A dam is a barrier that stops or restricts the flow of water or underground streams.
A dam is built to control water through the placement of a blockage of earth, rock across a stream or river. They usually store water in a reservoir which is then used for a variety of applications such as irrigation and municipal water supplies.
Three main problems that arise because of the construction of big dams are :
(i) Construction of dams across rivers leads to deforestation which results in the loss of biodiversity.
(ii) Constructing reservoir may result in the flooding of nearby towns and villages.
(iii) Construction of dams requires a huge amount of monetary investments.
