The Fight Over Waters of the US

Featured Image Credit: Whitney Kroschel

EPA Proposal (Dec. 11, 2018): Revised Definition of Waters of the US.

On December 11, 2018 the Trump Administration’s Environmental Protection Agency and US Army Corps of Engineers issued a proposal defining waters of the United States. The new proposal could eliminate protections for 18% of streams and 51% of wetlands nationwide.

How do we regulate waters right now?

The Clean Water Act (CWA) is currently the law of the land. Adopted by Congress in 1972, this Act protects waterways through federal jurisdiction by regulating pollution. The CWA is implemented by the US Environmental Protection Agency (EPA) and the US Army Corps of Engineers (Corps). By regulating pollution in US waterways, the CWA also made it necessary to define what is considered a waterway. Waterways protected by the CWA came to be known as “waters of the US”, or WOTUS.

Herein lays the controversy: How we define WOTUS ultimately decides which water bodies get protected and regulated. On December 11, 2018 the EPA issued a proposal with new definitions of WOTUS. If implemented, the new jurisdiction would dramatically scale back the number of water bodies protected by the CWA, many of which have been protected since the policy was enacted.

The CWA was adopted in 1972, why is WOTUS getting defined now?

Good question! There have actually been several twists and turns in trying to clarify and implement the CWA, and up until recently, Supreme Court decisions have guided interpretation of the law. To understand what the EPA is doing now, we have to back up a bit.

The goal of the CWA is the “restoration and maintenance of chemical, physical and biological integrity” of America’s waters for current and future generations. Water bodies such as rivers, lakes, permanent streams, and territorial seas are easily identifiable and thus fall under federal protection as “navigable waters”. But what about wetlands? What about those streams in the foothills that only run after a heavy rain or snowmelt? What about that swampy low-lying area in your backyard? What about that little duck pond that waxes and wanes in size based on rainfall and the time of year? Areas like these – and many others – can be difficult to define and thus have been categorized as “non-navigable waters”. The value of these waters is controversial. Furthermore, some sections of the Act include language such as “intrastate waters” and “any waters”, causing some to argue Congress intended to expand the Act beyond traditionally navigable waters (Mank 2007).

Up until 2001 the Corps and the EPA included protection for non-navigable waters, though some notable court cases modified the scope of wetland protection (e.g., Natural Resources Defense Council, Inc. v. Callaway; United States v. Riverside Bayview Homes, Inc.). In 2001 the rules changed. In the 2001 case, Solid Waste Agency of Northern Cook County (SWANCC) v. United States Army Corps of Engineers, the Supreme Court ruled that the Corps could not regulate wetlands isolated from navigable waters. The Court held that protected wetlands included those with a “significant nexus” to navigable waters, i.e., wetlands adjacent to navigable waters or that maintain an important connection with them were included. As to be expected, there was disagreement and inconsistency with how the lower courts interpreted SWANCC and what constitutes a “significant nexus” (Mank 2007). However, nearly all the lower circuit courts adopted the significant nexus test for determining the Act’s jurisdiction.

In 2006 things became further complicated in the case Rapanos v. United States which addressed wetlands located near, but not immediately adjacent to, navigable waters and that flow into them. The Supreme Court divided 4-1-4: Justices Scalia, Thomas, Alito, and Chief Justice Roberts wrote a plurality opinion, often referred to as the “Scalia opinion”, which narrowly defines jurisdictional waters as “relatively permanent, standing, or continuously flowing” and wetlands that have a physical surface water connection to these waters. This opinion is highly criticized due to its arguable dictionary definition, lack of scientific basis, and absence of ecological consideration. Justices Stevens, Ginsburg, Souter and Breyer issued a dissenting opinion that upheld the Corps’ broad regulation of wetlands, highlighting the ecological importance of the Act and leaving expert interpretation to the EPA and Corps. Critics of this opinion point out the onerous responsibility this puts on the Corps and lower courts to consider complex ecological relationships between wetlands and navigable waters.

Justice Kennedy’s lone opinion compromised between the ecological intent of the CWA and the constraint of the term ‘navigable waters’. He extended jurisdictional wetlands to those with a “significant nexus” to navigable waters (Mank 2007). Thus, wetlands that significantly affected navigable waters, either hydrologically or ecologically, were protected. Since Rapanos, lower court decisions have largely followed the Justice Kennedy’s significant nexus test.

Figure 1. An explanatory figure of the 2015 Clean Water Rule from the EPA.

That is, until the Clean Water Rule.

After Rapanos, the Corps and EPA promised to develop joint guidance to address the scope of the Act by defining WOTUS. The 2015 Clean Water Rule under the Obama Administration sought to clarify WOTUS such that implementation of the CWA and its jurisdiction would not heavily depend on court decisions. The Clean Water Rule broadened the scope of the Act’s jurisdiction by an estimated 3%, including protection for many smaller water bodies such as streams that only flowed seasonally, isolated wetlands, prairie potholes, and vernal pools. The EPA relied heavily on scientific evidence to develop the rule, emphasizing the importance of hydrologic connectivity in affecting water quality (Fig. 1). Although ecologists, conservationists, and hydrologists largely approved of the Clean Water Rule, more than 100 parties filed lawsuits after the new rule was issued. Many farmers, ranchers, developers, and industry groups argued the rule went too far, overreaching its jurisdiction. At present the rule is in effect in 26 states and Washington D.C. Due to injunctions of the Clean Water Rule’s implementation from district courts in North Dakota and Georgia, the other 24 states continue to follow guidance consistent with previous Supreme Court decisions, including the significant nexus test. In February 2017 President Trump signed an executive order directing the EPA to formally revise the Obama Administration’s 2015 Clean Water Rule.

The Most Recent Development

On the 11th of December 2018, the Trump Administration’s revision was proposed by the EPA and the Corps as the Revised Definition of “Waters of the United States” which states, “The agencies propose to eliminate the case-by-case application of Justice Kennedy’s significant nexus test, proposing instead the establishment of clear categories of jurisdictional waters….” The new definition closely aligns with the former plurality opinion after Rapanos – the Scalia opinion – which drastically narrows the scope of the Act by limiting the definition of WOTUS to permanently flowing waters and wetlands that have a physical surface water connection. The proposal eliminates protections for seasonally and intermittently flowing streams, as well as isolated wetlands. In other words, about 51% of all wetlands and 18% of streams nationwide (including more than a third of streams in the arid west) will lose protection under this rule.

The new rule sought to bring clarity and predictability to WOTUS, thereby reducing the burden of the EPA and Corps to account for many smaller water bodies including wet meadows, mudflats, and minor isolated wetlands that feed into larger waterways. In turn, this reduces the scope of environmental monitoring and permitting required by industry groups. The fate of newly unprotected wetlands would be left to the states. While supporters argue this allows states to manage their own local waters, water movement is not restricted by state boundaries as with many shared natural resources, such as air and aquifers. Thus, state-by-state regulation may be insufficient and cause much litigation.

As expected, many environmental groups (e.g., Ecological Society of America [ESA], Society of Wetland Scientists, and Consortium of Aquatic Science Societies) oppose this new WOTUS definition, stating “the EPA undermines the use of the best available science showing strong benefits of protecting wetlands and upland watersheds…. It will also require taxpayers to pay for costly infrastructure to prevent flooding that wetlands currently provide at no cost by absorbing stormwater” (ESA President Laura Huenneke). Wetlands are arguably the most valuable ecosystems on the planet, providing carbon storage, wildlife habitat, water pollutant removal, recreation, timber resources, and flood protection. Coastal wetlands in the U.S. alone provide an estimated economic value of $23 billion in merely storm protection (Costanza et al. 2008). Freshwater wetlands affect drinking water; more than one third of the U.S. population rely on drinking water from sources fed by seasonal streams that would be unprotected under this new rule (EPA 2009; 2018). Moreover, approximately 59% of all streams in the United States (excluding Alaska) are seasonal, including over 81% of streams in the semi-arid Southwest (EPA 2008).

And that is not even considering groundwater. The CWA only protects surface waters; groundwater regulation is decentralized in the US. But groundwater is fed by rainwater, which travels by way of small streams and water bodies to reach aquifers, as well as rivers and lakes. Groundwater is often connected to surface waters, and seasonal water bodies are important sinks of excess rainwater before it becomes groundwater.

The proposed WOTUS rule will be published in the Federal Register and a 60-day comment period will be allowed before becoming approved. However, like the 2015 Clean Water Rule, the Trump Administration’s WOTUS rule is expected to get tied up in courts by environmental groups. As the U.S. population grows and demand for natural resources rises, the divide between developers and conservationists about the scope of the Act will likely widen. Unless Congress achieves sufficient consensus to pass legislation defining the Act’s jurisdiction, the scope of the Act will continue to transform.

“Congress has within its power to determine the scope of the Clean Water Act. Despite 45 years of litigation over the scope of the act and three Supreme Court decisions that have gone ever[y] which way, they have only sown confusion that Congress has not been able to even begin to define what the Clean Water Act means. It’s really Congress’ responsibility to do that and it’s only been because that has not happened on a statutory basis that the courts have played such a crucial role. “ -Stephen Samuels, February 9, 2018. (Retired Assistant Chief of the Environmental Defense Section of the Environment & Natural Resources Division of the U.S. Department of Justice.)



Costanza, R., O. Perez-Maqueo, M.L. Martinez, P. Sutton, S.J. Anderson, and K. Mulder. 2008. The value of coastal wetlands for hurricane protection. AMBIO: A Journal of the Human Environment, 37(4):241-248.[241:TVOCWF]2.0.CO;2

Environmental Protection Agency. 2018. Proposed Rule: Revised Definition of “Waters of the United States”.

Environmental Protection Agency. 2009. Geographic Information Systems Analysis of the Surface Drinking Water Provided by Intermittent, Ephemeral and Headwater Streams in the U.S.

Environmental Protection Agency. 2008. The Ecological and Hydrological Significance of Ephemeral and Intermittent Streams in the Arid and Semi-arid American Southwest. Office of Research and Development Washington, DC.

Mank, B. 2007. Implementing Rapanos – will Justice Kennedy’s significant nexus test provide a workable standard for lower courts, regulators, and developers? University of Cincinnati College of Law Scholarship and Publications, pp. 291-349.

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Whitney Kroschel

Whitney Kroschel

I am currently a PhD Candidate at Louisiana State University in Baton Rouge, LA. My research interests are generally in the fields of plant ecology, seed ecology, and wetland science. My dissertation research is evaluating the effects of flooding on tree species composition in forested wetlands.

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