Last winter's big snowpack has helped ease the impacts that long-term drought has had on water storage in the Colorado River watershed, but reservoir storage levels are still low enough that provisions of a new drought contingency plan in Lower Basin states already are kicking in.
Some water officials and conservationists say the triggering of plan components reflects the fact that a single bountiful water year is far from enough for storage to recover from a mostly dry period dating back to 2000, and recently adopted drought planning measures are needed to prepare for the very real possibility that drier years will return. Those measures involve Upper Basin states including Colorado.
The reductions that the Lower Basin drought contingency plan already is requiring show that in its first year, the plan "is already working," Chuck Cullom, Colorado River programs manager for Arizona's Central Arizona Project, wrote in a blog on that entity's website.
The Central Arizona Project is a water provider that will see its supplies reduced by 192,000 acre-feet next year under the plan's provisions. That is the entire part of the state of Arizona's Colorado River water allocation that the state instead will leave in Lake Mead under the plan, as a result of projected water levels in that reservoir at the start of next year. Nevada and Mexico also will leave smaller amounts of their allocation in Lake Mead under the plan and a separate agreement involving Mexico.
The actions are required based on a Colorado River Basin report released Thursday by the U.S. Bureau of Reclamation. It projects that Lake Mead will begin next year with water at an elevation of 1,089.4 feet. That's less than a foot under a 1,090-foot threshold set by the Lower Basin drought contingency plan, below which the mandatory austerity measures begin. California will have to start leaving a portion of its allocation in the reservoir should surface levels go below 1,045 feet.
Lake Mead and Lake Powell upstream of it serve as the two largest storage pools in the Colorado River Basin. The Bureau of Reclamation reported that thanks to above-average snowpack, runoff from the Upper Basin into Lake Powell was 145 percent of average from April through July, raising Powell's elevation by more than 50 feet. But it is projected to remain 81 feet below full as of the start of next year.
The Bureau of Reclamation says that total Colorado River system storage today is at 55% of capacity, up from 49% a year ago.
"While we appreciate this year's above average snowpack, one good year doesn't mean the drought is over. We must remain vigilant," Brenda Burman, commissioner of the Bureau of Reclamation, said in a news release. "I applaud everyone who came together this year to get the drought contingency plans done. The additional actions under the contingency plans will help ensure the reliability of the Colorado River system for the 40 million people dependent upon it."
"One wet year doesn't change the fact that we have a lot left to do," said Bart Miller with the Western Resource Advocates conservation group.
He said the big snowpack provides some breathing room in dealing with the longer-term drought. Both Mead and Powell were full in 2000, before the river basin began experiencing a trend of far more dry years than wet ones, he said. The drought contingency planning is an effort to get out ahead of the problem and prevent larger-scale shortages, Miller said.
Cullom wrote in his blog that the mandatory reduction the Central Arizona Project is taking now, "while significant," is largely the same as what it has been leaving voluntarily in Lake Mead since 2015 under a conservation program for the reservoir. Jim Pokrandt, spokesman for western Colorado's Colorado River District, said in a column he penned on the recent developments that given Arizona's past reductions, in one sense what's occurring now is an accounting change. But the fact that mandatory cuts under the Lower Basin drought contingency plan have begun is a milestone as Colorado River Basin states grapple with the new normal of long-term drought, he wrote.
"This is a big deal for everybody on the Colorado River system," Pokrandt added in an email to the Daily Sentinel.
Drought contingency plans involving the Lower and Upper Basin states and the federal government took effect with their passage by Congress earlier this year. The Upper Basin plan includes provisions to operate reservoirs above Powell as needed to try to keep Powell's water high enough to continue generating power at Glen Canyon Dam. But another part of the Upper Basin plan involves investigating the use of demand management if needed in the event of a worsening drought, to avoid a forced curtailment of Upper Basin water uses to satisfy water obligations to Lower Basin states under a 1922 compact.
In Colorado, water officials are looking into the possibility of voluntary, compensated, temporary demand management approaches as a means of staving off mandatory, unpaid curtailments under the compact. It's expected that many demand management approaches would involve Western Slope agricultural operations.
Pokrandt said the milestone of the Lower Basin drought contingency provisions kicking in "certainly highlights the need" to determine if a demand management program is feasible. The Colorado Water Conservation Board recently created nine workgroups that have begun exploring the feasibility of such an approach, and entities including the river district and Grand Valley Water Users Association also are investigating the concept, Pokrandt said.