The Threats to the World's Fresh Water Supply

There are many problems that are associated with the world's freshwater supply. These problems stem around two main issues: availability and fitness to drink. First, even though the Earth has a great deal of water, only about 3% of this supply is made up of freshwater. (Kaufman and Franz, 1993, 281). Of this amount 75% is locked up in the polar ice caps, a little less than 25% is collected in ground water sources, and the remaining .5% is on the surface of the earth in lakes, rivers, streams, and in the atmosphere. (1993). The availability of freshwater is also limited by the water's distribution. Not all areas of the world have adequate supplies, or access to freshwater. Infrequent, or seasonal freshwater delivery through rain and other precipitation makes the dry seasons of the year difficult for people, who must travel great distances to gather water from communal wells, riverbeds, or oases to meet their freshwater needs. Droughts also decrease the availability of freshwater.

The staggering effects of little or no freshwater in an area for an extended period of time can be seen in Ethiopia that went from a fertile and productive valley to a dry area plagued with famine and disease. In addition to natural restrictions of freshwater supplies, agriculture also impacts the amount of freshwater that is available for use. Conflicts over water are common as people with different water use interests all try to get as large a share of the scarce water supply as possible.

This conflict can be seen in the United States' Southwest. Here access to the water found in the Colorado River is being argued over by farmers, ranchers, conservationists, recreationalists, homeowners, and commercial industries like the casinos on the Las Vegas Strip. Currently, the freshwater supply in the world is being stretched as far as it can go, and as the population increases the demand for freshwater will only increase. It is estimated that the demand for freshwater will increase 1.7 trillion gallons a year for every 8 million people that are added to the human population.

The second issue that impacts the world's freshwater supply is its fitness to drink. Many factors impact freshwater's drinkability. First water pollution is a major issue that has degraded many water sources' fitness. Pollution from raw sewage disposal in water systems, trash dumping, excessive sediments from soil erosion, chemical waste being dumped into drains and water systems, and petroleum pollution from people pouring used oil down storm drains. All of these pollutants impact the fitness of a freshwater source to be used as drinking water, and in some cases even for agricultural purposes. Overuse of a water source can also impact its fitness to use by reducing the level of water in the source. As the water level is reduced, the nutrients and salinity concentrates and makes it less fit for consumption. For example, the Aral Sea's mineral content has increased 300% because of irrigation and windblown sediments and sand being blown into the water. (Kaufman and Franz, 1993, 29-94).

References

Kaufman, Donald G. and Franz, Cecilia M. (1993). Biosphere 2000…Protecting our Global Environment. Dubuque, IA: Kendal/Hunt Publishing.