This thesis uses a model-based approach to finding optimal positions of flow datasensors in a water distribution network (WDN). Flow data sensors can be used toidentify and localize leaks in a network that lead to significant losses of both water and energy. A simple hydraulic model of a WDN was constructed as well as a graph theoreticdescription of the network. A framework for describing the information gained by aspecific sensor position was developed and used to formulate the sensor placement asan optimization problem.Two algorithms were constructed for finding the optimal placements under differentassumptions of the network. Three smaller networks of different complexity wereconstructed and on which the two algorithms were tested.The results show that a model-based approach indeed can be used to find optimalsensor placement under different assumptions of the system at hand and that theframework can be used not only for placement, but also for localization of leakspresent in the network.