In the next week or two, the water level at Lake Powell is likely to dip below a key target elevation of 3,525 feet above sea level — a benchmark water managers have long tried to avoid — according to Nick Williams, power manager for the Bureau of Reclamation’s Upper Colorado River Basin.
“I think we’re right at 2 feet above that target elevation,” Williams said. “At the rate we’re dropping we could be there in a week or two.”
In 2019, the Upper Basin and Lower Basin states in the Colorado River Basin signed drought contingency plans to protect the water in the region. Part of the Upper Basin deal included a Drought Response Operations Agreement, or DROA, which aimed to safeguard critical elevations at Lake Powell. DROA defined the 3,525-foot mark as an important “target elevation” for the reservoir. That target provides a 35-foot buffer above the lowest elevation at which Glen Canyon Dam can generate power, 3,490 feet above sea level.
More than 3 million customers use Glen Canyon Dam electricity and the federal government generates roughly $150 million in average annual revenue from selling that hydropower.
The water level at Lake Powell has not dipped below 3,525 feet since the reservoir was considered “full” in 1980. Last summer, U.S. water engineers made emergency releases from other reservoirs, including Blue Mesa west of Gunnison, to protect the target elevation at Lake Powell. The releases dropped the water at Blue Mesa by 8 feet, which forced an early end to the boating season and significantly impacted the local economy.
Williams said he couldn’t give a specific date that the water level at Powell would dip below the target elevation. “It can kind of vary a day here or there,” he said.
Powell’s elevation level could drop as low as around 3,522 feet, and sit below the 3,525 target for up to two months, Williams said. This dip, however, will be temporary; Williams expects the reservoir will rise back up above 3,525 feet once the spring runoff season begins.
Scientists are concerned that dry soil conditions will lead to another poor year for runoff. Although snowpack on April 1 was either at or slightly below 100 percent of average in each of the past two years, runoff was lower than expected.
Williams said that Powell dropping below the DROA target level in a week or two would not cause any immediate operational problems at Glen Canyon Dam.
Dave Kanzer, director of science and interstate matters at the Colorado River District, which is focused on water supply issues, said dropping below 3,525 feet is “very significant.” “It’s something the collective ‘we’ in the basin have been trying to avoid, unfortunately unsuccessfully,” Kanzer said. “It’s another in a series of wake up calls for the basin.”
“It’s not surprising considering the hydrology we’ve seen the last several years,” Matt Rice, American Rivers’ Colorado River Basin programs director, said. “I kind of get tired of saying this, but if there wasn’t a bright flashing red light with a siren, this is it for sure.” Not too long ago, Rice said, Powell dropping to this level was unthinkable.
The reservoir falling below 3,525 feet in March doesn’t necessarily change a lot, John Berggren, a water policy analyst at Western Resource Advocates, said. But, he said, a lot of basin-wide efforts have gone into protecting Powell from reaching this spot.
“3,525 is important; it’s a big deal,” Berggren said. “It really demonstrates this broader both short- and long-term challenges that face the Colorado River — that climate change and overuse can really impact the system pretty quickly.”
Williams said he doesn’t watch the elevation level at Powell hour by hour. “I know where it’s headed,” he said. He does, however, watch the forecast closely, hoping for any moisture that will help the reservoir maintain the target elevation.
“It was set for a reason,” Williams said. “And it’s something we’ve been trying to avoid.”