
In May, the U.S. Supreme Court issued a ruling in Sackett vs EPA that ended federal protections of some kinds of wetlands and tributaries under the U.S. Clean Water Act.
Like many organizations, ASLA released a statement condemning the decision. ASLA found the ruling “short-sighted” because it “ignores science and the well-documented hydrological understanding of the interconnection of water sources.”
This statement was rooted in ASLA’s long-held, science-based policy positions on the waters of the United States and wetlands, and a legacy of comments sent to administrations, including the Biden-Harris administration during its last rule making process in 2022. ASLA’s positions were crafted from feedback from members who found recent definitions of waters of the U.S. and policies unclear and not grounded in hydrological or climate science.
According to a national poll issued by The New York Times, 72 percent of Americans also disagreed with the recent Supreme Court decision and believe the “Clean Water Act should be read broadly and include things like wetlands.”
And as landscape architects and ecologists know, “what is a wetland isn’t as black and white as the Supreme Court defined,” said Steven Spears, FASLA, project principal with Momark Development and GroundWork.
“The Supreme Court decision was wrong for a number of reasons,” said Keith Bowers, FASLA, president and founder of Biohabitats and a professional wetland scientist. “The decision was not based on science.”
According to the Congressional Research Service (CRS), the recent Supreme Court ruling defines waters of the U.S. as “relatively permanent bodies of water connected to traditional navigable waters.”
It defined some wetlands as waters of the U.S. if they have a “continuous surface connection to other jurisdictional waters, so that there is no clear demarcation between the bodies.” But the decision excludes other wetlands that are “neighboring waters but are separated by natural or artificial barriers.”
“The ruling interpreted wetland adjacency differently. The Supreme Court said a wetland needs to have a surface nexus with a stream, river, or navigable water to be federally protected. But we know wetlands are connected to other water bodies through both groundwater and surface flows, which may be continuous or not,” Bowers said.
“There is a lot to unpack with the Supreme Court ruling and more clarity will come in time,” Spears said. But the Supreme Court decision “just sees wetlands on a black and white basis. It also fails to account for wetland quality.”
The Sacketts sued the EPA in 2008 because it classified wetlands on their property in Idaho as waters of the U.S. The wetlands were near a ditch that fed into a creek, which then fed into Priest Lake, a navigable, intrastate lake.
In its recent decision, the Supreme Court essentially found that “the wetlands were not waters of the U.S. because they were separated from the lake by a road – even though they were connected to the lake under that road by a culvert,” Spears said.
Spears thinks it’s possible the wetlands in question were low-quality and that filling them in had little impact on the broader water quality of the lake. But it’s hard to tell because the ecosystem services of the particular wetlands weren’t measured.
“The Supreme Court decision is frustrating because it just states a wetland is either a wetland or not, regardless of the performance of the wetland and what ecosystem services it provides.”
At Austin Green in Austin, Texas, Spears and his firm, GroundWork, led a redevelopment of a former sandy gravel mine that was created before the Clean Water Act went into effect in 1972.
The brownfield site included both high-quality wetlands and other low-quality wetlands that happened to form out of the dredging process. The 2,100-acre redevelopment preserves and enhances more than 850 acres of high-performing wetlands and other ecological assets as part of a public park along the Colorado River.

The team – which included landscape architects at Lionheart Places and ecologists at ACI Consulting – used the U.S. Army Corps of Engineers Ft. Worth District’s Texas Rapid Assessment Model (TRAM) to score the ecological service quality of the wetlands on the site and win approval of the project.
“We used the tool to conduct a land suitability analysis and planning process.This process informed the landscape architecture-led planning and design team as to which environmental systems were most desirable for protection and enhancement.”
“The model was used to identify high-quality wetlands that scored a 70 out of 100. We focused on how to raise their quality level to an 80 or 90. The redevelopment plan and park and open space network were curated around these ecological assets. There were also low-quality wetlands that scored a 1 out of 100, and some of those were filled in. What’s important to figure out is how a wetland performs, what is their worth. And if you need to fill in a wetland, mitigate or offset that elsewhere.”
While he doesn’t support the Supreme Court ruling, “now that it is the law of the land, how do we move forward?”
Spears wants to see a tool like the Army Corps’ TRAM as a national approach, with adjustments for important regional wetland and geomorphological differences. He noted that some Army Corps districts have wetland scoring tools and some don’t.
“Landscape architects can lean in and help establish the criteria for a new wetland scoring system. That will help us get away from ‘this is a wetland and that is not.’ We need to influence and help create a new wetland modeling process.”
Bowers thinks the ruling will open up lots of land and wetlands that were historically regulated to new development that will not be subject to federal approvals.
He thinks this is bad news for watersheds overall. “If you impact a river at its mouth, it won’t impact the system. But if you impact the wetlands – the headwaters – the water system can collapse. Wetlands are where you establish the ecological processes and then they migrate down the ecosystem.”
“I think all wetlands should be protected, as some wetlands that are low-quality today may not have been historically. As landscape architects, we should not impact any wetland if it’s in our power. With the climate and biodiversity crises, we need wetlands to sequester carbon and provide habitat. We need to do everything to minimize or mitigate impacts.”

For him, tools like TRAM can be useful in prioritizing which wetlands to save and restore. But he thinks the evaluation of any particular wetland’s quality should be rooted in a broader understanding of the watershed in which the wetland exists. He said the Supreme Court decision will increase the importance of watershed planning and the role of landscape architects in comprehensive planning for water resources.
The ruling also muddies the waters, so to speak, about how ephemeral waters will be considered in the future, potentially opening up future litigation.
According to CRS, “the majority opinion does not explicitly address ephemeral waters, which flow only in response to precipitation, or intermittent waters, which flow continuously during certain times of year, such as when snow pack melts. At a minimum, the majority’s interpretation would appear to exclude ephemeral waters.”
But a majority of Supreme Court justices also recognized that “‘temporary interruptions in surface connection’ – such as from low tides or dry spells” – happen in wetlands. “It is not clear how temporary such an interruption must be in order to preserve a wetland’s jurisdictional status.”
Hearing this, Spears seemed exasperated. In Texas, this lack of clarity on seasonal waters may impact how ephemeral streams and agricultural stock tanks are considered. “The Supreme Court seemed to create more problems than they solved.”
As regulations are rewritten, he sees opportunities for landscape architects to offer their deep expertise in designing with water and creating innovative approaches. He wants landscape architects to shape the next generation of water policy. “The reaction to Sackett vs EPA that is coming can help solve our water problems over the long-term.”
For Bowers, it’s important for landscape architects to be strong advocates for the preservation and restoration of wetlands through their projects and in their communities. “Try to insert policy standards and push for updates to zoning regulations.” And landscape architects can reach out to their Congressional representatives. “Legislators need to further clarify the definition of waters of the U.S.”

What else to know about waters of the U.S.
Since 1972, the Clean Water Act has protected the country’s aquatic environments from pollution. It was created by Congress to keep water bodies safe for wildlife and fishing and swimming. It has also protected communities’ drinking water supplies.
After the Act established federal jurisdiction over navigable waters, there have been a number of rulings by the Supreme Court. This is because the Clean Water Act never clearly defined what waters of the U.S. meant and instead authorized the U.S. Army Corps of Engineers and EPA to create that definition through regulations.
According to the Natural Resources Defense Council (NRDC), lawmakers were “inclusive” in their original conception of the waters of the U.S.
Legislators understood that it comprised “all the relevant parts of an aquatic ecosystem, including streams, wetlands, and small ponds—things that aren’t necessarily connected to the tributary system on the surface, but that still bear all kinds of ecological relationships to that system and to one another.”
And up until the 2000s, NRDC says, that inclusive definition of the waters of the U.S. was largely upheld through court cases.
The Supreme Court ruling in May came after multiple lawsuits filed in opposition to the Biden-Harris administration waters of the U.S. definition, which went into effect March 20, 2023. Those lawsuits halted implementation of the use of the definition in 27 states.
After the Sackett vs EPA decision, new guidance on the waters of the U.S. is being developed by the EPA and will be released in September.
The EPA and U.S. Army Corps of Engineers will also need to revise or amend a slew of regulations to be compliant with the Supreme Court decision.
To be specific, the ruling impacts many EPA regulations and programs that rely on a definition of waters of the U.S., including:
- Water quality standards and total maximum daily loads
- Oil spill prevention and preparedness programs
- State and tribal certification under Section 401 of the Clean Water Act
- Pollutant discharge permits
- Dredged and fill material permits
The U.S. Army Corps of Engineers, which operates in close collaboration with the EPA, will also need to update or revise its approach to military and civil engineering projects and permits that involve non-tidal and tidal wetlands.
Changes to these federal regulations and programs will also lead to cascading revisions of state regulations.
The Clean Water Act requires that state regulations adhere to its minimum requirements. It also allows states to go beyond the Clean Water Act and issue more stringent regulations. Some states have surpassed the federal level of water protection, while others have passed laws stating that only the bare federal minimum will be followed.