Why is it not wise to build a dam on a river?

Question

I was thinking of the effects the dam would have on the river. Also, the weathering effects.

Answer 1

Dams are great water storage devices provided that they are sited in a good location with stable geologic conditions.

The downfall is that the reservoir created by the dam will eventually silt up from the sedimentary material carried by the river gets piled up at the end of the dam.

In addition, the dam/reservoir can create localized effects on the ecosystem, destroying habitats, disrupting the food chain, etc. However, the overall benefits to man, generally outweigh the negatives to the ecosystem.

Answer 2

It's not necessarily true that building a dam on a river is always unwise. However, it is very important to thoroughly analyze the effects of such construction during the early stages. Placing a dam on a river affects the local ecosystem. It generally creates a lake and can reduce flow downstream. This may affect migration patterns of land and water animals, which can in turn affect the species that are in their food chains or webs. It can also affect irrigation in the area. In addition, the shifts in the water table caused by a dam project can lead to instability in the local soil and rock, possibly even leading to landslides and, in the case of Italy's Vajont Dam, a 250 meter megatsunami that killed nearly 2000 people in 1963.

Answer 3

A river is constantly fowing. If you build a damn, the water has to go somewhere.