The mayor of São Paulo, Ricardo Nunes (MDB), stated this Wednesday (14) that municipal management teams are working to reestablish circulation in the Anhangabaú Tunnel, in the center of the capital, after flooding that left cars and buses submerged during the heavy afternoon rain.
In a post on Instagram, at 6:30 pm, Nunes said that the volume of water was raised in a short period of time and that teams from different areas were mobilized to work in the region. At 7:14 p.m., a left lane was reopened.
"It was a really large and unexpected volume in a very short period, but we are here working to completely restore the city," he said.
According to the mayor, cleaning, hydrojetting, winching and pumping teams were mobilized to work in the affected areas. He also said that the tunnel was paralyzed in the South-North direction and that work sought to unblock the passage in both directions.
Cars piled up after flooding in the Anhangabaú tunnel, in SP — Photo: Reproduction/TV Globo
According to the city hall, 42 millimeters of rain were recorded in 40 minutes in the Anhangabaú stream region. The volume corresponds to 37% of the 112 millimeters forecast for the entire month of October in the city.
In the video, Nunes stated that it rained around 40% of the expected precipitation for the month.
There is a protocol to close the tunnel when there is a threat of flooding. This Wednesday, however, the road towards the North Zone was not closed before the flooding.
In a note, the Traffic Engineering Company (CET) informed that it adopted, on Wednesday afternoon, the State of Attention protocol planned for rainy days and that the closures in the Anhangabaú Tunnel began at 3:38 pm.
The images recorded, however, show that, with the rise in water levels, vehicles were bumped and overlapped. The horns of some cars went off during the flooding and chaos ensued inside the tunnel (see below).
Drainage pumps
The city council also informed, in a statement, that the Anhangabaú Tunnel has six drainage pumps, which operated uninterruptedly during the episode, with no problems reported.
According to the municipal administration, the system's flow, however, was not sufficient given the volume of water recorded.
The city hall also stated that the drainage system is monitored 24 hours a day using sensors and cameras. An emergency pumping truck was sent to reinforce the removal of water, and urban cleaning teams began to work in sections where the level had already dropped.
Chaos in the Anhangabaú Tunnel after heavy rain in the capital of São Paulo — Photo: William Santos/TV Globo
Cars and buses were submerged
Images taken by drivers show dozens of vehicles with water up to the windows inside the Anhangabaú Vale Tunnel. There are records of people clinging to cars to try to escape the flood and partially submerged buses.
As the water level rose, vehicles were bumped and overlapped. The horns of some cars went off during the flooding.
"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," he said.
Initially, the Fire Department reported that there were at least four victims in the incident, without specifying whether they were dead, injured or people awaiting rescue. Two vehicles were moved to the scene.
After the water level dropped, people who were trapped in the tunnel began to be rescued. TV Globo recorded the moment when some of them were removed in a fire truck.
History of flooding in Anhangabaú
The Anhangabaú Valley, in the center of São Paulo, has already undergone different interventions to try to reduce flooding in the region. In the 1980s, the valley's reurbanization project also sought to solve the floods that interrupted the road connection between the north and south regions of the city. The works began in 1986, during the administration of Mayor Jânio Quadros and continued during the following administration.
In 1991, during the administration of Mayor Luiza Erundina, Operation Urbana Anhangabaú was created, which provided for the raising of funds for interventions in the region, including works related to macrodrainage. The system was responsible for draining large volumes of rainwater.
Years later, City Hall announced new interventions to try to reduce the risk of flooding in the surrounding area. In 2006, work began to restore and expand the galleries of the Moringuinho stream, in the Avenida 23 de Maio region. In January 2007, the municipal administration of Mayor Gilberto Kassab announced the construction of two new galleries.
According to the City of São Paulo, the goal of the interventions was to reduce the volume of water that reached the Anhangabaú stream during rains by 15%, reducing the risk of flooding of the tunnel in the region. In September of that year, work was still in progress, according to the municipal administration.
More recently, Vale do Anhangabaú underwent new urban redevelopment. The works began in June 2019 and were delivered later, with changes to the structure and living spaces. The intervention, however, should not be confused with a definitive solution to the region's macro-drainage problems.
In May 2026, City Hall released a proposal for intervention in the drainage system in the Avenida Nove de Julho region, also with the aim of reducing flooding that affects the Center, including Vale do Anhangabaú.
Cars and buses float in the Anhangabaú tunnel during heavy rain in SP — Photo: Personal Archive
Flooding on Av. Nove de Julho — Photo: Reproduction
SP Civil Defense Alert — Photo: Reproduction
Forecast for the next few days
According to the CGE, areas of instability cause moderate to heavy rain with the potential for flooding in the early hours of Thursday (15). The weather remains unstable with short periods of improvement throughout the day.
Between the afternoon and evening, rain volumes are again expected to be more significant, with a minimum of 17°C and a maximum of 25°C.
On Friday (16), the spread of a cold front along the coast of São Paulo will cause another day with overcast skies, rainy weather and, due to the waterlogged soil, the potential for the formation of flooding and landslides in risk areas. In the afternoon, the largest amounts of rain occur, which may be accompanied by forecasts of thunderstorms and gusts of wind. Thermometers fluctuate between 18°C and 23°C.
Bandeira Terminal area, in the center of the capital, flooded after heavy rain — Photo: Personal archive
Photos from the western region of the capital of São Paulo — Photo: ALOISIO MAURICIO/FOTOARENA/ESTADÃO CONTEÚDO
