Water officials work to save Blue Mesa from critical lows

Blue Mesa Reservoir, the largest in Colorado and an emergency savings bank for Lake Powell, has been on a crash course with critically low water levels this summer, the kind that halt power production and keep dam managers up at night.

Officials have stepped in to cut dam releases and restrict water use, but they’re still facing grim possibilities if more rain doesn’t start falling soon.

The expansive federal reservoir stretches for nearly 30 miles between the city of Gunnison and Black Canyon of the Gunnison National Park. But it’s not just a scenic lake — it’s part of the plumbing of the West. Water experts say Blue Mesa serves as a proxy for Colorado’s water conditions and conditions in Lake Powell, an immense reservoir on the Utah-Arizona border. This year, it’s a clear demonstration of the record dry conditions straining water and renewable power supplies across the West.

“It’s kind of indicative of the entire state, when our largest reservoir is at less than 25%,” said Steve Pope, manager of the Uncompahgre Valley Water Users Association, which uses water from Blue Mesa for irrigating crops.

This year, people passing by Blue Mesa on U.S. 50 have a close-up view of what used to be the bottom of the reservoir. Visitors can walk its expanding shore, where a river winds through the lake’s floor and bright green grass is growing on long stretches of sand. In some places, the receding waterline has even revealed the foundations of an old town torn down to create the reservoir.

Managing Blue Mesa in a drought year means executing a careful dance between competing needs.

The reservoir’s water generates power as it passes through Blue Mesa dam’s turbines and flows downstream to farmers in the Uncompahgre Valley, known for its sweet corn. Its releases are designed to support endangered fish species and to flow through Black Canyon of the Gunnison, one of the longest, narrowest and deepest gorges in the world.

“I think everyone’s taking some sort of shortage. There’s not enough,” said Michelle Garrison, water resources specialist for the Colorado Water Conservation Board. “There will not be enough to fully meet all those needs.”

The Lake Fork boat ramp at Blue Mesa Reservoir is closed and locked on August 4, 2026. The Lake Fork, Elk Creek and Iola boat ramps have been closed to motorized boats at Blue Mesa because of the lake’s low water due to drought. Dean Krakel, Special to The Colorado Sun)

And in recent years, like 2021, Blue Mesa has had another purpose: sending emergency releases downstream to Lake Powell, which releases Colorado River water for use downstream in Arizona, California, Nevada and Mexico.

Congress authorized Blue Mesa and its sister dams, Morrow Point and Crystal, in 1956 as part of the Colorado Storage Project Act. Together, the three dams created more water storage and hydropower potential along a 40-mile stretch of the Gunnison River. 

Blue Mesa’s role in the broader Colorado River Basin, which spans most of the Southwest, is still being hotly debated as federal, state and tribal officials negotiate how to manage water in 2027 and 2028. The federal government released a plan July 31 that offers more clarity on the river’s future over the next 10 years, including using reservoirs like Blue Mesa to avoid critically low levels at Lake Powell.

This summer, Powell received about 15% of its normal inflows, forcing officials to draw emergency water from another upstream reservoir, Flaming Gorge. They couldn’t tap Blue Mesa for emergency water because it was so low.

It’s a good example of what Colorado officials mean when they say the state simply doesn’t have water to send downstream in dry years and can’t agree to mandatory water cuts as the broader basin struggles to adapt to a shrinking river, state officials said. 

“Blue Mesa tends to be pretty dry when Lake Powell is dry,” Garrison said. “When things are dry, it doesn’t usually have much water to contribute.”

The risky business of dam operation

As water managers tried to fulfill the reservoir’s release requirements this summer, they knew they were heading for trouble. 

Dam managers must continue releasing water for downstream priorities, like protecting endangered fish and growing crops, and meeting legal obligations while adjusting to ever-changing forecasts. But in a year with little water to spare, meeting all of these obligations had them running headlong toward extremely low water levels in the reservoir.

“There was a chance earlier that as low as 3,000 acre-feet would be left in live storage in Blue Mesa,” State Engineer Jason Ullmann told the CWCB board members during a mid-July meeting.

Blue Mesa’s previous low since filling was in 2018 at about 230,000 acre-feet of live storage, the amount of water that can be released from the dam’s outlets. 

Blue Mesa was expected to drop below its minimum power pool by November at the earliest, meaning it would not be able to generate hydropower until the water level increased. If the water drops much farther, it would sink below the dam’s outlets. At this point, the dam can’t release any stored water at all, a point known as dead pool.

“Once you get below minimum power pool, you’re also getting really close to dead pool,” Garrison said. “Then you can’t do anything, so it doesn’t leave you much buffer if you did need to make a release for some reason.”

The dam’s hydropower enters a larger system managed by the Western Area Power Administration, which draws electricity from many sources including power from natural gas and coal plants. Less power from Blue Mesa means less cheap, reliable, renewable energy in that system, officials said.

Water from Blue Mesa flows through the Gunnison Tunnel to reach cropland in the Uncompahgre Valley. Pope, the system’s manager, is mainly concerned about starting the system again in April as he watches Blue Mesa’s water levels drop. He needs certain flows to operate the tunnel effectively — there are pressure and suction concerns in the long tunnel that limit its operations. It takes hours to open and close it. 

“We can’t be bouncing it up and down based on whatever water’s available,” Pope said. “It’s our one sole source of continuous steady water that we can charge our system with and rely on.”

The association’s farmers need a water delivery through the tunnel in April for their crops, and if there’s not enough water coming down from Blue Mesa and its sister reservoirs, the association might have to assert its powerful water rights. 

These rights are old enough that they can turn off other water deliveries. In this case, that might mean drying up the river in the Gunnison canyon and cutting flows for endangered species. 

Pope doesn’t expect big impacts before the end of the water year in October. But if they have to start next season by cutting off other water rights, such as drying up Gunnison canyon, it’ll be hard for the entire system of rivers and reservoirs to recover, he said.

Changing the game plan

Water managers are pulling all of the available levers to avoid reaching critically low water levels at Blue Mesa, officials said. 

The Bureau of Reclamation, which manages the dam, cut releases for endangered fish and the Gunnison canyon, predicting the change will keep an extra 10 feet of water in Blue Mesa by the end of October, Garrison said.

In the Uncompahgre Valley, the Gunnison tunnel is essentially the sole source of water for farmers, Pope said. Other options had too little snowpack this winter to feed water into their irrigation ditch system.

The system is adapting to the record dry conditions successfully — to a certain extent and mostly based on sacrifices, Pope said.

A canal system built in the early 1900s after the opening of the Gunnison Tunnel in 1909 delivers water from the Gunnison River in the Black Canyon to the farmlands of the Uncompahgre Valley. (William Woody, Special to The Colorado Sun)

The Uncompahgre Valley Water Users Association has already limited its water users to 50% of their normal allocations. Farmers have fallowed large tracts of cropland.

“It’s not a voluntary sacrifice,” Pope said. “This has to be done.”

Even with water cuts, Blue Mesa could still drop low enough to stop power generation in 2027, Garrison said. 

And although there is a Super El Niño in the forecast that could bring more water to Colorado, water managers can’t manage around something that might happen — even as they hope for above-average snow and rain.

“I’ll believe it when I see it,” Pope said.

With average precipitation, Garrison estimates Blue Mesa is still likely to get about 80% of its normal inflows in 2027 because of this year’s dry conditions. It would need a top-10 wet year like 2019, or better, to recover from this year.

“It’s a hard year for everybody,” she said. “It’s a hard year for water users. It’s a hard year for fish. It’s a hard year for everybody.”