The water system of Alexandria

Alexandria was founded far from the Nile, on the arid coast of the Mediterranean, at the north-western edge of the Delta, on the eastern end of the Taenia, between a belt of lagoons and the margins of the Western Desert. The small harbour town invented by Alexander the Great in 331 became a metropolis under the Ptolemies, spreading its influence across the Mediterranean and remaining one of the largest cities in the ancient Mediterranean throughout the Roman era. According to Strabo, it was the “largest trading post in the world” (Geography, 17.1.13) before declining after the Arab conquest. As a rather distant port for Fustat, and then for Cairo during the Arab and Ottoman periods, it was no more than a large harbour town when Bonaparte’s troops arrived. One of its main activities at the time was to maintain and refill the hundreds of cisterns used to store drinking water, several dozen of which were used to supply ships anchored in the city’s harbours.

While it remains difficult to assess the importance of the city’s underground water resources in the context of the water system in the Greek and Roman periods, recent research has brought a new approach to the hydraulic techniques used by the Alexandrians. It has shown that the Ptolemaic city benefited from a water distribution infrastructure consisting of sub-horizontal galleries dug into the aquifer rock, in the form of multiple small closed complexes linked to the surface by vertical shafts. CEAlex excavations in the town centre and a number of archival documents have revealed a system comprising hyponomoi (underground canals) and phreatiai (wells from which water was drawn), with the well and the draining tunnel combining several functions at once: collecting and storing water for the tunnel, while the wells acted as inspection shafts, vent shafts used to regulate pressure in the tunnel and collection wells.

The combination of hyponomoi and phreatiai was an innovative adaptation of a system used by the Greeks to drain marshes. The oldest ensemble uncovered in Alexandria dates from the 3rd century BC. It was associated with the oldest saqieh, a very efficient water-lifting machine, unearthed in Egypt, thus confirming its Egyptian, and probably Alexandrian, origins. Other excavations have confirmed its presence in several residential areas of the Graeco-Roman city. Such infrastructure was obviously expensive, and while the system described was the norm in wealthy homes, poor or modest inhabitants went to the canal to draw their water, as Caesar reports:

« Alexandria is almost quite hollow underneath, occasioned by the many aqueducts to the Nile, that furnish the private houses with water; where being received in cisterns, it settles by degrees, and becomes perfectly clear. The master and his family are accustomed to use this for the water of the Nile being extremely thick and muddy, is apt to breed many distempers. The common people, however, are forced to be contented with the latter, because there is not a single spring in the whole city. »

TheAlexandrian Wars, V, 2

As the city grew, Alexandria’s link with the Nile quickly became a priority, and Menelaus, brother of Ptolemy I (Xenophon of Ephesus, Ephesiaka, IV, 1, 3), was commissioned to dig the Alexandria canal. Starting from the western branch of the Nile, the canal had a dual function: navigation and water supply, which explains its open-air design. It was used until the Arab conquest to transport foodstuffs from southern Egypt to Alexandria for both domestic consumption and export. It helped to develop crafts, industry and agriculture in the city’s chora, and it made a more or less direct contribution to the city’s supply of fresh and drinking water by refilling the aquifers. Studies are looking at the evolution of its course up until the work of Mohamed Ali, as well as the position and function of the nilometers and other installations along its route.

Various documents indicate that other canals contributing to the wider urban water system were dug under the Ptolemies, and then in Roman times (the Kibotos canal, the Basileia, Brucheion and Neapolis canals). During this latter period of possible aridification of the western Delta region, hydraulic works intensified (renovation of existing canals, extension of the southern section of the Alexandria canal, digging of an outfall basin and regulation of the canal’s water level to the east of the city) in order to achieve an abundant supply and regular distribution, even in periods of drought. Similar models prevailed throughout the Empire.

The first large public cisterns were built in Imperial Roman times, while small-scale hydraulic systems continued to rely on the hyponomoi/phreatiai pairing. Political decisions and the harmful effects of subsidence, which caused the salt water table to rise adversely affecting the quality of the water drawn from the subsoil, gradually made the Alexandria canal indispensable for the supply of fresh water. Water supply now took priority over navigation. Thus began the second era of Alexandrian hydraulics, that of the cisterns. Excavations and old documentation point to the presence of a real concentration of baths and cisterns to the east of the Eastern Harbour, as well as on a parallel line one step back, a visible sign of a context characterised by an increase in demand. These buildings, made of fired bricks bound with a very hard mortar and waterproofed with excellent quality hydraulic plaster, have been studied in various parts of the city and dated to between the 2nd century AD and the 6th/7th century AD.

After the Arab conquest, the city continued to benefit from the old infrastructure for several decades, until the Tulunids decided on a plan to restructure the city, starting with a reduction in its size and the construction of new walls, a decision dictated in part by environmental upheavals and dwindling drinking water resources. Within this space, they launched a new urban water management plan based on the construction of huge multi-storey public cisterns, such as the El-Nabih cistern, whose supply was still ensured by the hyponomoi/phreatiai combination, from which water was extracted using saqieh, but now only once a year, during the Nile flood.

Further reading:

M. Bergmann, M. Heinzelmann, « Schedia : Alexandria’s customs station and river port on the Canopic Nile », in P. Pomey (éd.), La batellerie égyptienne, Études Alexandrines, 34, Alexandrie, 2015.

S. Boulud, « Terra Santa : L’eau et le réseau hydraulique antique, in I. Hairy (éd.), Du Nil à Alexandrie, histoires d’eaux, catalogue d’exposition, Alexandrie, 2011, p. 403-405.

J.-Y. Empereur
« Du nouveau sur la topographie d’Alexandrie (note d’information) », CRAI 146, 2002, p. 921-933.
« Alexandrie : fondation royale et désenclavement du monde », in Cl. Nicolet, R. Ilbert, J.-Ch. Depaule (dir.), Mégapoles méditerranéennes, Paris – Aix-en-Provence, 2000, p. 239-241.
« Réseau viaire et approvisionnement en eau », in La gloire d’Alexandrie, catalogue d’exposition, Paris, 1998, p. 90-91.
J.-Y. Empereur, « Une ville de citernes », Alexandrie redécouverte, Paris, 1998, p. 127-130.

H. Fragaki, « L’eau à Alexandrie : croyances et mises en scène », in I. Hairy (éd.), Du Nil à Alexandrie, histoires d’eaux, catalogue d’exposition, Alexandrie, 2011, p. 278-287.

J.-Ph. Goiran, P. Carbonel, J. Cavero, Chr. Morhange, J.-Y. Empereur, « Géoarchéologie du port maritime d’Alexandrie , Égypte », Géochronique, 130, juin 2014, p. 26-29.

Th. Gonon, « Puisage de l’eau : la sakieh de Terra Santa », in I. Hairy (éd.), Du Nil à Alexandrie, histoires d’eaux, catalogue d’exposition, Alexandrie, 2011, p. 408-419.

I. Hairy
« Alexandria: A brief overview of the major hydraulics of the city, from its foundation to the Arab conquest, in K. Blouin (dir.), The ancient to modern Nile delta. Empires, societies, and environnments content, Cambridge, à paraître en 2021.
« Alexandrie : hydraulique urbaine à la fin du premier millénaire av. J.-C. », in S. Bouffier, I. Fumado Ortega (éd.), L’eau dans tous ses états, Archéologies Méditerranéennes, Aix, Marseille, Presses universitaires de Provence, p. 117-140.
« Rapport d’étude sur certains aménagements hydrauliques du chantier de l’ancien consulat britannique, fouille effectuée en 1994 et 1997 », Alexandrie, févr. 2017.
« L’eau dans la ville », Dossiers d’Archéologie 374, mars-avril 2016, Alexandrie grecque, romaine, égyptienne, p. 14-17.
« La domestication de l’eau  : de la Mésopotamie à la Méditerranée », in J. Guilaine (éd.), Invention des agricultures, naissance des dieux, Paris /Marseille, 2015, p. 48-57.
Du Nil à Alexandrie, histoires d’eau, Isabelle Hairy (dir.), Catalogue d’exposition, Alexandrie, 2011.
2 Courts métrages réalisés en collaboration avec Raymond Collet, dans le cadre de la collection des 13*13’ du CEAlex : De l’eau pour Alexandrie et La ville du dessous.
« Alexandrie médiévale. La question de l’eau », in Chr. Décobert, J.-Y. Empereur (éd.), Alexandrie médiévale 3, Études Alexandrines 16, 2008, Le Caire, p. 263-277.
Les coulisses de l’eau à Alexandrie, Les petits guides d’Alexandrie, Alexandrie, 2008, Traduction en arabe en 2016.
Avec Oueded Sennoune, « Géographie historique du canal d’Alexandrie », Annales Islamologiques 40,2006, p. 247-278.
« Une nouvelle citerne sur le site du Sérapeum », Alexandrina 2, Études Alexandrines 6, 2002, p. 29-37.
Avec Y.Guyard, « Exemple d’utilisation du S.I.G. : les citernes d’Alexandrie », Archéologia 350, nov. 1998, p. 4-5.

Laube, The unpublished excavation in the Basileia of Alexandria by the expedition Ernst von Sieglin in 1901, Études Alexandrines 51, Alexandrie, 2020.

M.-D. Nenna
« Les changements de niveau de la Méditerranée et l’archéologie », in J. Jouanna , Chr. Robin, M. Zink (éd.), Actes du colloque Vie et climat d’Hésiode à Montesquieu, Cahiers de la Villa « Kérylos » 29, Paris, 2018, p. 185-203.
« Alexandrie. Des siècles d’histoire urbaine », Dossiers d’Archéologie, 374, mars-avril 2016, p. 6-11.
« L’eau et l’hygiène dans l’Alexandrie antique », in I. Hairy (dir.), Du Nil à Alexandrie, histoires d’eaux, catalogue d’exposition, Alexandrie, 2011, p. 503-504.
« L’eau dans la nécropole du pont de Gabbari (Alexandrie, Égypte) », in A.-M. Guimier-Sorbets (éd.), L’eau, enjeux, usages et représentations, Quatrième colloque de la Maison René-Ginouvès, (Nanterre, 2007), Paris, 2008, p. 229-238.

Chr. Requi, « Jardin de l’Ancien Consulat britannique », Alexandrie 1997 : Rapport préliminaire de fouilles 1996-1997.

P. Rifa Abou El Nil, « Chantier du Diana, circulation de l’eau dans un quartier de l’Antiquité tardive, in I. Hairy (dir.), Du Nil à Alexandrie, histoires d’eaux, Alexandrie, 2011, p. 374-387.

M. Rodziewicz
« Ancient Baths in Alexandria », in M.-Fr.Boussac, Th. Fournet, B. Redon (éd.), Le bain collectif en Égypte, Études Urbaines 7, Le Caire, 2009, p. 191-201.
« From Alexandria to the West by land and by waterways », in J.-Y. Empereur, (éd.), Commerce et artisanat dans l’Alexandrie hellénistique et romaine, BCH-Suppl. 38, 1998, p. 93-103.
Les habitations romaines tardives d’Alexandrie à la lumière des fouilles polonaises à Kôm el-Dikka, Alexandrie III, Varsovie, 1984.

H. Silhouette, « Le Cricket Ground : approvisionnement en eau d’un quartier gréco-romain d’Alexandrie, in I. Hairy (dir.), Du Nil à Alexandrie, histoires d’eaux, catalogue d’exposition, Alexandrie, 2011, p. 367-370.