Nebraska sues Colorado over longstanding fight about South Platte River water
Nebraska sues Colorado over longstanding fight about South Platte River water
Jul 16, 2025
Lincoln Journal Star
More than a century after signing a compact agreeing to share water from the South Platte River, Nebraska on Wednesday sued Colorado, accusing its western neighbor of withholding more water than the compact permits it to and preventing Nebraska from building a canal the compact allows for.
In 1923, a legal dispute over the river’s water supply led the two states to sign the compact, under which Colorado agreed to allow 120 cubic feet per second of water to pass into Nebraska during irrigation season.
The compact also authorized the Cornhusker State to build a canal to capture at least 500 cubic feet per second of water during non-irrigation season, which runs from mid-October through February.
But in a 55-page complaint filed in the U.S. Supreme Court on Tuesday, Nebraska Attorney General Mike Hilgers’ office accused Colorado of violating both tenets of the compact by diverting as much as 423.6 billion gallons of water from Nebraska and blocking the state’s efforts to build a $628 million canal near Perkins County.
In the lawsuit, Hilgers said the alleged compact violations "threaten to drastically curtail Nebraska’s access to water" from the river that runs east from the Rocky Mountains into and through Nebraska.
The alleged breaches "have harmed Nebraska and pose a significant, ongoing threat to Nebraska, from its agricultural economy to the water security of its major population centers," according to the lawsuit, which Hilgers said "may be the most consequential lawsuit that this office will be a part of in my generation."
Attorney General Mike Hilgers speaks during a news conference at the state Capitol on Wednesday.
KENNETH FERRIERA, Journal Star
Hilgers unveiled the lawsuit at a Wednesday morning news conference at Nebraska’s Capitol alongside Gov. Jim Pillen, who said it was "crystal clear Colorado has been holding water back from Nebraska" for years, an issue he pledged to "fight like heck" to resolve.
"We’ve been losing to Colorado on this issue for too long. It’s time we win, and that’s where we’re going to do it at: the United States Supreme Court," Pillen said, later accusing Colorado of having "no interest in anything being fair and just."
"They want absolutely everything," the governor said. "They’re even stealing the water from their own farmers."
Officials in Colorado immediately pushed back on those claims, accusing Pillen and Hilgers of putting "politics above farming and ranching communities and the regional agricultural economy."
Nebraska Gov. Jim Pillen speaks during a news conference at the state Capitol on Wednesday.
KENNETH FERRIERA, Journal Star
"The failure to look for reasonable solutions and to turn to litigation is both unfortunate and predictable given the misguided effort driving the proposed canal," Phil Weiser, Colorado’s attorney general, said in a statement.
"Nebraska has now set in motion what is likely to be decades of litigation," Weiser said. "And if, after decades of litigation, the court allows Nebraska to move forward with its wasteful project, Nebraska’s actions will force Colorado water users to build additional new projects to lessen the impact of the proposed Perkins County Canal.
“When the dust finally settles, likely over a billion dollars will have been spent— tens of millions of that on litigation alone — and no one in Nebraska or Colorado will be better off."
At Wednesday’s news conference, Hilgers acknowledged the case may take up to five years to resolve but said the state only filed the suit after negotiations with Weiser’s office reached an impasse.
The canal project contemplated in the century-old contract sat dormant for decades until former Nebraska Gov. Pete Ricketts prioritized it late in his second term in 2022 as he and state water officials warned that flow from the South Platte dipped below the compact’s 120 cubic feet per second provision every summer — and the situation threatened to worsen as Colorado moved to spend billions on additional water projects along the river.
Nebraska lawmakers began setting aside money for the project in 2022 and have earmarked a total of $628 million for it. The state made its first purchase of land in Colorado for the project on Dec. 29, 2023.
The 1920s compact gives Nebraska the right to get land for the canal in Colorado, including by using eminent domain. The state gave some Colorado landowners a mid-April deadline this year to sell their land or face the possibility of Nebraska using that power to force the sale of land.
Attorney General Mike Hilgers speaks while flanked by Nebraska Gov. Jim Pillen during a news conference at the state Capitol on Wednesday.
KENNETH FERRIERA, Journal Star
Nebraska’s lawsuit alleges that Colorado officials have in recent years prepared to fight the intrastate use of eminent domain. Weiser in January told commissioners in Sedgwick County, Colorado — which borders Nebraska’s Perkins County — that "Colorado is prepared to defend its rights" under the compact should Nebraska follow through with its attempts to condemn the land.
Meanwhile, Colorado has allowed South Platte water that should flow to Nebraska to be diverted before it reaches the state "hundreds of times" in the past decade, Hilgers alleged in the lawsuit. In 2022, those diversions forced a water irrigation district in western Nebraska to shut down surface water irrigation operations for the majority of its service area due to a lack of water supply, Hilgers alleged.
"They’re holding more and more water all the time," said Dennis Schilz, an Ogallala farmer who sits on the board that governs the Western Irrigation District that borders Colorado. "Going back, Western has been shorted considerably over the years."
He said he’d spent "a long time waiting" for Wednesday’s lawsuit.
The suit asks the Supreme Court to compel Colorado and its residents to honor the century-old compact, award Nebraska water the state has been deprived of, and bar Colorado from impeding the construction of the canal, which the Pillen administration still hopes to complete by 2032.