Diagnostic approach of the drinking water network based on a hydraulic simulation model: Case study of the pressure stage 85 of the Greater Casablanca (Morocco)

Geographical Information Systems (GIS) and hydraulic models are decision support tools for intelligent, fast and efficient management of drinking water supply systems, particularly for diagnosing the functioning of water supply networks. In this work the software Arc-GIS was coupled with the hydraulic model EPANET 2.0, and applied to a case study area, Pressure Stage 85 of the Greater Casablanca, located in the West-central part of Morocco, at the edge of the Atlantic Ocean. This pressure stage is in the center of the Greater Casablanca and consists of three pressure sub-stages (85 Non-Modulated stage (85 NM), 85 Modulated stage (85 M) and 85 industrial stage (85 IND)). It has an overall linear form of about 1308 km (about 18% of the total network) with heterogeneity in age and type of pipes. The floor distributes a volume of 170,000 m³ / day, i.e. one third of the total volume distributed to the Greater Casablanca network. It is also characterized by a spatial heterogeneity of habitats (domestic and industrial areas) with a significant variation in topographic scores ranging from 0 to 85 m. The results of this work have shown that a coupling between a GIS and a hydraulic simulation model provides the drinking water system managers with efficient and rapid responses to better understand and analyze network malfunctions. This study permitted the modelling of the network hydraulic behavior during different periods of the day and identified the variation range of velocity in the network, to locate the areas with high pressure (> 5 bar) and the zones sensitive to leak's appearance. The analysis of these results allows us to recommend the installation of five pressure regulating valves at specific locations. The combination of GIS and hydraulic models as a management and performance tool helps the operator in the assessment of the reliability and the state of existing networks, to analyze and study solutions to problems and to plan and test the various scenarios for future management.