The theme of this final work is the preliminary solution for the drainage of the waste water of the Jarek Donji settlement with the first degree of purification. There is currently no quality sewerage system for rainwater drainage, which is one of the disadvantages of communal infrastructure in the area. Therefore, precipitation waters from a specific area are drawn to the pipeline and collector system by the nearby water treatment plant and further to the drainage of the river Krapina. Also, as a hydrologic feature of the observed basin, made through the budget, graphs of the ITP curve for the area of the Zaprešić basin, namely the Jarek Donji settlements on which a model system for rainfall drainage is planned. During the work, a digital ortho photo map (1 : 5000) of the larger Zaprešić area was used, as well as other accompanying features with the images. The final work contains an overview of the drainage system model and the hydraulic calculation of sewerage system made in the Urbano Canalis software. The graphs show the situation on the substrate used, the longitudinal and individual transverse profiles of the sewage system, the datasheet and excavation calculations. The final work was done with the help of the software Urbano Canalis and Auto CAD, which executed the calculations and the drawing of individual pictures and drawings.