Originally Published: 11 AUG 22 08:33 ET

Updated: 11 AUG 22 08:34 ET

By Ella Nilsen, CNN

(CNN) -- Democrats' unprecedented climate bill would throw $4 billion to states in the West for drought relief, thanks to last-minute negotiations in the Senate. Southwest lawmakers struck the deal in the 11th hour with hopes that it could buy the fragile Colorado River Basin more time amid its most intense drought in centuries.

Some states, tribes and cities are already reducing their water usage. Farmers are fallowing fields and changing how they irrigate as the water runs dry.

If the House passes the climate bill, it would answer the question that has been worrying Southwest lawmakers: How are we going to compensate farmers and residents for even steeper, voluntary water cuts?

With this funding, states could pay farmers not to farm and pay residents to dig up their lawns in favor of xeriscaping. The $4 billion could be doled out to ranchers, farmers, private communities, Native American tribes or businesses that voluntarily reduce their water usage or work to restore the habitat and ecology of the rivers.

Lawmakers told CNN the funding is long overdue. And it comes just as the US Bureau of Reclamation is set to cut Colorado River water allocations for the second year in a row. Federal officials have already taken unprecedented steps to try and save Lake Mead and Lake Powell, the two largest reservoirs in the country, which millions of people rely on for agriculture, hydropower and municipal water use.

But those steps still may not be enough to salvage the reservoirs and the river basin that feeds them, said Sen. Mark Kelly of Arizona, a Democrat.

"This thing is getting worse so fast that those cuts don't stabilize the system," Kelly told CNN. "We have to find more water to leave in Lake Mead and Lake Powell, but where does that water come from?"

As regular rainfall decreases in the West -- a consequence of the climate crisis -- that water must come from usage cuts.

Sarah Porter, the director of the Kyl Center for Water Policy at Arizona State University, said one helpful proposal has been for Southwest farmers to cut nearly 1 million acre-feet of their water usage per year. One acre-foot -- a foot of water spread out over an acre -- is roughly 325,000 gallons of water, which is enough to sustain a family of four for an entire year.

This bill is a "gamechanger," Porter told CNN, because it answers the question of how the government would pay those farmers to stop farming.

"This new provision, this money will fund voluntary conservation," Porter said. "And that's what we need to have happen."

A red-line demand

Kelly and other Senate Democrats including Colorado's Michael Bennet and Nevada's Catherine Cortez Masto struck a hasty deal with Senate Majority Leader Chuck Schumer to include the funding in the final days before the bill's passage.

They were aided by Arizona Democrat Sen. Kyrsten Sinema, a Senate swing vote who made drought relief funding a red-line demand in her own negotiations with Schumer.

The funding was not guaranteed -- lawmakers said the amount swung from $1 billion up to a final $4 billion. Bennet told CNN that when they finalized $4 billion, "it made me want to break down and cry."

The Bureau of Reclamation is looking to cut 2 to 4 million acre-feet of water usage to sustain Lakes Powell and Mead, starting next year, bureau commissioner Camille Touton said at a recent congressional hearing.

Bennet and Kelly said the drought is severe for farmers in their states, who are being forced to make tough choices for their crops and livestock. About 80% of Arizona's Colorado River allocation goes toward watering crops, Kelly said.

"They understand that we're trying to help, and they need to do their part as well," Kelly said.

"Everyone knows that nobody's making new water," Bennet added. "We're in a crisis and we've got to figure out how to do voluntary reductions and begin addressing this."

Water cuts vs. improving infrastructure

Last year, the Bureau of Reclamation was allocated around $8 billion for needed projects and infrastructure upgrades from President Joe Biden's bipartisan infrastructure law. But the $4 billion in the climate bill is fundamentally different, according to Porter.

"The infrastructure funding typically funds projects that will result in efficient water use, and we're at a point where we've identified or done a lot of those things," Porter said. "There just aren't many opportunities left; that's why we're at this point where we have to be looking at paying people to leave water in the system."

Going forward, longer-term solutions like water reuse and recycling are desperately needed, said Eric Kuhn, a retired former manager of the Colorado River Water Conservation District.

"My only hope is the majority of the money is spent on projects that permanently reduce and put the system in the balance, rather than covering the costs of temporary fallowing," Kuhn told CNN. "The system really needs to be more reactive to uncertain changes in hydrology due to climate change."

Experts and lawmakers told CNN that their main priority now is to salvage and stabilize water levels in Lake Powell and Lake Mead. Without these reservoirs, the West's water crisis would dramatically deepen.

"If we end up drying out Lake Powell and Lake Mead and get to the situation where it's unrecoverable, I can't imagine what the cost of that will be," Bennet said. "I'm glad we have a down payment that will buy us some time."