion, administrative rulemaking, and multi-state litigation, the Environmental Protection Agency (“EPA”) and Army Corps of Engineers (“ACOE”) have published a new regulatory definition of waters of the United States (“WOTUS”). On April 21, 2020, the EPA published a revised definition of WOTUS, dubbed the “Navigable Waters Protection Rule” (“2020 Rule”), in the Federal Register, 85 Fed Reg 22,250. The 2020 Rule represents the final version of the 2018 draft rule published on December 11, 2018. Now in its final form, the 2020 Rule went into effect nationwide on June 22, 2020, but a number of states and other local jurisdictions, as well as environmental and agriculture groups, have already filed suit seeking to challenge the 2020 Rule.


We previously discussed the background and significance of the WOTUS definition here. In sum, the Clean Water Act (“CWA”) regulations and restrictions apply only to “navigable waters,” which the CWA defines to mean “any waters of the United States, including territorial seas.” 33 U.S.C. § 1362(7) (emphasis added). The term “waters of the United States” is not further defined in the CWA. Thus, how federal agencies and courts define WOTUS determines the scope of agency jurisdiction under the CWA. The scope of jurisdiction is relevant for farmers, ranchers, timberland owners, homebuilders, developers, and others because if a proposed project or development includes jurisdictional waters or wetlands, the proposed project or development will likely be required to obtain approval from federal agencies before proceeding, adding delays and expense to the proposed project. Enforcement actions by the EPA and ACOE are also based on the scope of their jurisdiction over WOTUS.

The 2020 Rule follows years of uncertainty regarding the definition of WOTUS. In 2015, the Obama administration proposed revisions to the definition of WOTUS (“2015 Rule”) that many viewed as an expansion of CWA jurisdiction. In more than half of the states, federal courts issued a preliminary injunction against the 2015 Rule. Subsequently, the Trump administration delayed and repealed the 2015 Rule, though courts later deemed that effort invalid, leaving a patchwork of different applicable WOTUS rules across the country. In response to these decisions and concerns about the scope of the 2015 Rule, the Trump administration proposed a draft WOTUS revision in 2018. The 2020 Rule represents the final form of this previous draft, with minimal changes.

2020 Rule Provisions

Similar to the draft published in 2018, the 2020 Rule seeks to provide certainty by explicitly describing those waters or features that it seeks to cover, describing those waters or features that are explicitly excluded, and providing guidance for determining jurisdiction of waters or features that are not explicitly covered or excluded. First, the following are explicitly covered by WOTUS under the 2020 Rule:

  1. Territorial seas and traditional navigable waters,
  2. Perennial and intermittent tributaries to those waters,
  3. Lakes, ponds, and impoundments that contribute surface flow to territorial seas and traditional navigable waters, and
  4. Wetlands adjacent to jurisdictional waters.

Next, the 2020 Rule explicitly excludes twelve categories of waters and features from the WOTUS definition, including the following:

  1. Groundwater, including groundwater drained through subsurface drainage systems,‎
  2. Ephemeral streams and features that flow only in direct response to precipitation,
  3. Ditches, including agricultural ditches, that are not traditional navigable waters and are not constructed in adjacent wetlands and do not relocate a tributary of traditional navigable waters,
  4. Prior converted cropland, and
  5. Artificially irrigated areas that would revert to upland if artificial irrigation ceases.

When determining if a water body or feature meets one of the jurisdictional definitions or exclusions, federal agencies will consider the circumstances during a “typical year.” This definition will be important, especially in places like the Willamette Valley, in determining the division between an ephemeral stream, which only flows due to precipitation, and a perennial or intermittent stream, which flows seasonally or annually. The 2020 Rule defines a “typical year” to mean “when precipitation and other climatic variables are within the normal periodic range for the geographic area … based on a rolling thirty-year period.” Because a typical year is based upon the most recent thirty years, a typical year for a given region, water body, or water feature could change significantly over time because of climate change impacts.

While the 2020 Rule generally follows the 2018 draft rule, one significant change is the scope of jurisdiction over “adjacent wetlands.” The 2018 draft rule sought to define “adjacent” as only those wetlands that physically touch or have a continuous surface connection with jurisdictional waters. The 2020 Rule has a slightly broader definition of “adjacent” and includes those wetlands that “abut” navigable waters. “Abut” is defined to include when the delineated boundary of the wetland touches the delineated boundary of a jurisdictional water, but this definition does not require a direct surface connection. The practical impact of this broader definition is that wetlands that do not have standing or flowing surface water could still be jurisdictional if a delineated boundary borders a jurisdictional water boundary.

While this definition of “adjacent” is now broader compared to the 2018 draft rule, the 2020 Rule’s definition of “adjacent” is still significantly narrower than that of the 2015 Rule. For example, the 2015 Rule was criticized for including as jurisdictional any wetlands or other water features that were situated within the 100-year floodplain of a jurisdictional water, regardless of if a surface connection existed or if a delineated boundary was shared. The 2020 Rule removes any floodplain criterion and instead focuses on a direct surface connection or shared boundary, as discussed above.

Another noteworthy change in the new rules is the explicit exclusion of groundwater given recent contradictory Supreme Court precedent. Just last month, two days after the 2020 Rule was released, the Supreme Court ruled in County of Maui v. Hawaii Wildlife Fund, discussed further here, that discharges into groundwater may fall under the jurisdiction of the CWA to the extent that they represent the “functional equivalent” of a discharge directly into navigable waters. That is to say, according to the Supreme Court, in at least some cases, groundwater will fall under the jurisdiction of the CWA, whereas the 2020 Rule states that groundwater is completely excluded from CWA jurisdiction. This direct contradiction will need to be further addressed by the EPA, or interested parties will seek to address it through litigation.

Challenges to the 2020 Rule

Challenges to the 2020 Rule have been filed in multiple state district courts, including California, Colorado, Massachusetts, South Carolina, Maryland, Arizona, Washington, New Mexico, and Oregon. On July 19, 2020, the Colorado district court preliminarily enjoined implementation of the 2020 Rule, re-instating the 1986 rule and 2008 agency guidance based on Rapanos v. United States, 547 U.S. 715 (2006) as the means for defining the jurisdictional reach of the Clean Water Act in Colorado only. On the same date, the Northern District of California denied a motion for a nationwide injunction filed by California and a number of other states. There, the court found that the term “waters of the United States” is ambiguous, that Rapanos did not define the outer scope of the term, that agencies may receive Chevron deference for a new rule if the change is reasoned and explained, and that a change in administration does not make the new rule improper so long as the agencies satisfy the Chevron test, which the court found they did here. State of California v. Wheeler, Case No. 3:20-cv-03005 (N.D. Cal., June 19, 2020).

In Washington, the Washington Cattleman’s Association is challenging the 2020 Rule’s definition of intermittent and non-abutting wetlands, arguing that these definitions exceed the limits of the Rapanos plurality, which WCA is arguing is the controlling decision in that case. All of these cases will be important to watch, both as they relate to the difficult task of interpreting Rapanos and as to which version of the waters of the United States’ rule will control in various jurisdictions. It will also be important to see whether they will lead to a future, additional look at the term “waters of the United States” by the newly constructed Supreme Court of the United States.

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