The degradation of urban streams is a critical challenge for cities worldwide, often exacerbated by climate change. In Niterói, Brazil, the Itaipu Lagoon and its tributaries, such as Colibris Stream, face siltation, pollution, and riparian forest loss. This article presents and analyzes a six-year (2019–2025) community-led initiative for urban stream restoration, demonstrating a viable socio-technical model. The intervention, carried out by the organized civil society collective ‘Córregos da Tiririca,’ employed an adapted syntropic agriculture protocol to restore a narrow, degraded riparian strip. The core innovation, however, extends beyond the agroforestry technique to the social architecture that sustained it. The Collective evolved into a permanent community of practice, ensuring long-term stewardship. The experience was systematized into a four-phase replicability framework (Social Foundation; Participatory Diagnosis and Planning; Pilot Implementation and Adaptive Learning; Scaling and Institutionalizing Care). This study argues that the most significant outcome is this integrated model itself, where ecological technique and social process are mutually reinforcing. The results show significant ecological recovery along a 900-m stretch, with the establishment of a stratified forest (>70% canopy cover) and a documented return of biodiversity (194 species recorded via citizen science), all driven by collective action. Therefore, this article serves as a practical replication guide for organized civil society groups, offering a scalable strategy for urban watershed regeneration that reconciles ecological restoration with social mobilization and resilience.
Sarmento-Soares et al. (Sat,) studied this question.