Building a new dam.
Dams have been constructed in order to prevent floods, to solve the problem of drought and to generate energy. But building of a dam causes both good and bad effects.
The construction of a dam has many advantages. A dam can generate electric power by transition from hydro power to electric power by use turbine and generator. Some dam, used as tourist attractions and recreational activities, such as sailing or fishing. A dam is also used for prevent a sudden flood in the water flow range. A dam will act to slow down the speed of the water by the water flows through it only the appropriate quantity. In addition, a dam can catchment the water during flood season and release the water for used in agriculture, for consumption during water shortages.
At the same time, building of a dam impacts to environment and ecosystem in bad way. For example, it is deforestation because the construction of a dam requires a lot of space. It is destruction soil because the dam was built across the river. Cause water accumulates in the area above the dam. As a result, the land area above the dam was flooded for a long time which makes the loss of soil resources. And it also makes to animals homeless. It makes to aquatic animals can't lay eggs because changing of water's ecosystem from water flow is still water.
However, the construction of new dam has both advantages and disadvantages. In the present, building of dam is still a controversy between people who agree and disagree with this.