Quenching Istanbul’s thirst with aqueducts and cisterns

Clever feats of engineering that required precise calculations of slope and hill elevation, Istanbul’s aqueducts crisscrossed the city, bringing water to the imperial city Today in Istanbul we cross under the Aqueduct of Valens, but give this ruined, fourth-century structure little thought as we try to navigate traffic. It tells us though that during the Roman period, the city already had a population that exceeded the ability to find its water within its walls. Probably the pre-aqueduct structure in the city was the “tonoz,” a vaulted building designed to protect a spring. It’s still possible to find these today even though they aren’t used. There were also sacred springs or “ayazma,” around which sacred buildings were constructed for the devout in the hopes of a miracle. A further source of water collection was rain water falling off roofs into storage jars and cisterns.

The water brought to Istanbul was mostly from dams and reservoirs built in the Belgrade forest to hold water that then would be brought by aqueduct to Eğrikapı (Kaligaria Gate) located on the northwest side of the historic peninsula. From Eğrikapı, the water was piped to tanks at Atpazarı, Yenibahçe and Ayasofya and then further dispersed to palaces, mansions, baths and fountains. The Aqueduct of Valens brought water over 250 kilometers from near the modern town of Vize.

Aqueduct of Bahçeköy by W.H. Barlett.

The ingenious aqueduct

The aqueduct was an ingeniously clever feat of engineering at which the Romans were particularly good. (They also built superb drainage systems to flush away sewage but we don’t seem to have any Roman examples left in Istanbul.) While we think of aqueducts as bridges carrying water over...