In the current era, the digitization of geographical data is a transverse need of several engineering sectors, including the hydraulic networks management. Thus, water supply systems' modelling requires adequate tools in both the digitization and the simulation phases. This paper presents the QEPANET plugin, which aims at merging the flexibility of QGIS and the robustness of EPANET hydraulic simulations software. Several editing and graphical tools available with QEPANET are introduced to model new and existing water distribution systems, to read and modify existing text-based EPANET files, to run simulations and visualize results in a geo-referenced framework. In addition, an application is illustrated to underline the novelty and the practical functionality of the presented tool, such as 3D pipe lengths' automatic calculation and the supporting functionalities for the network drawing. The plugin is available via the official QGIS Python Plugins Repository and on the world-wide-web at https://gitlab.com/albertodeluca/qepanet.