Water Dynamics in an Infiltration Trench in an Urban Centre in Brazil: Monitoring and Modelling

Infiltration trenches are compensatory techniques that consist of a reservoir filled with granular material. Their function is to store and infiltrate runoff water generated by rainfall. The objective of this work was to evaluate the hydraulic performance and model the water dynamics of an infiltration trench installed in the city of Recife, Pernambuco, Brazil. For each event, the response time of the infiltration system, the percentage of the infiltrated volume and the dynamics of water storage processes were analyzed as a function of rainfall events. The Puls method was used to model the events. The monitoring data demonstrated that the infiltration trench had a positive performance, infiltrating a large part of the drained volume, even with system overflows. The analyzed events presented an average emptying time of 6 days. The infiltration trench achieved its objective of decreasing the volume drained on the surface. The application of the Puls method in simulations of the monitored events showed satisfactory results in the statistical criteria coefficient of determination, deviation ratio and coefficient of residual mass, obtaining efficient adjustments, apart from a few exceptions. This study allowed us to prove the positive contribution of the trench to the water budget.