Have the function of detain the water for a determine use, creating an artificial level difference. For SHP the dam does not have the function of water detention, but deviation of part of the water flow to the adduction system.
These characteristics define the manner of operation of the plant, which is the operation run-of-river type.
Dams can be constructed of several materials such as earth, rocks, concrete, and bricks or stones and works can be simple, as in the case of Micro Hydro or complex and expensive as in the case of SHP, in general Dams are the most expensive part of an SHP.
To build a Dam it must consider two conditions:
- Have stability for any load condition
- Present degree of tightness consistent with its life time and risks assumed.