Your Watershed column: The ‘new normal’ for water
A quote from the Colorado water managers meeting, covered in the Post Independent on July 22, reaffirmed the parched landscape we all see: “About every river in the state is at least less-than-half of its average. Many of them are at a quarter of their average flows for this time of year. It’s just awful out there. There is no water in the rivers.” The U.S. Bureau of Reclamation released a May 2018 statement foreshadowing that grim statement with another: “2018 has brought record-low snowpack levels to many locations in the Colorado River Basin, making this the driest 19-year period on record.”
While hardships because of this drought are evident, the only reason why this historic drought isn’t a crisis is because of the nearly-full reservoirs at the start of the drought in 2000. Drought is a prevalent term through news and media today, and its usage is beginning to come under scrutiny. The word “drought” implies a temporary condition. When does a trend of 19 years imply permanence?
The Colorado River Research Group (CRRG) is a collection of 10 veteran Colorado River research, water management and policy scholars. Their mission is to “provide a nonpartisan, basinwide perspective on matters pertaining to the Colorado River, helping all those with a stake in the river identify, justify and implement actions that sustainably meet society’s demands for water while maintaining the distinct attributes of the Colorado River ecosystem.”
In a CRRG March 2018 publication, “When is Drought not a Drought? — Drought, Aridification, and the ‘New Normal,’” the CRRG argues that perhaps our Colorado River basin is no longer in a period of drought, but in a period of aridification: transitioning to a period of increased water scarcity, with a dryness that is permanent and not temporary.
Throughout the CRRG publication, numerous scientific publications and historical data collections are referenced. The drought of the 1950s received significantly less precipitation than our current 19-year period has received, but streamflows between the two are very similar because our region is now significantly hotter, resulting in increased evapotranspiration and sublimation rates. In reality, we haven’t just been looking at a precipitation-reduced runoff decline throughout this cycle, but at a temperature-induced runoff decline as well. Even with some models predicting future “wetter” periods, it’s likely that temperature increases will overwhelm any precipitation increases.
Increasing amounts of dust on snow is also creating a small projected decrease in runoff, and it is certainly causing that runoff to occur sooner in the season. Any human activity that breaks up soil spreads dust into the air, and wind carries it to the Rockies, where it lands on snow and helps absorb sunlight, heating up and melting the snowpack. The early runoff robs the late season of flows, threatening water supplies and fueling wildfire seasons. Luke Runyon’s article “The Rocky Mountains Have a Dust Problem” in conjunction with the Center for Snow and Avalanche Studies further describes this issue.
The Colorado River Research Group is one of the first to put scientific numbers to question how to appropriately describe the trend of the last 19 years. The CRRG has a number of publications that can be found on its website, and it will be presenting on this publication at the annual conference of the Rocky Mountain Farmers Union this fall. Naturally only time will tell if arid is the new normal, but if the trend continues, we’ll all have to consider a change in perspective and definition.
Jon Nicolodi writes a monthly column for the Middle Colorado Watershed Council, which works to evaluate, protect and enhance the health of the Middle Colorado River Watershed through the cooperative effort of watershed stakeholders. To learn more about water in our region, join them on a Watershed by Bike tour down Glenwood Canyon on Sept. 15. To learn more about the event and the MCWC, go to http://www.midcowatershed.org. You can also find the Council on Facebook at http://facebook.com/midcowatershed.
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