Note: This post has been updated with remarks from Gov. Mary Fallin

One day after the Oklahoma Legislature launched a joint study of Oklahoma water and development of a new, 50-year water plan, two of the state’s largest tribes filed a federal lawsuit over their rights relating to water in Sardis Lake.

The Chickasaw and Choctaw nations are suing Gov. Mary Fallin, members of the Oklahoma Water Resources Board and its executive director, the city of Oklahoma City and the Oklahoma City Water Utility Trust.

In addition to the Sardis issue, the tribes are also seeking to block other water sales or transfers from within treaty territory as defined by the 1830 Treaty of Dancing Rabbit Creek that are attempted without their consent.

“Because sustainable management of our water resources is imperative for the progress and prosperity of all Oklahomans, we have worked deiligently to establish a working relationship with the state on this issue,” said Chickasaw Governor Bill Anoatubby. “”Unfortunately, our efforts have been unsuccessful, leaving us no realistic alternative to legal action.”

Last June the OWRB entered into an agreement with the metropolitan water trust for sale of the rights to store Kiamichi Basin water in the reservoir, precipitating a protest from the tribes. The agreement includes the trust’s payment of $29 million in assumption of the state’s debt to the U.S. Army Corps of Engineers for construction of Sardis, plus $15 million for a permit giving the trust control of about 90 percent of Sardis’s sustainable yield, according to the court filing.

In their 36-page complaint, the two tribes say the legal action is necessary to protect water rights they say were granted to them by treaties with the federal government.

“If the defendants succeed in unilaterally selling Treaty Territory water resources, the plaintiff nations’ ability to protect and enforce their water rights would be severely prejudiced,” the tribes’ complaint states.

The Choctaws and Chickasaws are seeking  a declaratory judgment and injunctive relief against the named state officials barring further action on the water trust’s permit until the legal action has been adjudicated under appropriate federal law relating to tribal water rights.

“”The Choctaw Nation is committed to protecting and preserving the sustainability of water in southeast Oklahoma and the rest of the state,” said Choctaw Chief Greg Pyle. “We will continue to seek a resolution that works for all of us, and i have faith that through the court, we can reach a decision that is fair, meaningful, and serves the best interest of all Oklahomans.”

Gov. Mary Fallin issued a news release Friday in response to the lawsuit. She was in Washington, D.C. on an economic development trip.

“I was surprised to learn that the Chickasaw and Choctaw nations had elected to file a lawsuit against the state of Oklahoma, especially while I was out of town promoting Oklahoma as the go-to place to do business and raise a family,” Fallin said. “This kind of action is, quite frankly, not helpful to our efforts to create a better and more prosperous home for all of our citizens.

“Moving forward, it is important for the state of Oklahoma that the tribes, the state and all other parties have a productive conversation about water rights outside of the courtroom. I am committed to pursuing solutions that benefit all Oklahomans, and I will continue to work in good faith to find common ground and resolve this issue.”