Six pumps worked nonstop, but were unable to prevent flooding that left 28 vehicles submerged in the SP tunnel

The six pumps installed in the Vale do Anhangabaú Tunnel, in the center of São Paulo, worked uninterruptedly during the storm on Wednesday (14), but were not enough to prevent the flooding that left 26 cars and two buses submerged.

According to the City of São Paulo, the equipment did not present any failures. However, the system's drainage capacity was surpassed by the volume of water that reached the region in a short period of time.

In just 40 minutes, the equivalent of what was expected for 11 days of October rained in the Anhangabaú stream. 42 millimeters of rain were recorded, corresponding to 37% of the 112 millimeters forecast for the entire month in the capital.

The force of the water turned the tunnel into a completely flooded area. Images recorded by drivers show vehicles covered in water up to the windows and people trying to get out of the cars.

"We saw water entering the tunnel and within five minutes the water reached the car door. As a result, we had to get out of the vehicle", reported a driver who was at the scene.

According to the Traffic Engineering Company (CET), the tunnel closures began at 3:38 pm, after the adoption of the State of Attention protocol for rainy days.

The city hall reported that the drainage system is monitored 24 hours a day, using sensors and cameras. Despite this, the amount of water that reached the tunnel exceeded the flow capacity of the pumps.

An emergency pumping truck was mobilized to reinforce drainage. Urban cleaning teams were also called in to work in areas where the water level had already dropped.

After the water receded, the people who were trapped in the tunnel were rescued. Initially, the Fire Department reported the existence of at least four victims, without detailing their health status.

Wednesday's flooding was not the first to hit the Anhangabaú Valley Tunnel.

In 2021, heavy rain also caused the flooding of one of the lanes towards the South Zone. In 1999, a major episode left around 160 vehicles submerged in the region, including three buses.

Since the 1980s, different urban interventions and drainage works have been carried out or announced to try to reduce flooding around the valley.

Among them are the recovery and expansion works of the Moringuinho stream galleries, which began in 2006, and the construction of new galleries announced in 2007.

More recently, in May 2026, the City of São Paulo published a proposal for intervention in the drainage system in the Avenida Nove de Julho region, with the aim of reducing flooding that affects the Center, including Vale do Anhangabaú.

Wednesday's rain also caused flooding in other areas of the city. In Brasilândia, in the North Zone, a resident died after her house was hit by a landslide.

According to the Climate Emergency Management Center (CGE), the Sé meteorological station recorded 48.5 millimeters of rain, the highest accumulated among the agency's stations.

In the Alto Tietê Telemetric Network, the Sapateiro stream, in Ibirapuera Park, recorded 67.8 millimeters. Parque da Aclimação accumulated 64 millimeters.

The storm was also accompanied by strong gusts of wind, which reached 88.9 km/h at Congonhas Airport, at 4:44 pm.

The forecast is for more rain this Thursday (15). The state's Civil Defense warns of the possibility of accumulations of up to 80 millimeters in Greater São Paulo throughout the day.