FARMINGTON — A decades-old battle over water rights continues between the Navajo Nation and San Juan County water users.

Both sides are proceeding with challenges to a settlement case, which has been in the courts since the 1960s. Although there was a Monday hearing in the case, it is not expected to go to trial until August.

"We could lose it all," said Victor Marshall, attorney for the San Juan Agricultural Water Users Organization, one of the organizations opposing the settlement.

The organization represents not only agricultural water users, but also industrial and municipal users, including the cities of Aztec, Bloomfield and Farmington, Marshall said.

The San Juan Navajo Water Rights Settlement was agreed to by the state of New Mexico, the Navajo Nation and the United States in December 2010 when then Navajo Nation President Joe Shirley, Jr. and Secretary of Interior Ken Salazar signed it.

The settlement grants the tribe about 606,000 acre-feet of diversion water, or water to be used and then re-used, from the San Juan River. It grants more than 325,000 acre-feet of depletion water, or water that will not be returned to the river. One acre-foot of water is about 326,000 gallons.

Some are worried that the agreement could significantly boost the price of water and reduce water availability in the region.

"We have always conceded that they (Navajo Nation water users) are entitled to a substantial amount of water," Marshall said. "But those ditches supply everybody — towns, farms, industry, and homes — with water."

Opponents do not know how much water the tribe should receive because they say the state has been ambiguous about how much water actually is available in the state, Marshall said.

The Office of the State Engineer was unavailable for comment Wednesday.

"The history of the West is everyone is always thinking there's more water than there is," Marshall said.

Figures vary, but it appears between 45 and 60 percent of the state's stream surface water flows in the San Juan River. That water is distributed throughout the state and as far as Texas.

Opponents do not believe the tribe needs as much water as it is given in the settlement, which is why they are countering the settlement in state district court.

"Of course it's not too much," said Stanley Pollack, attorney with the Navajo Nation Department of Justice, who said opponents are going off of misinformation.

According to Pollack, the tribe hopes to use the water for irrigation in the Hogback area, but mainly for municipal and industrial water users in the more rural areas of the reservation.

It would be used for the pipeline projects planned between Gallup and Shiprock, and also between Gallup and Window Rock.

Marshall's more than 10,000 clients from the San Juan Agricultural Water Users Association, however, are worried there is not enough.

For years, the organization has tried to protect its share of water from the Navajo Nation, which they are afraid is going to sell its share of water.

"Not going to happen," Pollack said, saying that while the tribe might be able to sell its water rights, other states likely could not buy them.

Most states that would be interested in purchasing the rights — Nevada, California, and Arizona — already consume their share of water, Pollack said, and their sources will be reliable longterm.

"If I'm reading the tea leaves correctly, the Navajo Nation is not interested in leasing its water," Pollack said.

If it did, however, the cost of water would surely rise, putting locals in competition with large municipalities, Marshall said.

"We'll be litigating for years to come," he said.