‘Shrinking in supply, growing in demand’
By Summit Voice
FRISCO — Since the 1980s, warmer spring temperatures in the Rocky Mountain region have been melting the snowpack earlier, with increasing temperatures tabbed as the main factor in the decline, according to the U.S. Geological Survey.
The agency carefully tracks streamflows and snowpack measurements, with decades of data now showing clear trends toward shorter winters, earlier spring runoff and an overall 20 percent shrinkage of the snowpack in the mountains of the western U.S.
The researchers say at least part of the changes are due to global warming caused by heat-trapping greenhouse gases, but that natural variability is also a factor. Regardless of the exact cause, the snowpack decline is already causing major headaches for water managers in the region facing dwindling supplies and increased demand.
The Colorado River Water Conservation District will focus on some of the emerging critical water questions during its annual water seminar (Sept. 13, 9 a.m. to 3:30 p.m.) in Grand Junction. USGS researcher Greg Pederson, who is the lead author on some of the key snowpack studies, will discuss how spring is killing the Rocky Mountain snowpack, especially at lower elevations, where the effects of warmer temperatures are more pronounced.
Spring snowpack has declined across the northern hemisphere and has been below average almost every year for the past decade, even in big snow years like the winter of 2010-2011. Since 1990, spring snow cover has only been above average three times.
The seminar’s keynote speaker is John Entsminger, a top manager with the Southern Nevada Water Authority. Entsminger will outline how climate change and reduced water deliveries to Lake Mead have put Las Vegas water planners on edge.
Other presentations include an overview from River District general manager Eric Kuhn, a seasonal climate outlook from NOAA meteorologist Klaus Wolter and talk by a U.S. Bureau of Reclamation official explaining the agency’s recent announcement that it will likely reduce water deliveries downstream from Lake Powell.
The seminar also includes information on the progress of the Colorado Water Plan, including a panel discussion with representatives from both sides of the Continental Divide.
Filed under: climate and weather, Colorado, Colorado River, Drought, global warming, rivers, water Tagged: | Rocky Mountain snowpack, The West, United States Bureau of Reclamation, United States Geological Survey