Nebraska officials said on July 16 that the state is suing Colorado at the U.S. Supreme Court over the right to use water from the South Platte River, which winds through both states.

The U.S. Constitution gives the Supreme Court original jurisdiction, or authority, to try disputes between the states as a court of first impression.

In such cases, the court often appoints a judicial officer called a special master to hear the case and issue a recommendation to the justices on how to rule.

Nebraska and Colorado entered into the South Platte River Compact in 1923.

Both states’ legislatures approved the compact, and Congress ratified it in 1926, which means it carries the force of federal law.

The compact imposes limits on the amount of water each state may take from the river throughout the year.

Nebraska and Colorado disagree on several issues, including diverting water from the river for Nebraska’s planned Perkins County Canal.

Nebraska also says Colorado is now illegally diverting water from the South Platte River.

Water diversion for the canal is expected to begin in Colorado. After the canal is built, Nebraska will redirect water between Oct. 15 and April 1 of each year.

The compact also allows for water to be diverted outside that timeframe, Nebraska officials said in a 2022 planning document.

A spokesperson for the Colorado governor’s office previously called the canal, which will cost hundreds of millions of dollars to build, a “boondoggle” and a “political stunt.”

The spokesperson also predicted the canal would never be built.

Colorado is now engaging in “unlawful water diversions that have deprived Nebraska of its right to water during the irrigation season,” a statement issued by Nebraska Gov. Jim Pillen and Attorney General Mike Hilgers said.

Colorado is also “obstructing Nebraska’s efforts to construct the Perkins County Canal,” the statement said.

The Supreme Court’s public information office told The Epoch Times that the document that initiates a lawsuit between states, called a bill of complaint, had not yet been placed on the court’s online docket at the time of publication.

Nebraska said Colorado has violated the compact and that its actions, which may “drastically curtail” Nebraska’s access to water from the river, have harmed the state.

These actions present a “significant, ongoing threat to Nebraska, from its agricultural economy to the water security of its major population centers,” the bill of complaint states.

As a result of Colorado’s actions, Nebraska’s Western Irrigation District recently had to cut off most of the river water needed for irrigation at Nebraska farms.

Colorado’s “unlawful water diversions” have prevented as much as 1.3 million acre-feet of water from flowing to Nebraska, the complaint says.

That figure is more than 10 times what the Washington water utility pumps for its 700,000 residents over a year, the bill of complaint said.

At the same time, Colorado’s actions are preventing Nebraska from building the Perkins County Canal, which is provided for in the compact, according to the document.

Hilgers said his state’s lawsuit “will ensure that Nebraska receives all the water to which it is entitled under the compact and that Nebraska’s agriculture and economy are protected.”

“Water is the essential lifeblood of Nebraska’s economy, and it’s my goal to protect one of the state’s most important assets,” the attorney general said.

Pillen said the lawsuit was filed “only after we made every reasonable effort to resolve our differences with Colorado.”

“Ultimately, Nebraska must push forward to secure our water for future generations. Although we hoped to avoid a lawsuit, we are confident we remain on schedule to complete the Perkins County Canal by 2032,” the Republican governor said.

The Epoch Times contacted the office of Colorado Attorney General Phil Weiser for comment, but no reply was received by publication time.

The Supreme Court is now in its summer recess.

After Nebraska’s bill of complaint has been officially docketed by the court, Colorado will be required under court rules to file a reply in the case.

This article by Matthew Vadum appeared July 16, 2025, in The Epoch Times.