The Leonardo da Vinci structure designed to redirect water through a movable barrier was a sluice gate.
Leonardo studied sluices as part of his extensive investigations into canals, rivers, and hydraulic engineering. A sluice gate is a movable barrier that controls the flow or level of water in a channel. Raising or lowering it can divert water, regulate a canal, or protect an area from flooding.
His hydraulic studies were closely connected with projects in northern Italy, where canals supported transport, agriculture, and urban water management. Leonardo observed how water moved around obstacles and through openings, recording practical details as well as theoretical ideas.
A sluice gate is not itself a canal lock. A lock uses chambers and gates to raise or lower boats between different water levels, while a sluice primarily controls water flow. Leonardo’s interest in both systems reflects the overlap between mechanical invention and civil engineering in his notebooks.