The Valens Aqueduct of Constantinople: Hydrology and Hydraulics

A hydrological and hydraulic engineering analysis has been carried out on the Valens aqueduct system constructed from around AD 345 and serving Constantinople. A GIS analysis of previous field observations combined with a digital elevation model confirmed the aqueduct’s likely route and slope. Macrophysical Climate Modelling revealed that contemporary weather data was an appropriate proxy for the time of the aqueduct’s construction, and modern flow data was obtained for some of the springs that fed the aqueduct. Existing, previously documented remains, especially at intakes, were considered, and the industry standard software HEC–RAS was used to simulate the performance of the aqueduct system with a view to understanding the amount of water it could have delivered to the city, the seasonal variation in supply and the most likely configuration of the aqueduct, where this was not clear from existing archaeology. It was concluded that the most likely configuration for the aqueduct system was a fourth and a fifth century channel continuing separately and in parallel to the city walls, which might have delivered flow the range of 0.73 m3/s in the driest month of October to 1.73 m3/s in the wettest month of March over an average year.