Last spring, as it became clear that what snowpack we had was rapidly disappearing and we weren't getting any more, there was a flurry of media attention to the Drought of 2012. Temperatures soared, fires across the West filled the skies with smoke, and official drought declarations were made.
But then the monsoon rains came, and it started to feel like things weren't so bad. Given that we just officially finished the 2012 Water Year (water years run Oct 1–Sept. 30), it's a good time to take stock of where we really are in terms of our water supply.
According to the September drought update from the Colorado Water Conservation Board, all of Colorado remains in drought, which ranges from "severe" to "exceptional." August and September rains eased conditions in the central mountains, while portions of the eastern plains stayed dry and slipped into "exceptional" drought, the most severe category reported by the U.S. Drought Monitor (http://droughtmonitor.unl.edu/ ). From Mesa County straight north, drought conditions were rated "extreme."
The impact of the exceptionally hot and dry 2012 water year was buffered by good reservoir levels at the start of the year from the wet winter the year before. Farmers in the Grand and Uncompahgre valleys with reservoirs upstream managed decent harvests, even though ranchers in the mountains, who rely more on natural stream-flows and grazing conditions, were hurting. Next year's outlook is uncertain, and water managers are being conservative about putting further pressure on reservoirs. The Uncompahgre Valley Water Users Association decided to cut off water deliveries two weeks early to keep more water in storage for the 2013 growing season.
Reservoir storage levels around the state are low, and more extreme conservation measures are likely next year if winter storms fail to significantly refill them. Grand Valley domestic water providers have warned that another dry winter could lead to mandatory restrictions and higher water rates. According to the Natural Resource Conservation Service, reservoir storage levels at the end of August for some of the state's major river basins were as follows:
• Colorado River Basin: 64 percent of average, and 63 percent of capacity. At the same time in 2011, the basin's storage levels were at 111 percent of average.
• Gunnison River Basin: 63 percent of average, and 52 percent of capacity. At the same time in 2011, the basin's storage levels were at 108 percent of average.
• South Platte River Basin (includes Denver and the northern Front Range): 71 percent of average, and 44 percent of capacity. At the same time in 2011, the basin's storage levels were at a whopping 121 percent of average.
• Arkansas River Basin (includes Colorado Springs and Pueblo): 63 percent of average, and 19 percent of capacity. At the same time in 2011, this basin was already beginning to experience drought and had storage levels at 85 percent of average.
Drought conditions and reservoir storage levels on the Front Range matter to Western Slope water users, and vice-versa, because of the extent to which Front Range water users rely on trans-mountain diversions. On average, about 500,000 acre-feet/year flows from Western Slope headwaters streams (mostly in the Colorado Basin) into the South Platte and Arkansas River Basins to irrigate crops and provide water to cities. An acre-foot is about enough to supply 2-3 households' domestic water needs for a year.
Weather forecasters are having a tough time predicting what the coming winter has in store. Forecaster Klaus Wolter at the University of Colorado expects that October–December 2012 are likely to be wet in eastern Colorado, but there are no clear signals indicating what conditions in western Colorado will be like. For January–March 2013, Wolter said conditions look good for moisture for northeast and north-central Colorado, while the only part of the state with a strong risk for dry conditions is in the southwest.
So — don't panic, but also don't forget about the drought just because it's not so hot anymore and we've had a few rainy days!
If you're interested in keeping track of how Colorado's water picture is evolving, check out the Colorado Water Conservation Board's "Flood and Water Availability Task Forces" page, where much of the information in this article came from, at http://cwcb.state.co.us/public-information/flood-water-availability-task-forces.
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 www.coloradomesa.edu/WaterCenter.blog comments powered by Disqus