ALBUQUERQUE, N.M. (AP) — The promise of a permanent water supply for several American Indian tribes in the West came one step closer to reality last fall when Congress signed off on more than $1 billion worth of water rights settlements.

Now, just months later, New Mexico's top water officials are concerned the state is not on track to meet a federal deadline for paying its share to implement the settlements. Without the state's $130 million share, the settlements could unravel and decades of litigation and negotiation could go down the drain.

"There is a real sense of urgency because we were thinking we had plenty of time to basically work this over a 10-year period. The reality is we do not," said Sen. Carlos Cisneros, D-Questa, who is sponsoring legislation that would allow the state to tap into its severance tax bonding capacity to pay for the settlements.

Congress approved water rights settlements last November with several tribes in northern New Mexico, the White Mountain Apaches in Arizona and the Crow Tribe in Montana. The agreements followed the end of another long battle over water rights the year before on the nation's largest reservation, the Navajo Nation. With all five settlements come hundreds of millions of dollars in federal funding for the purchase of water rights and the construction of new pipelines and other infrastructure that will deliver water to the tribes and neighboring communities.

Montana has set aside its $15 million share required as part of the Crow settlement, which must be ratified by the tribal membership. However, New Mexico has banked less than one-tenth of the money required for following through on the settlements involving the Navajos and the pueblos of Taos, Nambe, Pojoaque, San Ildefonso and Tesuque.

The state established a special fund as part of the Indian Water Rights Act in 2005 to prepare for the day the settlements would be approved and implemented. Since then, requests have been made to add anywhere from $12 million to $15 million to the fund each year, but the appropriations have been far less and New Mexico has only $10 million in the fund, said State Engineer John D'Antonio.

D'Antonio said he understands the state is grappling with a more than $400 million budget shortfall, but New Mexico has an obligation under the settlements to pay its part — and in some cases, it must pay as soon as 2017.

"I feel like we're getting behind and running out of time," he told The Associated Press. "What I would hate to happen is, with all the work and progress that we've made, that somehow the state falls short in coming up with its share of the funding. We need to start doing it sooner than later."

The state engineer's office, lawmakers and top budget officials have been meeting to talk about possible solutions. It's not clear whether Cisneros' idea for tapping into severance taxes will win out or whether lawmakers will opt for a more temporary solution to add at least some money to the fund this year and work on a more permanent solution over the next year.

"This is not something people are taking lightly," said New Mexico Department of Finance and Administration Secretary Rick May, who has been involved in some of the talks.

At stake for the states involved in the Indian water rights settlements is a huge pot of federal money. In Montana, for example, the state is leveraging its $15 million share for the Crow project for $460 million in federal funds. The New Mexico settlements are slated to bring in more than $1 billion in federal funds while the state contributes $130 million.

"You infuse $1 billion into the state on construction work, people are going to go to work and it helps the economy. No question about it," Cisneros said. "It would be frivolous of us to in any way run the risk of losing that money."

Besides the potential economic boost, water managers in both Montana and New Mexico said the agreements offer more water security for the tribes and the states.

"By settling the claims, at least it gives us a mechanism by which then we can begin talking about how these water rights could be used for other purposes in dire circumstances," said Estevan Lopez, director of the Interstate Stream Commission in New Mexico.

While Montana has broken out of its drought, New Mexico's snowpack is meager and more dry conditions are forecast for later this year.

The lack of funding in New Mexico also has caught the attention of the state's congressional delegation. Given the work that went into getting the settlements approved by Congress and signed by President Barack Obama, they expect the settlements to be fully funded.

"This is both a short-term and a long-term thing," said Jude McCartin, a spokeswoman for U.S. Sen. Jeff Bingaman, D-N.M. "This is an accomplishment for the long-term because it had been in the courts for decades. But to not fund these water settlements in the near term means that job creation will not go forward and that would be a shame."