Large-capacity underground structure goes into operation on the border between São Paulo and ABC, with numbers that draw attention for the stored volume, depth, occupied area, and integration into the metropolitan drainage system.
The Government of São Paulo put into operation, on December 23, 2025, the Piscinão Jaboticabal, a containment reservoir with the capacity to store 900 thousand cubic meters of water, a volume equivalent to 360 Olympic swimming pools.
The structure is located on the border between São Paulo, São Caetano do Sul, and São Bernardo do Campo and is part of the macro-drainage system of the Metropolitan Region, according to the State Department of Environment, Infrastructure, and Logistics.
Called a “subterranean lake” in the title due to its storage scale, the equipment is technically a flood detention reservoir.
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Its function is to temporarily receive part of the water volume directed by the drainage network and allow the flow to occur in a controlled manner after the peak accumulation.
The capacity of 900 thousand m³ is the main technical data of Jaboticabal.
According to the state government, the project is 13 meters deep, occupies an area of 130 thousand m², and connects the Jaboticabal Stream, near the Anchieta Highway, to the Ribeirão dos Meninos.
To assist in the removal of accumulated water, six sets of motor pumps were installed, each with a flow rate of 850 liters per second.
The investment reported by the State is approximately R$ 573 million.
The project is part of a water infrastructure package estimated at R$ 25 billion, which includes interventions in drainage, reservoirs, river depollution, sanitation, and support to São Paulo municipalities.
Dimension of Piscinão Jaboticabal
The Piscinão Jaboticabal stands out, according to the São Paulo government, for the storage volume planned in the project.
The 900 million liters reported by the State are equivalent to 360 Olympic swimming pools, a comparison used by the state administration to gauge the project to the public.
In practice, the reservoir is not a leisure area nor an open lake intended for public use.
It is a hydraulic engineering structure built to receive large volumes of water during drainage system overloads.
After temporary storage, the water needs to be removed with the support of the motor pumps installed on site.
During the start of operations, Governor Tarcísio de Freitas stated that the goal was to have the equipment functioning during the period of highest demand in the system.
“Today we are here and Jaboticabal is the largest detention basin in Latin America, with 900 million liters, equivalent to 360 Olympic swimming pools,” said the governor, according to the Secretariat of Environment, Infrastructure, and Logistics.
The governor’s statement attributes to Jaboticabal the status of the largest detention basin in Latin America.
According to data released by the State, the structure was designed to operate in an area of up to 100 km² and benefit about 1.5 million people in ABC and the São Paulo capital.
Where the underground reservoir is located
The location of Jaboticabal helps to understand the role of the reservoir within the metropolitan drainage network.
The structure is located between São Paulo, São Caetano do Sul, and São Bernardo do Campo, in a region connected to watercourses used in urban drainage.
The project establishes the connection between the Jaboticabal Stream and the Ribeirão dos Meninos, two significant points for local drainage.
This connection places the reservoir in an interface area between municipalities, which explains the regional reach attributed to the project by the São Paulo government.
The municipality of São Bernardo do Campo reported that the project is linked to the Rudge Ramos region and neighborhoods that historically face problems during periods of higher water volume.
São Caetano do Sul also associated the operation of the reservoir with areas such as Jardim São Caetano, Fundação, Centro, Santo Antônio, Cerâmica, São José, and Mauá.
Even with the impact described by municipalities and the state government, the central data of the equipment remains linked to storage capacity.
In an urbanized region with limited space for large surface interventions, detention reservoirs are used by the public authorities to increase the temporary retention of water within the drainage system.
The project also appears in long-standing discussions about infrastructure in Greater ABC.
The Intermunicipal Consortium of Greater ABC states that the Jaboticabal Detention Basin had been debated for more than ten years and was among the structural measures of the 2016 Regional Macro and Microdrainage Plan.
The project began to advance again in 2019, after meetings between regional mayors and the State Government.
How the pumping system works
The operation of the reservoir depends on the combination of storage and controlled water removal.
First, the system receives the excess volume directed by urban drainage.
Next, the sets of motor pumps perform the gradual drainage, with an individual flow rate of 850 liters per second, according to data released by the state government.
This type of operation requires periodic maintenance, according to usual practices of urban reservoir management.
Detention structures can accumulate sediments and debris carried by the drainage network, making cleaning and dredging necessary measures to preserve the operational capacity reported in the project.
SP Águas, an agency linked to the São Paulo government, performs cleaning and maintenance of 27 reservoirs in the Metropolitan Region of São Paulo.
In April 2026, Semil reported that these facilities had a combined capacity of over 4.8 billion liters and that investment in maintenance and cleaning since 2023 had reached R$ 169.78 million.
With the start of operations, Jaboticabal becomes part of this set of metropolitan structures.
The capacity of 900 million liters represents a significant portion of the temporary storage system managed by the State, according to official data released by Semil.
Investment in containment reservoirs
In addition to Jaboticabal, the São Paulo Government reported that it has invested nearly R$ 1 billion since 2023 in the construction of containment reservoirs.
Among the mentioned deliveries are the EU-09 and EU-08 reservoirs in Franco da Rocha, with a combined capacity of 268 thousand m³.
The State also mentioned TG-09, on the border between Franco da Rocha and Francisco Morato, and RA-01, known as Piscinão Antonico, next to Morumbi Stadium in São Paulo’s capital.
In the case of Antonico, the project also includes the canalization of the stream of the same name.
In June 2026, Semil reported that between 2023 and 2025, the State Water Resources Fund contracted R$ 1.17 billion in investments.
Of this total, R$ 982.2 million were directly allocated to municipalities, with resources applied to structural works in urban drainage, sanitation, loss control, and water management.
Another axis mentioned by the state government is IntegraTietê.
In January 2026, Semil stated that about R$ 22 billion had already been secured for actions to depollute the Tietê River since 2023, with investments by Sabesp planned and underway between 2024 and 2026.
In Jaboticabal, the technical set includes 900 thousand m³ of capacity, 13 meters of depth, 130 thousand m² of area, and six sets of motor pumps.
This data places the reservoir among the main containment works reported by the São Paulo government for the Metropolitan Region of São Paulo.
The state secretary of Environment, Infrastructure, and Logistics, Natália Resende, stated at the delivery that the project faced a slow pace and challenges before progressing.
“This work is very representative because it is just that. It was moving at a slow pace, with a series of challenges that we managed to overcome,” she said, according to the state government.
With the operation of the Piscinão Jaboticabal, the State now has a large-capacity reservoir in an area connecting the São Paulo capital and the ABC region.
The structure was presented by the government as part of a broader water security strategy, based on drainage, storage, sanitation, and river recovery works.
