The states of Colorado and Kansas have agreed on a settlement over the Republican River in eastern Colorado.

On Friday the attorneys general of the two states announced that Colorado would pay Kansas $2 million to resolve a dispute over Colorado’s overconsumption of water from the Republican River. The settlement comes on top of another with Nebraska from last February, in which Colorado agreed to pay the state of Nebraska $4 million for overuse of Republican River water. Both payments are due Dec. 31, 2018, but have already been approved by the General Assembly in the annual projects bill for the Colorado Water Conservation Board.

The Republican River, and the three states that draw water from it, is governed by a multi-state compact that dates back to 1943. Under that compact, 49 percent of the river’s water would go to Nebraska, 40 percent to Kansas and 11 percent to Colorado.

But the compact has been fraught with dispute and decades of litigation between the three states.

The headwaters for the river’s south fork start near Burlington, Colorado; the north fork headwaters are just south of Holyoke, Colorado. The settlement announced Friday deals only with the river’s south fork.

The settlement originated in a dispute that began in 1999, when Kansas sued Nebraska for taking more water than it was entitled to. Colorado sided with Nebraska, which had been accused of using wells to drain the river, an action Kansas claimed should be counted against Nebraska’s allocation. Nebraska sought a modification of the compact to change how the allocation was determined. It wanted to exclude groundwater from the allocation since it was not originally designated in the compact. Colorado agreed with Nebraska, but in 2003, the U.S. Supreme Court sided with Kansas. In order to partially satisfy a settlement from that judgment, in 2011, Colorado drained Bonny Reservoir near Burlington, which was on the South Fork, and sent that water to Nebraska and Kansas.

Both sides celebrated the end of the dispute, which avoids a return trip to the U.S. Supreme Court – at least for now.

“This settlement is an investment in the basin to ensure a better future for Kansas water users,” said Kansas Governor Jeff Colyer in a statement Friday. “Kansas and Colorado are committed to continuing to make the compact work for the benefit of the citizens of our states, and this settlement recognizes the ties that bind our states together and is an important step for the economic development of the region.”

Colyer’s Colorado counterpart, Gov. John Hickenlooper, added that the settlement “provides funds that could be used in the Republican River Basin within Kansas and Colorado. We look forward to seeing the additional opportunities created for cooperative water management between the states.”

According to Colorado Attorney General Cynthia Coffman, the agreement will “allow us to move forward in partnership with our neighbor states while avoiding long, costly litigation. This is a positive resolution for the citizens of Colorado and Kansas.”