Water supply networks in Roman period- The case of Athens

The Hadrian's Aqueduct is a project that dates almost 2000 years from the completion of its construction. The external aqueduct of the project still has the ability to transport water from the springs of Parnitha, to the city of Athens. It has been studied enough to know many things about its operation. On the contrary, in the second part of the Hadrian's Aqueduct, the distribution network within the city remains a completely unexplored until now field. Given all the above, this diplomacy examines this little-studied, internal network. In addition, the Pompeii network is considered as a second case of a Roman internal water supply network. In this way, this text lists two Roman internal water supply networks that differed significantly, since the first operated by gravity flow and the second by pressure flow. It turns out, however, that the basic points of their operation and their arrangement are common. It is also concluded that these networks covered the needs of the cities by operating with constant flow, without any existence of storage. In the first two chapters there is a review of the evolution of hydraulic science and technique over the years and among different cultures. Furthermore, it is presented what is prevailed in relation to the water supply of ancient Athens, before the construction of the Hadrian's aqueduct. In addition, there are presented the basic elements of the Roman baths, since it is the most important recipient of the Roman distribution networks, which did not exist before. In particular, Section 2.4 lists the key features of the Pompeii distribution network, as highlighted by the oversupply of archaeological finds. At the end of this section, using the equations that apply to the lead pressure pipes of the city, flow rate through a series of pipes and water supply received by some costumers, have been identified. In this way, it turned out that one of the largest Roman baths, the Stabian, with an area of 2400 m2, consumed 271000 L per day. Because the distribution network of Roman Athens has not been studied at all, it was necessary in Chapter 3 to gather all the findings related to the hydraulic works of Hadrian within the city. These findings were classified based on their common characteristics. Additionally, they were placed in Google Earth, using the addresses where they were found which are included in the archeological excavations. From the characteristics of findings, it is concluded that, in the network of Athens, the flow was gravitational. They were performed in closed sections with free surface. Also based on the findings, the distribution networks of the two cities, Athens and Pompeii, although they are significantly different, they both followed the standard arrangement of Roman internal water systems. In the last chapter, the Google Earth database was converted to a raster file for display in a GIS environment. At the same time, with input data of the Digital Terrain Model of Attica, vector and raster files were produced, necessary for the understanding and the analysis of the gravitational flow of the network pipelines. Thus, in this chapter the three main branches that carried water from Lycabettus to the outskirts of the city and the branching of one of them in the area of Hadrian's extension, is depicted. At the end of the chapter, through the Manning equations that apply to pipelines with free surface, flow rate Q (L/s) and velocity V (m2/s) were calculated in some cases were calculated. The flow within them, as it turned out, was subcritical.