The thesis presents several conceptual designs of sewer systems and wastewater treatment for settlements in municipality Radovljica, where it is not taken care of wastewater drainage. Main focus is on the left bank of river Sava, settlements Dvorska vas, Zgornji Otok, Spodnji Otok, Mošnje, Črnivec, Brezje, Dobro Polje, Ljubno and Posavec. The connections between the settlements were analysed according to longitudinal profiles. The results show there are a lot of pumping stations needed with long distances of pressure pipelines. Therefore three, technical and economical better, conceptual solutions of sewer systems are presented. First sewer system connects settlements Dvorska vas % Mošnje, second one Črnivec % Dobro Polje and third one Ljubno % Posavec. All three systems are dimensioned with two possibilities of water treatment plants for each sewer system % common water treatment plant or separate water treatment plant for each settlement. For chosen conceptual solutions, economical analyses of separate water treatment plants and common water treatment plant are made. To dimension sewer system Dvorska vas - Mošnje program SEWER+ has been used.