A noria (ناعورة, nā‘ūra, from , nā‘urā) is a machine for lifting water into an aqueduct using energy derived from the water's flow.
It consists of an undershot waterwheel to which are fixed a series of containers that lift water from the river to the aqueduct at a higher level. Unlike the water wheels found in mills, a noria does not provide mechanical power to any other process. Its concept is similar to the modern hydraulic ram, which also uses the power of flowing water to pump some of the water out of the river.
Norias can also be powered by other means. Such norias could theoretically be used in series. A noria can raise water to somewhat less than its full height. The largest noria in the world, with a diameter of about 20 meters, is located in the Syrian city of Hama.
It performs a similar function to chain pumps (including the saqiya), and other pumps, that of moving water from a lower elevation to that of a higher elevation, but these are generally powered by other means, not by a waterwheel).
Norias later became more widespread during the Muslim Agricultural Revolution and were in large-scale use in the medieval Islamic world, where Muslim inventors and engineers made a number of improvements to the noria. For example, the flywheel mechanism used to smooth out the delivery of power from a driving device to a driven machine, was invented by Ibn Bassal (fl. 1038-1075) of al-Andalus, who pioneered the use of the flywheel in the noria and chain pump (saqiya). In 1206, Al-Jazari introduced the use of the crankshaft in a noria and saqiya, and the concept of minimizing intermittent working was implied for the purpose of maximising their efficiency.
Muslim engineers used norias to discharge water into aqueducts which carried the water to towns and fields. Some of the norias used in the medieval Islamic world were as large as 20 meters in diameter, the one in Hama being a surviving example still used in modern times. It has 120 water collection compartments and could raise as much as 95 litres of water per minute.