The Medway and its tributaries and sub-tributaries have been used for over 1,150 years as a source of power. There are over two hundred sites where the use of water power is known. These uses included corn milling, fulling, paper making, iron smelting, pumping water, making gunpowder, vegetable oil extraction, and electricity generation. Today, there is just one watermill working for trade. Those that remain have mostly been converted. Such conversions include a garage, dwellings, restaurants, museums and a wedding venue. Some watermills are mere derelict shells, lower walls or lesser remains. Of the majority, there is nothing to be seen. A large number of tributaries feed into the River Medway. The tributaries that powered watermills will be described in the order that they feed in.