Water Lines: Potential consequences of an early spring
Free Press Weekly Columnist
Last week, I noticed crocuses blooming in my yard. I like crocuses, but it makes me a little uncomfortable to see them blooming in Grand Junction in early February. Will the unseasonable warmth trick other blossoms, like the all-important peach blossoms, into coming out early as well, only to be destroyed by the inevitable late freeze? What about this year’s water supply?
As plants all over the valley begin breaking dormancy, ditch companies are contemplating the possibility of an early start to the irrigation season. A longer growing season means more water use, of course, and the same warm spell that is prompting plant growth in the valleys has coincided with dry times in the mountains.
After ending December 2014 above average, the snowpack in the Upper Colorado River basin has added very little moisture so far in 2015. As of Feb. 12, the amount of water held in the snow in the Colorado River Basin in Colorado was just 89 percent of average for this time of year. Other Western Slope river basins are in worse shape, with the Yampa and White river basins at 83 percent of average, the Gunnison at 71 percent of average, and the southwestern basins at a mere 58 percent of average for this date.
Dry conditions in southwestern Colorado are especially concerning, because this area has failed to reach “average” snowpack levels for several years in a row. This has led to the first-ever shortage in deliveries from the San Juan River to central New Mexico through the San Juan: Chama project.
Mostly healthy reservoir levels in Colorado mean that local irrigators are unlikely to suffer in the short term, even if dry conditions continue. However, the Colorado basin-wide imbalance between supply and demand will likely be exacerbated by the warm, dry winter experienced across the West.
On the demand side, the intense drought in California continues, increasing that state’s reliance on Colorado River water. On the supply side, as of Feb. 9, the snowpack for all basins upstream from Lake Powell was at just 85 percent of the median for this time of year, and the reservoir was just 46 percent full.
In the short term, this confluence of factors could hasten the day when Arizona farmers with the most junior water claims come up short, as their deliveries of Colorado River water are cut. Upstream, efforts to keep water levels in Lake Powell high enough for the Glen Canyon Dam to keep producing hydropower are likely to intensify. Increasing releases from upstream reservoirs, such as Flaming Gorge and Blue Mesa, and incentivizing cutbacks in water use by both farms and cities are two of the avenues identified by Upper Colorado River Basin state officials to prop up Powell.
An increasing number of studies indicate that higher demands on reduced supplies are not just a temporary consequence of the current regional drought, but could become a chronic condition. The recently released Colorado Climate Change Vulnerability Study, developed by researchers at the University of Colorado and Colorado State University for the Colorado Energy Office, recaps data on the observed warming of Colorado’s climate in recent decades along with climate projections in order to assess what sectors of the state’s economy and environment could be stressed as the climate continues to change.
The study notes that towns and irrigators with little storage upstream are at risk for water shortages as the snowpack continues to melt off earlier, further dropping late summer stream flows. Low flows in late summer can stress fish as well, and shorten the season for rafters. The study also notes that fruit growers are vulnerable to crop losses from frost damage due to early budburst. You can find the complete study at http://wwa.colorado.edu/.
It’s still not too late for spring storms to bring back cooler temperatures and rescue the 2015 water year, but it’s also not too early to start planning for the possibility that at some point, what seems like a crazy-early spring could become our new normal.
This is part of a series of articles coordinated by the Water Center at Colorado Mesa University in cooperation with the Colorado and Gunnison Basin Roundtables to raise awareness about water needs, uses and policies in our region. To learn more about the basin roundtables and statewide water planning, and to let the roundtables know what you think, go to http://www.coloradomesa.edu/WaterCenter. You can also find the Water Center on Facebook at Facebook.com/WaterCenter.CMU or Twitter at Twitter.com/WaterCenterCMU.
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