Leonardo da Vinci designed canal locks to control water levels between waterways at different heights.
Leonardo worked on hydraulic engineering in Milan, where canals supported transport, irrigation, and urban water management. His improvements to lock mechanisms included arrangements of gates that allowed boats to move between sections with different water levels. The system reduced the need for a canal to remain at one continuous elevation.
A canal lock is not a dam or a water wheel. A lock is a chamber bounded by gates; water is added or released until the vessel reaches the level of the next section. A water wheel instead converts moving water into mechanical power.
Leonardo did not invent the general idea of the lock, which existed before his work. His importance lies in studying and improving hydraulic mechanisms, especially the practical details of gates, channels, and navigation. His designs helped make the engineering of canals more efficient and reliable.