Definition of Dams

Dams are earth or concrete barriers built across the drainage course to impound water.

The lakes they create are called reservoirs.

Dams are among the largest and most important projects in civil engineering.

Components of a Dam

The natural ground on either side of a dam is called abutment.

There are two types of abutments:

Left abutment
Right abutment

These are named according to their orientation.

The ground below the dam is called foundation and also is very important. The use of this term in dam engineering is different than that in buildings and other structures.

Purpose of a Dam

It Provides flood control
It Provides water storage
It Provides hydro electric power

How dams prevent Floods ?

Most dams are expected to provide some flood control. When heavy precipitation and snow melt occurs producing a high flow rate in the river, we want the dam and reservoir to temporarily store some of the flood water. This side where there is high flow rate due to snow melting is known as upstream side. This reducing flow rate on downstream side of the dam and preventing floods.

Reference : Geotechnical engineering principal and practices by Donald P Coduto