Dam Construction in the Islamic Civil Engineering
FSTC Research Team*
Table of contents
2. Dams and Construction Techniques
3. Water Management and Water Storage
4. Aspects of Dan Construction in Iraq and Iran
5. Transfer of Hydraulic Technology to Europe
6. The Destruction of Islamic Engineering Works
7. Bibliography and Further References
Note of the editor
This article has been published on www.MuslimHeritage.com in December 2001 in PDF format. We present it to our readers in a new editing in HTML, with illustrations. © FSTC 2002-2009.
* * *1. Introduction
In his ‘History of Dams', Norman Smith, began his chapter devoted to Muslim dams , by stating that:
"Historians of civil engineering have almost totally ignored the Moslem period, and in particular historians of dam building, such as there have been, either make no reference to Moslem work at all or, even worse, claim that during Umayyad and Abbasid times dam building, irrigation and other engineering activities suffered sharp decline and eventual extinction. Such view is both unjust and untrue ."
Similar point is raised by Pacey, who notes that it is often said that hydraulic engineering "made little progress under the Muslims", and that the latter's achievements hardly evolved beyond the Greeks or Romans undertakings. Pacey corrects this view, pointing out that the Islamic civilisation adapted ancient techniques "to serve the needs of a new age", and that the Muslims extended the application of mechanical and hydraulic technology enormously . The works of these first scholars such as Smith, Pacey and others to attract attention to the achievements of the classical Islamic world in civil engineering was followed by a more sustained effort on the Islamic material culture and technology by professional historians who published noteworthy works in the recent period. We mention here the works of Donald R. Hill and Ahmad Y. Al-Hassan .
Figure 1: Satellite view of Aswan High Dam in Egypt. Completed in 1970, this gigantic dam was one of the largest earthen embankment dams in the world. It is 111 m tall, 3830 m long and nearly 1000 m wide. Its construction has had immeasurable impacts on the Egyptian economy by regulating the Nile river flooding, providing storage of water for agriculture and for generating electricity. (Source).
Dam construcion was part of engineering projects conceived of by Muslim scientists in all contexts of applying knowledge for social and economic needs. A story from the 13th century, narrated by Ibn abi Usaybi'a in Tabaqat al-atibba', which may well be true, says Ibn al-Haytham went to Egypt hoping to persuade its ruler to undertake an engineering project to regulate the flow of the Nile by the installation of a dam over the river. Then after he saw the monuments of ancient Egypt, he was humbled and concluded that if such a project was possible, they certainly would have thought about it. Moreover, the prospective site, just south of Aswân, did not match the scholar's expectations, and he admitted failure. To escape almost certain punishment at the hands of the ruler, he had to feign madness until his patron died in 1021 . If true, then Ibn al-Haytham would have been the first to suggest a dam which later became the Aswan dam.
2. Dams and Construction Techniques
The Muslims built many dams in a rich variety of structures and forms. The majority of the earliest Muslim dams were completed in Arabia itself; and full information on their height, length, and ratios between height and length is given by Schnitter. He also specifies that with the exception of the Qusaybah dam near Medina, a 30 m high-205 m long structure, which was slightly curved in plan, the alignment of all others were straight . About half such dams were provided with a flood overflow at one end, and often with a downstream training wall to guide the spilled water to a safe distance from the dam's foot. Schnitter also observes that about a third of such very early dams (7th-8th century) are still intact .
Figure 2a-b: Khaybar Dam called Sadd Qasr al-Bint in the Arabian peninsula. It is one of the largest ancient dams, probably built by the Queen of Sheeba in pre-Islamic times. It is a big stone construction on a dried out river bed. Although it had been breached for about one third of its length, it is nevertheless an impressive 20 metres high and about 135 metres long. The upstream face is plastered with yellow mortar, the downstream face with bare stone. (Source).
In Iraq, in the vicinity of Baghdad, a considerable number of dams were built during the Abbasid Caliphate . Most such dams are on the Tigris, but a few are on water diversions, further illustration of high engineering skills. In Iran can be found the Kebar dam, dating from the 13th century, the oldest arched dam known to have survived . The dam has a core of rubble masonry set in mortar, the mortar made from lime crushed with the ash of a local desert plant, the addition of ash making the lime hydraulic. This resulted in a strong, hard and impervious mortar, ideal for dams, the very reason for such dam's long life, and the absence of cracks in it. Much earlier than this dam, in today's Afghanistan, were three dams completed by King Mahmud of Ghaznah (998-1030) near his capital city. One, named after him, was located 100 km SW of Kabul, and was 32m high and 220m long .
Dam construction in Muslim Spain was prolific. In the city of Cordoba, on the river Guadalquivir, can be found what is probably the oldest surviving Islamic dam in the country . According to the 12th-century geographer al-Idrisi, it was built of Qibtiyya stone and incorporated marble pillars . The dam follows a zig¬zag course across the river, a shape which indicates that the builders were aiming at a long crest in order to increase its overflow capacity. Remains of the dam can still be seen today, a few feet above the river bed, although in its prime, it was probably about seven or eight feet above high-water level and eight feet thick .
Techniques used by Muslim masons and engineers reached great heights of ingenuity. On the river Turia, still in Spain, modern measurements have shown that the eight canals have between them a total capacity slightly less than that of the river, thus raising the possibility that the Muslims were able to gauge a river and then design their dams and canals to match . Smith elaborates on such skills .
Muslim engineers used sophisticated land surveying methods to locate their dams in the most suitable sites, and also to lay out very complex canal systems. For such, they used astrolabes and also trigonometric calculations . Around Baghdad water was diverted into the Nahwran Canal which supplied water for irrigation, whilst improvements were made to existing, old systems .
Dams were built of carefully cut stone blocks, joined together by iron dowels, whilst the holes in which the dowels fitted were filled by pouring in molten lead . An impressive structure of masonry is Hill‘s impression of the dam at Marib in Yemen, with its carefully cut and fitted blocks using lead dowels in their joints . It was also fourteen metres high and 600 metres long, with elaborate waterworks including sluices, spillways, a settling tank and distribution tank. So strong a structure, it survived for about ten centuries until lack of financial and technical means made it impossible to maintain .
Figure 3: View of the moder Marib dam in Yeman taken in 1986. The Marib dam blocks the Wadi Adhanah in the valley of Dhana in the Balaq Hills, Yemen. The current dam is close to the ruins of the Great Dam of Marib, dating from around the 7th century BCE. It was one of the engineering wonders of the ancient world and a central part of the south Arabian civilization around Marib. (Source).
Back in Spain, according to Scott, the masonry of the reservoirs was of the finest description, and the cement used was harder than stone itself . Contingencies were provided for in such manner that no overflow occurred, and no damage resulted even during the worst flooding. Evidence of Muslim engineering ‘genius' is the fact that these dams needed hardly any repair in a thousand years . The eight dams on the Turia River at first sight seem to have an exaggerated amount of weight placed on their foundations, the masonry of each dam going some fifteen feet into the river bed, and further support provided by the addition of rows of wooden piles. Such solid foundations were justified by the river's erratic behaviour, which in times of flooding reaches a flow that is a hundred time greater than normal, the structure having to resist the battering of water, stones, rocks and trees . These dams, now over ten century old, still continue to meet the irrigation needs of Valencia, requiring no addition to the system .
On the River Segura, the Muslims built a dam in order to irrigate vast lands in the Murcia region . Because of the nature of the terrain, not just the location, but the design and construction had to be absolutely perfect, too. The height of the dam was only 25 feet, yet its base thickness was 150 and 125 feet, which may seem excessive. Such thickness was necessary to meet the softness and weakness of the river‘s bed to prevent it from sliding along. The water flowing over the crest initially fell vertically through a height of 13-17 feet on to a level platform, running the length of the dam. This served to dissipate the energy of the water spilling over the crest. The over-flow then ran to the foot of the dam over flat or gently sloping sections of the face. In this way the whole dam acted as a spillway and the energy gained by the water in falling 25 feet was dissipated en route. Thus the risk of undermining the downstream foundations was greatly reduced. Like with other dams, rubble masonry and mortar were used for the interior, and the whole was finished with large masonry blocks .
By far, the most original Muslim reservoirs are to be found in the region of Qayrawan in Tunisia. A lengthy (about 270 pages) account of such structures is offered by 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.
3. Water Management and Water Storage
Water management in all its intricacies, from Andalusia to Afghanistan, Bolens reminds, was the basis of agriculture, and source of all life. All the Arabic books of filaha (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 focused its efforts on lesser ones .
Figure 4a-b: The sluice gates of the old dam of Marib in Yemen: (a) the gates are clearly visible on the right hand side of the river; (b) close up view of the sluice gates. (Source).
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-Maqrizi  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 Mameluks, to dig and clean canals and maintain dams. As in Iraq, the sultan took over the larger structures, and the people over 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-jusur .
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 . The vestiges of many such hydraulic works can still be seen today .
4. Aspects of Dam Construction in Iraq and Iran
In early Islamic times, Roman and Sasanid dams were carefully maintained, but the demands for irrigation water and power was so great that in the more populous provinces dams became more numerous than they had been in pre-Islamic times. Many new dams were necessary as part of the extensions to the hydraulic systems in Iraq.
Perhaps the most impressive of these dams, the remains of which can still be seen, was a diversion dam over the River ‘Uzaym at the point where it leaves the hills called the Jabal Harmin. The main body of the dam is a masonry wall 575 feet long which at the western end turns through a right angle and continues for 180 feet to form one bank of the canal called Nahr al-Batt. The dam has a maximum height of something over 50 feet, but this rapidly reduces towards the sides. In fact for the first 150 feet at the eastern end, the dam is only 13 feet high. The cross-section of its central portion has a neat trapezoidal profile, 10 feet thick at the crest and 50 feet thick at the base. The water face is vertical and the air face is built to a uniform slope with the masonry stepped. The dam was built of cut masonry blocks throughout, connected with lead dowels poured into grooves. This is quite a common Muslim technique and in the ‘Uzaym dam was apparently used as a complete alternative to mortared joints. The alignment of the structure is not straight, and this reflects an attempt, as usual, to utilize the natural shape of the site as advantageously as possible .
Figure 5a-b: Inscription on the dam built by the Umayyad Caliph Mu‘awiya in 58 AH / 678 CE near Ta'if in the Hijaz, Saudi Arabia. (a) Image of the inscription in Kufic script; (b) its transcription. The translation of the inscription reads: (1) This dam [belongs] to servant of God Mu‘awiya (2) Commander of the believers. ‘Abdullah b. Sakhr built it 3. with the permission of Allah, in the year fifty eight. O (4) Allah, pardon servant of God Mu‘awiya, c- (5) ommander of the believers, and strengthen him, and make him victorious, and grant the (6) Commander of the believers the enjoyment of it. ‘Amr b. Habbab wrote [it]. (Source).
In Iran, the Muslims added dams to the existing Sasanid systems. A new dam called the Pul-i Bulaiti was built at Shustar on the River Karun, the main purpose of which was to provide power for milling. The mills were installed in tunnels cut through the rock at each side of the channel, with the dam providing the necessary head of water. Another example is the bridge-dam at Dizful which was used to power a great water-wheel working a mechanism which raised water 50 cubits and supplied all the houses of the town .
The Buwayhids held the real power in Iraq and Iran from 320/932 until 454/1062, and the greatest builder of the dynasty was ‘Adud al-Dawla. Among his works was the impressive dam called the Band-i Amir, built about 349/960 over the River Kurr in the province of Fars between Shiraz and Istakhr. This dam was seen by the geographer al-Muqaddasi shortly after it was constructed. He speaks of it as follows:
"‘Adud al-Dawla closed the river between Shiraz and Istakhr by a great wall, strengthened with lead. And the water behind it rose and formed a lake. Upon it on the two sides were ten water-wheels, like those we mentioned in Khuzistan, and below each wheel was a mill, and it is today one of the wonders of Fars. Then he built a city. The water flowed through channels and irrigated 300 villages ."
This dam, which is some 30 feet high and 250 feet long still survives. It is made of solid masonry and does make use of a rubble masonry core. Iron bars set in lead were used to connect the blocks. Both Al-Muqaddasi and Ibn al-Balkhi agree that the stones were set in mortar, and this, in addition to binding the whole construction together, would also have served to make the dam watertight. The use of "tempered cement and sifted sand" indicates that the engineers were aware of the need for careful preparation of their mortar. Al-Balkhi writes "even an iron tool could not scratch it" This indicates that the mortar was of excellent quality and that the dam was a very thorough and solid piece of work. It is not at all surprising that it has had such a long and useful life .
5. Transfer of Hydraulic Technology to Europe
The Islamic mastery of hydraulic technology is far more advanced than acknowledged by some of the sources many are too keen to follow, and which hence distorts the exact role of Muslim engineering skills. Indeed, Gimpel  and White  consider that the Muslims hardly made any contributions in such a field. Reality, however, is quite the opposite. First, 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.
Figure 6: An acequia flowing toward Granada from the spring in the village of Alfucar in the foothills of the Sierra Nevada, was first built in the 13th century and is still flowing today. (Source).
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 were expelled, economic crisis always followed . As a result, 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 at the time the Europeans came into contact with the flourishing Islamic civilisation (12th-13th centuries). Also, the fact that Western technology in nearly every respect is identical to the Islamic one offers further evidence of such impact.
Several ancient dams built during the classical age of Islamic civilisation are still existing. Among them, Khadlu bridge (in two stories) in Isfahan, Iran, built during the reign of Shah Abbas II, serving both as a bridge and a dam. It is one of the most elaborate combined bridges of the world, 133.5m in length and 12m in width. It can be changed into a temporary dam by blocking its spans. Wide and thick timbers (stop - logs) had been prepared to be used for this purpose and create a beautiful reservoir on one side of the bridge. The second floor, constructed on the main spans, includes its most fascinating feature, i.e., the pavilions set into its width called "Princes Pariours" and once decorated with faience stucco carvings, and inscriptions. The main parlor was used for the king's receptions and festivals. In terms of architectural style, it is unique all over the world .
6. The Destruction of Islamic Engineering Works
Like with much else regarding Islamic civilization, the great achievements of dam construction suffered ruin and destruction as a result of military conflicts. In the Islamic East, dams did not escape in their vast majority the terrible onslaught of the 13th century. In 1220, the armies of Jenghis Khan devastated the whole eastern parts of the Muslim land. The destruction of al-Jurjaniyah dam south of the Aral Sea diverted the River Oxus from its course and deprived the Aral Sea of water, causing it to nearly dry out centuries later . A hundred and sixty three years later, in 1383, it was Timur's hordes, which this time completed the work of their predecessors. The Tartars laid the land waste, Zaranj the capital of the province of Sistan, suffering terrible fate; its dams and all its irrigation works completely laid waste. A similar fate befell the Band-I-Rustam, and the region of Bust . Today, hardly anything survives in those lands, once the seats of great civil engineering accomplishments.
Figure 7: Aerial view over Wadi Hanifa Wetlands, Riyadh, Saudi Arabia in which appears the al-Ha'ir dam in the southern section. (Source).
7. Bibliography and Further References
– Lucie Bolens: "Irrigation", in Encyclopedia of the history of Science, technology, and Medicine in Non Western Cultures, edited by Helaine Selin. Kluwer Academic Publishers. Dordrecht/Boston/London, 1997, pp. 450-2.
– C. Cahen: "Irrigation in Iraq", Encyclopedia of Islam, New Edition, vol. 5, Leiden, Brill, pp. 864-5.
– A. Daux: Recherches sur l'originalité et l'emplacement des emporia phéniciennes dans le Zeugis et le Byzacium. Paris, 1849.
– J. Gimpel: The Medieval Machine, Pimlico. London, 1976.
– J.H. Harvey: "The Origins of Gothic Architecture", Antiquaries Journal, 48, pp. 87-99.
– D.R. Hill: Islamic Science and Engineering. Edinburgh University Press, 1993.
– Donald R. Hill and Ahmad Y. Al-Hassan: Engineering in Arabic-Islamic Civilization. Part One (retrieved 26.12.2009).
– Patrick James: Une Histoire Revisée des Barrages-Voûtes: Des Barrages Romains aux Ouvrages Modernes en Béton (2004).
– Guy Le Strange: The Lands of the Eastern Caliphate. London, 1905.
– Al-Makrizi: Khitat. Cairo, 1853-4, vol. 1.
– Al-Nuwayri: Nihayat al-Arab. Cairo, 1923, vol. 1.
– A.Pacey: Technology in World Civilization, a Thousand year History. The MIT Press, Cambridge, Mass., 1990.
– E. Pelissier: Description de la Régence de Tunis; Exploration scientifique de l'Algérie pendant les années 1840-41-42. Paris, 1853.
– H.Rabie: "Pre-20th century Irrigation in Egypt", in Encyclopedia of Islam, New Edition, vol. 5, pp. 862-4.
– J. Read: The Moors in Spain and Portugal. Faber and Faber, London, 1974.
– H. Saladdin: Enquêtes sur les installations hydrauliques romaines en Tunisie. Tunis: , published by Direction des Antiquites et Beaux Arts, et La regence de Tunisie, 1890-1912.
– M.Shaw: Voyages de Shaw MD dans plusieurs provinces de la Barbarie et du Levant. La Haye, 1743, vol 2.
– N.J. Schnitter, A History of Dams. A.A. Balkema, Rotterdam, 1994.
– N. Smith, "A History of Dams." The Chaucer Press, Peter Davies, London,1971.
– A.Solignac: "Recherches sur les installations hydrauliques de kairaouan et des Steppes Tunisiennes du VIIème au XIème siécle", Annales de l‘Institut des Etudes Orientales, Algiers, X (1952), pp. 5-273.
– R. Thouvenot: "Les traveaux hydrauliques des Romains en Afrique du Nord", Réalités marocaines. Hydraulique, Electricité, Casablanca, 1951.
– A.M. Watson: Agricultural Innovation in the Early Islamic World. Cambridge University Press, 1983.
– Wegmann, E. The Design and Construction of Dams, John Wiley & Sons, New York, 1922.
– Lynn White Jr: Medieval Technology and Social Change. Oxford, 1964.
 N. Smith, A History of Dams, "A History of Dams." The Chaucer Press, Peter Davies, London,1971.
 Ibid, p. 75.
 A. Pacey, Technology in World Civilization, a Thousand Year History, The MIT Press, Cambridge, MA., 1990, p.8.
 For a useful outline containing references, see Donald R. Hill and Ahmad Y. Al-Hassan, Engineering in Arabic-Islamic Civilization. Part One (retrieved 26.12.2009).
 Quoted in A. I. Sabra, "Ibn al-Haytham: Brief life of an Arab mathematician", Harvard Magazine, A. I. (October-December 2003 (retrieved 27.12.2009).
 N.J. Schnitter, A History of Dams, The Useful Pyramids, A.A. Balkema, Rotterdam, 1994, pp. 81-2.
 Ibid, p. 82.
 N.Smith, "A History of Dams", op. cit., p.78.
 D.R. Hill: Islamic science and Engineering, Edinburgh University Press, 1993, p. 168.
 N.Schintter, A History of Dams, op. cit., pp 88-9.
 N.Smith, "A History of Dams", op. cit., p. 90.
 D.R. Hill, Islamic Science, op. cit., p. 161.
 Ibid, p.165.
 N.Smith, "A History of Dams", op. cit., p. 88.
 See Willy Hartner, "Al-Battani", Dictionary of Scientific Biography, C. C. Gillispie (ed.), vol.1, Ch. Scribner's Sons, New York, pp. 507-516 and John J. O'Connor and Edmund F. Robertson, "Abu Abdallah Mohammad ibn Jabir Al-Battani", MacTutor History of Mathematics archive.
 A. Pacey, Technology in World Civilization, op. cit., p. 9.
 Ibid, pp. 9-10.
 D.Hill, Islamic Science, op. cit., p. 159.
 S.P. Scott, History of the Moorish Empire in Europe, J.B. Lippincott Company, London and Philadelphia, 3 vols; vol. 3, 1904, pp. 601-2.
 Ibid, p. 602.
 N.Smith, "A History of Dams", op. cit., p. 93.
 N. Smith: "A History of Dams", op. cit., pp. 94-7; D. Hill, Islamic Science, op. cit., pp. 166-7.
 A. Solignac, "Recherches sur les installations hydrauliques de kairaouan et des steppes tunisiennes du VIIème au XIème siècle", in Annales de l'Institut des Etudes Orientales, Algiers, X (1952), pp. 5-273.
 A list that includes Arabic numerals, the invention of the pendulum, the use of the compass in navigation, the vaulted arch in construction, blood circulation, and so on and so forth, all attributed to various sources other than Islam despite all evidence in favour of the Muslims. On the other hand, acts such as the burning of the famed Library of Alexandria were attributed for centuries to the Muslims despite the flimsy nature of evidence. The library was proven to have been burnt centuries before the Muslims entered Egypt: See E. Gibbon, The decline and Fall of the Roman Empire, for instance.)
 M. Shaw, Voyages de Shaw MD dans plusieurs provinces de la Barbarie et du Levant; 2 vols., La Haye, 1743; vol. 2, pp. 257-9; and E. Pelissier, Description de la Régence de Tunis; Exploration scientifique de l'Algérie pendant les années 1840-41-42, Paris, 1853, pp. 279-280.
 A. Daux, Recherches sur l'originalité et l'emplacement des emporia phéniciennes dans le Zeugis et le Byzacium, Paris, 1849.
 H. Saladdin, Enquêtes sur les installations hydrauliques romaines en Tunisie, published by Direction des Antiquites et Beaux Arts et La regence de Tunisie, Tunis, 1890-1912; R.Thouvenot, "Les traveaux hydrauliques des Romains en Afrique du Nord", Réalites marocaines, Hydraulique, Electricite, Casablanca, 1951.
 Lucie Bolens, "Irrigation", in Encyclopedia of the history of Science, Technology, and Medicine in Non Western Cultures, edited by Helaine Selin, Kluwer Academic Publishers. Dordrecht/Boston/London, 1997, pp. 450-2; p. 451.
 C. Cahen, "Irrigation in Iraq", Encyclopedia of Islam, New Edition, Brill, Leiden.
 H. Rabie, "Pre-20th century irrigation in Egypt", in Encyclopedia of Islam, vol. 5, pp. 862-4.
 Al-Nuwayri, Nihayat al-Arab, Cairo, 1923, vol. 1, p 265.
 Al-Maqrizi, Khitat, Cairo, 1853-4, vol. 1, p. 61.
 H. Rabie, "Pre-20th century irrigation in Egypt", op. cit., p. 862.
 Ibid, p. 863.
 N. Smith: "A History of Dams", op. cit., preface, p. 1.
 A.M. Watson, Agricultural Innovation in the Early Islamic World, Cambridge University Press, 1983, p. 104.
 N.Smith: "A History of Dams", op. cit., p. 81.
 Le Strange, The Lands of the Eastern Caliphate, London, 1905, p. 239.
 D.R. Hill, Islamic Science, op. cit., p. 160.
 N. Smith, "A History of Dams", op. cit., pp. 79-83.
 Ibid, p. 81.
 Al-Muqaddasi, Ahsan al-taqasim fi ma'rifat al-aqalim, ed. De Goeje, Brill, 1906, p. 444.
 N. Smith, "A History of Dams", op. cit., pp. 84, 91.
 Jean Gimpel, The Medieval Machine, Pimlico, London, 1976.
 Lynn White Jr: Medieval technology and social Change, Oxford, 1964.
 A.M. Watson, Agricultural Innovation, op. cit., p. 104.
 D.R. Hill, Islamic Science, op. cit., p. 161.
 N.Smith, "A History of Dams", op. cit., p .103.
 On the expulsion of the Muslimsfrom Spain and Portugal, see Jean Read, The Moors in Spain and Portugal; Faber and Faber, London, 1974; Charles. H. Lea, A History of the Inquisition of Spain, 4 vols; The Mac Millan Company, New York, 1907, vol. 3, pp. 317-409; S.P. Scott: A History of the Moorish, op. cit., vol. 3.
 D.R. Hill, Islamic Science, op. cit., pp. 168-9.
 Including paper making, new architectural techniques, university teaching, the construction of hospitals, windmills, the use of the compass, etc.
 Architecture [in Iran] After Islam http://www.farhangsara.com/architecture_after_islam.htm.
 N. Smith, "A History of Dams", op. cit., p. 86.
* The original article was produced by Salah Zaimeche, Salim Al-Hassani, Talip Alp and Ahmed Salem. The members of the new FSTC Research Team have re-edited and revised this new version. The team now comprises of Mohammed Abattouy, Salim Al-Hassani, Mohammed El-Gomati, Salim Ayduz, Savas Konur, Cem Nizamoglu, Anne-Maria Brennan, Maurice Coles, Ian Fenn, Amar Nazir and Margaret Morris.
by: FSTC Research Team, Sun 30 December, 2001