| MadSci Network: Earth Sciences |
Drought conditions vary in intensity, duration, and frequency of occurrence from place to place. In addition, the amount of water available (both surface water and ground water) and the amount that people want to use varies from place to place. All of these factors affect the need for water restrictions. Fundamentally, this need or lack thereof depends on the ratio of water needed to water available, which is affected by precipitation, ground-water recharge and discharge, evapotranspiration, water use, and temporal variation in all these factors. Local and state laws and regulations also affect the ability of governments to impose water restrictions. Taking all of this into account, it is clear that the kinds of restrictions imposed are going to vary a lot from one place to another. That said, I can give you some information about how the present drought has affected Alabama. During this past summer the drought was most intense in south Alabama and least intense in north Alabama. Farmers relying on precipitation or irrigation water from surface-water sources had problems and crop yields suffered quite a bit. Some others who need to use surface water (e.g., paper mills and power plants) had difficulty getting enough water. Some industrial facilities along rivers had to operate at less than full capacity. Owners of domestic wells and springs found in many cases that their water supplies dried up, and new sinkholes formed in sinkhole-prone regions.
However, few municipalities felt the need to impose water restrictions. This is because most public water supplies in Alabama are quite resilient. About half of Alabamians rely for their drinking water on ground water from public water systems. Most public water systems in Alabama that rely on ground water maintain sufficient supplies of deep ground water so that they are not affected immediately by drought, even an intense drought. Some Alabama public water systems that rely on surface water supplies (chiefly reservoirs) were not so fortunate. The most well known example is the City of Birmingham. This city has several different water supplies, but one of the largest is Lake Purdy. Lake Purdy's water level falls considerably every summer, but in the summer of 2000 the lake nearly dried up completely. Birmingham was close to an emergency, and instituted mandatory limits on water use.
The mayors of Birmingham, Homewood, Hoover and Vestavia Hills declared a water emergency in September, adding police power and criminal penalties to the outdoor watering ban. Residents of the four cities faced fines of up to $200 or jail time for any outdoor water use - sprinkling lawns, washing cars, running fountains or filling swimming pools (Katherine Bouma, The Birmingham News, http://www.alabamalive.com/news/birmingham/Sep2000/29-e431427b.html Birmingham?s Lake Purdy was below 39 percent of capacity in September (Byington, 2000), and almost completely dry by the time the autumn rains began.
General information about water availability and water use in Alabama is available from the Geological Survey of Alabama in a variety of publications. Please contact the Publications Sales office if you need more information. Some information about surface water resources is also available from the U.S. Geological Survey.
David C. Kopaska-Merkel Head, Ground Water Section Geological Survey of Alabama P. O. Box 869999 Tuscaloosa AL 35486-6999 (205) 349-2852 fax (205) 349-2861 www.gsa.state.al.us
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