Gestion d’un réseau d’eau potable en milieu alpin ; modélisation du réseau, projections climatiques et stratégies d’adaptation

The impact of global warming on drinking water networks is becoming more and more important. Water distributors must adapt as soon as possible in order to anticipate the different hazards. A better understanding of their network, as well as of the different problems to come, must be acquired in order to plan adequate adaptation strategies. This project is composed of two parts; the first one focuses on the modeling of the drinking water network of Lourtier, located in the upper part of the Val-de-Bagnes. In order to improve the under- standing of its behavior, the objective was to be able to model the chlorine injections in the network. This modeling can also be used for an optimized disinfection of the network. The second part focuses on the impact of global warming on drinking water networks, more precisely those located in alpine environments. Some adaptation options are discussed, and a resilience analysis of a drinking water source is performed, which is used for planning adaptation strategies. We were able to validate the modeling of a large part of the drinking water network, with a corre- lation of 99.95% between the measured and modeled pressures. Chlorine modeling has been performed and shows good results (99.3% correlation between measured and modeled concentrations), but more measurements will have to be taken to validate this model. An application of this model will be very useful for water distributors, allowing them to better estimate the location and the quantity of chlorine to use during a disinfection of the network. We were also able to validate the hydrological model of the analyzed water source. This allowed us to see the future trends of the outflow of this groundwater source ; shift of the peak flow due to the early snowmelt, decrease of ≃10% of the monthly flow by the end of the century during the summer period and appearance of more important low flows in summer. All this allows us to see the importance of research in the fields of modeling and resource management, and also the need for water distributors to adapt as soon as possible, in order to have an intelligent and sustainable management of their entire network.