São Marcos Dam Downgraded After Controlled Lowering and Repairs

Overview

• The incident began after heavy rain on Wednesday that dumped about 174 millimeters in 24 hours and led Corsan Aegea to find fissures with visible leaks in the spillway and parts of the buttress.
• Corsan activated its Emergency Action Plan and the Defesa Civil sent a Cell Broadcast warning, prompting the preventive removal of roughly 170 people from about 60–75 buildings and the suspension of a nearby school.
• Teams used the dam’s bottom discharge and multiple pumps to lower the reservoir and specialists including divers inspected and began filling cracks with sealant, and Corsan reported on Friday that tests showed no structural movement.
• Despite the downgrade from emergency to a safer operating zone, pumps are still running, technical monitoring and alert levels remain active, and many families are staying with relatives or in hotels supported by the company.
• The Barragem Arroio São Luiz is a roughly 50-year-old municipal reservoir that holds about 250,000 cubic meters of water, so authorities say the risk is geographically limited to homes next to the dam and the Rio Jaguari but warn that expert laudos and weather forecasts will determine when people can safely return.