20 January 2025
Vila Sahy: a protection barriers and landslide mitigation project to address a global hazard with innovative solutions
Landslides, intensified by climate change and urbanization, demand innovative mitigation strategies like Maccaferri's solutions, showcased in Brazil's Vila Sahy disaster recovery.
In the face of growing urbanization and climate change, which exacerbates extreme weather events, landslides pose a severe hazard on a global scale, driven by intense rainfall, seismic activity, and human activities that destabilize slopes. Each year, landslides cause thousands of fatalities, especially in areas with inadequate infrastructure and mitigation strategies. According to the figures collected by the World Bank, landslides affect over 4.8 million people globally every year, incurring economic losses estimated to be in the billions of dollars range, while data from the International Disaster Database shows that between 1998 and 2017, landslides killed approximately 18,000 people worldwide, with substantial impacts across Asia, South America, and parts of North America.
Among the example of some of the most disastrous events there is the Vila Sahy one, a neighborhood in São Sebastião, São Paulo, Brazil, which experienced one of the deadliest landslides in the country’s recent history during the Carnival festivities in 2023. Triggered by record-breaking rainfall, the landslide claimed over 60 lives and highlighted the urgent need for robust landslide mitigation strategies in Brazil’s high-risk areas. In less than 24 hours, some regions on São Paulo’s northern coast received an unprecedented 627 mm of rainfall, making it one of the most intense rainfall events ever recorded in the country within such a short span. This tragic event drew attention to the need for effective landslide mitigation strategies, particularly in vulnerable coastal regions frequently subjected to intense storms and rainfall.
In response to the Vila Sahy landslide, Maccaferri was instrumental in providing solutions to attend a comprehensive mitigation project tailored to the region’s unique environmental set up, which is characterized by steep hillsides that are naturally prone to instability, especially under conditions of heavy rainfall. Furthermore, the soil in the area is often loose and lacks the depth and cohesion needed to handle excessive water. The project included a combination of static and dynamic barriers specifically designed to protect the community from future landslides and debris flows, involving the use of gabion barriers to mitigate the mudflow, some Reno Mattresses that were laid along the channels to prevent erosion, MacMat to protect the slope surface, enhancing soil cohesion and reducing erosion risks over time, Dynamic Barriers to absorb and dissipate energy from fast-moving debris flows, offering a proactive solution to contain and redirect landslides, as well as Water Channeling Systems, to create an effective drainage system.
Maccaferri’s approach to landslide mitigation intervention offers significant advantages over conventional strategies: the use of natural and durable materials promotes environmental integration, allowing vegetation to regrow and ecosystems to adapt around the installed structures. This combination of adaptability and resilience makes it possible to build these defenses quickly and with minimal environmental disruption. The design also prioritizes rapid installation, which is critical in emergency response scenarios, where speed can save lives. The Vila Sahy project serves as a model for similar high-risk areas worldwide, demonstrating how engineering innovation can help communities mitigate risks, reduce fatalities, and build resilient infrastructures that protect lives and livelihoods.
Technical Highlights Box:
• Gabion – 3166 m³
• Reno Mattress – 2310 m²
• Macmat HS – 2750 m²
• RB 2000 Barrier – 2800 m² (10 Barriers)
• Debris Flow Barrier – 156 m² (2 Barriers)