What machine did Leonardo da Vinci design to create a controlled flow of water for irrigation?

Leonardo da Vinci studied and designed versions of Archimedes’ screw to move water for irrigation.

An Archimedes’ screw consists of a helical surface inside a tube or around a shaft. As the screw turns, pockets of water are carried upward. The machine can raise water from a lower level to a higher one and has long been used for irrigation, drainage, and other water-management tasks.

The device predates Leonardo by many centuries and is traditionally associated with Archimedes of Syracuse. Leonardo therefore did not originate the basic invention. His contribution was to study, draw, and adapt screw-based water-lifting machinery within his broader investigations of hydraulics.

This machine differs from a water turbine. A turbine extracts useful rotary power from moving water, while an Archimedes’ screw normally uses rotary power to move water upward. That difference in energy direction is a common source of confusion.