This paper describes a hydrological-hydraulic analysis of stormwater runoff in the area of the Kukci. The aim of this paper is to analyze the areas of flooding in the area of Kukci in Poreč-Parenzo and, based on this, to assess the impact of the implementation of two different approaches to flood mitigation. One solution is the construction of retention, and the second solution is the implementation of LID elements for the purpose of returning the hydrological regime to the natural state of the catchment area. The QGIS program was used to create the basic model, determine the characteristics for each sub-basin and georeferencing part of the urban development plan of the Kukci area. The obtained data were then used for the hydrological-hydraulic analysis carried out in the SWMM program. In the SWMM program, 5 different models were created, and for each model a hydrological-hydraulic analysis of stormwater runoff was performed. The first model describes the natural state (zero built-up), the second model the current state of the Kukci area (with an implemented classic storm drainage system) and the third model describes the future state (with an extended classic storm drainage system). Furthermore, the fourth model refers to the future state with predicted retention and the fifth model to the the future state with the implementation of LID elements. The results points to the problem of the classic storm drainage system for intense rainfall. Additionally, the implementation of retention and LID elements resulted in reduced amounts of flow in critical locations.