This paper presents a project solution for the construction of a public sewage system for both sanitary and stormwater drainage for the settlement of Ćunski, located on the island of Lošinj. The project envisions the construction of a separate sewage system, aiming to divert stormwater and sanitary sewage through two distinct systems. The construction of the sewage system is expected to significantly improve the quality of life and have a substantial impact on environmental protection. Spatial planning documents and information from the Mali Lošinj tourist community were utilized to design the sewage system. The introduction outlines the geographical, climatic, geological, and hydrogeological features of the settlement's location. The spatial planning documentation, which serves as the basis for the project solution, is presented. Subsequently, both the existing and the new drainage systems are described. The entire construction process is detailed, from trench excavation and installation of all sewage network components to backfilling and system commissioning. The characteristics and installation methods for all sewage system elements are thoroughly detailed. The software "Urbano Canalis 10," developed by StudioARS d.o.o., was used for creating a site plan of the new sewage system and conducting hydraulic calculations. Based on network object data, static calculations for collectors, pump station dimensioning, and pump chamber design were conducted. Using excavation data obtained from "Urbano Canalis 10," along with information about materials and transport, an approximate cost estimate was compiled. The paper concludes with graphical attachments illustrating: the system layout, longitudinal profiles, a characteristic trench cross-section, details of cascade and inspection chambers, details of adjusted cascade and inspection chambers, and a detail of a chute with a bypass tunnel, pumping stations, drains, and oil and grease separators.