Leonardo da Vinci designed water-wheel mechanisms to produce continuous mechanical power from flowing or falling water.
His notebooks contain studies of wheels, gears, and water flow. In these designs, moving water turns a wheel, and the wheel’s rotation can be transferred through gearing to perform work. Such systems could drive machinery more continuously than human or animal power.
Leonardo did not invent the water wheel; water-powered wheels had been used for centuries before his studies. His contribution was detailed analysis and redesign of mechanical systems, including ways to improve transmission and control. This distinction matters because Leonardo is often credited too broadly with inventions that he actually refined or documented. His water-machine drawings belong to a larger body of Renaissance engineering work on mills, pumps, canals, and industrial power.