Leonardo da Vinci helped develop canal-lock designs for overcoming changes in water level.
During his work in Milan, Leonardo studied canals and proposed improvements to gates and lock arrangements. A canal lock uses a chamber between gates: water is added or released to raise or lower a boat between two different levels. This makes navigation possible where a canal cannot remain at one uniform elevation.
Leonardo is especially associated with improvements to canal engineering in the Milan region, including work connected with the Naviglio system. The underlying lock principle was not invented entirely by Leonardo, but his drawings and practical studies helped refine how locks could be built and operated.
A canal lock is often confused with a sluice gate. A sluice controls or diverts water, while a lock is a chamber that changes a vessel’s elevation. Leonardo’s contribution belongs to the broader history of hydraulic engineering rather than to the invention of canals themselves.