Spillway (noun)

A channel or structure for carrying surplus water from a dam or reservoir over or around it.

Origin:

Early 17th century: probably a derivative of spill.

Examples:

1. The spillway of the dam had to be opened to release the excess water.
2. The spillway was designed to divert the flow of water away from the dam.
3. The spillway gate was controlled by a computer system.
4. The spillway was essential in preventing the dam from overflowing.
5. The spillway was engineered to handle a large volume of water.