Evaluation of the effect of soil type on the infiltration trench clogging: a long term approach

In recent years, limitations linked to traditional urban drainage schemes have been pointed out and new approaches were developed introducing more natural methods for retaining and/or disposing of stormwater. Such practices include infiltration and storage tanks in order to reduce the peak flow and retain part of the polluting components. The impact of such practices on stormwater quantity and quality is not easily assessable because of the complexity of physical and chemical processes involved. In such cases, integrated urban drainage models may play a relevant role providing tools for long term analysis of infiltration structures efficiency. In this study, the effect of the clogging phenomenon has been assessed by means of a long term modelling approach. In particular, a simplified conceptual modelling approach for the simulation of the infiltration trenches has been worked out. The analysis has been applied considering different soils as well as different design criteria. Particular care was addressed to the simulation of infiltration structures considering performance reduction due to clogging phenomena. On the basis of a long-term simulation of 6 years rain data, the performance as well as the effectiveness of an infiltration trench measure are assessed. The study confirmed the important role played by the clogging phenomenon on such infiltration structures.