All structures needed to hold a single body of water. A man-made structure together across stream or channel, watercourse, or natural drainage area which impounds or diverts water.

 

 

What are reasons for having dams?

Some dams stop flooding and save villages. Others are a source of hydroelectric power. They use turbines that are pushed by the water to create a source of energy. Some change the flow of river channels. Others are used to create artificial lakes (reservoirs).

 

 

Are animals affected negatively by dams?

Not as much as you would probably think. Sometimes animals are killed during the actual dam building process. Once the dam is built, the fish adapt to the life in a dam and go against the current.

 

 

How do dams affect erosion?

A river sometimes can carry silt, sand, and occasionally small pebbles. When the water slows down at a dam it is stripped of all these things. This causes the water to be more erosive and erodes more of the sediment upstream.

 

 

What are most dams constructed of?

Basically concrete. Sometimes engineers may use materials from nearby, such as earth and rock, when designing a dam, depending on the nearby resources.

 

 

How is a dam built?

Well to build a dam you have to make a temporary dam first, because construction workers will have to stop the flow of the river in order to build a dam. These temporary dams are not strong enough to last long and need to be maintained often.