Living with dams

Abstract

The dams dilemma Man has always tried to change his environment to serve his needs. Manipulation of natural systems has been practised on an ever-increasing scale, with ever increasing consequences for the characteristics and functioning of these systems. Many problems arose because man was not aware of, or neglected to take into account, the ecological laws. Manipulation of natural systems such as rivers, lakes and estuaries have included the construction of dikes and dams, cutting off river bends, and placing sluices and weirs. These interventions serve a wide variety of purposes for different stakeholders in society, such as industry, agriculture and civilians. Many interventions in water systems have proved to be an effective way to solve the actual problems of these different stakeholders. However, although the effects of interventions might be beneficial for one group of stakeholders, it is increasingly recognised that these interventions often also have negative effects on the functioning of the system, and thereby harm the interests of other stakeholders. The sum of the interventions might even (and often do) have a negative net total effect on the water system as a whole. One such intervention is the construction of dams. The number of large dams in the world is estimated at 45,000 and each year about 300 are added to this figure. The total amount of smaller dams in the word is estimated at 800,000!