Reservoir reaches second-lowest level in history
Photo by: 
Chris Rourke

A drive along Hwy. 50 west of Gunnison offers a telling glimpse of the effects of drought. Colorado’s largest man-made body of water — Blue Mesa Reservoir — has been reduced to a puddle in some areas.

Based on figures kept by the federal Bureau of Reclamation (BOR), the reservoir is at its second-lowest level since it was first filled in 1965. On Monday, Blue Mesa contained 259,545 acre-feet of water — or 32 percent of capacity.

“We had one of the worst snowpacks on record for the mountains upstream of Blue Mesa,” said BOR hydrologist Erik Knight. “I think our rain season — spring, summer and monsoon season — was probably the worst on record. It wasn’t the worst snow year, but when you combine that with the lack of rain we had in the summertime, I think that’s what brought all the stream levels down and all the inflow levels down so far.”

Knight expects Blue Mesa to reach its lowest point this year sometime in late December.

This year’s levels are lower than what occurred in 2002 when storage sank to 263,000 acre-feet by mid-October. Knight said that flows out of Blue Mesa this year are greater than what occurred in 2002 due to a federal decision in 2012 to change dam operations in an effort to protect four species of fish.

This year, flows must be maintained at 300 cubic feet per second in the Gunnison River below Blue Mesa, further emptying the reservoir.

Low water levels have persisted for much of the summer, decreasing the availability of boat ramps. The Ponderosa and Stevens Creek ramps never opened. Iola and Lake Fork closed early. National Park Service (NPS) spokeswoman Sandy Snell-Dobert said the lack of accessibility to boat ramps inconvenienced fishermen and added to their expense.

“Many boaters have preferred ramps and locations on the reservoir and having to use ramps farther from fishing sites uses more fuel and makes for a longer ride in rough waters should the weather turn,” she wrote in an e-mail. “I don’t think we have numbers yet to find out if low waters really impacted visitation, but I suspect it did, particularly later in the season.”

In addition, low water levels allowed blue-green algae to bloom, producing a substance known as cyanotoxins, which are toxic to both humans and animals.

After sampling and analysis, cyanotoxins were found in a portion of Iola Basin at Blue Mesa in concentrations that exceeded safe exposure levels. As a result, the NPS issued a water quality advisory.

“The cyanotoxin issue should be diminishing with the cooler weather and decreasing water temperatures,” Snell-Dobert said. “We still highly recommend staying out of the nearshore waters and keeping pets out of it.”

Yet, despite the lack of water, outfitters say they’ve been flexible enough to keep business afloat.

Gunnison Sports Outfitters owner Andy Cochran said fish have congregated in certain spots which has made successful excursions more likely.

“The fishing has been good,” said Cochran. “Salmon season … congested the boats. Historically, there have been more than one place where they will stage up and you can fish for them. But because there wasn’t enough water for the salmon to stage, they were all basically in one place.”

Cochran noted one area of Blue Mesa where standing trees below the water’s surface have become a hot spot for fish, which encircle the submerged logs. However, he noted the low water has also exposed more hazards for boaters.

“You’ve got to be careful,” he said. “There are a lot of underwater humps that aren’t underwater anymore.”

As for the coming winter, Knight, Snell-Dobert and Cochran agree with most in the Gunnison Valley in hoping for big snows.

Knight said the reservoir and storage system is set up well to accommodate a very dry year, but two years back-to-back will pose challenges for water users, and impacts will be seen in a greater way. Also, even with an average winter ahead, it could take a few years to rebuild storage in the Blue Mesa.

“With 2002, it took until 2006 until we refilled the reservoir,” Knight said. “Things can turn around fairly quickly but when it’s fairly dry, you need perhaps two years of good conditions to get back to full.”


(Chris Rourke can be contacted at 970.641.1414 or at chris.