Pitfalls of Ping Pong WOTUS Policy

Ever-changing Waters of the United States (WOTUS) policy impacts both the regulatory and consulting spaces, as well as environment and infrastructure.


  • History of Waters of the United States and the Clean Water Act
  • WOTUS and the Navigable Waters Protection Rule (NWPR)
  • Regulatory Changes Due to the NWPR
  • NWPR Litigation

Moderators Jeremy Schewe, PWS, Chief Scientific Officer, Ecobot 

Presenters and Panelists Donna Downing, JD, Senior Legal Policy Advisor, Association of State Wetland Managers
Matt Stahman, PWS, Director of Regulatory, Resource Environmental Solutions
Gordon Shaw, PWS, Senior Wetland Specialist, Burns & McDonnell
Royal Gardner, JD, Professor, Stetson University College of Law

The Past is Prologue: Definition of WOTUS Over Time Waters of the United States (WOTUS) is a threshold term in the Clean Water Act (CWA), that establishes which waters are regulated by the Act’s programs. The CWA regulatory programs address “navigable waters,” defined in the statute as “the waters of the United States, including the territorial seas.” Legislative history indicates that the term should be interpreted as broadly as the Commerce Clause allows. Whether a particular water body is jurisdictional as a WOTUS  is a key threshold question for deciding if the water is subject to the regulatory provisions of the act. If it’s not a WOTUS, it’s not subject to those regulatory provisions; if it is a WOTUS, it is. The CWA does not define WOTUS; Congress left further clarification to the agencies. The EPA and the Army Corps of Engineers have defined WOTUS by regulation since the 1970s.

“With the inherent statutory ambiguities, and a great deal at stake, it’s not surprising that scope of WOTUS has been the focus of extensive rulemaking efforts over the decades, and as well as subject to considerable litigation, including three U.S Supreme Court decisions so far,” says Donna Downing, JD, Senior Legal Policy Advisor, Association of State Wetland Managers. “With respect to Clean Water Act jurisdiction, the past is prologue.”

Many of the CWA jurisdiction issues raised today by the regulatory definition of WOTUS and challenges in the courts were present in earlier definitions. The regulatory definition of WOTUS has been reviewed by the federal courts many times, beginning with the 1975 case NRDC v. Callaway decision of the District of Columbia district court, which held that Congress intended the CWA jurisdiction to be as broad as the Commerce Clause allows. The EPA and the Army Corps also explicitly referenced the Commerce Clause in their definitions of water starting in the 1970s, including both navigation-based commerce and interstate commerce, generally. 

  • EPA 1973 definition:  Navigable waters and their tributaries; interstate waters; intrastate waters used for interstate commerce.
  • Corps 1975 definition, which replaces the initial definition focused on navigation: Navigable waters; waters subject to the ebb and flow of the tide; coastal or adjacent wetlands; tributaries; intrastate waters used for interstate commerce.
  • EPA & Corps 1979 definition: Waters used for commercial navigation in the past, present, or future with reasonable improvements; waters subject to ebb and flow of the tide; interstate waters; intrastate waters use/degradation of which could affect interstate commerce; impoundments of WOTUS; tributaries of WOTUS; territorial seas; adjacent wetlands.

That final definition, which is often called “the 1986 definition,” despite being in place earlier, looked very similar to that in place until 2015, when the Obama administration changed it. 

Initial efforts to narrow the definition of WOTUS resulted in a 1979 EPA regulation that excluded waste treatment systems from WOTUS , including treatment ponds and lagoons designed to meet the requirements of the Act. In other words, they had to be treating something. In 1993, EPA and the Army Corps promulgated a second exclusion from regulatory definition of WOTUS for Prior Converted Cropland (PCC). PCC includes wetlands manipulated to grow commodity crops sold in commerce prior to 1985. In federal register preamble language in 1986 and 1988, EPA and the Corps provided examples of WOTUS generally not considered to be Waters of the United States, including features such as: not entitled drainage and irrigation ditches; excavated and dry land; and artificially irrigated areas that would revert to upland if irrigation ceased. This preamble language affirmed the emerging agency’s practice of the time. The scope, the applicability, and permanence of exclusions remain a hot issue today. 

Another long-standing issue with WOTUS is the extent to which geographically isolated wetlands and waters can be Waters of the United States. In 1985, in response to a congressional inquiry, then-EPA counsel Frank Blake indicated that isolated waters can be WOTUS, if they’re used by migratory birds or endangered species. This language was included in the Federal Register Preambles from 1986 and 88 by the Corps and EPA, illustrating the kinds of commerce lengths the agencies felt were sufficient to assert jurisdiction over a water as a Water of the United States. The examples included use of the water as habitat by migratory birds or endangered species, or to irrigate crops sold in commerce. These examples became known as the “migratory bird rule,” even though not a rule, but preamble language, nor is it entirely about birds. 

Then the U.S Supreme court ruled in Solid Waste Agency of Northern Cook County v. U.S. Army Corps of Engineers (referred to as SWANCC)in 2001. The Court held that an isolated, interstate, non-applicable water cannot be considered WOTUS based solely on the presence of migratory birds. This effectively invalidated the so-called “migratory bird rule.” SWANCC did not invalidate the regulatory definition of WOTUS, but qualified how it was applied to isolated waters. 

The Supreme Court addressed the question of WOTUS again in 2006, in the Rapanos decision. Rapanos explored the extent to which non-navigable tributaries and their adjacent wetlands were WOTUS. The 4-1-4 split decision didn’t help clarify the situation. There was not a majority opinion, in other words, although all justices seem to acknowledge that WOTUS was broader than just traditional navigable waters. Two standards emerged: the plurality’s relatively permanent standard, and Justice Kennedy’s significant nexus standard. The court, again, did not invalidate the regulatory definition of WOTUS, but qualified how it was applied. 

After Rapanos, EPA and the Army Corp issued guidance indicating that a water should be considered a WOTUS if it met either Scalia’s relatively permanent standard or Kennedy’s significant nexus standard. Scalia and Kennedy standards use jurisdictional terms that differ from those typically used by aquatic scientists. There is “relative permanence,” “continuous surface connection,” “similarly situated,” “significant nexus,” “isolated.” The implementation challenge for agencies, as well as the regulatory community, was: does a particular water have the characteristics called for by the legal terms, as defined by the agencies and the courts? Rapanos resulted in a surge of scientific research and papers on connectivity among WOTUS, exploring in a scientific context the new legal concepts of significant nexus and relative permanence.

After Rapanos, the water’s relationship to traditional navigable waters largely determined whether that water was a WOTUS, either because it flowed to the traditional navigable water at least seasonally, thus meeting the relatively permanent standard, or because it had a significant nexus to the traditional navigable water, satisfying the significant nexus standard. 

Regarding the Obama administration’s Clean Water Rule from 2015 and the Trump administration’s Navigable Waters Protection Rule from 2020, it is notable that the two regulatory definitions differ in their approaches to the degree to which science informs the scope of WOTUS. 

The Clean Water Rule acknowledged in its preamble that science alone could not determine jurisdiction, since the definition had to be within the authority granted by the Clean Water Act and consistent with the overall statutory framework and construct of the Act. Nevertheless, the Clean Water Rule relied heavily on aquatic resource science to inform its definition of Waters of the United States. 

The Navigable Waters Protection Rule replaced the 2015 with one more consistent with Justice Scalia’s relatively permanent standard from Rapanos. The rule preamble emphasizes the definition is based on law and policy objectives, including acknowledging states’ primary responsibility and authority to manage its water resources, and downplayed the role of science. Indeed, the EPA science advisory board and independent body noted that the Navigable Waters Protection Rule “offers no comparable body of peer reviewed set evidence and no scientific justification for disregarding the connectivity of waters excepted by current hydrological science.”

The changing definition of WOTUS is a challenge. As EPA and the Army Corps considered revisions to the definition of WOTUS, debates over what the definition should be are likely to continue raising the role of commerce, exclusions from the definition of Waters of the United States, status of geographically isolated waters, and the role of science and informing the scope of orders among other issues.

Why is WOTUS such a complex and recurring issue? First, it’s a threshold question, determining whether the Clean Water Act regulatory provisions apply or not. Its scope is tied to Congress’s Commerce Clause authority to enact the Clean Water Act, so it evolves as the courts consider the scope of the commerce clause itself. WOTUS is posed and defined in legal terms, the interpretation of which are informed by science, but there’s an imperfect fit between the law and the science in the terms of the terms. Some view WOTUS as a vehicle for raising other large issues, such as property rights or federal state responsibilities for environmental protection, and WOTUS has many institutional players with strong opinions.

From Obama’s Clean Water Rule to Trump’s Navigable Waters Protection Rule (NWPR) “We’ve seen many different features on the landscape be considered Waters of United States,” says Matt Stahman, PWS, Director of Regulatory, Resource Environmental Solutions. “From the territorial seas, traditional navigable waters, and then up the watershed through perennial streams, intermittent streams, ephemeral streams, and all those adjacent wetlands and impoundments that surround all of those features on the landscape, including some that are separated behind the artificial or natural structures… every one of these features at some point in time has been looked at as a Waters of the United States or has been considered a potential Waters of the United States.

“Post-Rapanos 2008, there were many straightforward jurisdictional waters, but also gray features on the landscape or waters that were being considered on a case-by-case basis. This was a fairly complex landscape and navigate, for those of us who have dealt with wetland delineations, or jurisdictional determinations under the U.S. Army Corps of Engineers. Every project came with its challenges to figure out what was the Waters of the United States.”

Then came the Clean Water Rule during the Obama administration, EPA 2015. It attempted to lend some certainty to exactly what were Waters of United States, and take some of the case-by-case considerations out of the post-Rapanos landscape. The biggest difference was the addition of distances, meaning that waters were considered either jurisdictional, if they were within a certain distance from other jurisdiction of waters, or potentially jurisdictional on a case-by-case basis. The distance provision generated a lot of the concern and pushback from different interest groups around the country. 

Under Trump’s Navigable Waters Protection Rule (2020), areas that had formerly been considered jurisdictional for the first 40+ years of the Clean Water Act were no longer. A few phrases in particular have been treated as open to interpretation, which we delve into below.

The first paragraph of the rule reads:

Waters of the United States means:

  • (1) Jurisdictional waters. For purposes of the Clean Water Act, 33 U.S.C. 1251 et seq. and its implementing regulations, subject to the exclusions in paragraph (2) of this section, the term “waters of the United States” means:
  • (i) The territorial seas, and waters which are currently used, or were used in the past, or may be susceptible to use in interstate or foreign commerce, including waters which are subject to the ebb and flow of the tide;
  • (ii) Tributaries;
  • (iii) Lakes and ponds, and impoundments of jurisdictional waters; and
  • (iv) Adjacent wetlands.

The rule is very simple: if a water is not listed in these four sub-parts of paragraph A, it is not a Water of the United States. 

The rule defines some key phrases that apply to these terms, including “inundated by floodwater,” “contributes surface water flow,” and “direct hydrologic surface connection,” in a typical year. “In a typical year” is defined as a rolling 30-year period of averages within normal periodic range. That raises a new consideration as to what is normal or what is a typical year, as it could change year to year as weather patterns shift across the country. 

For wetland scientists, the most relevant of these terms is “inundated by floodwater” from an adjacent jurisdictional tributary or other Waters of the United States. If you’re working with Navigable Waters Protection Rule, some of the most critical terms to consider, which have been clarified or tweaked in paragraph C, are:

  • Adjacent wetlands: Now includes wetlands that are inundated by flooding in a typical year by the territory seas, a jurisdictional tributary, or an impoundment of that tributary

  • Intermittent: Clarified somewhat to mean “surface water continuously flowing during certain times of a typical year, and more than indirect response to precipitation.” Those familiar with the definition previously used by the Army Corps of Engineers were used to “intermittent” being  influenced by groundwater at some time of year in order to provide some of its flow, which is no longer the case.

  • Lakes and ponds, and impoundments of jurisdictional waters

  • Tributary: Redefined as “a river stream or similarly natural occurring surface water channel that contributes surface water flow in a typical year” (emphasis added.) By “contributes surface water flow,” tributaries, as far as jurisdiction is concerned, are limited to perennial or intermittent channels. They do not include ephemeral channels any longer. It is important to note that tributaries do not lose their jurisdictional status in certain circumstances, including a channel that might go through subterranean portions, or which has been channelized for some portion of its length. 

  • Typical year

Regulatory Changes Due to the Navigable Waters Protection Rule Gordon Shaw, based in Kansas City, MO, works with Burns & McDonnell Engineering. In his capacity as an environmental consultant, he has seen the effects of changing WOTUS policy in his work with the 404 process. Many of the projects Burns & McDonnell works on receive authorization by nationwide permits, rather than individual permits. As a result of the changes brought about by the 2020 Navigable Waters Protection Rule, Shaw and his colleagues have seen that fewer waters are considered jurisdictional, there is less need for pre-construction notifications, and there are some permitting changes on the federal level.

Fewer Waters are Jurisdictional

“Waters in the upper reaches of the watershed are being excluded, especially ephemeral streams and wetlands adjacent to them,” Shaw noted. “These are waters where a lot of times farmers are not farming these areas, probably because they’re too wet, or there may be a channel there.”

“We’re also noticing a distinctive change in farmed wetlands. It seems like, before the rule, there was more of a gray area.” But now, Shaw says, it’s more of a black-and-white issue, where farmed wetlands will not be included. 

Fewer Pre-Construction Notifications Filed

Shaw has noticed a need for fewer pre-construction notifications, due to less stream, ephemeral stream, and wetland impacts. “That [previous] 300-linear-foot limit may be a moot point now, with the new nationwide permits that have just come out.”

There is less ambiguity and less concern on what’s considered jurisdictional, Shaw says, including the definition of a waste treatment system, which is specifically addressed in the rule. It’s given clients more confidence that htey understand the rule and regulations correctly.

State Responses to the Rule and Changes to Federal Permitting

“We’re noticing some state responses to the rule, including the one in Colorado, where the states are concerned that fewer waters are going to receive protection. So the Navigable Waters Proection Rule was not effective there for some time. It has now become effective,” says Shaw.

Some states, including Florida, have assumed responsibility for the 404 program. Other states are assuming jurisdiction in those areas that are now excluded from federal protection, including in Ohio, where there is now an ephemeral stream permit, such that no federal permit is required to fill in an ephemeral stream in Ohio, but a state one is.

Effects for Clients

“With fewer permit applications, we’ve noticed that there’s less costs, less mitigation, that makes her happy clients, happy applicants,” Shaw says. “Delineators at some point it may be easier to determine what’s a Water of the U.S. and what’s not.  There’s no certificate, significant nexus test now. You do need, however, to identify that direct connection to Waters of the U.S., and you may need to also prove that a stream is not a jurisdictional stream, and prove that it is ephemeral. In summary, we’ve found that fewer waters are considered Waters of the U.S.”

NWPR Litigation: Past and Future At least 12 cases have been filed challenging the NWPR. These include those filed by the Washington Cattlemen’s Association and the New Mexico Cattle Grower’s Association, which contend that the NWPR is too broad, and that the scope of the CWA should actually be narrower. Most, however, are challenging the NWPR as being too narrow, and not protecting enough waters. 

“Cases have been filed from sea to shining sea,” says Royal C. Gardner, Professor of Law and Director, Institute for Biodiversity Law and Policy at Stetson University. That’s because, when the regulated community challenged the Obama administration’s Clean Water Rule, one of the cases went to the Supreme Court–”Not on merit,” Gardner said, “but on the question of which court had jurisdiction to consider Clean Water Act jurisdiction.” Ultimately, the Court held that challenges to the WOTUS must begin in district courts, rather than the court of appeals, where it could be consolidated nationally. This was a win for the regulated community, since groups can now file in any district court in the country.

In the future, says Gardner, “you’ll see claims made that the rule is is arbitrary and capricious, for failing to consider comments, or arbitrary and capricious for failing to explain the rationale for the change. Or failure to consider the impacts of reduced jurisdiction. With respect to the substantive challenges, it would be that the Navigable Waters Protection Rule is an unreasonable interpretation of the Clean Water Act.”

What if the Biden administration decides not to defend the rule? Those cases don’t go away, says Gardner, since industry groups will have intervened, and they’ll defend the rule. “I think we will see some of these cases proceed, even if the Biden administration decides to go forward with a rulemaking.”

Now, if a Biden rule is issued, which can take a long time, “maybe they will go with the two-step approach that the Trump administration did with repealing the Navigable Waters Protection Rule first, which would then bring us back to the 2019 rule which is technically the pre 2015 status quo. If they do this, then that should actually move out this current round of litigation. And then of course we would then start a new round of litigation,” Gardner says.

But what if a court actually strikes down the NWPR in the interim, befure the Biden administration does anything? “Well, it will very much depend on the scope of relief, in terms of how broadly the injunction will apply,” explains Gardner. “Will it apply only to the parties that are before the court? Will it be limited to the state in which the court resides? Perhaps it might be as broad as the circuit in which the court resides, or it could be a nationwide injunction. This is a complicated controversial area in terms of the scope of these injunctions. So that is something to watch for as well. So we might actually see at least in the interim a ping pong patchwork policy.”

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