COLORADO —Aug. 5, U.S. Drought Monitor reported 100 percent of the state abnormally dry or in extreme drought conditions for the first time in eight years consistent with a broader transformation of the Southwest amid climate warming. A combination in Colorado of paltry spring snow, warmer temperatures that triggered earlier melting of winter mountain snowpack, feeble rain through summer, and parched soil from previous dry years led to this formal label.
It’s the fourth time in two decades — following 2002, 2006 and 2012 — that all of Colorado was designated as abnormally dry or in a drought.
Hardest hit so far are farmers and ranchers in the Colorado River Basin and the Rio Grande River Basin as water flows, from tributary streams down to main streams diminish. August 12 the Rio Grande River was flowing at 203 CFS which is 600 CFS below the 121 year average.
“These drought conditions we’ve had to live with since 2002 in the Rio Grande Basin, more often than not, the years are average or below average. We have this unique underground aquifer that helps us bridge some of the gaps. But the gaps are so big, and we have stressed the aquifer probably beyond its capacity,” said Rio Grande Water Conservation District Manager Cleave Simpson, an alfalfa grower in the San Luis Valley, where farmers have been trying to reduce groundwater pumping for eight years.
“We will lose ground this summer. We’ve got to figure out how to farm with less water, or farm less acres,” Simpson said. “You hear about people selling cows. You just feel it. I mean, in Alamosa, 11 out of 13 days in a row were record highs for us — just bizarre. And in one day in June — in 12 hours —we set both a record low and a record high.”
Colorado mountain snowpack, near normal April 1 and once a predictor of sufficient water through fall, may not be as reliable. Now in the West “things can change quickly,” U.S. Department of Agriculture snow survey director Brian Domonkos said. “This week’s U.S. Drought Monitor assessment designated all of Colorado, and much of the West, in some stage of drought, which can trigger federal payments for agricultural producers. It shows most of southern Colorado in extreme drought, much of the rest of the state including the northeastern plains in severe drought, with moderate drought elsewhere and a few patches of western Colorado abnormally dry.
During those decades, people across the Southwest have endured hotter, drier conditions that scientists link to climate change caused by burning fossil fuels. Some scientists compare the shift to aridity to historic “mega-droughts” confirmed in tree-ring and other studies that show periodic shifts over the past 1,200 years to hot-and-dry conditions lasting 40 years or longer. It means shriveling crops and dying forests primed to burn, often uncontrollably due to past suppression of wildfires. It means shrinking water flows in streams and rivers. It means people in crowded cities competing for shady open space.
Gov. Jared Polis has activated Colorado’s traditional “drought plan” to track impacts, save water, coordinate local responses and help hard-hit farmers.
“We take it seriously,” said Conor Cahill, Polis’s press secretary. “Our goal is to work with our federal partners to get assistance and resources to impacted communities.”
But the increasingly hot and relatively rainless conditions over the past six weeks are bolstering an emerging consensus among climate scientists that, beyond a temporary drought with an end, Colorado and much of the West are mired in a multi-decade shift.
“We know that temperatures in Colorado and the world will continue to increase so long as we emit vast quantities of greenhouse gases into the atmosphere every year,” said Colorado State University water center senior scientist Brad Udall, who has researched a 13 percent depletion of Colorado River water and refers to “aridification” because “drought” implies an eventual return to normal.
“Temperatures, for hundreds of years, are not going to return to 20th century averages. We need to be thinking in terms of more frequent periods of very hot and dry — unlike anything we’ve experienced before,” Udall said.
The hot and dry conditions have caused “reduced wheat yields this summer, reduced pasture forage and probably reduced corn yields as well,” said Peter Goble, climate and drought specialist in the state’s climatology office.
“The Eastern Plains of Colorado missed out on timely rains in May and June. It was a punch in the gut for farmers and ranchers at the worst time of the year. In recent weeks, this has spread to the Front Range urban corridor. We haven’t had any good, statewide, drought-busting rains for a long time,” Goble said. “Our temperatures are warming without an increase in precipitation to counteract that. Soil moisture available to crops, grasses, trees and other plants is dried up more quickly,” he said. “Given the warming temperatures, we need to be prepared as a state.”