Water Management and Drought policies
Drought Policy Resources
Frequently Asked Questions
1. What is meant by drought?
There are many definitions of drought including:
• Meteorological drought is defined as the degree of dryness compared to some “normal” or average amount and the duration of the dry period.
• Agricultural drought links various characteristics of meteorological (or hydrological) drought to agricultural impacts, focusing on precipitation shortages, differences between actual and potential evapotranspiration, soil water deficits, reduced ground water or reservoir levels, and so forth.
• Hydrological drought is associated with the effects of periods of precipitation (including snowfall) shortfalls on surface or subsurface water supply (i.e., streamflow, reservoir and lake levels, ground water).
• Socioeconomic drought associates the supply and demand of some economic good with elements of meteorological, hydrological, and agricultural drought. It differs from the aforementioned types of drought because its occurrence depends on the time and space processes of supply and demand to identify or classify droughts.
National Drought Mitigation Center “Understanding and Defining Drought."
But according to Kelly Redmond of the Western Regional Climate Center, the best and most universally applicable definition is simply “insufficient water to meet needs.” Redmond, K., 2002. The Depiction of Drought. Bull. Amer. Meteor. Soc. 83(8), 1143-1147, August.
2. Are droughts becoming more frequent or intense?
According to the National Climatic Data Center, "in areas where a drought or excessive wetness usually accompanies an El Niño, these dry or wet spells have been more intense in recent years. Other than these areas, little evidence is available of changes in drought frequency or intensity.” Scientists at the National Center for Atmospheric Research have reported that “the fraction of global land experiencing very dry conditions …rose from about 10-15% in the early 1970s to about 30% by 2002. Almost half of that change is due to rising temperatures rather than decreases in rainfall or snowfall.”
3. Do droughts come in cycles, how do droughts get broken, what will the future bring?
These questions are addressed by Dr. Klaus Wolter of NOAA-CIRES in A Meteorological Perspective on Drought.
4. Is there anything we can do to mitigate the impacts of drought?
Researchers with the Western Water Assessment project at the University of Colorado analyzed drought response strategies of eight Denver-area cities to the drought of 2002 in Kenney, D., R. Klein, and M. Clark, 2004: Use and Effectiveness of Municipal Water Restrictions During Drought in Colorado. Journal of the American Water Resources Association, February, 77-87. They found that programs featuring mandatory outdoor watering restrictions were associated with anywhere from 13% to 56% savings in water use, depending on the measurement used and the severity of the restrictions. Voluntary outdoor watering restrictions were of limited value and, in some instances, water use actually rose while voluntary restrictions were in place.
Future research by the Western Water Assessment will focus on the effectiveness of various demand strategies put in place by a major Front Range city. These researchers took a more in-depth look at the drought response strategies of Aurora, Colorado in Kenney, D.S., Goemans, C., Klein, R., Lowrey, J., and Reidy, K., 2008. Residential Water Demand Management: Lessons from Aurora, Colorado. Journal of the American Water Resources Association, Vol. 44, No. 1, pp. 192-207. They found that pricing and outdoor water restriction policies interact with each other so that total water savings are not additive of each program operating independently; the effectiveness of pricing and restrictions policies varies among different classes of customers (i.e., low, middle, and high volume water users) and between predrought and drought periods; and real-time information about consumptive use (via the Water Smart Reader) helps customers reach water-use targets.
Drought-related publications and links from the Colorado Water Resources Research Institute
Drought and climate presentations, Colorado Climate Center
“Colorado River and Drought” (Prometheus weblog)
Materials from Natural Resources Law Center 2005 conference, “Hard Times on the Colorado River: Drought, Growth, and the Future of the Compact”