What canal-lock design is often associated with Leonardo da Vinci?

The canal-lock design often associated with Leonardo da Vinci is the miter lock.

A miter lock uses two gates that meet at an angle pointing upstream. Water pressure pushes the gates together, helping them seal the opening when the lock is full. Leonardo studied and developed canal engineering while working in northern Italy, where waterways were essential for transport, irrigation and urban water management.

The association with Leonardo is strongest in accounts of his improvements to canal locks, especially designs connected with Milan’s waterways. However, the basic idea should not be treated as an entirely isolated invention created from nothing by Leonardo; water-control gates had earlier precedents.

Leonardo’s importance was his systematic treatment of hydraulic problems. His notebooks examine how gates, channels and water levels could work together, turning practical canal construction into a subject for detailed mechanical analysis.