Design water levels
The windpump is designed to supply clean groundwater from 60 metres below the dock via the four granite gargoyles on the eastern edge into the water body. The level can e raised above 4 metres, filling the moat which isolates the nesting area from the dock edge. Water can then be allowed to escape over the weir into the Albion Channel, flushing out detritus. The water flows along to Surrey Water and from there it can flow into the Thames. This diagram shows the various water levels at each stage of the system.
FraserBorwick 