In what way can ancient water supply systems serve as an ‘anchor’ to raise and increase awareness of contemporary issues relating to the availability and consumption of drinking water in an urban environment? I will try to answer this question in relation to my project ‘Engaging with Istanbul’s Water Heritage’, which focuses primarily on increasing knowledge about the tangible and intangible remains of the city’s rich and multilayered water heritage. This heritage comprises the remains of water supply systems dating from both the Roman-Byzantine and Ottoman periods, which consisted of pipes, channels, tunnels, bridges, and collection points, of which mainly the monumental aqueduct bridges have survived. These include the so-called Valens Aqueduct, an aqueduct bridge that formed part of the Valens water supply line, which came into use in 373 and is situated in the heart of Istanbul’s historic centre (Figures 1 and 2); sections of the Valens line located in forest areas outside the city in Thrace (Figures 3 and 4); and Ottoman aqueduct bridges primarily built during the sixteenth century by the architect Sinan as part of the Kırkçeşme water supply system, now on the outskirts of the present-day metropolis (Figures 5 and 6). Other installations that formed part of these water supply systems, and of which the remains or traces are still visible, include above-ground and underground cisterns, baths, fountains, water kiosks, water towers and distribution chambers. The groundbreaking publications for research on the Byzantine water supply system of Istanbul was The Water Supply of Byzantine Constantinople by James Crow, Jonathan Bardill, and Richard Bayliss (2008) and Kâzım Çeçen's Sinan's Water Supply System in Istanbul (1996) and his other publications in Turkish on the Ottoman water supply systems.
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| Fig. 1 Valens aqueduct, over Atatürk Boulevard, 2022 © M. Verhoeven. |
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| Fig. 2 Valens Aqueduct near Kadınlar Pazarı, 2024 © M. Verhoeven |
The Valens line was not the city’s oldest water supply system. Emperor Constantine (r. 306-36), who gave his name to the city he founded in 324, did not build Constantinople from scratch, but as a continuation and extension of the city that Emperor Septimius Severus (r. 193-211) had built on the peninsula surrounded by the salt waters of the Bosphorus, the Propontis (now the Sea of Marmara) and the Golden Horn. However, it was Emperor Hadrian (r. 117–38) who had previously constructed a water supply line designed to provide the lower parts of the peninsula with fresh water, as the lack of fresh water had been a problem from the outset. Following the city’s expansion in the fifth century, the Valens line – which drew water from springs some 200 km away – was extended by a further 200 km or more, and has therefore rightly been described as ‘The Longest Roman Water Supply Line’ (Çeçen 1996).
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| Fig. 3 Kumalıgerme aqueduct, near Çatalca, 2026 © M. Verhoeven |
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| Fig. 4 Kurşunlugerme aqueduct, near Gümuşpınar, 2026 © M. Verhoeven |
The water supply system has a history of interruptions and blockages caused by natural disasters such as earthquakes and droughts, invading armies, and poor maintenance and neglect. According to the ninth-century chronicler Theophanes, in 766 Emperor Constantine V felt the need to restore the Valens Line after it had been out of use since 626 as a result of a siege by the Avars. For this restoration, he had specialist labourers brought in from across the empire:
On 16 November of the same 5th indiction [766] the eunuch Niketas, a Slav, was ordained the emperor’s decree patriarch of Constantinople. There ensued a drought, such that even dew did not fall from heaven and water entirely disappeared from the City. Cisterns and baths were put out of commission; even those springs that in former times had gushed continuously now failed. On seeing this, the emperor [Constantine V] set about restoring Valentinian’s (sic) aqueduct, which had functioned until Herakleios and had been destroyed by the Avars [in 626]. He collected artisans from different places and brought from Asia and Pontos 1,000 masons and 200 plasterers, from Hellas and the islands 500 clay-workers, and from Thrace itself 5,000 labourers and 200 brick-makers. He set taskmasters over them including one of the patricians. When the work had thus been completed, water flowed into the City.
(transl. Mango and Scott in Crow, Bardill & Bayliss, 2008, 236)
A partial revitalisation of the ancient water systems took place following the conquest of Constantinople by the Ottoman Turks in 1453, under the leadership of Sultan Mehmed II. Just as in Roman times with regard to the emperor, the water supply was the direct responsibility of the sultan himself. Mehmed’s biographer, Tursun Bey, tells us that investigations into how the ancient systems functioned formed the basis for their repair and renewal:
For the sake of remedying the water shortage, however, he deigned to make inquiries. Now, in the time of Istanbul’s blossoming, water had come from a distance of six or seven days’ journey. The old lines were found. Breaking through the inside of the mountains, one had led these (lines) through these (mountains) and had a river from far away flow over water channels parallel to the level of the soil and built, by placing one arch of blocks of pure marble next to another, one aqueduct next to another. But under the influence of the weather and the change from day to night and night to day, the work had become completely dilapidated. The Sultan sent capable technicians to restore and renew the destroyed arches and collapsed tunnels, and probably also to furnish and strengthen them with lead. […] And in a suitable place at an aqueduct he made forty wells.
(Tursun Bey, The History of Mehmed the Conqueror, transl. Bardill in Crow, Bardill & Bayliss, 2008, 242)
The complex of forty fountains, Kırkçeşme, which, according to Tursun Bey, the sultan had built near the aqueduct we now know as the Valens Aqueduct Bridge in the heart of the historic city, gave its name to the main water supply line during the Ottoman period. For this Kırkçeşme line, the infrastructure of the ancient Hadrianic line was restored and revitalised. An expansion and innovation of the Kırkçeşme line took place between 1554 and 1563 under Sultan Suleiman, carried out by the architect Sinan. He built the aforementioned monumental aqueduct bridges, for which he clearly followed and was inspired by the ancient examples and which, according to Çeçen, he surpassed.
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| Fig. 5 Mağlova aqueduct, 2022 © M. Verhoeven |
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| Fig. 6 Güzelce aqueduct, 2022 © M. Verhoeven |
Today, both the Roman and Ottoman monumental aqueduct bridges bear witness to the efforts made in the past to facilitate and ensure the city’s water supply. These historic installations are no longer in use, nor are the cisterns, distribution chambers, water towers, water kiosks and most of the fountains that were connected to them. With regard to the distribution chambers and water towers, it is noteworthy that only examples from the Ottoman period have survived (Figure 7). It may be that they were an Ottoman innovation, but it is likely that the Ottomans drew on Roman models. We are familiar with such installations from Rome and Pompeii, but there is no material evidence of their existence in Istanbul prior to the fifteenth century.
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| Fig. 7 Water tower near Hagia Sophia, 2022 © M. Verhoeven |
While the visible remains of the historical systems are no longer in use for hydrological purposes, contemporary consumers are hardly aware of the efforts made in water management because the modern water supply system is largely invisible. Every day, Istanbul’s 16 million inhabitants need to be supplied with fresh water. Water seems to come ‘as normal’ from the tap but the metropolis brings 50 percent of its water from other provinces because its own reservoirs are drying up. Given the limited and diminishing availability of fresh water as a result of climate change, pollution and population growth, it is important that people become aware of the efforts that need to be made in this regard and of their own role in using water more responsibly. The existing water heritage can play a role in this. Water heritage can be used to illustrate that water supply and water management in Istanbul have been a challenge for centuries and that they require considerable effort. Here I present two initiatives aimed at utilising and bringing to life ancient water heritage to raise public awareness of contemporary water issues in the urban environment of Istanbul.
The first initiative is the Istanbul-Su database (Su means water in Turkish) which can be accessed via https://istanbul-su.rich.ru.nl/. The goal of the database is to map Istanbul’s historical water-related installations in order to make the complex networks of water supply systems visible and increase knowledge about them among both scholars and a wider audience of interested parties. The database offers metadata on Istanbul's historical water supply systems and the installations that were part of them such as aqueducts, cisterns, fountains, and baths. For each installation, the database contains information such as its type, purpose, persons or institutions involved, source texts, images, and events related to the installation such as restorations, additions and damages. A map shows the location of the installations. This not only highlights the diversity of Istanbul’s water heritage but also its development over time. It also demonstrates the continuity of the city’s water supply throughout the centuries. The data entry, which is based on scientific research, is an ongoing project.
The second initiative is the KarDes Istanbul’s Water HeritageWalking Tour (developed by the Hrant Dink Foundation focusing on the heritage of religious and ethnic minorities in Turkey). With this mobile application users can explore Istanbul’s material and immaterial water heritage through the ages. The stops include structures such as cisterns, aqueducts, hammams, fountains, water kiosks, mosques, and churches, as well as the stories of Istanbul’s traditional fire brigades, water carriers, bath attendants, and fishermen. The tour does not just emphasize the continuities and breaks in water supply and usage over more than 1600 years, but also highlight the shared importance of water and water-related culture across ethnic and religious divides. Users can read or listen to the information, as well as view the (historical) images and photographs. There are also references to further information. The development of the app was a partnership of the Hrant Dink Foundation, VU (Amsterdam), the Netherlands Institute in Turkey, and Radboud University, funded through a Vrije Universiteit Connected World Social Impact Award.
By considering Istanbul’s water heritage from the perspective of the concept of ‘anchoring innovation’, I hope to have demonstrated that, in both the Roman-Byzantine and Ottoman periods, renovations and innovations to the water supply system drew upon and built on knowledge and experience from the past. The initiatives described illustrate how the remains of this centuries-old water supply system and the knowledge about it can be used to raise awareness of contemporary issues relating to the availability and consumption of drinking water in an urban environment.
Mariëtte Verhoeven (Radboud University Nijmegen)
Mariette Verhoeven is a lecturer in Ancient and Medieval history at the Radboud University Nijmegen. She specializes in late antique/early Christian and Byzantine cultural and architectural history, especially of Ravenna and Constantinople. Her current research project is “Engaging with Istanbul’s Water Heritage. Sustainable solutions for increasing knowledge and public awareness”. This project explores the potential of Istanbul’s historical water heritage as a driver of sustainable solutions to contemporary and future challenges regarding water supply and use.
Additional Reading
Crow, James, Jonathan Bardill, and Richard Bayliss. The Water Supply of Byzantine Constantinople (London: Society for the Promotion of Roman Studies, 2008).
Çeçen, Kâzım. Sinan’s Water Supply System in Istanbul (Istanbul: T.C. İstanbul Büyük Şehir Belediyesi, İstanbul Su ve Kanalizasyon İdaresi Genel Müdürlüğü, 1996).