Istanbul’s 1,900-year-old water network stretches from Rome to Sinan

Istanbul’s water infrastructure dates back to structures built during the Roman period nearly 19 centuries ago. The Kırkçeşme Water System stands out as an extensive engineering network that met the city’s water needs through dams, aqueducts, galleries and distribution structures.

Istanbul’s dams, aqueducts, galleries, distribution chambers and fountains, which survive today as cultural heritage, form parts of a vast system that has met the city’s water needs for nearly 19 centuries.

The city’s earliest documented water facilities were built during the reign of Roman Emperor Hadrian. Water drawn from sources outside the city was carried to populated areas through canals and watercourses.

Infrastructure spanning Rome and Byzantium to the Ottoman era

As Istanbul’s population grew in the 4th century, so did its need for water. Water was brought to the city from distant sources through transmission lines established during the reign of Emperor Valens. The Valens Aqueduct, known today as the Bozdoğan Aqueduct, became one of the system’s key components.

After the conquest of Istanbul, Fatih Sultan Mehmed had the city’s dilapidated watercourses repaired and restored to operation. In subsequent periods, new structures were added to the water facilities and the existing infrastructure was further developed.

The Kırkçeşme Water System, built by Mimar Sinan during the reign of Sultan Suleiman the Magnificent, became one of the most extensive examples of Istanbul’s water infrastructure. Its approximately 55-kilometer transmission line consisted of 33 aqueducts, galleries, inspection shafts, water towers, distribution chambers and other distribution structures.

Water was carried from Belgrad Forest to the city center

The Kırkçeşme system used rainwater and spring water collected in the Valide, Topuzlu, Kirazlı and Sultan Mahmud dams in Belgrad Forest. The water advanced along two main branches, east and west, before converging at Başhavuz south of Kemerburgaz.

After resting and being cleared of sediment in Başhavuz, which was approximately 14 meters deep, the water was transferred to the main transmission line. Described by Mimar Sinan as being “as deep as the Galata Tower,” the structure served as an important point where water from different sources was gathered in one place.

From Başhavuz, the water passed through the Mağlova Aqueduct and reached Istanbul via Uzunkemer, Güzelcekemer and Paşakemeri. The two-story Mağlova Aqueduct, approximately 36 meters high, carried the water from one side of the valley to the other.

When the water reached the city center, it passed through the Bozdoğan Aqueduct, which had been part of Istanbul’s skyline for nearly 16 centuries. Completed in A.D. 378 during the reign of Valens, the aqueduct was also repaired during the Ottoman period and continued to serve the water system.

Taksim took its name from water distribution

One of the water system’s important stops within the city was the Taksim distribution chamber. Water brought into the city was divided here into branches and directed to fountains and other distribution points; the area took its name from this division, or “taksim,” of the water into different lines.

Water was distributed to neighborhoods in a controlled manner through water towers, pipes and distribution chambers. The water towers visible on the outer wall of the Şehzade Mosque balanced the pressure of high-flow water and prevented it from damaging the pipes.

After passing through the water towers, the water reached distribution points such as the Eğrikapı distribution chamber and the one at Taksim. From there, underground lines carried it to square fountains, streets and neighborhoods. The system is believed to have supplied water to more than 30 fountains.

Daily water capacity reached 30,000 cubic meters

Prof. Dr. Kadir Pektaş, a faculty member in the Department of Art History at Istanbul Medeniyet University’s Faculty of Arts and Humanities, said Istanbul’s water infrastructure was developed during the Byzantine and Ottoman periods after originating in the Roman era.

Pektaş said the Kırkçeşme Water Facilities were a vast, interconnected engineering network that carried water from Belgrad Forest to Istanbul. He said the system delivered approximately 17,500 cubic meters of water to the city each day when it was established by Mimar Sinan, and that this amount rose to as much as 30,000 cubic meters following subsequent additions.

Inspection shafts were placed above the galleries at intervals of 20 to 40 meters along the system, and new water sources located along the route were incorporated into the network. Aqueducts were used to carry the water across valleys.

Proposal for a cultural route around the historic water network

With the construction of modern dams, treatment plants and new transmission lines, most of the historic structures completed their original functions and gained cultural heritage status. Some dams, however, continue to contribute to the water system today.

Alongside protecting the historic water structures individually, there are calls to preserve the entire network stretching from Belgrad Forest to the city center. Proposals include developing the Kırkçeşme Water System as a cultural route and restoring the historic fountains dismantled during roadworks in the 1940s.