Massive Green River water diversion project scrapped after Supreme Court decision

SALT LAKE CITY (ABC4) — The Utah Supreme Court ruled on a controversial pipeline project in Eastern Utah last Friday.

In January 2018, Water Horse Resources, LLC proposed a pipeline project that would send 55,000 acre-feet of water every year from the Green River to the state of Colorado. However, on Nov. 7, 2020, the Utah State Engineer rejected the application.

The proposal sought to pipe water to be used for “beneficial use in Colorado.” However, a district court found Water Horse failed to establish evidence that the water can be put to beneficial use in Colorado.

The pipeline would extend through Wyoming before dropping into an undecided location in Colorado.

Colorado officials declined to sign onto the project citing the lack of clear authority to administer the diversion of water into the state.

Water Horse appealed the district court’s decision, leading to a years-long legal battle. On Friday, Oct. 17, 2025, the Utah Supreme Court reaffirmed the initial decision of the state engineer to reject the project.

“Water Horse failed to establish a reason to believe that the exported water can be put to beneficial use in Colorado,” the Supreme Court opinion reads. “The district court correctly declined to disturb the state engineer’s decision.”

Water Horse did not immediately respond to ABC4.com’s requests for comment.

This is not the end for the project. According to the court’s opinion, a renewed application could be submitted and potentially approved by the state engineer.