(AP) — A federal judge in Nebraska has dismissed a lawsuit that challenged a state-approved plan to pump groundwater into surface-water streams that feed into the Republican River.

U.S. District Judge Joseph F. Bataillon ruled Tuesday that the federal government was immune from the lawsuit, and declared the case a state matter in which he shouldn’t intervene.

The plan was designed to help Nebraska meet its obligations to Kansas under the Republican River Compact, a water-sharing agreement. Nebraska has faced lawsuits in recent years for allegedly overusing its supply.

The lawsuit was filed by two local irrigation districts and three farmers in southern Nebraska. They argued that a $2.1 million pipeline project to pump the water will deny them access to their rightful share.