Analysis of risks to water contamination in Lajeado Stream as a mechanism to prevent water security in Dois Córregos (SP)

Abstract

Urbanization accompanied by population growth has brought with it environmental impacts such as soil impermeability and the occupation of permanent preservation areas. In addition, it has intensified urban flooding, soil erosion and river silting. The objective of this study was to analyze the risks of water contamination in the Lajeado Stream as a subsidy for water security in Dois Córregos (SP). To this end, the methodology was based on the identification of risks in loco and documentary analysis. The risk prioritization matrix tool was applied, according to severity and probability of occurrence and cataloged into constructed, natural, social and productive risks (matrix from 0 to 20). The risks were classified as serious (risk 16) and very serious (risk 20) ​​and refer to changes in the watercourse, soil impermeability, disposal and accumulation of solid waste, presence of irregular occupation/constructions in the surroundings and specific points with erosion processes along the watercourse. The study shows that urban expansion in Dois Córregos changed the Lajeado Stream and caused environmental impacts in several points, such as erosion processes on the banks, silting of the bed, absence of Permanent Preservation Areas (APPs), accumulation of solid waste along the analyzed stretch, in addition to the lack of urban planning. The priority recommendations are socio-environmental awareness, environmental monitoring, improvement of the drainage system and urban cleaning services, preparation of projects aimed at implementing green infrastructure and raising financial resources.