Tailraces

Part of speech: noun

Definitions

1. Channels that carry water away from a waterwheel, turbine or hydroelectric plant after it has passed through the machinery
2. Man-made outflow canals that discharge spent water from a mill or power station back into the river below
3. Watercourses built to lead used water from a dam or wheel onward so it can flow freely downstream again

Etymology: A "tailrace" is the channel that carries water away from a mill wheel or turbine once it has done its work, and "tailraces" is simply its plural. The word is a plain compound of "tail" and "race". In this sense "race" is the older English term for a artificial channel or watercourse, especially one built to carry water to or from a mill, while "tail" refers to the end of something, here the outflow end rather than the inflow end. The pairing therefore describes the water's path: it runs in along the head race that feeds the wheel, and leaves by the tailrace at the back of it.

Synonyms: tailwater, outflow channel

Antonyms: headrace