Modelling impervious pavements with the Low Impact Development module of the Storm Water Management Model

Abstract

During the last few decades, resolution for hydrologic models has increased considerably. In addition, the growing development of Sustainable Urban Drainage Systems (SUDS) has led to the implementation of new parameters and modules in those models. For example, Storm Water Management Model (SWMM) implemented the Low Impact Development (LID) module, which is designed to model SUDS techniques. However, hydrological modelling with the LID module presents relevant differences from the general SWMM model procedure. This research proposes a new approach for modelling the hydraulic response of impervious pavements in urban areas, based on the model provided by the SWMM LID module, instead of the general model. Results show that, when modelling with the SWMM LID module, it is possible to obtain runoff hydrographs that match those obtained by the general SWMM model, modifying just one parameter: the pavement permeability. This approach would be useful to compare alternatives that can be implemented in a given area by modifying only one model parameter. It would be possible to switch from pervious to impervious surfaces without changing the model itself.