Athens has always been an area with little rainfall, and consequently, water resources have always been scarce. Thus, from the very beginning, its inhabitants had to develop basic water collection and distribution systems for the water supply of the city. These systems gradually improved with the passing of time and the progress of technology.
Ancient Athens was primarily supplied with water from springs and local wells. One of the most famous natural springs was the Spring of Caliroi (the source of the Ilisos River). There were also many natural springs surrounding the cliff of the Acropolis such as the springs of Klepsidra, Asklipios, and the Erechtieda Sea. Water was available within the ancient city at local fountains such as the Fountain of Pan, the Panopos Fountain, the Springs in the Attalos Gallery and at the foot of the Areios Pagos Hill.
In their continuing effort to satisfy demand of water, the ancient Greeks relied heavily on an intricate system of small aqueducts, which also supplied the many fountains mentioned earlier with water. The oldest aqueduct on the Athenian Plain was the Pelasgiko Aqueduct that supplemented water available from the Ilissos river, with water coming from Hymettus Mountain. Between the years 540-530 B.C., Pisistratos constructed a new underground aqueduct about 2.800 m long, that collected additional water from the Hymettus Mountain. Thanks to the project completed by Pisistratos, water reportedly flowed in abundance, meeting the needs of the city residents.
In later efforts to augment the water supply, the Ancient Greeks also constructed small reservoirs and cisterns. Some of the most famous such works where the Hamosterna and the Pikrodafni Reservoirs.
With the fall of Athens to Rome in the years that followed, the city lost its freedom but also its ability to promote large-scale public works. Nevertheless Greece managed to become an important center of culture and learning thus earning the admiration of many influential roman emperors. The Roman emperor Hadrian, was one the most important admirers of Greece and during his reign many major public works were constructed that have left their mark on the city of Athens. The Hadrian Aqueduct was one such project.
The Hadrian Aqueduct was completed in 140 A.D. and consisted primarily of a underground tunnel, 25 km. long, which was constructed manually through solid rock by hundreds of slaves using simple tools such as chisels and hammers. The aqueduct was designed not only to transfer water towards the city but also to collect it through a number of smaller catchment works along the way.
The Hadrian Aqueduct began at the foot of Mount Parnitha in the area of Tatoi and transported water by gravity to a stone reservoir on the hill of Lycabettus in the city of Athens. This reservoir was referred to a Hadrian’s Reservoir and had an initial storage capacity of 500 cubic meters of water. The Hadrian Aqueduct and Reservoir were the main sources of water for the city of Athens in the years that followed. It operated without change until the time of the Turkish Occupation (which began in 1456). From this point on, the Roman aqueduct and reservoir were left to deteriorate.