Federal forecasts for water supply in the Colorado Rivers, the source of water for 40 million people, have decreased significantly as the snow season eases in the new year.
Water flowing into Lake Powell is estimated to be 79% of its historical average, according to the December monthly report from the US Bureau of Reclamation. A big factor is the poor showing of snow in the Rocky Mountains, but it’s not time to panic, water experts say.
This December, we still have several months of accumulation potential, said Russ Schumacher, Colorados state climatologist. There is no reason to worry about the fact that the snowpack is small at this point because there is still time to finish that. But we also know that, as the climate warms, the snowpack we’ll get won’t be as far away.
In the Colorado River Basin, which spans seven Western states, a system of reservoirs captures water and releases it intricately to provide a steady flow to farms, cities, industries and ecosystems around the basin. .
This Fresh Water News story is a collaboration between The Colorado Sun and Water Education Colorado. It can also be found at sawateredco.org/fresh-water-news.
The largest reservoirs are Lake Powell on the Utah-Arizona border and Lake Mead on the Arizona-Nevada border. Together, they can store up to 53.9 million acre-feet of water, or about 92% of reservoir storage capacity in the entire Colorado River Basin.
Both fell to historic lows in the early 2020s. The good water year of 2023, when the basin saw above-average snow and rain, brought the reservoirs back from the brink of a crisis, but it was nowhere near its normal conditions, much less almost at full capacity.
A bad water year with below-average rainfall and warmer conditions could send reservoirs back to dangerously low levels, experts say. At Lake Powell, Glen Canyon Dam can no longer generate hydroelectric power when the water level drops below 3,490 feet or release water when the level falls below 3,370 feet.
The scene at Lake Powell has gotten worse since the start of the water year in October. The Bureau of Reclamation estimates that a total of about 9.4 million acre-feet of water will flow into Lake Powell between October 2023 and September 2024.
That estimate dropped by nearly 2 million acre-feet. The December forecast estimated the reservoir would receive about 7.62 million acre-feet of water in September, about 79% of the 30-year average from 1991 to 2020.
Two million acre-feet is enough water to fill Blue Mesa twice as Colorado’s largest reservoir or to supply a year’s worth of water for about 4 million average urban households.
For reference, in previous years record snowpack sent more than 12 million acre-feet of water into the massive reservoir.
Even with the 7.62 million acre-feet expected to flow into Powell, Glen Canyon Dam is scheduled to release 7.48 million acre-feet of water downstream of Lake Mead, an amount set by interstate agreements that governs how the reservoirs operate.
Some projections show that reservoir levels could be low enough to trigger more emergency releases into Lake Powell from Upper Basin reservoirs, such as Blue Mesa, located on the Gunnison River near the town of Gunnison. .
River officials are calling on Blue Mesa to send water to Lake Powell in 2021 to raise water levels in reservoirs. That debt will be paid by the end of December, said Chuck Cullom, executive director for the Upper Colorado River Commission, an interstate body that helps manage water in the Colorado Rivers.
Between now and 2026, I’m just going to highlight to people that it’s going to be Groundhog Day in the early spring and summer in terms of lowering critical levels, Cullom said during a Dec. 13 meeting of the Upper Colorado River Commission. in Las Vegas.
Snow accumulation in the mountains of Colorado, Wyoming and Utah provides a lot of water for the Colorado River Basin. Right now, that snowpack is off to a good start, Schumacher said.
Federal data showed snowpack in the Upper Basin of Colorado, New Mexico, Utah and Wyoming was the third lowest at the end of December since 1986, he said.
It’s similar to 2018, a year that nobody wants to repeat in the Southwest, Schumacher said.
That was a year that started badly and never recovered, he said.
This year, warmer water temperatures in the Pacific Ocean are causing El Nio weather patterns, which typically bring less rain to the Southwest and less moisture to the mountains of northern Colorado.
At this point in the winter, the way greater uncertainty is that we just don’t know what the weather will be like in the next few months, Schumacher said.
As manager of the Uncompahgre Valley Water Users Association, Steve Pope checks the snow reports every day.
The association draws water from the Gunnison Basin, which feeds the Colorado River, through the Gunnison Tunnel and uses water in the Uncompahgre Valley to supplement the supply.
Most snow basins stack up from January to March, Pope said, so it’s too early to panic.
It’s still early, he said. The next three months are pretty good, and we could have a significant snowpack again this year if Mother Nature cooperates.
Story Type: News
Based on facts, either observed and verified directly by the reporter, or reported and verified from knowledgeable sources.
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