LAS VEGAS (KLAS) — It’s snowing today in the central Colorado Rockies, likely the last hurrah for a year to remember for everyone who depends on water from the Colorado River — including Las Vegas.
It’s just past the early April peak when scientists calculate the final snowpack levels for the year. Today, that measurement hit 160% of normal, just above where it was a week ago.
And now, the snow begins to melt faster than new snow accumulates. By next week, temperatures in the central Rockies will near 60 degrees. As the snowmelt begins, tributaries will swell, dams will fill and the Colorado River will flow toward Lake Mead in Nevada, and beyond to pipes and canals that supply Arizona and California.
Colby Pellegrino, deputy general manager for the Southern Nevada Water Authority, said it’s a welcome change but it won’t erase the drought.
“We have learned throughout the Colorado River’s history, and acutely through this drought, that one good year is simply not enough to change the long-term trajectory of our reservoirs. The snowpack is now at a point where are expecting to see good run-off into the river system, and that will help maintain water levels in Lake Mead,” Pellegrino said.
The Colorado River supplies water for more than 40 million people in parts of seven states. We have been closely monitoring the snowpack levels — described by scientists as Snow Water Equivalent (SWE). Here’s a look at how the levels have changed over the past six months, beginning with Oct. 24, when SWE was at 229% of normal in the Upper Colorado River Basin:
Water scientists — hydrologists — say the snowpack levels aren’t meaningful until April arrives. The fluctuations of where the snow falls and how long it sticks around are too unpredictable to truly say it’s a “good year” or a “bad year” until April arrives.
So the 160% figure from the U.S. Bureau of Reclamation today is that “good year” we’ve been waiting to shout about. But it’s part of the bigger story of climate change, which has had a major effect on the Colorado River.
“While one good, wet year is not enough to make up for 20 years of extreme drought conditions, it is certainly a welcomed change. We would really need to see an extended period of consecutive years of above-average runoff to make a meaningful difference in the water supply deficit,” Pellegrino said.
“Absent that unlikely reality, continued reductions by all water users are necessary to bring the Colorado River system into balance,” she said.
“While this year may help stave off deeper reductions, the future of the river is less water for everyone and we need to continue to adapt to that reality,” Pellegrino said.
David Fordham, who runs the water-data.com website, said, “It’s exciting to see a water year like this.”
He has been monitoring snowpack levels for years, and a graph on his website shows just how far above normal this year is in comparison with the past 10 years.
Fordham’s website uses data that’s a little different from the Bureau of Reclamation’s numbers. He said that’s because he gets information from more monitors, and some of the historical data on “averages” is calculated differently. Regardless of that, “water year 2022” is one for the record books.
Fordham said 1984 was the biggest year for water flow in the Colorado River in the 59 years of data he looks at. A similar year would likely fill Lake Powell — one of the current priorities for water managers at the Bureau of Reclamation.
But what about Lake Mead?
Last summer, a group of conservationists presented information — not really a secret, but a truth about the Glen Canyon Dam that no one had talked about. As water levels in Lake Powell dropped and the federal government started holding back more water, the reason became clear.
The conservationists described the problem as “antique plumbing.”
The pipes that feed water to turbines in Glen Canyon Dam are the same pipes that send the water downstream to Lake Mead. And while federal officials said they were concerned about damaging the turbines if the water levels dropped lower, they would be unable to deliver the required amounts of water downriver if Lake Powell dropped below the “penstocks” that feed the turbines.
The “Law of the River” — the Colorado River Compact of 1922, along with all the legal agreements that came after — mandates that 7 million acre-feet of water is released from Glen Canyon Dam. That water is contracted to Arizona, California and Nevada.
If Glen Canyon Dam can make hydropower, that’s one thing. But if it can’t let through enough water, you can expect lawsuits to come quickly.
The seven states that rely on the Colorado River — Arizona, California, Colorado, New Mexico, Nevada, Utah and Wyoming — have had plenty of disagreements over river water. But the truth about Glen Canyon Dam is of critical importance to Nevada, Arizona and California.
Several conservationists have advocated abandoning Lake Powell completely in favor of a “one pool” system — Lake Mead.
Among those voices is Kyle Roerink, executive director of the Great Basin Water Network. We asked him for a statement about the snowpack this year.
“Despite the seemingly continual number of storms and the healthy snowpack data, we have to understand the changing circumstances that water managers must consider today compared to 40 years ago,” Roerink said.
“Surface and groundwater supplies will get relief. But soil moisture deficits, the albedo effect, and warmer spring temperatures will likely lead to earlier runoff patterns, less groundwater recharge and other factors that will make coming out of the drought more difficult this year than it was for past generations,” he said.
The albedo effect has to do with how fast snow melts. Dust and smoke that settles over snow make it melt faster because it doesn’t reflect the sun as easily.
“We cannot believe that Mother Nature flushed away our problems this winter,” Roerink said.
“We have to also factor in human management. Lake Mead will continue to decline this summer as part of an effort to save Lake Powell. We are so out of sync, one big winter won’t realign much. But it does provide some optimism,” he said.