Drenagem urbana e soluções baseadas na natureza : estratégias para o controle de alagamentos em João Pessoa, Paraíba

Abstract

The intensification of urbanization and the increase in soil impermeabilization have amplified the occurrence of urban flooding. This research analyzed how urban drainage is addressed in the normative instruments of the municipality of João Pessoa, Paraíba, evaluating the potential for incorporating sustainable measures based on Nature-based Solutions (NbS) as a complementary strategy to mitigate the hydrological impacts associated with flooding events. The study combined documentary analysis of municipal legislation, interviews with two public managers, and hydrological modeling using the Storm Water Management Model. The empirical application was conducted in the Torre neighborhood, where critical rainfall scenarios were simulated with the implementation of permeable pavements and rain gardens in 50% of the analyzed impermeable area. The results indicate that, although there are instruments related to sanitation and climate adaptation, sustainable drainage is not yet fully institutionalized in the municipality. The interviews revealed technical recognition of the importance of NbS, but also pointed to normative, financial, and institutional barriers. The modeling indicated a significant reduction in the maximum water depth and accumulated volume. Regarding the maximum accumulated volume, Section 2 presented the most expressive result, with a reduction of 82.7%, suggesting greater sensitivity to the implemented interventions. This behavior indicates that the adopted measures acted efficiently in retaining and infiltrating water at the source, delaying surface runoff. Concerning maximum water depths, Section 1 showed the greatest reduction compared to the other sections, reaching 33%, which may be associated with hydraulic limitations of the inlet structures present at the site. Regarding the emptying time, Section 2 also showed the greatest reduction (17%). The more modest results suggest that the final runoff remains conditioned by the structural capacity of the existing drainage network. In other words, drainage efficiency continues to be limited by the installed infrastructure. It is concluded that the implementation of NbS is feasible and necessary; however, it depends on legislative advances, intersectoral integration, and the strengthening of specific public policies for sustainable urban drainage.