Dam
device · 2900 BC · Ancient world
A structure that holds back water.
What it is made of
- Concrete dam wall — has part. A mass of concrete that holds back the water by its weight.
- Dam spillway — has part. It lets floodwater through.
- Dam gates — has part. They regulate the release of water.
Principles and materials it uses
- Roman concrete — is made of. Ancient dams; modern ones are made of concrete.
- Reinforced concrete — is made of. Concrete dams.
- Stone — is made of. Sadd el-Kafara (~2700 BC) is an embankment of stone.
- Clay — is made of. The core of the dam is clay and earth.
- Universal gravitation — uses. Stability through its own weight.
Where it is used
- Hydroelectric power station — is part of. The dam creates the head of water.
History: what it evolved from and what it influenced
- Levee — evolved from. A retaining structure.