Roman Cofferdam

The castellum divisorium was a Roman water control structure, used to divide the single inflow from an aqueduct into multiple water supply lines feeding a city’s water distribution network. This particular castellum was found in the ruins of Pompeii. It divides the incoming flow into three channels and feeds each of these streams into one of the city’s three water mains. Flow into each channel was controlled with a wooden gate within the castellum.