Methodology for defining the design storm for sizing the infiltration system

A methodology aimed at defining design storm for sizing infiltration systems, as a part of the stormwater management according to the low impact development approach, is presented in the paper. The proposed analyses are based on numerical models for simulating the runoff and discharge of rainfall into infiltration systems. Preliminary design-storm curves for Rijeka are developed, and results of the numerical model sensitivity analysis are presented. An example of the infiltration system design is also shown. The importance of successive analysis of different durations of rainfall, so as to define a critical design situation, is emphasized