Urban Water Supply , Wastewater , and Stormwater Considerations in Ancient Hellas : Lessons Learned

Urban water, wastewater and stormwater management practices in ancient Hellas, from the Minoan to the Roman times are briefly reviewed. In the Prehistoric Hellas palaces and other settlements tended to be located at dry places, at a distance from rivers or lakes. During the Bronze Age decentralized water supply and wastewater and stormwater management of small-scale systems were dominant. These systems are characterized by their salient architectural and hydraulic features and perfect adaptation to the environment. On the other hand, under tyranny, cities grew significantly and the first large-scale urban water infrastructures were developed. During the periods of democracy the Hippodameian system of city planning included the public hydraulic works. This period is also characterized by significant scientific progress in the hygienic use of water in public baths and latrines. Finally, Romans used the scientific knowledge and the experience of small scale constructions of the Hellenes, to construct large scale hydraulic works using sophisticated techniques.

In the long history of humankind the basic force that determined his action was the need to secure food and water.Most of the early settlements of the humankind were established in temperate areas near water sources that ensured sufficient water supply.. Most excavations of prehistoric human habitations had one thing in common; all were located near sources of a spring, river, lake or stream.During the Neolithic age (ca.5700 -3200 BC), the first water projects (such as dams and irrigation systems) were developed in Mesopotamia and Egypt, in order to control the water flow, due to the food needs (Angelakis et al., 2013).
However, the first hydraulic works for water supply and wastewater management were constructed during the Neolithic Age (a) in El Kowm (or Al Kawm), located near the city of Palmyra, in Syria, and (b) in the eastern Crete, Hellas.In these locations the first domestic infrastructures for water and wastewater were built.At the end of the 4th millennium BC to the beginning of the 3rd millennium BC the early Mesopotamian cities had networks of wastewater and stormwater drainage.Also wastewater disposal facilities, such as drainage networks, were available in the Late Urak Period (ca.3300 -3200 BC) at Habuba Kabira.Minoan regions (e.g.Crete and other Hellenic islands) and Mohenjo-Daro (in modern day Pakistan in the Indus Valley) are early examples of settlements with water supply and sanitation.These hydraulic works were developed in an impressive way since the Bronze Age (ca. 3200 -1100 BC)

Roman Hellas (ca. 31 BC -395 AD)
Many important and monumental constructions were made during Roman period in conquered Hellas, as a part of a culture based on artistic and structural features of flourishing Hellenic ancient centuries (Angelakis et al. 2013).Aqueducts that were constructed in specific sites of the country, could be classified in a separate category of the monuments of this period, being in many cases successful feats of ancient engineering (De Feo et al., 2010;De Feo et al., 2013).
Romans constructed the works to supply water to each Roman town, usually channeling the required quantities from the nearest sources, which abstained up to tens of kilometers from.The construction of the water line was different along the axis, depending on the terrain.As a basic rule, the aqueduct had to maintain a gentle inclination (0.1% or 0.2%), so that water can be transported all the way by gravity.Thus, the conduit was a shallow trench in the more parts, but wherever there were valleys or river beds, that it was constructed upon water bridges.Finally the water crossed hills, passing through tunnels.
The construction methods of surface and subterranean works were depended on soil quality of each area.In rocky soils (limestone) channels were carved above or below the surface.On the other hand, surface channels, underground channels with supported roof, or channels at shallow depths that used to be covered by stone slabs, were built wherever the soil was loose.Also, the ceramic elements were necessary structural material, and the use of mortar was required.At the construction of a water bridge, stone or ceramic briquettes were used.The bridges were consisted of columns that need to support the conduit, at distance of about 5 m, forming arches.many cases, Roman aqueducts supplied more water than the amount necessary for their daily needs, because the water was also used for hygienic reasons.The bath for instance was a daily habit for Romans.Thus, many Roman public baths have been discovered in the central districts, such as the hypocaust in the basement of the Russian Church in Athens or in regional agglomerations (Rafina), even in rural areas or islands such as the town of Sami in Kefalonia.In any case, the water was available at the place of use through distribution systems, including piping and tanks at the end or along the route of the aqueduct.Furthermore, in some cases there was tank near the springs in order to control the pressure.
In Hellenic land, there are several Roman aqueducts and the most important are those of Corinth, Nicopolis, Mytilene, Patras, Thessaloniki, Eleusis and Athens.In addition, the aqueducts of Kavala and Halkida, which repaired during the Ottoman occupation, were constructed during the Roman period.
It is worth to examine with more detail the famous Hadrianean aqueduct of Athens.Its construction started by Hadrian, but the project completed by Antoninus (140 AD), aiming to supply water to the Roman district of Athens.This aqueduct differs totally from all other of the Roman period, because it was constructed subterranean all along its route.The Hadrianean is a project based on technology of earlier times aqueducts of Hymettus, Megara and Aegina (Chiotis & Marinos, 2012).The water flowed from Parnitha springs into the tunnel, but the aqueduct also collected underground water along its route.For this reason, it was dug under the level of the water table and the amount of collected water increased along the path.Additionally, the discharge was complemented from assistant aqueducts that carried water from other regions.So we can conclude that the Hadrianean was an eclectic aqueduct which was enriched by underground waters and spring water (Chiotis & Chioti, 2011).The main underground axis was about 20 km long (or 25 km taking into account the secondary branches).Two surface channels carried the water of Parnitha at Dimogli (Olympic Village today), where an inclined gallery had to direct the total quantity into the tunnel, at a depth of 30 m.The tunnel was constructed by wells opened at a fixed distance of about 35 m between.Some impressive construction details of the carved underground tunnel (coated or uncoated) highlight the magnificent task, such as collecting water from the walls, the mounting of the roof, and the flow rate control through local level depression or small shaft incurvation.Some of the tunnel technical characteristics are depicted in Figure 4.The water was distributed through a piping system, starting from the main tank at Kolonaki, which was filled by the supply line.Hadrianean surpassed all aqueducts of the Roman time in terms of operation and construction.This is confirmed by the fact that the aqueduct was in use until 1930, for Athens water supply.However, its operation was not continuous over the centuries, as it was repaired and expanded before being restarted, after the end of Ottoman rule (early 20th century).It is still in use until today, watering the public land areas that the tunnel runs through.

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Figure 4. T walls a . Archaeological and historical evidences, revealed a cultural explosion