Chemist Allison Dederick checks water quality in the lab at Ute Water Conservancy District in Grand Junction. The district began drawing water from the Colorado River on June 10, 2021, which will require the district to treat its supply differently. (Handout)

For 65 years, the Ute Water Conservancy District serving Grand Junction and Mesa County  has let the Colorado River flow on by, while drawing drinking water from pristine runoff 11,000 feet high on Grand Mesa.

The severe, ongoing drought has now forced other plans. 

The utility has for the first time begun to mix Colorado River water into its Grand Mesa reservoir releases to meet the peak demand of 90,000 customers and preserve backup supplies quickly evaporating in summer heat. 

Ute Water, the largest provider between Denver and Salt Lake City, says it must protect supplies in its 96%-full Jerry Creek reservoirs as long as possible given the dry conditions. All of the utility’s Grand Valley service area is in a state of exceptional or extreme drought.

Ute Water has rights to pull a relatively small amount from the Colorado, but says its junior rights are likely to be cut off later this summer, when river flows decrease. 

The utility says it began taking about 7 cubic feet per second from the Colorado on June 10, or about 14 acre-feet per day. An acre-foot is enough water to cover an area roughly the size of a football field in a foot of water, and serves the needs of two to three households for a year. 

Tightening up on resources is crucial after the “back-to-back drought that we’ve been concerned about for many years,” Ute Water external affairs manager Andrea Lopez said. “2018 was a pretty bad year, ‘19 was decent, ‘20 was pretty bad and now we’re in ‘21, where runoff just wasn’t as generous as we hoped it would have been. . .  Over time it just gets worse and worse and we’re definitely seeing the impacts of aridification.” 

Water managers and ranchers across western Colorado say soils are so dry after a string of down years that vegetation is dying off, and depleted snowpack soaks into the ground long before it reaches streambeds. At a recent water conference in Basalt, Lopez said, water engineers talked of snow evaporating before ever melting into a liquid. 

Ute Water’s reservoirs have stayed full through careful management, Lopez said. Starting to add in river water shares is “simply utilizing another tool that we have in our toolkit to help mitigate” supply challenges.

Ute Water Conservancy District Water Supply Coordinator Tim Fox uses a piezometer to measure water levels in an underground aquifer. (Handout)

Ute Water’s customers, who surround downtown Grand Junction and stretch to Fruita and Palisade, will start paying a 2% surcharge on their bills to account for electric power and water treatment costs from using Colorado River water in the mix. The utility’s reservoir water falls naturally from the Grand Mesa reservoirs, but water must be pumped up from the Colorado River to a treatment plant. 

For customers who use about 3,000 gallons a month, the extra cost will be less than 50 cents. Ute Water does not like to call it a “surcharge,” insisting it’s a “drought pumping impact rate.” 

Treatment will make the less-pristine Colorado River supply drinkable, but will leave customer water “hard” or full of minerals like calcium carbonate. The minerals can leave a mark on clothing and some kitchenware, the utility said. 

As with domestic water use in other cities, most of the water Ute Water draws from the Colorado will go right back in downstream. Of the 14 acre-feet a day Ute Water plans to use, only about 1.4 acre-feet will be consumed, or disappear from the system. The remainder comes back into sewage treatment plants, is treated, and goes back into the river toward the Utah border. 

Lopez said Ute Water engineers do not know how long their water rights on the Colorado will last this summer before more senior users put a stop to drawdowns by junior rights holders. The Colorado River, along with nearly every other basin in the state, is suffering greatly from years of poor runoff. 

The Colorado’s flow on Thursday near Palisade was about 850 cubic feet per second, according to U.S. Geological Survey gauges, a far cry from the 30-year median flow on that date of about 4,960 cubic feet per second. 

Mesa County’s population has seen steady growth for decades, to more than 155,000 people today from about 50,000 in 1970.  

While utility managers are changing water conditions for their humans, state wildlife managers are trying to preserve conditions for fish and flora. Colorado Parks and Wildlife has asked anglers on the Dolores River in southwest Colorado to stop fishing after noon, giving trout in overheated, shallow waters a break.

Wildlife officials said similar calls for fishing restrictions are likely to come soon on other popular fishing stretches, including many portions of the Colorado River from Kremmling west to Glenwood Springs. 

Ute Water is using its supply changes as an educational tool with its consumers, Lopez said, avoiding drastic mandatory use cutbacks but asking for voluntary changes in habit. 

“We just really want people to be aware,” she said, “now that drought is touching our community directly and impacting our water supply and our water quality.” 

Michael Booth

Michael Booth is a Colorado Sun reporter covering health, health policy and the environment. Email: Twitter: @MBoothDenver