"The hope was that the seven basin states that helped govern the operations of the Colorado River would come up with a plan for how we're going to operate the river after 2026. That didn't happen," said Cynthia Campbell, director of policy innovation for the Arizona Water Innovation Initiative.

“The people who are doing the farming are rational people who are thinking through their economic futures,” Porter said. “I think there are plenty of farmers in the state of Arizona who simply don’t think (more) groundwater regulation is going to be better for them.”

What they're saying: Arizona officials framing state water as a national interest was "well played," Sarah Porter, director of the Kyl Center for Water Policy at ASU's Morrison Institute for Public Policy, told Axios.

The letter shows Arizona's willingness to move beyond a negotiated settlement and seek unilateral action by the Interior Department, she said.

Still, the lack of a deal or hints at any coming soon suggests that the federal government may have to act on its own. If so, Arizona State University water policy expert Sarah Porter said, “I think there’s a good likelihood that there won’t be an agreement and that the states will wind up in court.” Porter directs ASU’s Kyl Center for Water Policy.

"The difference between the two basins interpretation of those parts of the Colorado [River] Compact is the reason why there's a disagreement over how much the Upper Basin should sign up for in terms of leaving more water in the system," Sarah Porter, director of the Kyl Center for Water Policy at Arizona State University, told The Tribune last week.

Cynthia Campbell, the director of policy innovation for ASU's Arizona Water Innovation Initiative, said "there is no plan" prepared to replace the prior agreement. For about three years, states have been negotiating with no progress.

"The seven states cannot agree on how to divide up a smaller river, and how to deal with shortage and how to adjust or adapt operating conditions for that shortage," Campbell said.

That could add further urgency to the talks, said Sarah Porter, director of the Kyl Center for Water Policy at Arizona State University.

“How much snow you get in a winter can change how motivated people are to make certain deals,” Ms. Porter said.

“We have to come to terms with the fact that we just don’t have the water that we used to have,” said Jay Famiglietti, science director for Arizona State University’s Arizona Water Innovation Initiative. “We have a growing population. We need to grow more food. We still want to pursue economic growth. We just can’t do everything anymore, and so there will have to be painful decisions that are made.”

The states have been positioning themselves to argue in court, said Sarah Porter, director of Arizona State University's Kyl Center for Water Policy.

"The negotiators, I think, have tried really, really hard, and sometimes it may just not be possible to come to an agreement," Porter said.

There still may be room to reach a consensus, she said, but if they fail, "we are very, very likely to be in a situation where the states are in court."