Developing a Geographical Information System for a water and sewer network, for monitoring, identification and leak repair - Case study: Municipal Water Company of Naoussa, Greece

Abstract: This thesis presents the design and implementation of a Geographic Information System (GIS) for the Naoussa Municipality Water and Sewer Company for better water utility management. The methodology contained field data collection like the valves, sewer manholes, hydrometers, and hydrants in two ways, UAV photogrammetry, and traditional surveying, the georeferencing process, photogrammetric processing, the digitization of old paper maps and the geodatabase design. Moreover, the thesis investigates the resulting accuracy from the application of classical topographic methods in relation to that of UAV photogrammetry for mapping and collecting data on valves, hydrants, hydrometers, pipes, and other water utility infrastructure. The products produced from the use of such systems are characterized by high-precision results. Accuracies ranging between 0.15 - 0.29m have been achieved. The classical survey method gave more accurate results when compared with those produced by the UAV method. By using 85 GCPs, an accuracy of 4.5cm was achieved in the final orthophoto. Three indicative network management scenarios are implemented within the GIS environment. With these scenarios, the possibilities of managing the network are highlighted in terms of the coherence and integrity of the data, but also in terms of the introduction of new objects in the network and finally in terms of the network analysis possibilities that can be carried out by GIS. This thesis tries to present and analyze the advantages and possibilities presented by GIS concerning urban water supply networks. It shows how a GIS can help the water company in its everyday work. Using GIS to manage the water company’s utility data has allowed more flexibility over the previous analog system when analyzing data, and the management of the water network is more efficient. Keywords: Water and sewer network, GIS, UAV, surveying, photogrammetry, orthophoto, geodatabase