Leonardo da Vinci helped develop the miter lock, a canal-control structure that manages changes in water level.
A lock has a chamber between gates. Boats enter, the gates close, and water is added or released until the chamber matches the level of the next section. Miter gates meet at an angle pointing upstream, allowing water pressure to press them together and improve the seal.
Leonardo worked on canal engineering in northern Italy, including projects connected with Milan. He is often credited with improving the design and practical use of canal locks, especially mechanisms for operating gates and controlling water. The basic lock principle, however, predates Leonardo, so it is misleading to call him the sole inventor of the canal lock.
Locks made it possible for boats to pass between waterways at different elevations. They also supported irrigation and water management. Leonardo’s canal studies combined surveying, hydraulics, construction, and mechanical design.