The U.S. Supreme Court’s 2023 decision on Sackett v. Environmental Protection Agency dramatically weakened protections for millions of acres of the West’s essential wetlands and streams. Under the ruling, only bodies of water with a “continuous surface connection” to a “relatively permanent” traditional, navigable water body can be legally considered part of the waters of the United States (WOTUS) and therefore covered by the Clean Water Act.
The court’s definition excludes wetlands with belowground connections to bodies of water as well as those fed by ephemeral or intermittent streams. In effect, an estimated 60% of wetlands have lost federal protection, according to a National Resources Defense Council report. The language in the decision was ambiguous — exactly how wet a wetland has to be to fall under WOTUS and qualify protections was left up to federal agencies.
Wetlands are critical to both human and ecosystem health as well as for climate change mitigation. But they are also prime targets for dredging, filling and other disruptions because of their proximity to water and rich, fertile soil.
Under President Biden, the EPA broadly interpreted Sackett, focusing on protecting wetlands adjacent to bodies of water, with no explicit threshold for how often they had to be flooded. In March, however, Donald Trump’s EPA released a memo indicating that it plans to restrict all WOTUS, although it’s not yet clear by how much.
“The current EPA seems to be using Sackett as a springboard to find any perceived ambiguities and narrow the definition of WOTUS further,” said Julian Gonzalez, senior legislative counsel at Earthjustice.
“The current EPA seems to be using Sackett as a springboard to find any perceived ambiguities and narrow the definition of WOTUS further.”
In the absence of federal regulations, state dredge-and-fill permitting programs can protect wetlands, and California, Oregon and Washington all have broad protections for non-WOTUS wetlands and streams. And since the Sackett decision, Colorado and New Mexico have passed laws restoring clean water protections for waters excluded from WOTUS. “It’s a dereliction of duty on the federal government’s part by not appropriately protecting the waters of the U.S. and that leaves it up to the states to fill in those protections,” said Rachel Conn, deputy director of Amigos Bravos, a New Mexico conservation organization.
The result is a patchwork of laws protecting the nation’s wetlands. But if more Western states were to emulate their neighbors’ efforts and take action, millions of acres of wetlands could be saved, even in the absence of strong federal protections.
National Resources Defense Council estimates are based on scenarios in which the federal government adopts two interpretations of Sackett that are supported by industry and some states: one, excluding wetlands adjacent to intermittent or ephemeral streams (bottom of range), and another, excluding wetlands that are not wet or flooded most of the year (top of range). According to legal experts, the EPA’s current guidance suggests that the administration will limit WOTUS significantly, excluding most wetlands. Alaska is excluded from this graph due to lack of data.
Arizona
Wetland oversight is primarily conducted through the Surface Water Protection Program (SWPP), administered by the Arizona Department of Environmental Quality. House Bill 2691, passed in 2021 before Sackett, established the SWPP, which allows the state to protect some waters not covered under the Clean Water Act.
Wyoming
While Wyoming lacks a permitting program, it does bar the discharge of any pollution or wastes into its waters without a clean water permit. In addition, Wyoming established a Wetland Banking Fund before Sackett to encourage individuals and companies to preserve wetlands. It enables entities to bank wetland credits earned from wetland conservation projects and use them later to offset a development’s impacts on wetlands, with the goal of achieving “no net loss of wetland function and value in the state.”
Colorado
Wetland protections are primarily governed by House Bill 24-1379, a law passed in 2024 that aims to restore Clean Water Act protections to state wetlands that lost them owing to Sackett. It establishes a state permitting program.
New Mexico
The Pollutant Discharge Elimination System Act (SB 21), which was signed into law on April 8, gives the state authority to regulate surface waters. It creates a statewide permitting program and addresses polluted groundwater that falls outside federal programs.
How wetlands work
Approximately 40% of species, including half of all federally listed species, rely on wetlands, which act like sponges for excess water, offering billions of gallons of flood protection and storing this water for later use. Their plants, roots and microbes filter pollution from drinking water and also store 20%-30% of the world’s total soil carbon. But Western states have lost 50% of their wetlands since colonization, and roughly half of the region’s remaining ones are degraded.
Illustrations by Hannah Agosta/High Country News
SOURCES: From Gold, 2024 in Science/Environmental Defense Fund, National Resources Defense Council, U.S. Fish and Wildlife National Wetlands Inventory, Wetlands International.
This article appeared in the July 2025 print edition of the magazine with the headline “In defense of wetness.”
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