Drought Fact Sheet
History of Drought
· The Dust Bowl drought was a natural disaster that severely affected much of the United States during the 1930s. The drought came in three waves, 1934, 1936, and 1939-40, but some regions of the High Plains experienced drought conditions for as many as eight years. The "dust bowl" effect was caused by sustained drought conditions compounded by years of land management practices that left topsoil susceptible to the forces of the wind.
· During the 1950s drought, the Great Plains and the southwestern U.S. withstood a five-year drought, and in three of these years, drought conditions stretched coast to coast.
· The three-year drought of the late 1980s (1987-1989) covered 36% of the United States at its peak. The drought, beginning along the west coast and extending into the northwestern U.S., had its greatest impact in the northern Great Plains. By 1988, the drought intensified over the northern Great Plains and spread across much of the eastern half of the United States.
· During the 1990's and early 2000's the southern and eastern parts of the country experienced multi-year droughts. Prior to that many saw drought as mostly a western phenomenon. But when the Washington DC area, New York, Florida, Georgia, Texas, and New England experienced severe droughts it became a national issue - not just a western one.
Four Stages of Drought
Phase 1 -
5 to 10 percent shortage (voluntary reductions)
Initiate public information campaign. Explain drought situation to the public and governmental bodies. Explain other stages and forecast future actions. Prepare and disseminate educational brochures, bill inserts, and so forth.
Phase 2 -
10 to 20 percent shortage (voluntary or mandatory reductions)
Mandate voluntary conservation actions listed in Phase 1. Continue rigorous public information campaign. Explain drought conditions. Disseminate technical information. Ask consumers for 10 to 20 percent mandatory or voluntary water-use reductions (depending on available supplies for future years).
Phase 3 -
20 to 35 percent shortage (mandatory reductions)
Institute rationing programs through fixed allotments based on per capita or per household data. Outside allotment can be based on lot size, past usage, or other data. Require all homes to have low-flow showerheads and toilet displacement devices or ULF toilets before granting an increased allotment. Require pool covers for all municipal pools.
Phase 4 -
35 to 50 percent shortage (mandatory reductions)
All of emergency stage (Phase 3) steps intensified. Monitor production for compliance with necessary reductions weekly. Allocate water on a per capita or per household basis for residential customers and apartments. No additional water for outdoor or summer usage. No potable water used by landscape meters.There are lots of drought contingency plans in place across the country. Some of them use a staged approach as described here, others, however, are embracing the modern approach of drought preparedness - to put into place programs and projects to minimize and/or avoid drought impacts. This has been a major endeavor at a national level.
Water Use and Drought
· On average, 50 to 70 percent of home water is used outdoors for watering lawns and gardens. However, this is variable across the country. In multi-family settings the numbers are quite different, with inside use greatest; in mild or moderate climates the numbers are closer to 50 percent. In Los Angeles, for example the lots sizes and microclimates yielded vastly different percentages between outdoor and indoor use.
· Average household water use annually: 127,400 gallons.
· Average daily household water use: 350 gallons.
· On average, 2.3% of all wastewater is reused. However, in some parts of the country reuse is required and/or mandated and the percentages are often 20-25% of an area's water budget is recycled water.
· Some treated wastewater is reused for irrigation and other non-potable applications.
· For astronauts aboard NASA's International Space Station with very limited resources, water reuse is the only practical option.
· The Earth has recycled and reused water naturally for millions of years.
Water Restriction Programs
· Utilities enforce and promote water restrictions through rates, municipal ordinances, federal laws and regulations, and financial incentives.
· Offering financial incentives to install efficient plumbing or change out grass for plants.
· Allowing the public to water only on certain days by enforcing municipal ordinances.
· Banning fountains unless they run on recirculated water.
· The future we may see these drought restriction programs phased out as the industry heads to drought preparedness. Drought preparedness activities would include ongoing conservation programs, water reuse applications, water storage and management projects, groundwater conjunctive use, Aquifer Storage and Recover (ASR), etc.
Drought Prediction & Monitoring
· Scientists generally don't know how to predict drought more than a month in advance for most locations. Predicting drought depends on the ability to forecast two fundamental meteorological surface parameters, precipitation and temperature. We know that anomalies of precipitation and temperature may last from several months to several decades. How long they last depends on topography, air-sea interactions, soil moisture and land surface processes, internal dynamics, and the accumulated influence of dynamically unstable synoptic weather systems at the global scale.
· The Standardized Participation Index (SPI) was noted as an important new drought-monitoring tool that is receiving widespread acceptance in many countries. The SPI needs to be tested and applied in more drought-related areas.
· The Drought Monitor product recently developed in the United States could serve as a model for integrating meteorological and hydrological information into a single product for the purposes of detecting and tracking drought conditions and development. The U.S. Drought Monitor is issued on a weekly basis. More information on the Drought Monitor can be found at http://drought.unl.edu/dm/monitor.html