Leonardo designed this dredger to clean and maintain canals. The dredger is held stationary while four scoops rotate. The scoops have holes in them to let the water drain out. The remaining sludge is deposited into the barges on the left. The height of the axle is adjustable. When the axle is lowered, the dredging scoops reach deeper into the riverbed. When one area is cleaned, the dredger can be pulled forward to clean the next section.