Effects of LID Implementation on Hydrological Processes in an Urban Catchment under Consolidation in Brazil

The increase of urban areas with high population concentration in small spaces in developing countries such as Brazil brings serious social and environmental problems. Based on this reality, simulations of four different urbanization scenarios were carried out: the current scenario, the future scenario made highly impervious by the occupation, the possible scenario with the insertion of LID (low-impact development) structures and zoning measures, and the planned scenario with territorial planning. In this respect, both real rainfall data and design storm data were used to test LID through a calibrated hydrological model. The expansion of urban occupation from the current scenario to the future caused a 16% increase in the volume of output hydrographs of the catchment under analysis. The insertion of LID structures and zoning measures decreased the surface runoff volume by 13.8%, from the future scenario to the possible. For real rainfall data, the hydrographs had their peaks retarded with the insertion of LID structures and occupancy control measurements. The performance of the LID structures was higher with lower total rainfall.