Colorado defends water rights in South Platte River case

DENVER — Colorado officials are asking the U.S. Supreme Court to reject Nebraska’s lawsuit over the South Platte River, arguing the state is meeting its legal obligations under a century-old water compact and that Nebraska’s claims are premature.

In a brief filed this week, Colorado said it has complied fully with the South Platte River Compact and has not interfered with Nebraska’s plans to construct the Perkins County Canal. State officials said there is no legal dispute for the court to resolve at this time.

The South Platte River, which originates in Colorado, provides water for much of the state’s Front Range cities and agricultural lands before flowing northeast into Nebraska. The South Platte River Compact, approved in 1923, outlines each state’s rights to use water from the river.

While Nebraska has the right to build the Perkins County Canal, the state has not advanced the project for more than a century. Nebraska recently began early planning and permitting work with the U.S. Army Corps of Engineers, but Colorado officials said significant study and review are still required before construction can begin.

Colorado water officials believe Nebraska’s lawsuit is an attempt to gain leverage in future negotiations over the compact rather than address an actual violation. They say Colorado continues to honor its commitments by allocating water based on the compact’s terms and ensuring both states receive their allotted shares.

“For more than 100 years, the Colorado State Engineer’s Office has worked closely with Nebraska to ensure compliance with the compact,” said Jason Ullmann, the state engineer and director of the Division of Water Resources. “We were surprised and disappointed by Nebraska’s lawsuit and remain hopeful that both states can continue discussions to meet our shared water needs.”

Nebraska claims Colorado has allowed water uses that reduce flows downstream during the irrigation season, but Colorado officials dispute those allegations.

The Supreme Court, which has exclusive jurisdiction over disputes between states, must decide whether to take up Nebraska’s case. The lawsuit, “Nebraska v. Colorado,” is listed as case number 220161.