The Omeyad Caliph Hichem Ibn Abdelmalek (724-743 A.D) ordered his Governor in Kairouan, Obeid Allah Ibn El Habhab, to build 15 basins to provide the city with water including those of Sidi Youssef Dahmani which are still there today.

The biggest Basin of Sidi Dahmani has an interior diameter of 73m, and the smaller one 27m.

However, these basins had been constructed long before the famous Aghlabid Basins.

Sorry, your browser doesn't support Java(tm). The main artistic hydraulic design during the Aghlabid dynasty was the construction of two big basins. The construction lasted from 859 to 863 A.D. These basins are 950m from the ‘Door of Tunis’( Bab Tounes) and stretch over an area of 11000m2.

Abu Ibrahim Ahmed Ibn Al Aghlab (6th prince 856-863 A.D.) completed the most famous of these facilities.

A small decantation basin :

It has a simple polygonal shape with a diameter of 37.40m. It has a capacity of 4119m3 that receives water from two sources. First via an aqueduct stretching over 30 km to the west of Kairouan from the “Adine-Henchir Eddouamis” aquifer (originally used by the Romans before the Aghlabites, and by the Fatimids later); second, by a small dam built on Oued Marguellil before flowing into another bigger basin.

There have 45 arches in total (17 inside and 28 outside), and 16 niches.
The junctions were done in one block and of similar shape.
The depth from the hood of the basin wall to its sill is 4.87 m

Junction :

The junction between the two basins has a width of 2.22 m and is crossed all the way by a tunnel measuring 2.30m in width and 2.14m in height under the key whose radius is 1.15m

According to El Bekri’s description, this opening is called “sarh”

A big basin : This vast and harmonious construction is named "majel" by ”El Bekri” and "birkat " (biçat al aqiq) by Abdulwahab.

It is a lateral polygon of 64 nearly equal sides of a 129.67m diameter and a volume of 57764 m3 of water.

Its outside perimeter stretches over 405m.

This basin has 64 interior buttresses, 58 simple buttresses on tops of angles, and 61 simple buttresses in the middle.

However, angular and middle buttresses don’t exist in the site of the pumping water's cisterns.

In addition to providing the city with water, the big basin was used occasionally by Aghlabite Emirs (notably Zyadat Allah III) for pleasure and entertainment.

He used a boat called “Zellej” that allowed him to reach the platform at the center of the basin.

Maçonnerie :

les deux bassins sont construits en moellons bruts reliés par un mortier de chaux et de sable  avec fréquemment une proportion assez forte de cendre végétale revêtu d'un enduit étanche au mortier de tuileaux de 0m04 d'épaisseur.

Cisterns for pumping out water :

These are two independent vaulted rooms communicating with the big basin. They are pierced by numerous openings which allowed for water pumping out.

Water pumping took place from the terrace through chimneys having square sections (of 0.5m per side). The covered blockage has several openings located in every gallery at the top of the arch and distributed throughout the upper part of the cradle.

Every cistern is constructed on the outside by an oblong plan measuring 29.20m in length and 1150m in width. Their storage capacity is 917m3 of water.

Global storage capacity :

• Small basin: 4.119m3
• Big basin: 57.764m3
• Pumping cisterns: 917m3

Total: 62.800m3

Pilaster : At the center, one pilaster was erected to neutralize the currents caused by winds.

These currents could destabilize the static balance of the basin. This pilaster was also used to organize certain festivities.

Mohamed Rebai
info@kairouan.org