The latest WOTUS rule, explained

Kristen Schlemmer
February 9, 2023

On January 18 of this year, the U.S. Environmental Protection Agency and Department of Army published what is intended to be the final rule redefining “waters of the United States,” also known as “WOTUS.” WOTUS is a threshold term in the Clean Water Act that establishes the geographic scope of federal jurisdiction under the Clean Water Act–but which has long been left undefined by Congress. For the greater Houston region, the definition of WOTUS is especially important when it comes to protecting wetlands and the immense benefits they provide local communities, including reducing flood risk, capturing carbon, and improving water quality.

Through three presidential administrations, Bayou City Waterkeeper has submitted comment letters to WOTUS rulemakings and permits that don’t offer sufficient wetland protections, participated in three lawsuits (two locally and one at the U.S. Supreme Court), filed administrative enforcement complaints, and created community mapping tools to enable residents to better understand how a planned development might affect their own neighborhoods. 

Which is to say we care about this issue, a lot. Our region is home to some of the most unique and diverse wetlands in the world. These wetlands are not only home to millions of migratory birds that benefit from the rich coastal habitat, but they also maintain water quality, serve as nature’s best defense against flooding, and capture carbon.

Absent a court ruling to the contrary, the new WOTUS rule will go into effect on March 20, 2023. 

Learn more about how we’re defending the new rule against attack in Defending our wetlands in court, again.

Below, we’ll show how this rule reinforces earlier jurisdictional definitions of WOTUS while strengthening jurisdiction over wetlands by articulating the scientific factors agencies must consider. While we work to defend the rule, we’ll continue to support communities concerned by wetland loss through education, community science, and legal tools, while also working to develop stronger policies to protect wetlands at the regional level. 

How does the new rule protect wetlands?

In creating protections for “adjacent wetlands,” the new rule closely follows the definition of “waters of the United States” that was in place before 2015. The rule defines “adjacent” to mean “bordering, contiguous, or neighboring” and protects wetlands that are:

  • Adjacent to a traditional navigable water (like one of our many bayous, rivers, or bays)
  • Adjacent to a tributary or impoundment of a traditional navigable water (that is, tributaries or impoundments of a local bayou, river, or bay) that are relatively permanent, standing, or continuously flowing and have a continuous surface connection to those waters
  • Adjacent to tributaries or impoundments when the wetlands either alone or in combination with similarly situated waters in the region, significantly affect the chemical, physical, or biological integrity of a traditional navigable water, like one of our many bayous, rivers, or bays. 

Importantly, the rule clarifies that jurisdiction should also extend to wetlands that are not “adjacent” in several key circumstances, a change that could have important ramifications for our region. Specifically, the rule contemplates that when a wetland is not “adjacent,” it nevertheless warrants protection under the Clean Water Act when wetlands are:

  • relatively permanent, standing, or continuously flowing, with a continuous surface connection to traditional navigable waters (like bayous, creeks, rivers, or bays) or their tributaries or impoundments; or
  • either alone or in combination with similarly situated waters in the region, significantly affect the chemical, physical, or biological integrity of traditional navigable waters (like bayous, creeks, rivers, or bays).

The rule further explains that the phrase “significantly affect” requires a “material influence” on the chemical, physical, or biological integrity of a traditional navigable water (like our bayous, creeks, rivers, and bays). To evaluate whether a wetland has this level of effect or influence, the rule instructs agencies to assess the following functions:

  • Contribution of flow;
  • Trapping, transformation, filtering, and transport of materials (including nutrients, sediment, and other pollutants); 
  • Retention and attenuation of floodwaters and runoff;
  • Modulation of temperature in traditional navigable waters (like our bayous, creeks, rivers, and bays); or
  • Provision of habitat and food resources for aquatic species located in traditional navigable waters.

Beyond these factors connected to the chemical, physical, and biological integrity of our waters, the rule instructs agencies to consider:

  • The distance from a traditional navigable water (like our bayous, creeks, rivers, and bays);
  • Hydrologic factors, such as the frequency, duration, magnitude, timing, and rate of
  • hydrologic connections, including shallow subsurface flow;
  • The size, density, or number of waters that have been determined to be similarly situated;
  • Landscape position and geomorphology; and
  • Climatological variables such as temperature, rainfall, and snowpack.

Should we be concerned that this is the only protection for wetlands in our region?

Yes. The Clean Water Act is vital for protecting wetlands across our region. But even at its best, we should view it as the floor, not the ceiling, on wetland protections. 

When the Clean Water Act applies, it triggers a permitting program, which directs permit applicants to avoid and minimize wetland impacts and mitigate for any unavoidable wetland losses. This creates a regime that has allowed over-development of our floodplains, so long as wetlands’ functions are restored in some other location. This system of mitigation often has not fully compensated for lost wetlands and has not done enough to restore flood protections to communities. 

We need these federal protections to be as strong as possible, but to truly protect communities from flooding and climate change, we also need to adopt policies that preserve large expanses of natural systems, with the goal of preserving their flood benefits and ability to capture carbon for communities across our region living on the frontlines of disaster and climate change. This is something Bayou City Waterkeeper is actively working on. 

Is it true that wetlands converted for farming are exempt?

Not exactly. The final rule exclusion for prior converted cropland only covers wetlands.  Wetlands can be covered under the prior converted cropland exclusion if they meet USDA’s longstanding definition of prior converted cropland. Prior converted cropland loses its exclusion status if there is a “change in use” – meaning the area is no longer available for the production of an agricultural commodity. 

This is especially relevant in the Katy Prairie and other areas used for agriculture historically which are now being transformed into suburban developments.

Must agencies reassess jurisdictional determinations or permits issued under the Navigable Waters Protection Rule?

Absent a court ruling, it is clear that the new WOTUS rule will apply to jurisdictional determinations moving forward. But what happens when a federal agency has already evaluated jurisdiction under a previous rule — especially the Navigable Waters Protection Rule, which excluded most wetlands from jurisdiction?

Before explaining the process the federal agencies will follow for reassessing jurisdiction under the new rule, we first want to explain what an “approved jurisdictional determination,” or “AJD” is. A jurisdictional determination is a written Corps document indicating whether a water is subject to regulatory jurisdiction under section 404 of the Clean Water Act, which prevents destruction of wetlands without a permit. When a jurisdictional determination is approved, it means the Corps has approved a written statement and map identifying the limits of WOTUS on a particular parcel.

The EPA and Army Corps’ January 2022 guidance, which is reiterated in explanatory materials accompanying the new WOTUS rule, states:

  • Agencies must follow the definition of WOTUS in effect on the date the Corps completes

an AJD—not on the date of the AJD request. This means all AJDs issued after the NWPR was invalidated on August 30, 2021 must follow pre-2015 regulations.

  • Stand-alone AJDs issued under the NWPR before August 30, 2021 that do not trigger any permitting processes generally will not be reevaluated unless new information justifies their revision before expiration. See also Regulatory Guidance Letter (RGL) 05-02 (June 14, 2005).
  • New permit decisions cannot rely on AJDs issued under the NWPR; jurisdiction instead

must rest on the scheme set forth under the pre-2015 regulations. If a permit moves

forward under an AJD issued under the NWPR, it is unlawful.

  • Permit determinations made before the NWPR was invalidated that rely on a NWPR AJD generally will be allowed to remain in place, subject to 33 C.F.R. § 325.7, which allows modifications based on the public’s interest.


We’ll continue to share more information about WOTUS and our efforts to protect regional wetlands in the coming months. For any questions or help evaluating a development’s impact on WOTUS, please contact us at

Bayou City Waterkeeper is a bold advocate for communities across the Lower Galveston Bay watershed. Through sound science and creative legal strategy, we work toward a shared vision of water justice. As we shape policy solutions that embrace the strength of our region’s natural systems, we are most effective when we center the experience of communities most vulnerable to water, climate, and infrastructure Injustices.