Are there any good dams?

Question

Are there any good dams? I'm speaking from an environmental point of view. I always though of hydroelectric power as good because it's pollutionless, but I'm aware that there are environmental consequences such as warmer water. Even so, isn't hydroelectric still a very good way to generate electricity (plus control floods...)? Are some dam designs better than others?

Answer 1

What happens when dams are constructed ?

Water is stored in a reservoir, which didn't exist as such earlier. What happens to the environment . Will the reservoir damage the ecology of the place? what will happen to the flora and fauna which will go underwater ? what happens to the inhabitants of the place who's land will be submerged? Normally these dams are built in inaccessible areas, inhabited by tribals or marginalized nationals . what will happen to them ? what benefits do they get ? Will the dam really be a boon or is it just an eyewash to make money for someone ? All these concerns must be addressed before a dam can be labeled as good.

Answer 2

Dams prevent floods, store water and generate electricity which improves the environment of those people affected.  

A better question is if there are any bad dams.

Answer 3

Dams are all good. They control flooding, provide storage resevoirs, and generate low cost non polluting power.

Do they have an environmental impact? Yes. Anything man does has an impact, just as any species. We could just kill of man, then we wouldn't need dams.

Answer 4

All dams are site specific, so its not that the design is better, usually the sites.

I feel that hydro is the best use to make electricity.

Answer 5

Some are; some aren't. In my area, there is a push to remove as many old dams as possible, in order to allow free movement of fishes. Part of the problem is that people want dams to be all things to all people. However, if you want a dam for flood control, you need the level of the water kept low. If you want it for fishing or hydroelectric power, you want the level kept high. If you want to control some pest species, you need the level to be fluctuating. A dam built for water supply will be managed to retain all the water possible during a drought. However, the state fisheries people will want a release of water to maintain stream levels downstream. You have to decide on an individual basis.

As far as design, there are fish ladders that can be added to a dam to allow some fish movement. They're expensive and they don't always work.