Snowfall in Colorado’s high country and along portions of the Front Range recently added moisture to the state, however, researchers from Colorado State University’s Colorado Climate Center warn about the increasing threat of an exceptionally dry winter. The climatologists report that Colorado is currently experiencing a serious two-year state-wide drought and headed toward a multi-year drought. They add that the state’s water managers and citizens should prepare for ongoing serious drought conditions at least throughout 2003.
"Following three years of drier than average conditions, the 2002 drought was serious in terms of low precipitation and diminished water supply, and while Colorado experienced very intense drought conditions during the last growing season, it was an average drought for most parts of the state," said Colorado State atmospheric science professor and State Climatologist Roger Pielke Sr. "However, with the continuing lack of precipitation this winter, we are now recognizing that Colorado is entering into a serious multi-year drought."
Climate Center researchers say that the 20 years ending in 1999, during which the state also witnessed massive growth and a great increase in municipal water demand, was the longest drought-free period in Colorado, and wetter than average based on historical data.
"We live in a semiarid region and are always on the edge of drought," said Climate Center research climatologist Nolan Doesken. "Many people were lulled into complacency as a result of greater-than-average precipitation during the 1980s and 1990s."
According to Pielke and Doesken, Colorado’s leaders have not given enough thought to coping with a multi-year drought. For the near future, they suggest water conservation and water use efficiency measures should be continued throughout the winter months. For the long term, the climatologists recommend that Colorado’s water managers and communities need to work together to develop effective plans for long-term irrigation and municipal water use.
This year, January proved to be one of the driest on record at several locations in Colorado. Additionally, many parts of the state witnessed warmer than average temperatures that promoted early snow melt and an increased rate of evaporation.
"Due to the current drought situation, and the state’s water supplies already being so low, the lack of precipitation in January is making it even less likely that Colorado will quickly recover from the current drought," said Pielke. "Additionally, because of the cumulative effect from the 2002 drought, Colorado is at even more risk today than at this time last year."
The Colorado State climatologists believe that many of the effects of last year’s drought will last several years, even if precipitation returns to average or above average for the remainder of 2003. Furthermore, they suggest that making up the current water supply deficit in the next one to two years is unlikely.
Members of the state drought task force agree, and recently predicted that 2003 will be no better and might even be worse than 2002, meaning Colorado citizens will likely face continued water restrictions and potential wildfires.
Colorado’s snowpack, approximately 25 percent below normal, is critical because it provides the majority of Colorado’s year-round water supply, melting into rivers, streams and reservoirs. The January Colorado Water Supply Outlook stated that a below average snowpack was measured statewide for the sixth consecutive year and that dry soils and well below average reservoir storage across the state only add to water concerns. The outlook suggests that water users should keep close tabs on snowpack and consider all feasible water conservation measures.
Colorado’s statewide reservoir storage has been below normal since September 2001, and is currently about half of average. According to the Colorado Division of Water Resources January water supply conditions update, stream flows continue to be significantly below average, and with snowpack also below average, stream flow forecasts are for a below average runoff. The division suggests that it would be prudent for water users to at least make plans for another year of low runoff in 2003.
Climate Center researchers emphasize that it usually takes several seasons for reservoirs and aquifers to recover from a drought of the magnitude of 2002. Part of the problem is that Colorado’s reservoirs are so depleted that an average snowpack and precipitation year will not replenish the water supply. Much of the precipitation that falls this winter will be absorbed by the extremely dry soils and replenish shallow aquifers before running into already low reservoirs. More in-depth drought information can be found on the Climate Center’s Web site at climate.atmos.colostate.edu/.
While hoping for improvement, Pielke and Doesken recommend that Coloradans plan for continued serious drought. Climate history has shown that March through early June precipitation is often effective in a recovery from drought in several parts of the state. However, the flip side is that if these coming months do not provide several widespread long duration precipitation events, the drought will continue to worsen.