The U.S. government may have to pay tens of millions of dollars—or more—to landowners along the Missouri River after a court ruled it worsened flooding there since 2007 that killed crops and wrecked homes and businesses.

The U.S. Court of Appeals for the Federal Circuit upheld a lower court’s 2020 ruling that the federal government must pay for the landowners’ loss of value to the land. But the appeals court went even further in its decision last Friday, saying that the government must also pay them for crops, farm equipment and buildings lost to the flooding and finding the government contributed to the devastating flood of 2011.

Courts have found the U.S. Army Corps of Engineers responsible for recurrent flooding since 2007, three years after it changed how it manages the Missouri River’s flow to better protect the habitat of endangered fish and birds. It did so by notching dikes to increase water flow, keeping more water in reservoirs and reopening historic chutes, allowing the river to meander and erode banks.

Farmers, businesses and other landowners say that unconstitutionally deprived them of their land. The courts have largely agreed, finding that the government violated constitutional protections against taking property without just compensation. That Fifth Amendment protection is often seen in cases of eminent domain, which allows a government to seize private property, with compensation, for a public purpose.

Federal officials argue that the changes the Corps made were necessary to comply with the federal Endangered Species Act and a separate requirement from Congress passed in 1986 to protect fish and wildlife.

The ruling comes as federal and state officials wrestle with the rising costs of floods made more severe by climate change, and droughts that will require tough water management choices.

It’s the sort of conflict that will only worsen—and become more expensive, said James Elliott, a sociology professor at Rice University whose focus is on the confluence of human society and the environment.

“We tend to think of these as environmental issues, but really, they’re financial issues, right?” he said. ”We’ve got a lot of development in a lot of places where it’s just not sustainable.”

The Corps manages floodplains, levees, and other water infrastructure across the U.S., making critical decisions on emergency management. Any resulting court decision, and even a settlement, could have long-lasting consequences on how floodplains and ecosystems are managed in the future, although the government has indicated in court documents that the Corps is dedicated to its plan that protects endangered wildlife.

In total, the government now faces liability for floods in six of the eight years spanning from the beginning of 2007 through 2014, including particularly devastating losses in 2011.

Land value loss alone for which the government was found liable was estimated to be around $10 million by lower courts. Attorneys for the landowners had estimated that total damages could exceed $300 million. Total damages across the Missouri River basin in 2011 were estimated at around $2 billion, according to the National Climatic Data Center.

“So, if you consider how much those crop losses and the 2011 flood damage would be, you can extrapolate from there that it will be significant,” said Seth Wright, of Posinelli Law Firm in Kansas City, Missouri, who is the lead trial attorney for the landowners.

Wright said that if the history of the nearly 10-year-old legal case is an indicator, the government is likely to appeal the latest ruling to the U.S. Supreme Court.

“It’s certainly frustrating to our clients,” Wright said. “We’re a decade into this lawsuit and a decade-and-a-half from the first flood. It’s time for the government to step up and pay.”

Federal officials argue that the courts have overlooked key factors in the case, noting that the plaintiffs’ land still occasionally flooded even before the Corps made changes to the river’s management in 2004. They say a publicly available document warns of possible changes to Corps’ flood protections.

In court documents, officials argue the landowners “should have recognized long ago that the System was built to serve multiple, congressionally authorized purposes, not flood control alone,” and that they’ve never “had a property right to any particular level of federal flood-control protection.”

More than 370 landowners in Nebraska, Iowa, Kansas, Missouri and the Dakotas are currently represented in the lawsuit, and a merger with another class-action lawsuit of an additional 60 landowners could happen later.

Lawmakers from affected states have said the Justice Department should settle. In 2020, seven Republican U.S. senators from Nebraska, Iowa, Kansas and Missouri urged the Army to negotiate with landowners.

A spokesman for the Army Corps of Engineers on Wednesday referred questions to the U.S. Department of Justice, which said Thursday that it is considering its next steps following Friday’s ruling.