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There is already a date set for the start of construction of an underwater tunnel designed to solve the mobility crisis between two Brazilian cities. With a length of 580 meters, the project promises to transform local and regional logistics, but will the financial and technological challenges be overcome in time?
On the coast of Santa Catarina, an unprecedented construction proposal promises to transform mobility between the cities of Itajaí and Navegantes.
Um mega underwater tunnel, 580 meters long, will begin to be built between 23 and 29 meters below the bed of the Itajaí-Açu river.
This project is considered one of the most daring in Brazil and promises to be the definitive solution to a historic transport crisis in the region.
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But will this ambitious project be able to resolve traffic bottlenecks and transform the local economy, as its creators promise?
To understand more about the impacts of this grandiose project and what is really at stake, it is necessary to closely monitor the progress of the project, which already has a start date: 2026.
What is Promobis and how does the tunnel fit into the plan?
This underwater tunnel is part of Promobis (Integrated and Sustainable Mobility Project), a mobility project designed to transform transportation in the region.
Budgeted at US$ 340 million (approximately R$ 2,07 billion), Promobis is not limited to the tunnel.
It includes a set of works that, if successfully executed, have the potential to transform the infrastructure of the Santa Catarina coast.
The project is the result of a public-private partnership (PPP) involving CIM-AMFRI (Association of Municipalities of the Foz do Rio Itajaí Region) and the government of Santa Catarina, with support from the World Bank.
This consortium signed a protocol of intentions in October 2024, with a contribution of US$ 24 million from the Santa Catarina government.
Engineer João Luiz Demantova, technical coordinator of the project, highlighted in recent interviews that the mobility project is a necessary advance to meet the logistical potential of the region, which is home to the second largest port complex in Brazil in terms of container movement.
Traffic problems affecting the region's economy
Itajaí and Navegantes are separated by about 350 meters of river and by a land transport network that, in practice, is far from ideal.
The distance between the two cities, which is less than 25 km, is marked by constant traffic jams.
These traffic jams affect both the quality of life of the inhabitants and the logistical flow of the region, one of the pillars of the Santa Catarina economy.
João Luiz Demantova explained that the need to overcome this logistical obstacle became clear in 2015, when the feasibility study for the project was carried out.
With the increase in traffic at the Port of Itajaí and the lack of efficient transport alternatives between the two cities, the underwater tunnel became the most viable solution.
Before deciding on the tunnel, the construction of a bridge was discussed, but height limitations due to the Navegantes airfield made this option unfeasible.
An unprecedented work in Brazil
To date, Brazil has no large-scale underwater tunnel projects.
In an interview, Paulo Bornhausen, state secretary for International Articulation and Strategic Projects, highlighted that the technology for building underwater tunnels is already a reality in Asia and Europe, with several projects being carried out on these continents.
However, in Brazil, this technology is still in the adaptation phase, which makes the project even more challenging.
The tunnel will be built using prefabricated modules that will be submerged under the Itajaí-Açu river.
According to Bornhausen, the project will not only meet the need to improve transportation between the two cities, but will also help foster regional development, with the connection of strategic areas for industry and commerce.
The economic impact and costs of the project
The construction of the underwater tunnel has an estimated cost of US$180 million.
The project also includes the construction of three traffic lanes in each direction, with one designated for bus rapid transit (BRT), as well as areas for pedestrians and cyclists.
According to the feasibility study, public investments, totaling US$120 million, should generate a return of US$290 million in regional economic growth within 15 years.
The project is expected to be partially financed by toll collection.
Fares can vary between R$4,50 and R$10, depending on the mode used.
The consortium responsible for the project brings together 11 municipalities in Santa Catarina, including Itajaí, Navegantes, Balneário Camboriú, Camboriú and Bombinhas, which together represent savings of R$73,29 billion, or 17,1% of Santa Catarina's GDP.
The importance of the project for regional development
For Bornhausen, the construction of the underwater tunnel represents a “real bypass” for a region with great growth potential, but limited by logistical difficulties.
The lack of transport alternatives between the two cities directly impacts the flow of goods and the mobility of people, which prevents the full development of the region.
Furthermore, the work is part of a larger project that aims not only to improve local transport, but also to implement a regional public transport system, with 70 electric buses and an active mobility program in Balneário Camboriú.
Other underwater tunnel projects in Brazil
The idea of building underwater tunnels is not exclusive to Santa Catarina.
In São Paulo, a similar project is underway to connect the municipalities of Santos and Guarujá.
The tunnel, which will be 1,5 km long and 860 meters underwater, is budgeted at R$5,96 billion and is scheduled for completion in 2028.
Like the project in Santa Catarina, this work is financed through a PPP and aims to improve the transport infrastructure between the two municipalities.
The future of mobility in Santa Catarina
Promobis and the underwater tunnel represent an important step in the transformation of mobility in Santa Catarina.
The expectation is that, with the completion of the works, the region will become more competitive, attracting new companies and boosting economic growth.
However, technical and financial challenges must be overcome to ensure the success of the work.
Do you believe that projects like this are the key to solving mobility problems in large Brazilian cities?
I hope it goes from paper to reality.
… I sincerely hope that these works are completed from start to finish, without financial problems and work stoppages, without political games and that they finish on the scheduled date!!!