Colorado River Basin Reservoirs drained to fill Lake Powell
The country’s western drought is so severe that state forecasts that the Colorado River will flow into Lake Powell have fallen by the equivalent of 10 Lake Dillons in just six months in 2021, according to a key new report.
When the report was released on Friday, U.S. water engineers said they will be drawing water from the Flaming Gorge, Blue Mesa and Navajo reservoirs for the first time to protect electricity production at Glen Canyon Dam on Lake Powell, where the water level is below the current Turbine inlets threatens to fall.
The office now predicts that 2.5 million acres less water will flow into Lake Powell through natural runoff in 2021 than forecast six months ago. This loss is ten times the total working capacity of Lake Dillon Reservoir along I-70 in central Colorado.
The Bureau of Reclamation’s sobering 24-month forecast and dam operating plan said the decade-old system of massive storage buckets on the Colorado has served tens of millions of Western residents well, but the ongoing drought and climate change prompted an early and dramatic move to Plan B.
“Here we are now in 2021, and the basic assumptions that we have relied on are beginning to erode,” said Wayne Pullan, director of the office’s Upper Colorado River Basin.
Pullan said it is important to begin replenishing Lake Powell in collaboration with other reservoirs, state officials across the basin, and environmental, agricultural and recreational interests “now that we have reached the place we feared we could reach him ”.
“It will take the best everyone has to give to thread this needle,” said Pullan.
Pain ahead for the states of the Upper Basin
The new plan, announced to support Powell for the remainder of this year, signals pain for all states of the Upper Colorado Basin Wyoming, Colorado, New Mexico, and Utah. A sunken basin in upstream reservoirs can impact fishing, aquatic recreation, and more. In the coming years, more conservation pilots will be in the works to pay ranchers to give up some of their water without sacrificing long-term rights.
The Flaming Gorge Reservoir on the Green River in Utah and Wyoming will move an additional 13,000 acres of water downstream towards Colorado in July and jump to 42,000 acres in August. By the fall, Flaming Gorge will have contributed a total of 125,000 acre-feet to protecting the Lake Powell hydropower plant.
Blue Mesa Reservoir, west of Gunnison, will add a total of 36,000 acres of feet as of August, 18,000 in September, and 4,000 in October. Blue Mesa dams the Gunnison River, which flows into the Colorado River at Grand Junction.
The Navajo Reservoir on the Piedra and San Juan Rivers in southern Colorado and northern New Mexico will give up a total of 20,000 acre-feet to Lake Powell in November and December. Taken together, the releases will raise Lake Powell 3 feet, enough to protect hydropower production. The idea of storing additional water in Lake Powell from the upstream reservoirs became the official federal plan in 2018.
Federal officials said in a news conference on Friday that the additional releases will mean a 2 meters drop in the already depleted Blue Mesa pool, 2 meters from Navajo and 4 feet from Flaming Gorge.
“These reservoirs vary in size,” said Christopher Cutler, a manager in the Bureau of Reclamation’s water and electricity services division. “The larger the reservoir, the less altitude difference there will be with the given amount of water.”
The federal agency said it had no choice but to move more water to power the Lake Powell Dam after the drought destroyed its previous river predictions.
Blue Mesa Dam at Blue Mesa Reservoir near Gunnison, Colorado on July 16, 2021. Federal officials will use water stored in Blue Mesa, Flaming Gorge, and Navajo Reservoirs to raise the level of Lake Powell downstream To keep this important pool viable, generate hydropower. (Dean Krakel, Special on The Colorado Sun)
Lake Powell will only have 3.2 million acres of natural inflow this year, only 30% of the total for a normal year, the office said. As part of the agreement between the Upper Basin states and the Lower Basin states of Nevada, California and Arizona, the office will unlock a total of 8.23 million acre-feet of users downstream from Lake Powell in 2021 following the ongoing 22-year drought in the southwest.
“Yes, the snow cover wasn’t that great,” said Pullan. “But the real concern was with the dry soil. And on top of that, things just dried up. ”
Water officials in western Colorado this year have spoken of soils ravaged by prolonged drought that siphon off any runoff before it reaches the creek beds, and of blanket of snow simply evaporating into warm air.
Another federal report, pending in August, is expected to review the long-awaited cuts in releases from Lake Powell and Mead to the compact Lower Basin states in 2022 as the reservoirs fall below the trigger levels set out in the compact agreement between the seven states fell. Arizona will be the first to suffer severe cuts next year and expects to lose up to 500,000 acre-feet of water from the levels it received in recent years. This will mean a loss, especially for farmers.
The effects are already noticeable
Upper compact states should not be affected by the cuts in 2022 under the official agreement. But Colorado water experts say the effects of compact “calls” are already there.
“I’d say Colorado is already facing real consequences, but so far they have been limited to the farming community, mostly on the western slope, and the environment as the streams are very low and warm,” said Andy Schulteiss, managing director of the nonprofit Colorado Water Trust, which helps organize water purchases to promote river health.
“Many ranchers and farmers have been cut off (by local suppliers) this year because of extremely low flows, and many more will follow in the coming months. That means that their main source of income is gone or severely restricted, ”said Schulteiss.
More formal, compact cuts in the water available in the Upper Basin states “seem inevitable and not far away,” he added.
The latest US drought monitor ranks almost all of western Colorado in the extreme or exceptional drought categories, along with most of Nevada, Utah, Arizona, and much of California. Climate researchers have identified the 20-year-old as one of the worst “mega-droughts” in the West in 1,200 years.
Federal officials who announced the partial replenishment of Lake Powell on Friday were asked what they will do when there is no drought aid and the upstream releases are insufficient.
“We are now preparing for this by modeling,” Cutler said. “So next year we’re not just modeling normal hydrology, but dry and extremely dry.”