Urban Floodplain Park in Perus River Watershed, São Paulo - Brazil: Concept and Desing Criteria (PAP014742)

Código

PAP014742

Autores

Aluisio Pardo Canholi, Melissa Cristina Pereira Graciosa, ADRIANO RICARDO ESTEVAM, Roberto Falanque, Gustavo Coelho

Tema

Flood risk management in mega cities

Resumo

Perus is a 146.000 inhabitants district located in the North Region of São Paulo city, within the Juqueri River basin. Perus River, a tributary of Juqueri River, has a 28 km² watershed, which area is in process of urban expansion and, therefore, flood occurrences are increasing in frequency and severity. Large amounts of green areas in the upstream part of the basin allow the adoption of detention measures in order to protect the downstream urbanized area, to avoid the urbanization of the floodplain and to promote flood control and sustainable urban development in long term sceneries. This paper shows the application of a combined methodology that considers both flood control, city planning and landscape architecture concepts to develop an efficient, suitable and feasible solution for such a complex urban area. Althoug located within the limits of the largest city in Latin America, São Paulo, the Perus River watershed has about 50% of its floodplain preserved. However, this preserved area is under high pressure of urbanization, due to its location and the lack of urban area available in the city. The lower and the higher parts of the watershed are preserved, whereas the middle part is totally occupied by the urbanization, mainly residential. The project was developed according to Upper Tiete River Basin Masterplan (DAEE, 2009). Its objective was to promote flood control in Perus District downtown, by integrating hydrological goals with city planning and urban landscape architecture. The main challenge was to manage several demands e interferences, as well a large number of stakeholders, in order to guarantee the project could be implemented. Hydrological and hydraulics simulation were performed in order to obtain the hydraulic deficits and the necessary detention volume that could allow the channel to transport the 100-years flood. Than, the detention basins were sized and desingned considering, as well as possible, the natural configuration of the terrain and gravity operation. The studied area was divided in 5 subareas, so called Nucleus. The Junction of Perus River with its main tributary, Areião River, called Nucleus 1, was planned to receive the main urbanistic and park elementes. Nucleus 2 enhanced the Areião River watershed and also contains urbanistic and landscape elements. Nucleus 3 is located in an environmental protection area and encompasses the 550.00 m³ detention basins, gravity operated. Nucleus 4 and 5 encompass the downtown of Perus District, where channel are confined between the railway and an avenue. This reach of the river defined the maximum allowed discharge that should be attended by the detention structures upstream. Floodplain parks represent a city planning solution that combines flood protection and urban landscape architecture, by providing integration between hydrological elements and urban development. In São Paulo city, the lack of areas for urban growing put the remaining floodplains in constant risk of occupation. Perus District has one of the last non occupied floodplains of the city and the Municipal Government initiative of implementing the project described is innovative and provides both flood protection and green recreation areas for local population.