The latest Drought Monitor map shows how big an impact the recent rainstorms had in recharging dry soil. The white area is drought-free.
What a difference a week can make. The epic rainstorm that hovered over Colorado’s Front Range effectively quashed a lingering drought. But climate scientists caution against rejoicing too quickly.
This has happened before. Ask state climatologist Nolan Doesken about Colorado’s history of flash floods and he can rattle them off in a flurry: Sept. 1938; June 1965; May 1969. All of those had some impact on the Front Range.
“But this is a big one,” Doesken said. “It’s not a run-of-the-mill, every year, every few years kind of event. It’s the kind of thing that somewhere in the state might occur more than once in a century, but at any given location the severity is something that you may not see for hundreds of years.”
Doesken said a full picture of the flooding won’t be available for some time, making it difficult to compare the storm to other flash flooding events in Colorado. During this storm, rivers flowed with such intensity that stream gauges were damaged or destroyed.
Some of those other flooding events came after dry spells, Doesken said, and returned to drought not too long after.
“The lesson is, we don’t know what’s going to happen next. And there’s no guarantee that we’re out of the drought woods,” Doesken said.
The Front Range was drenched. The Western Slope wasn’t. Neither was the southeastern corner, a pocket of which is still categorized as being in extreme or exceptional drought.
“There’s now this concern that maybe we’re going to see more big rains and more flooding, but the reality is, that weather events happen and then we revert back to our regular seasonal cycles. With plenty of meteorological ups and down to go with it,” Doesken said.
This storm doesn’t mean much for the state’s system of reservoirs either. A few were filled to their max by torrential rains, but Doesken said water managers had to push much of it downstream. Small agricultural reservoirs kept their diversions sealed off major rivers to avoid being filled up with the murky, debris-filled runoff.
Many of the Front Range’s primary reservoirs are on the western side of the Continental Divide, which saw little precipitation from this storm.
Doesken said parts of the state are in much better shape in terms of drought than they were a year, or even a week, ago.