The snow keeps falling across Utah, which will likely benefit beleaguered waters like the Great Salt Lake and Lake Powell. But it’s too soon to say how much of a difference it will make.
Snowpack is well above average in watersheds across the state, according to the latest data from the U.S. Natural Resources Conservation Service’s Snow Survey. The Southeastern Utah basin is an astounding 190% above normal for this time of year, and other drainages that feed the Colorado River are close behind. All that snow has done little to lift Lake Powell’s elevation to date, which currently sits at about a quarter of its capacity and around 30 feet above the point where it will no longer be able to generate hydropower.
Still, there are reasons to be optimistic.
“There’s not a better script we could have written for the first half of this [winter],” said Jon Meyer, assistant state climatologist and a scientist with the Utah Climate Center at Utah State University.
Further upstream, snowpack at the Colorado River’s headwaters is also looking healthy, The Denver Post reports.
That doesn’t mean Utahns should get lax about cutting back on consumption or that the state’s water woes will be solved this winter.
“It’s a marathon, not a race,” Meyer said. “Conservation going forward, no matter what the year looks like, is going to have to be on the mind of everybody.”
Runoff season typically starts in late April or early May, and anything can happen between now and then — the snow might keep coming, or the storms could turn lackluster. But at least there’s a good chance the snow currently stored in Utah’s mountains will eventually flow to the state’s parched reservoirs and the Great Salt Lake.
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“That’s one of the real benefits of the summer monsoons and fall weather we had in 2022,” Meyer said. “It set the stage for an efficient spring runoff.”
That’s because soils aren’t parched like they have been in past years, which means snowmelt won’t get sucked into the ground before it reaches streams.
In 2020, for example, the Upper Colorado River Basin saw above-average snowpack, but inflow to Lake Powell was only 50% of normal due to dry soils that absorbed runoff like a sponge, noted Amy Haas, executive director of the Colorado River Authority of Utah.
“While recent forecasts for the Upper Colorado River Basin are very encouraging,” Haas said, “unfortunately a healthy snowpack doesn’t necessarily translate to an increase in flows into Lake Powell.”
A single winter isn’t going to make the massive reservoir recover, Meyer agreed, or solve all the tensions between states that rely on the Colorado River.
“We’re going to need a couple years of these kinds of conditions,” Meyer said, noting there’s no historical precedent in Utah for the kind of winter big reservoirs like Lake Powell would need to rebound in a single season.
Utah’s climate sees decadal oscillations between wet and dry periods. The Utah Climate Center forecasts it will begin to shift back to a wet period this year, although the prediction doesn’t quite make the Upper Colorado River Basin look soused in the year ahead.
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Graphic generated by the Utah Climate Center forecasts water supply flowing just south of Lake Powell in millions of acre-feet. The center uses data from oceans and their influences on the climate to model future conditions.
And Utah’s booming population growth, along with climate change that will bring less precipitation over time, means the state will likely grapple with water security issues for the foreseeable future, Meyer warned.
“One wet year,” Meyer said, “certainly does not give us much optimism for the long-term state of our water resources.”
The Colorado River Basin will need more than a year or two of wet conditions, Haas also noted, before the people who depend on it can rest easy.
“Given that Lake Powell and Lake Mead are at their lowest levels ever,” Haas said, “it could take years of above-average inflows to achieve levels that are safely above critical elevations. In the meantime, water managers can’t get complacent about a few good storms, or a single decent water year.
from The Salt Lake Tribune https://ift.tt/sMw6Sxc
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