Watermill and Aqueduct

Watermills exploit the energy of water and are used for grinding grain. They fall into two types:

Those with vertical wheels were widely adopted in the classical world from as early as Vitruvius (first century B. C.). This type is also known in Syria, e.g. Hama and Antioch on the Orontos river as well as on the Iberian Peninsula. It should be noted, however, that this type was used for lifting water, but not for producing power to run machinery. Under this category falls the nâura or noria, a water wheel with hinged compartments that dip into a stream and carry water to the top of the wheel where it is discharged into an aqueduct. Another more simple water-raising machine is the sâqiyah which uses animal power (see the reconstructed sâqiyah at Qusayr ‘Amra).

The second type of water-mill is the horizontal wheeled mill which can be divided into two groups based on the differing methods of water delivery and associated superstructure: 1) Mills which are driven by the force of water hitting horizontal paddles, for instance down a horizontal chute, and producing a slow rotation; and 2) Raised-tower, horizontal-wheel type. It consists of a horizontal wheel connected by a straight shaft to grinding stones lying in the same plain; the water flowing rapidly down the tower is directed onto the turbine. The known remains of water-mills in Jordan are of this type; their distribution is widespread along the wadis running into the Jordan River and the ‘Arabah depression (e.g. Wadi Hisban, Wadi al-‘Arab, Wadi ibn Hammad and Wadi Kufranjah). Their simple design makes them economical to build and easy to maintain. In this type the mill-stone, of solid basalt, was the single most expensive part of a mill apparatus. All that is required to operate this type of mill is a stream of fast-flowing water, hence their location on perennial wadis. To ensure a steady supply of water, channels were dug to lead water off from upstream to the mill-tower. Sometimes we find an aqueduct supported on stone arches associated with the mill, to carry water from one side of the wadi to the other.

This custom was already used in Roman times. For instance, at Fontvieille in Provence (South of France), one of the joined aqueducts was actionning four mills with a high fall of water.

These milling installations are extremely difficult to date because they were rebuilt in the nineteenth century. We know, however, that such mills existed in the sixteenth century because they were taxed. It is likely that they were built in the Mamluk period, perhaps in the fourteenth century. This date accords with the chronology of sugar production in the Jordan Valley which employed a related technology of water-driven mills to grind the cane for the extraction of sugar. An even earlier date is indicated by the tenth century geographer al-Maqdisi who describes Amman as, “having many streams, the water of which works the mills”. At Cordoba, the same system was in use on the river Guadalquivir during the Umayyad Caliphate. Probably inherited from the Romans and largely developed by the Arabs, the technology left traces in the Spanish vocabulary, rich in irrigation related words of Arabic origin, e.g. tahuna for a mill, acena for a water-wheel, and acequia for irrigation canals.