WASHINGTON-Supreme Court justices pressed government attorneys in March on their argument that the treaties that put the Navajo on reservation lands implied an intent-but not a duty-for the government to provide water to the tribe.

"Could I bring a good breach-of-contract claim for someone who promised me a permanent home, the right to conduct agriculture and raise animals, if it turns out it's the Sahara Desert?" Justice Neil Gorsuch asked Frederick Liu, the assistant to the solicitor general, who was arguing the case.

It came during a two-hour hearing over the Navajo Nation's claim that the government has breached its agreement with the tribe, and needs to create a plan for meeting the tribe's water needs. Critics say the tribe is looking for more than just a plan, but instead is looking to gain access to Colorado River water to which it does not now have rights.

"If all you got was a plan, that wouldn't do you any good, would it?" Justice Samuel Alito asked the tribe's attorney, Shay Dvoretzky. "You may have used words in describing your relief that doesn't require the allocation of water from the Colorado River. But, in the end, that's what you really want, isn't it ... do you deny that?"

Despite the long and sometimes arcane arguments, Navajo Nation President Buu Nygren said he is "optimistic" that the justices understand the tribe's need for the federal government to step up and give the tribe "the fundamental things that they asked for back in the day."

"It's not like they're giving up rights or studies or infrastructure to somewhere else outside the United States," Nygren said. "It's actually in the heart of America, which is the southwestern part of the United States, and they should be more than happy to develop that area."

The hearing concerned a 20-year-old Navajo lawsuit challenging a 60-year-old Supreme Court ruling on rights to Colorado River water. But Monday's arguments turned largely on the more than 150-year-old treaties that created the Navajo reservation.

All parties in the case agreed that the government bears some responsibility for protecting the tribe's water rights, but they disagreed over how much of an obligation it is and whether the government has met it or not.

Dvoretzky told the justices that the need is real, noting that members of the Navajo Nation use an average of seven gallons of water a day, compared to 80 to 100 gallons of water consumed daily by most Americans. Nygren said outside the court that the amount of water the Nation is using currently is "just to survive," and that is not "the quality of life that we want."

Even though it is bordered on the west by the Colorado River, the tribe does not have rights to the river under Arizona v. California, the 1963 case that allocated the Colorado water to states and tribes in the Lower Colorado Basin.

Liu argued that the case protected Navajo rights to waters on its own reservation – groundwater and the Little Colorado and San Juan rivers, among others. The government, which represented the Navajo and other tribes in the 1963 case, said it has lived up to its responsibility by protecting the tribe's access to those on-reservation sources and that its only other obligation is not to interfere with those rights.

"In exercising its own sovereignty, the Navajo Nation is free to develop its own infrastructure projects, including by drilling water to access the cheapest source of water on the reservation, groundwater," Liu said in his opening statement.

"What the Navajo Nation cannot do, however, is to impose on the United States a duty that the government has never expressly accepted," he said.

Several justices pressed Dvoretzky on the tribe's push for a water management plan, and whether that would necessarily entail government funding of the infrastructure needed to tap, treat and deliver water to homes across the sprawling reservation. And Liu argued that a ruling for the Navajo could open the government to "similar suits across reservations in the country."

Dvoretzky said that while a plan could ultimately require infrastructure, that is not the immediate goal.

"The government hypothesizes a parade of horribles, where the government would have to be building pipelines across, you know, miles and miles and miles of territory," Dvoretzky said. "We're not talking about anything like that."

As for the government's treaty obligations, Dvoretzky said they are clear: The Navajos agreed to move to a new "permanent homeland" on the reservation and take up agriculture, which the government agreed to support.

"Water was something that was simply inherent in the permanent homeland, and making it suitable both as a permanent homeland and for the very purpose of agriculture," Dvoretzky said. "You can't carry out the purpose of that agreement without water."

That argument was picked up by several justices, who asked Liu how the government does not have a duty to provide water under the treaty.

"If there's a contract and the contract gives a right to one party, then just by the nature of how rights work, it gives a duty to the other party," Justice Elena Kagan said. "So there's a contract here and it gives a right to the Navajos, you say so yourself, that means it puts a duty on the other party to the contract, which is the U.S. government."

Other justices noted that the tribe has no authority to exercise its water rights, since the government would represent it in most legal challenges and it holds the tribe's water and other resources in trust.

"They can't assert their rights in their own name because you hold it in trust. So you not only control it, but you're the only one who can assert their interests, is that correct?" Justice Sonia Sotomayor asked Liu.

Justice Brett Kavanaugh asked Dvoretzky why the courts need to be involved in a dispute that Liu said would be better resolved by Congress. Dvoretzky said the courts are the proper venue for the dispute, and that leaving the question to Congress would be a mistake.

"We've been waiting half a century for the political branches to solve this problem for the nation," Dvoretzky said. "It hasn't happened."

Even if the justices agree, it would not be the end of the case for the Navajo Nation, which would be allowed to take its case back to the federal district court that had rejected it. But Nygren said he is hopeful that the Navajo can move one step closer to addressing their water issues.

"What I campaigned on to become president last year was just basic necessities – water, electricity, broadband, better public safety – in order for us as a nation to be thriving and prosperous on our own," Nygren said. "The fundamental thing is water: You need water to build roads, water to farm, water to bring to families and build (those) communities."