FLAGSTAFF, Ariz. (AP) — A Native American tribe with one of the largest outstanding claims to water in the Colorado River basin is closing in on a settlement with more than a dozen parties, putting it on a path to piping water to tens of thousands of tribal members in Arizona who still live without it.

Negotiating terms outlined late Wednesday include water rights not only for the Navajo Nation but the neighboring Hopi and San Juan Southern Paiute tribes in the northeastern corner of the state. The water would come from a mix of sources: the Colorado River that serves seven western states, the Little Colorado River, and aquifers and washes on tribal lands.

The agreement is decades in the making and would allow the tribes to avoid further litigation and court proceedings, which have been costly. Navajo officials said they expect to finalize the terms in the coming days.

From there, it must be approved by the tribe’s governing bodies, the state of Arizona, the other parties and by Congress.

“We have the right Congress, we have the right president, and it’s very hopeful,” Navajo President Buu Nygren told The Associated Press on Wednesday. “Because next year might be a whole different ballgame. It’s going to be very uncertain.”

The proposal comes as Native American tribes, states in the Colorado River basin and Mexico are working on a long-term plan to share a diminishing water source that has served 40 million people. Tribes, including the Navajo Nation, were left out of a landmark 1922 treaty that divided the water in the basin among seven states.

The Navajo Nation has long argued that states treat the tribe as an afterthought. Any settlement reached would be separate from that long-term plan and stand on its own.

About one-third of the homes on the Navajo Nation do not have running water. Infrastructure projects outlined by the Navajo Nation include a $1.7 billion pipeline to deliver water from Lake Powell to tribal communities. The caveat being that there is no guarantee that Congress will provide the funding.

Both the Navajo and Hopi tribes are seeking the ability to lease water and to store it in existing or new reservoirs and impoundments.

“Some of our families that still live within those communities still have to haul water to cook their food, to make lemonade in the summer for their kids, to make ice, all little simple things to make your daily life easy and convenient,” Navajo Nation Council Speaker Crystalyne Curley said.

On Wednesday, the Navajo Nation cited climate change, cost, competition for water and the coronavirus pandemic as reasons to move toward a settlement. Arizona, in turn, would benefit by having certainty over the amount of water that is available to non-tribal users. The state has had to cut its use of Colorado River water in recent years because of drought and demand.

Tom Buschatzke, director of the Arizona Department of Water Resources, said Wednesday that while progress is being made on a settlement with the Navajo Nation, the agreement isn’t complete.

Sarah Langley, a spokeswoman for Flagstaff, the largest city that is a party to the settlement, said it is hopeful the negotiations are productive.

Arizona — situated in the Colorado River’s Lower Basin with California, Nevada and Mexico — is unique in that it also has an allocation in the Upper Basin. Under the settlement terms, Navajo and Hopi would get about 47,000 acre-feet in the Upper Basin — nearly the entire amount that was set aside for use at the Navajo Generating Station, a coal-fired power plant on the Navajo reservation that shut down in late 2019.

The proposal also includes about 9,500 acre-feet per year of lower-priority water from the Lower Basin for both tribes. An acre-foot of water is roughly enough to serve two to three U.S. households annually.

While the specific terms for the San Juan Southern Paiute Tribe remain under discussion, Congress could be asked to establish a small reservation for the tribe whose ancestral land lies in Utah and Arizona. The tribe’s president, Robbin Preston Jr., didn’t immediately respond to emailed questions from the AP.

The Hopi Tribe’s general counsel, Fred Lomayesva, declined to comment.

The Navajo Nation, whose 27,000 square-mile (70,000 square-kilometer) reservation also stretches into New Mexico and Utah, already has settled its claims to the Colorado River basin there.

The Navajo and Hopi tribes came close to reaching a pact with Arizona to settle water rights in 2012. Both tribes rejected federal legislation that accompanied it, and the tentative deal fell through. It also wasn’t broadly supported by Navajos and Hopis who saw negotiations as secretive, leading to a loose effort to recall then-Navajo President Ben Shelly and then-Hopi Chairman LeRoy Shingoitewa.

Recently, the Navajo Nation Water Rights Commission has been holding public hearings across the reservation to ensure tribal members are aware of what is involved in a settlement and why the tribe pursued it, tribal officials said.

“We have a united front to our chapters, our schools and even our small businesses, families,” Curley said. “It’s inclusive of everyone. Everybody should be able to know what the terms are.”

The federal government in recent years has poured money into tribal water rights settlements. The U.S. Supreme Court also ruled the government does not have a treaty duty to take affirmative steps to secure water for the Navajo Nation, complicating the tribe’s fight for water.

___ Naishadham reported from Washington, D.C.