Modelling water quantity in low impact development solution for stormwater management in residential area: a case study

D.J. Carvalho1*, M.E.L. Costa1, C.S. Conserva2, L.M.S. Andrade2, S. Koide1

1 Civil and Environmental Engineering Department, Faculty of Technology, University of Brasília, Brasília, Brazil;
2 Faculty of Architecture and Urbanism, University of Brasília, Brasília, Brazil;
* e-mail: d.junqueirac@gmail.com

Introduction

Conventional solutions for stormwater management have been causing a series of problems to the environment and the urban population. These solutions include designing a drainage system with large conduits that aim to rapidly convey the water away. However, due to the large volume of runoff generated by the surface impermeabilization and the presence of pollutants, problems such as flooding and diffuse pollution of the receiving water bodies often occur. In Brazil, despite the studies that show that this type of structure is outdated and that there are more modern technologies that can be applied to minimize the impacts, the traditional approach is still used in the design of new stormwater systems (Souza et al. 2012).

Low impact development (LID) solutions are a sustainable alternative to stormwater management that have various benefits, including the reduction of runoff volume, the increase of infiltration and possibly the enhancement of the water quality. There are different types of LID practices, for example, rain gardens and infiltration trenches, but all of them require proper planning and integration with the urban design. In the study of the application of LID solutions, modelling has been shown to be a useful tool, being performed to quantify the practice’s benefits (Shamsi 2010; Méndez 2018). Thus, this study aimed to compare the performance of a traditional and a low impact development solution in terms of water quantity by hydraulic and hydrological modelling.