At one end was a gatehouse. The tank outlets were connected with a power pump and a turbine that was used to open the gates of the outflow pipe. The  diameter outflow conduit extended  into the harbor from the northern end of Moon Island.
One end of the structure had a gatehouse. A power pump and a turbine, which controlled the gates of an outflow pipe, were connected to the tank outlets. The outflow conduit, with a diameter that extended into the harbor from the northern side of Moon Island, was the main feature.