Colorado River reservoirs buoyed by snowmelt, but officials brace for drier times ahead
This year’s unusually deep Rocky Mountain snowpack is now expected to lift both Lake Mead and Lake Powell from critically low water storage levels and leave them about one-third full, federal and state officials said Friday at a joint Colorado River briefing in Phoenix.
It means the Southwest’s shortage won’t worsen in the coming year, and that Lake Powell will be able to repay a debt to Lake Mead, the larger reservoir downstream, incurred last year when the government held back water to protect hydropower generating capacity at Glen Canyon Dam.
At least until snow starts flying again this fall, that’s where the good news begins and ends. The river remains in crisis, and recent history during a 23-year megadrought suggests scarcity may reassert itself in the coming year.
“Each time we’ve had one of these better inflow years it was followed by a drier inflow,” said Dan Bunk, chief of operations for the U.S. Bureau of Reclamation’s Boulder Canyon Office at Hoover Dam. It happened in 1999, and again in 2011, the only year during this drought that has stacked more snow in the region than this winter did. It also happened after a helpful winter in 2019.
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This year’s snowpack peaked on April 7 at 161% of what has become the median over the last 30 years, Bunk said. The resulting flows into Lake Powell are projected to outpace the norm at 172%. They’re big numbers, but will still leave the nation’s largest and second-largest reservoirs only about a third as full as they were when the 21st century began.
The dangerously low reservoirs will rise to a level that, for at least next year, won’t tip the region into a deeper tier of mandated cuts than it has already experienced, officials say. But Arizona’s already painful reductions will have to stay in place until it’s clear what the future brings.
“We’ll just take what we can get this year and cross our fingers that next year isn’t too dry,” Bunk said.
Arizona's cutbacks will remain in place
Through a combination of federally mandated cuts and compensated conservation actions, Arizona is leaving 592,000 acre-feet of its share of the Colorado in Lake Mead this year. Each acre-foot is about 326,000 gallons and, if pumped only to homes and not onto farmlands, would be enough to sustain perhaps three households for a year.
Those reductions will continue, and the government is working out deals to compensate farmers to use still less on a temporary basis. So far the new agreements have targeted 260,000 acre-feet, Bunk said, with more to come. Next up is rollout of a federal program to help pay for more efficient water infrastructure, and for permanent savings such as grass lawn removals.
The big runoff from this year’s snowmelt will enable Reclamation to move nearly a half-million acre-feet that it had held back in Lake Powell last year, which will help prop up Lake Mead. It also will allow Reclamation to replenish water it released to Lake Powell from Flaming Gorge and other upstream reservoirs on an emergency basis last year.
The productive winter also helped enable a flush of water from Glen Canyon Dam to aid Grand Canyon's environment this spring. That water remains in storage, merely shifted downstream to Lake Mead, but fears about Lake Powell's plunging waterline had prevented such a flood for years.
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A longer-term plan is still in the works
It’s likely a one-year reprieve, and Arizonans must keep working to conserve, state Department of Water Resources Director Tom Buschatzke said.
“We can’t squander that gift” by taking a break from reducing water demands, he said.
The federal government is currently taking comment for an emergency program to prop up the reservoirs, assuming that dry weather returns in the coming year. If that assumption is correct, Central Arizona Project General Manager Brenda Burman said, 2025 and beyond could be “quite devastating” for Arizona, she said.
The U.S. Interior Department released a draft of options for that plan earlier this spring. One idea, which would hit central Arizona hardest, would continue cutting water based on established water rights that reward those who first put the water to use. Those rights tend to favor California generally, and farmers near the river in both Arizona and California. But another alternative under study would cut uses across the region by percentage instead of by priority, and that option would take more from California and less from Arizona.
Federal officials last month suggested they do not prefer either plan in its entirety, but instead treat them as “bookends” bounding a more nuanced approach they hope the states can still work out among themselves.
The states are still working on it, and are meeting for frequent negotiations, Buschatzke said Friday.
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Brandon Loomis covers environmental and climate issues for The Arizona Republic and azcentral.com. Reach him at brandon.loomis@arizonarepublic.com or follow on Twitter @brandonloomis.
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 @azcenvironment on Facebook, Twitter and Instagram.
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This article originally appeared on Arizona Republic: Colorado River reservoirs rise, but officials say drought isn't over
