With contributions from Kirti Datla.

The Sackett case is, at bottom, a case about the scope of the Clean Water Act, and specifically the extent to which it protects wetlands. of the Act’s programs apply to what the Act calls “navigable waters.” The Act, somewhat unhelpfully, defines that term as “waters of the United States,” commonly referred to as WOTUS. Since the Clean Water Act was enacted in the early 1970s, the federal agencies in charge of the Act—the Environmental Protection Agency and the U.S. Army Corps of Engineers—have put out regulations to interpret that term.

Fairly early on, the agencies determined that some wetlands fall within the definition of WOTUS. A wetland is an area covered with water, or where water is present just at the surface of the soil for all or large parts of the year. Wetlands provide lots of benefits, such as filtering out pollutants before they reach larger bodies of water like rivers, sequestering carbon, and housing plants and wildlife. Although the Corps and EPA have sometimes adjusted their views on precisely which wetlands count as WOTUS under the Clean Water Act, they have consistently agreed across all presidential administrations that some wetlands are covered.

The Sacketts own a piece of property near Priest Lake in Idaho. When they decided to build, they began filling in the wetlands on their property without attempting to seek a permit or otherwise comply with the Clean Water Act. After a neighbor noticed, the EPA told the Sacketts the wetlands on their property were covered by the Act and ordered them to undo the damage they’d done to those wetlands. The Sacketts then challenged that determination and their case reached the Supreme Court this Term the issue the Court agreed to decide was the test for determining whether wetlands fall within WOTUS.

The Court accepted that some wetlands do fall within WOTUS, but it adopted a narrower definition of which wetlands . It held that the Clean Water Act extends to only those wetlands that are “are as a practical matter indistinguishable from waters of the United States.” What that means is that for a wetland to be protected under the Clean Water Act, it has to be (1) adjacent to (2) a relatively permanent body of water that is connected to traditional interstate navigable waters, like a river or a lake, and (3) have “a continuous surface connection with that water, making it difficult to determine where the water ends and the wetland begins.” The Court’s holding is narrower than even the position of President Trump’s Administration, which had taken an extremely narrow view itself.

It’s difficult to provide an exact number, because the Supreme Court’s new, narrow test will have to be interpreted and applied in practice we estimate that almost half of wetlands will lose the protection they used to have under the Clean Water Act. This means that, for example, a developer who would have had to get a permit before bulldozing a wetland and filling it in would not need to do so anymore. The permit process allowed the implementing agencies to build in protections or for the public to weigh in on the impacts to the wetlands, but that process won’t happen anymore.


The effect of the decision will go far beyond wetlands destruction. There is a reason that even though this case was brought by a couple, the groups lining up on their side included the mining industry, the construction industry, and oil and gas companies. This decision makes those industries’ projects easier to pursue, leading to all the environmental harm that those kinds of projects cause, such as the destruction of beautiful places, pollution, and climate change impacts.

It will have effects on everyone. Take flooding for example. The decision makes it easier to fill in wetlands, turning them into paved or built-in land. Wetlands are critical to flood control. They absorb flood waters and rainfall, acting like a sponge, preventing dangerous flash flooding and stopping water from entering homes and other buildings.

The decision also increases the risk that pollutants will enter the rivers, streams, and lakes that we fish and swim in. That’s because wetlands act like filters. They trap pollutants that enter the water and flow long distances—think of pesticides running off fields or chemicals flowing off streets in industrial areas stop those pollutants from making their way to bodies of water that we use all the time.

know that children are particularly vulnerable to environmental harm. For example, pollution can have consequences to development during pregnancy and to children’s developing brains. of the air pollution that will follow from industrial projects that the decision makes easier, of course, has harmful consequences, such as increasing asthma rates in children.

There are groups doing important work in the wake of Sackett and making sure they have the resources to do that will be critical to mitigate the effects of this decision.

State-level advocacy. With so many wetlands losing federal protection under the Clean Water Act, there is an opportunity for the States to step up and protect them with state law instead. There are many states with a great number of wetlands but very few state-level legal protect wetlands. These include many of the States along the Gulf Coast and Alaska. This is the time for advocacy to put in place state-level protections to fill in the gap created by the Sackett decision.

Federal advocacy. The Clean Water Act is a federal law, so Congress can the Supreme Court’s decision. It can do that by amending the Act to that it covers more than the narrow slice of wetlands the Court’s decision allows. Here too, this is a critical moment for groups engaging in advocacy to achieve that legislative action.


Protection. It’s all the more important to make sure that the Clean Water Act is used to protect the wetlands that are still covered after the Court’s decision. The Sackett ruling narrowed which wetlands get federal protections, but it didn’t eliminate protections for all wetlands. There are groups that use the enforcement provisions of the Act to make sure that polluters don’t get away with ignoring the Act and to make sure that the federal government carries out its duties under the Act. Their efforts, which often involve decades of advocacy and litigation, deserve support.