LAS VEGAS (KLAS) — In a surprising move, the U.S. Bureau of Reclamation is releasing much more water from Lake Powell in an effort to shore up Lake Mead’s water level. But how much it will help and how long this will last is not known at this time.
Beginning on April 1, 2023, Reclamation began the process of releasing more than twice the previously scheduled amount of water downriver through the Glen Canyon Dam. “The release volume from Glen Canyon Dam for April 2023 will be increased to 910,000 acre-feet because of the increased snowpack throughout March,” Reclamation Public Affairs Officer Becki Bryant told 8 News Now.
“They are doing several things at once. And they are not necessarily being secretive about this, but they are definitely not broadcasting this information vigorously, either,” according to John Weisheit of LivingRivers.org.
“They are balancing the two reservoirs — Powell and Mead,” Weisheit said. “Recall also that the Upper Colorado River Commission asked Reclamation to stop transferring water from Flaming Gorge Reservoir to Lake Powell, and Reclamation complied. The reason is indeed the snowpack accumulation is significant this year.”
This directive came from Reclamation’s Upper Colorado Basin office. The spike in the total amount of water being released can easily be seen on charts provided by Reclamation. The last time this amount of water was suddenly released, according to Reclamation, was at the end of March 2021.
Over the last 10 years, this type of sudden release of water from the Glen Canyon Dam occurred at the end of November in 2008, 2012, 2013, 2014, 2018 and 2021.
“Hourly releases during April 2023 will fluctuate from a low of approximately 10,533 cubic feet per second (cfs) during the early morning hours to a high of 18,533 cfs during the afternoon and evening hours,” Bryant said. She added that the amount of water released from Lake Powell could be revised again as Reclamation evaluates the amount of water entering Lake Powell.
Bryant added that the “water released from Glen Canyon Dam [and] Lake Powell flow downstream (Colorado River) to Lake Mead and the increased releases from Lake Powell would help boost Lake Mead.”
Current lake levels
As of Wednesday, April 12, 2023, Lake Powell’s water level remains at a historic low and has dropped almost two feet since March 30. However, the water from the main Colorado snowpack melt has yet to arrive in Lake Powell.
“Lake Powell will not fill this year. Its capacity is way too large to fill in one year,” said Zachary Frankel, executive director of the Utah Rivers Council. “Plus, the Bureau is trying to maximize storage at Mead, which is slightly larger but also too large to fill in one year (by itself). That’s why there is more water coming from out of Powell in April than originally anticipated.”
The Colorado Rockies snowpack that provides the majority of water to the Colorado River basin remains close to 160% of normal, according to Reclamation.
Downriver at Lake Mead the water level has risen around four inches since the beginning of March. Lake Mead remains forecast to drop around 10 feet by the end of this year, according to Reclamation.
Estimates on the amount of water expected to come down the river at Lake Powell this year reached 177% of normal, “providing much-needed water after record-low water levels,” according to an April 7 briefing from the Western Water Assessment.
Just a month earlier, the Bureau of Reclamation had estimated Lake Powell inflow at 113% of normal.
But March brought snowfall this year that built snowpack throughout the Upper Colorado River Basin. Maps updated today show the Snow Water Equivalent (SWE) at 159% of normal. The beginning of April is regarded as the typical peak of snowpack levels — when spring temperatures rise and snow begins to melt faster than new snow accumulates.
Some parts of the basin have staggering amounts of snow (compared to normal levels). The Lower San Juan region’s SWE is currently at 1,084% of normal. The crucial Colorado Headwaters region, where the river is born in the central Rocky Mountains, is at 129% of normal.
But now conditions are rapidly shifting as temperatures increase.
“We have had some strong winds and the snowpack has dust on it, and sublimation appears to be in progress; it was quite warm yesterday and today,” Weisheit said. Dust means snow will melt faster as it reflects less sunlight.
The risk of flooding exists in Utah and western Colorado, where precipitation was 150% to 400% of normal in March.
Weisheit, who lives in Moab, Utah, said, “The high-altitude scree of the La Sal Mountain peaks outside of Moab are visible from my backyard. The basins still have accumulation, but the peaks do not.” It’s part of the climate change story he has seen unfold on the river.
“Thirty years ago, the peaks stay covered by late May or early June. In fact, we river guides once said: ‘If it is June 1 and the peaks are visible, the peak has already happened. If they are still covered on June 1, then the peak river flow is yet to arrive.’ That quote is never true anymore. The peaks are always visible well before the arrival of June 1.”
Effects on the Colorado River
Weisheit said the releases from Lake Powell are ahead of anticipated releases to build up sandbars in the river below Glen Canyon Dam. Those releases will add 40,000 cfs to the river in the near future, he said.
“They may be doing test flows, incidentally, to disadvantage smallmouth bass that have been sucked through the penstocks and turbines and into the Colorado River through Marble and Grand canyons, Weisheit said.
The Bureau of Reclamation said in late February that smallmouth bass — described as a predatory species — had begun to spread below the dam as the river temperature increased.
“However, right now the elevation of Lake Powell is the lowest it has been since 1965, and it is highly likely that non-native fish are being sucked through the penstocks,” Weisheit said. “I find this quite ironic.”