Water management in all its intricacies, from Andalusia to Afghanistan, was the basis of agriculture, and source of all life. Muslims did much to develop hydraulic technology and deploy water management equipment including hydro-power dams.
By far, the most original Muslim reservoirs are to be found in tmhe region of Qayrawan in Tunisia. A lengthy (about 270 pages) account of such structures is offered by the French Solignac. These reservoirs, possibly for their high aesthetics, and like many other Islamic achievements, were attributed, despite all evidence, to both Phoenicians and Romans. Such erroneous views were adopted by a number of scholars until modern archaeological excavations and advanced studies proved the Islamic origin of such structures. These reservoirs have two basins, one used for decantation, one as a reserve, and at times a third one for drawing water out of it. Other than their impressive numbers, over two hundred and fifty in the region, such reservoirs also offer a great attraction in their form and structure.
The photograph of the `Basin des Aghlabides,' built in the ninth century by Abu Ibrahim Ahmed reveals, indeed, a sort of temple of water, it is hoped, still preserved in its majesty.
Water management in all its intricacies, from Andalusia to Afghanistan, Bolens reminds, was the basis of agriculture, and source of all life. All the Kitab al-Filahat (books of agriculture), whatever their origin, Maghribian, Andalusian; Egyptian, Iraqi; Persian or Yemenite, insist, and meticulously, on the deployment of equipment and on the control of water. The authorities of the time played a crucial role in that, too. In Iraq, as a rule, hydraulic tasks of a vast nature were left to the state, while the local population focussed its efforts on lesser ones.
In Egypt, a more elaborate picture comes out. There, indeed, the management of The Nile waters was most crucial to every single aspect of life, and dams responded to such necessity. Both al-Nuwayri and al-Makrizi stressed the role of maintenance of dams and waterways of the Nile for maximum benefits. It was the responsibility for both sultans and holders of large holdings, under both Ayyubids and Mamelouks, to dig and clean canals and maintain dams. As in Iraq the sultan took over the larger structures, and the people the lesser ones. Most distinguished Amirs and officials were also made chief supervisors of such works. Under the Mamluks there was even an officer for the inspection of dams for each province of Egypt: the Kashif al-Djusur.
Dams are used to store water, and this has major implications on economic and social life. Smith observes that `not only do dams represent some of the most impressive achievements of engineers over the centuries, but their vital role in supplying water to towns and cities, irrigating dry lands, providing a source of power and controlling floods is more than sufficient to rank dam building amongst the most essential aspects of man's attempt to harness, control and improve his environment. Effective storage and use of water for irrigation, for instance, can have dramatic repercussions, in cheapening the process and bringing into use lands that were hitherto impossible or uneconomic to irrigate.
Both Spain and Sicily offer good illustrations of that. Water is also stored for the aim of providing power for milling. In Khuzistan, at the Pul-I-Bulaiti dam on the Ab-i-Gargar, the mills were installed in tunnels cut through the rock at each side of the channel, constituting one of the earliest examples of hydro-power dams, and not the only one in the Muslim world. Another example is the bridge-dam at Dizful, which was used to provide power to operate a noria that was fifty cubits in diameter, which supplied all the houses of the town. Many such hydraulic works can still be seen today.
Transfer of Hydraulic Technology to Europe
The Islamic mastery of hydraulic technology is far more advanced than acknowledged by some of the sources many writers are too keen to follow. Some references are keen to distort the exact role of Muslim engineering skills. Indeed, to the likes of Gimpel and White, the Muslims hardly made any contributions in such a field. Reality, however, is far the opposite. First and foremost, the hydraulic works of the Ancients were found by the Muslims in a terrible state of decay and ruin, and they did not just repair them, but also added considerable skills of their own. To Spain, for instance, the Muslims brought irrigation techniques which not only laid the foundations for the prosperity of the country, but also with nothing as elaborate and as efficient seen before in Europe.
After the country was retaken by Christian forces, the Muslims, masters of great skills then, were allowed to retain their functions and serve the new crown. Alongside builders, paper and textile makers, manufacturers of iron and experts of all sorts, the Spaniards also retained and used Muslim irrigation works, their attendant rules and even regulations. And as soon as the Muslims, who refusing to be baptized as Christians were expelled, or massacred, economic ruin, and famine always followed. And Spain never recovered its former prosperity and levels of advancement once the Muslims had been eliminated from its land. Hill also notes that the introduction of desilting sluices, the arch dam, and hydropower made their first appearances in the Islamic world, observing that it is `difficult to see how these can be other than Muslim inventions.'
Further illustration of Islamic impact in the field is not just obvious through the works of Hill, Pacey, Smith and others, it is also visible via the works of Muslim engineers themselves as can still be observed through the remains of old age storage structures all over the Islamic land. Furthermore, White's, Gimpel's and their followers' argument lacks historical backing, for the major changes that took place in Europe, and not just in terms of hydraulic technology, but all others, did, and without one single exception, at the time the Europeans came into contact with the flourishing Islamic civilisation (twelfth-thirteenth centuries), and not the centuries before. Also, the fact that Western technology in nearly every respect is identical to the Islamic one offers further evidence of such impact.