A race is a current of water flowing quickly through a narrow or restricted channel. Such currents can occur in nature or they can be man-made. A tidal race flows with the changing tides, typically through a channel from one end of a sand or mud flat to another. A human-made millrace, on the other hand, takes advantage of the steady flow of a river or stream. A channel is dug into or raised above the ground, allowing a strong, controlled current of water to move away from the river in order to power a mill wheel. The head race leads water toward the wheel (sometimes from a gather pond or reservoir), while the tail race channels it away, typically back to the river. Cedar Falls, Iowa, was once the site of a notable millrace; constructed in 1848, it provided much of the city with hydropower until the installation of electrical power made it obsolete. As Edgar Lee Masters writes in The Sangamon, “At last I wanted to take a shortcut from the dam to the shore. The millrace was between me and the dam, but I did not know it was the millrace, or for that matter what a millrace was. It was a still body of water boarded in, and not more than six feet across, but it was very deep, twenty feet or more.”

Lan Samantha Chang