Journal of Earth Sciences and Geotechnical Engineering

Sammara and its Canals

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  • Abstract

    As the history of this land continues to unfold, we come to the time when the capitol of the State was moved to a new city to the north of Baghdad, which was called Samarra, and this was the opportunity taken by the Khalifahs to build new palaces and excavate new canals and open more land for cultivation. In this paper details on the building of Sammara by Khalifah  al- Mu’tasim, son of Khalifah Harun al- Rashid and moving the capitol to it from Baghdad in the year 836 and remaining as such until 892 are given. One of the main reasons which led al-Muʿtaṣim to build Samarra and moving to it was the problems raised by the presence of his Turkish slave-soldiers in Baghdad and the friction they had created with the population. Al-Muʿtaṣim construction works in Samarra, the various public buildings, and numerous palaces he constructed here are described. As the city was located on the eastern bank of the Tigris, water supply could not be drawn to it by gravity since its location was higher than the river and even higher than the Katul Kisrawi canal adjoining to it from the east. Therefore, the irrigation works of al- Muʿtaṣim were concentrated on the western bank of the Tigris, which he had already connected it to the right bank by building a bridge.  The main irrigation work he embarked upon was the construction of Nahr Ishaqi Canal. This old canal dated to the Partho- Sassanid era but it had to be re-excavated and remodeled since it was already filled up by sediments and abandoned. More over the canal had to be extended for a very long distance downstream to irrigate all the qati’as he had given to his top generals and courtiers to develop into cultivations and farms. These farms then produced all sorts of crops and fruits while the large date palm orchards planted here gave the best types of dates. Moreover, the canal in its downward route supplied water to the large tract of land that al- Mu’tasim had reserved for the encampment of his Maghariba troops which was called “Istablat”. Details of the barracks, housing quarters, stables and training arena of the encampment are presented in addition to the three branch canals off taking from Nahr Ishaqi, which were to irrigate also the extensive pastureland that was reserved for the 140,000 cavalry horses to graze in. The canal was then followed to its end in the other old canal called al- Dujail canal. The works of al- Mu’tasim, however, were no match to what his grandson al- Mutawakkil had done which are described. This Khalifah was determined to irrigate Samarra by gravity from the Tigris and to have plentiful water supply to the city and to his palaces and to his many artificial ponds. He embarked on a daring project by constructing a dual kariz and open channel conduit system taking water from the Tigris at a location forty kilometers north of Samarra and running for great part of its length along the Katul Kisrawi canal adapting to the hilly topography of the land. The scheme was then described following its course after crossing the Katul by an aqueduct to an earth reservoir. This reservoir was built to retain the incoming water before distributing it to the main city dual Kariz, and to the canal supplying the Dakka palace. In addition to the flood escape channel that was known as the Nahr Murayr which took off from the west side of the reservoir and passed down to the Tigris where it poured. The main city Kariz system is followed and the details of its branching network are fully described. Such details covered the water supply to the racing courses, the Dar Khilafa palace and its unique pools intended for the Khalifah’s pleasure and the water supply to Abu Dulaf Mosque congregational mosque with its famous fountain. Having finished in the Tigris at al- Matira this stream could not irrigate the 5000 hectares of land of al- Hayr, or the wild animal reserve created by al- Mutawakkil to practice his hobby of hunting, as this land was above its course. The al- Hayr was so important to al- Mutawakkil that he excavated a new canal directly from the Katul, which commanded the whole area, called it Nahr al Nyzak and gave from its final reach a branch to another palace he built there and supplied one more of his favorite ponds adjoined to it. The construction works of al- Mutawakkil were not confined to Samarra but he extended this to build a new city 18 kilometers to the north of Samarra and called it al- Mutawakkiliyya, and here he again built new government compound, a mosque and gave qati’as to his sons, generals and may more people to build houses and palaces. He built for himself another palace and called it al Ja’fari. To supply the new city with water, he ordered the excavation of a new canal, which he called Nahr al Ja’fari. The intake of this canal was on the Tigris River some forty kilometer north of Tikrit and it followed a course parallel to the river for a considerable distance before it crossed the Katul Kisrawi by an aqueduct and then entered the city. This project proved an engineering failure as the ground, which had to be dug, was extremely hard and the work had to be stopped after spending twenty five million dirham. While some of these works may be considered as grand works, they were very costly and deprived public works such as irrigation networks from their share necessary for their maintenance and proper functioning. This extravagance coupled with political intrigues led to the assassination of al- Mutawakkil in a plot that was planned by his own son. This point marked the beginning of the decline of al- Khilafa which took some more time till it finally collapsed in 1258 fall of Baghdad on the hands of the Mongols. In addition to Samarra and its irrigation work described also the Nahr Dujail canal flowing on the western bank of the Tigris not far downstream from Samarra. Much older than Samarra itself, it was irrigating a large tract of land extending to Baghdad. In description of the course of the canal followed its western branch, which had gone out of use at the Abbasid times and also concentrated attention on the eastern branch that was known as Nahr Batatiya. It irrigated the Tusuj of Maskin before it reached the northern parts of Baghdad and branched into a dense network of watercourses that supplied al- Harbbiyyah quarter. Further details are presented of the various places and parts of this quarter that benefited from these watercourses before the full supply was exhausted.  The details as given augment therefore the description of the canal networks serving Baghdad (the round city and the Karkh districts) that had originated from Nahr Isa. The Abbasid Khilafa after it had experienced its golden era began after the assassination of al- Mutawakkil, a long process of slow but steady decline due to multiplicity of reasons.

    Keywords: Sammara, al- Dujail, Nahr Isa, Kariz system, Iraq