Western Colorado’s water situation is getting more complex, as drought and climate change continue to collide with the needs of farms, ranches, and cities.
Ironically, the increasing distribution difficulties center on an artificial lake that sits astride the Utah-Arizona border. That would be Lake Powell, which is definitely experiencing problems; at the end of December, the reservoir was measured at just 42 percent of full capacity.
Jim Pokrandt, of the Colorado Water Conservation District, recently laid out the problem to an audience in Montrose.
“The number one issue these days is the potential curtailment of water use in western Colorado because of Lake Powell’s low levels.”
Two types of curtailment could happen. One is a mandatory uncompensated curtailment, meaning water rights owners get less water and no money. The alternative is a voluntary and temporary compensated curtailment.
It’s all about who gets to use water from the Colorado River. “We’re all ‘snow farmers; we ‘harvest snow’, and our big silo is Lake Powell,” Pokrandt explained. “Lake Powell lets western Colorado use water in this area, against our obligations to the lower basin states in poor times; we’ve had 16 years of poor times in the last 20 or so. The silo isn’t getting enough.”
Last winter’s snowpack was pitifully low, but things have improved on the Western Slope this winter. “It’s actually looking really good,” in Pokrandt’s view. “The Gunnison River Basin got up to 120% (of average) with these three storms,” by the middle of February.
As for Lake Powell, “our peak is well-above last year, so our ‘crop’ is truly good,” Pokrandt reported. Last year’s snowpack was the 3rd worst on record at the reservoir.
The Water Conservation District is part of a larger system, governed by the 1922 Colorado River Compact, encompassing seven western states and the Republic of Mexico. “In what states are the headwaters of the Colorado River for Lake Powell? Well, Wyoming, Utah, Colorado, and a little bit in New Mexico. But, the preponderance of snow pack comes from the state of Colorado and the high elevations, above 9,000 feet.”
But despite the good snow pack we’ve had so far this winter, there is still a problem that will affect the level of runoff into the reservoir system. “What happens with runoff?,” Pokrandt asked rhetorically. “You get the solar input. The snow starts melting. It goes into the ground. If the ground is dry, it’s going to take the greater share of that until the soils are saturated. Finally when the soils are saturated, then you start getting accretion to the streams and rivers. So, this is what the last five years of hot summers have done. They’ve dried out the soils. These are the high elevation areas I’m talking about. So, the runoff is not going to be as bountiful as the snowpack might predict.”
This means that our local reservoirs, such as Blue Mesa, probably won’t have a strong recovery year. “Here, our runoff forecast as of Feb. 1, for this basin and Blue Mesa runoff, is predicted to be about 550,000 acre/feet. That’s about 81 percent of normal. Blue Mesa is about 30 percent full right now.’’ The bottom line is that Blue Mesa is not going to fill, according to Pokrandt.
As for Taylor Park Reservoir, 81,000 acre/feet is predicted, which would be about 82 percent of average.
The Ridgway Reservoir looked like a mudflat last summer. This year, “It’s expecting 81,000 acre/feet from the Uncompahgre River,” said Pokrandt. But Ridgway might come close to filling because of its relatively small size.
As for the Colorado River, “Last year, it produced maybe four million acre/feet of runoff.” That was not enough to provide for everyone’s irrigation needs, according to Pokrandt.
Pokrandt says the Bureau of Reclamation is the federal agency charged with scientifically forecasting Lake Powell’s future. “2018 was, again, one of the lowest. The most probable forecast is 7.7 million acre/feet in 12 months flowing into Lake Powell. That’s still about 3 million acre/feet below the long-term average. (1 acre/foot=325,851 gallons, i.e. enough water to cover an acre of land, one foot deep).
“What’s more, 9 million acre/feet is going to come out of Lake Powell. The reservoir is going to go down to an elevation of 32 to 36 feet, and you’re still going to have a deficit of inflow vs. outflow. That’s just another sign that we’re at risk of having to curtail water.” Pokrandt says the Bureau of Reclamation will probably force the states to deal with the situation before it becomes critical.
To end on a positive note, Pokrandt reports that Colorado is expected to receive above-average precipitation for the next three months. We’ll need every drop.