What Causes Water Shortages?
Water shortages can be caused by drought, lack of precipitation, and pollution.
Drought:
Drought is a long period of dryness, usually occurring during the summer, when there is little or no rainfall. Droughts may cause surface water to dry up, and if severe enough, cause levels of ground water to fall below pumping range. A drought this severe has far-reaching consequences. Lack of water causes crops to fail and livestock to lose weight. Industries using water for cooling, or in production, may have to lay off workers and close temporarily. Air conditioning use increases during summer droughts so more electricity is generated. And people tend to need more water during a drought, for watering lawns and gardens, more frequent showering, or just "cooling off".
Lack of Precipitation:
Lack of precipitation during the winter and spring can cause water shortages the following summer, even though summer rainfall is normal or above normal. Winter and spring are South Carolinas wettest seasons, the time when our ground water systems are recharged and reservoirs filled. Thus, a dry winter and/or spring has the potential for causing water shortages the following summer.
Pollution:
Since pollution is a major cause of poor water quality, it can cause both temporary and long-term water shortages. There are two basic types of water pollution:
Point - The source of the pollution is specific. For example, a pipe that dumps sewage or waste into a lake or stream.
Non-point - The source of the pollution is general. For example, runoff from agricultural and urban areas which carries soil, chemicals, solvents and other materials into a lake or stream.
Lakes and streams have a limited natural ability to rid themselves of impurities, but it is a very slow process and some impurities can never be removed. Prior to our industrial expansion, population growth and the increased use of chemicals, lakes and streams could handle small amounts of wastes without harmful effects on water supplies. Now, however, the self-cleaning process cannot cope with the amounts and types of wastes being discharged into lakes and streams. Our wastewater must be cleaned at treatment plants before being returned to a lake or stream. Wastewater treatment plants are expensive to build, and large amounts of energy are needed to treat and move the wastewater- resulting in higher costs and higher taxes.
Short term, pollution caused water shortages include those caused by floods, when water for restricted use must be trucked into affected communities. Long-term, pollution caused water shortages have occurred in some areas of coastal South Carolina when ground water is pumped out faster than it is replenished and saltwater replaces the freshwater in the wells. New and deeper wells must be drilled or new sources of water must be found.
Drought and Pollution:
A combination of drought and pollution can cause a water shortage. Drought reduces streamflow, leaving insufficient water for diluting normally acceptable amounts of pollutants. The pollutants become concentrated, making the water unsuitable for drinking. Only a period of steady rain can solve this type of water shortage.
Water Quality Requirements:
Even in cases when the water quality meets primary or health related standards, public objection to aesthetic standards such as taste, color, or odor could eliminate large amounts of usable water sources.
Demand:
Water shortages can also occur when the sudden demand of new industry, or a large increase in population, is too much for an existing water and sewer system. Finding additional water, and increasing freshwater and sewer capacity, solves the problem.
Waste:
Whatever the cause of a water shortage, its severity is magnified by waste. Water conservation can postpone, but not prevent, water shortages. But lack of conservation can, and will, increase both the frequency and severity of present and future water shortages.