This paper provides a preliminary design of a water supply system for a part of the town of Labin. The water supply system is a combined system, it is a combination of a thrust and gravitational system with a water tower. The water is pumped from the water-intake with the help of a pump station to the water tower, subsequently the water descends by gravity and supplies the population. All the piping in the water supply network (supply and delivery) are made of cast-iron, and the network itself is divided into three segments. Segments 1 and 2 provide to the population and tourist objects (two hotels and a camp), segment 3 provides to the population and the industrial area. Hydraulic analysis was done with the aid of the software WaterdCAD V8i and Urbano Hydra. In addition, an analysis was made for conditions with and without fire. For the town of Labin the possibility of two simultaneous fires in residential areas and a fire in the industrial area were defined. Accordingly three different scenarios have been made. The first scenario is made in case of one fire, the second scenario simulated the occurrence of two simultaneous fires, while the third scenario was made with two simultaneous fires and a fire in the industry. Upon completion of the analysis a comparison between results was made. Within the WaterCAD V8i software graphs were created for variability in flow capacity, velocity and working pressure inside the water supply system, and within the Urbano Hydra longitudinal and transverse profiles were drawn up.