LAS VEGAS — With the water level in Lake Mead hovering near a point that would trigger a first-ever official shortage on the Colorado River, representatives of California, Arizona and Nevada are trying to wrap up a plan to prevent the water situation from spiraling into a major crisis.

The plan is formally called the Lower Basin Drought Contingency Plan. But at an annual Colorado River conference this week, many water managers stressed that it’s merely a stopgap plan to get the region through the next several years until 2026.

It might also rightly be called a temporary rejiggering of the rules, a quick fix to stave off a reckoning, or an initial step toward planning for a future with less water.

Looming over the negotiations is a long-term issue that is intensifying the strains on the river: climate change.

Some of the water wonks at the Colorado River Water Users Association conference called the proposed drought plan a temporary “bridge” solution, or a first step toward larger efforts to address the river’s pattern of over-allocation and adapt to climate change in the seven states that depend on the river.

“It will be a short-term solution to stave off the immediate impacts of the problems that we’re seeing,” said Cynthia Campbell, a water adviser for Phoenix. “Lake levels are going down just too fast.”

The idea is simply to stop the free-fall, she said, and provide a short window of time to begin to plan bigger steps.

“If this plan is successful, I think the whole idea is to kind of give us a ledge, you know, to stand on for just a while,” Campbell said, “until we can come up with a better way of actually addressing the more institutional problems that we have, of over-allocation and aridification.”

Rising temperatures strain river

The river has long been overused to supply farmlands and cities across the West. And during the past few decades, rising global temperatures have added to the strains.

The higher temperatures have shrunk the average snowpack in the mountains, reduced the flow of streams, and increased the amount of water that evaporates off the landscape.

Since 2000, the amount of water flowing in the Colorado River has dropped 19 percent below the average of the past century. Scientific research has found that about half the trend of decreasing runoff from 2000-2014 in the Upper Colorado River Basin was the result of unprecedented warming.

The river basin, which stretches from Wyoming to Mexico, has been drying out during what scientists say is one of the driest 19-year periods in the past 1,200 years.

At this week’s meetings in Las Vegas, managers of water agencies said there is widespread recognition that the Colorado River system needs long-term adjustments to adapt as rising temperatures increasingly sap the river’s flow and lead to longer, more intense droughts.

“We need to come up with a real long-term solution for the Colorado River where we bring into balance the inflows and the uses,” said Jeffrey Kightlinger, general manager of the Metropolitan Water District of Southern California. “We can’t do that overnight. It’s a tough challenge.”

But he said the proposed drought plan, which Metropolitan has approved, offers a transition period and buys time to put together long-term solutions that address the river’s chronic overuse and the stresses of climate change.

Lake Mead is now just 38 percent full, and federal officials project the reservoir is likely to fall below a threshold that would trigger a shortage declaration in 2020.

Sorting out the details of a deal

Even with the reservoir’s dire situation hanging over the negotiations, finishing a drought plan has proven difficult.

Pressing for Arizona and California to sign on to the proposed three-state drought agreement, federal Bureau of Reclamation Commissioner Brenda Burman has given the states a deadline of Jan. 31.

She announced the deadline on Thursday, saying if the states fail to meet that deadline, the federal government will get involved and step in to prevent the reservoirs from falling to critically low levels.

Arizona’s top water officials say they’re optimistic they will be able to finish nailing down the details of agreements in the state to take a plan to the Legislature for approval in January.

This set of agreements would enable the state to join the larger three-state pact by spreading around the impacts of the water cutbacks, providing “mitigation” water to farmers in central Arizona, and paying compensation to other entities that would contribute water.

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A few details remain to be worked out, including proposed funding to help farmers in Pinal County who face some of the biggest cutbacks in water deliveries.

Paul Orme, a lawyer who represents four agricultural irrigation districts in the area, said the growers are seeking $15 million to $20 million in funding from the state Legislature and the Central Arizona Project, as well as matching funds from the federal government.

That money would help drill between 40 and 50 new wells and pay for pumps and other infrastructure to help the farmers start to use more groundwater to partially replace the Colorado River water they’re going to lose.

In addition to securing funding, Orme said the farmers also want to pin down details of the “mitigation” water they expect to receive as part of the agreements.

What happens after 2026?

Jennifer Pitt, the Colorado River program director for the National Audubon Society, said a great deal is at stake in the talks on the Drought Contingency Plan, because if the collaborative approach fails, decisions on how the river is managed could start to be made in more disruptive ways by the courts or federal officials.

“The most worrisome future is we don’t have the framework, we don’t have the collaboration, and the hydrology continues to tank, and it seems like the problems multiply,” Pitt said. “The Drought Contingency Plan is the key to avoiding really catastrophic problems for people and wildlife and birds in the Colorado River Basin.”

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The proposed plan would be a temporary fix on top of the existing 2007 guidelines for managing shortages.

Another round of more complex negotiations is scheduled to begin in 2020 on new guidelines to replace the existing rules starting in 2026.

“I think some people see the real challenge is going forward with the renegotiation: What happens post-2026? And what is the arrangement for sharing less water?” said Sharon Megdal, a board member of the Central Arizona Project. “I think a lot of people are already looking forward.”

The legal framework that divides the Colorado River among seven states and Mexico was established during much wetter times nearly a century ago, starting with the 1922 Colorado River Compact. The four states in the river’s Upper Basin were allocated 7.5 million acre-feet of water per year, while another 7.5 million acre-feet went to the Lower Basin states of Nevada, Arizona and California, and 1.5 million acre-feet was allotted for Mexico.

Some observers have suggested that because the old rules no longer seem to work, it may be time to reallocate the river. But water managers who have been involved in the latest negotiations say the idea of attempting a complete reallocation seems unrealistic and would probably be riddled with conflict.

Megdal said she’s heard Israeli water experts, who are accustomed to a different water-rights system, suggest that a lot could be solved by restructuring water rights along the river.

“I personally think right now that’s a nonstarter,” Megdal said. “I think maybe through discussion people might get to a point where, ‘Hey, we have to look at these very fundamental aspects of our allocations.’ But I don’t think people will start there.”

'We are anticipating a drier future'

The Colorado River and its tributaries provide water for about 40 million people and more than 5 million acres of farmlands that produce crops including hay, cotton and much of the country’s vegetables.

Arizona is entitled to 2.8 million acre-feet of water from the Colorado River annually. Under the terms of the proposed three-state deal, the state would face cutbacks of 512,000 acre-feet, or 18 percent of the state’s total.

Nevada and California would contribute by accepting larger water cuts than they would otherwise have to under the current guidelines for shortages. And if the three states sign on, Mexico has pledged under a separate deal to contribute by temporarily leaving more water in Lake Mead, too.

Federal officials include climate models in their projections of scenarios for the Colorado River. And the drought plan was drafted taking into account the rise in temperatures over the past three decades.

“There is a lot of information out there about what climate change means for Lake Powell and Lake Mead and for the basin as a whole,” Burman told reporters.

“We’re water managers," she said. "And our job, whether we’re in flood, whether we’re in drought: to deliver water, deliver it reliably, and that’s what we’re being counted on for. That’s what the economies of the seven basin states are based on. So we look ahead at all the risks and we put that together.”

Arizona’s top water officials have called the Drought Contingency Plan a transitional bridge in planning for getting less water from the Colorado River in the long run.

“It’s not really a climate-adaptation program, because I think climate-adaptation programs would go much further than just this plan,” said Tom Buschatzke of the state Department of Water Resources. “But it definitely recognizes the fact that we are anticipating a drier future.”

Ted Cooke, general manager of the Central Arizona Project, said the plan has “some characteristics of a climate-adaptation plan, but maybe it’s baby steps in that direction.”

Some of the attendees at the meeting said it doesn’t really matter what the plan is called, as long as it gets the job done for the time being.

“Many of the people at the table are considering a future that has less water,” said Bart Miller of the group Western Resource Advocates. “Effectively, it’s either drought adaptation or climate adaptation. But it’s learning to live with less, and to try to build a thriving community that is using less water.”

Ian James writes about water and the environment for The Arizona Republic. Reach him at ian.james@arizonarepublic.com, 602-444-8246 or on Twitter at @ByIanJames.

Environmental coverage on azcentral.com and in The Arizona Republic is supported by a grant from the Nina Mason Pulliam Charitable Trust. Follow The Republic environmental reporting team at environment.azcentral.com and at OurGrandAZ on Facebook, Twitter and Instagram.

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