spillway
n. countable C1 Advanced US //ˈspɪɫˌweɪ// UK //spˈɪlweɪ// spill·way
n. a channel or opening in a dam that lets extra water flow out safely. It prevents the dam from breaking by controlling the water level.
n. a channel or opening in a dam or levee designed to carry off surplus water. It serves as a safety mechanism to prevent structural failure during periods of high flow.
The spillway released a large amount of water after the heavy rain.
Engineers monitored the lake level closely to ensure the spillway would handle the expected spring melt.
The primary spillway was designed to handle a one-in-a-century flood, though secondary channels were also constructed to provide additional capacity during extreme weather events.