Hello,
This might help, i stated a few of my thoughts and opinions.....Hope this helps!
Construction of dam: scarcity for animals. Rivers are free-flowing freshwater water bodies. In river diverse range of species live. River provides food and water for animals and other species. Many organisms require free-flowing rivers to complete their life cycles. Construction of dam impact on species Dams change the course of water flow, the water temperature and natural conditions also change. This prevents water availability of animals. Also most animals are dependent on free-flowing rivers and freshwater for their water supply. During the building of a dam, rivers are redirected from the regions they previously supplied to the dam, which deprives the animals of what was their source of water. Dams also cause reduced quantity and flow of water in rivers, leading to scarcity of water for animals that relied on it as a source.