Exploring the Use of Low Impact Development Strategies in a Low-Income Settlement in São Carlos, Brazil

The challenges of applying integrated stormwater management strategies in developing countries such as Brazil are particularly complex due to economic, environmental, and wider social issues in these localities. Factors like housing deficits, real estate speculation, urban land costs, massive demand for affordable housing, and the attempt to associate economic development with environmental preservation have led researchers in the drainage field to seek different models of urbanization. In this context, the present work aims to explore the possibilities of using low impact development (LID) strategies in a low-income settlement in the city of São Carlos, Brazil for the runoff management (two-year return period). To evaluate the feasibility and hydrological performance of the proposals, three scenarios were simulated in Storm Water Management Model (SWMM): Scen.CONV, a conventional urbanization and storm sewer drainage system; Scen.WELL, a conventional urbanization associated with the use of an infiltration well to disconnect the lots; and Scen.LID, which uses vegetative swales and infiltration trenches associated with urbanistic changes such as land use/imperviousness coefficients and roads typologies. Comparing Scen.CONV with Scen.WELL, the results indicated a potential 18% reduction in the linear length of buried conduits and a 40% reduction in the number of curb inlets. In the Scen.LID, the use of combined LID strategies allowed for the source control of all of the surface runoff, excluding the need for conventional drainage systems. The results also indicated a decrease of 60% in the peak flows of Scen.CONV in comparison with Scen.WELL and of 100% in relation to Scen.LID.