Cities will use 12 sand Maracanãs to widen beaches – 01/02/2024 – Daily Life

The race over the last six years for works on the country’s coastline projects the use of more than “12 Maracanãs” of sand to widen beaches.

The strategy is currently the most advocated by oceanographers to mitigate coastal erosion. Experts, however, criticize its high cost of implementation and maintenance, as well as pointing out the existence of limited projects that could generate problems along the coast in the future.

Survey carried out by Sheet identified 24 large-scale interventions carried out between 2018 and 2023 or projected to occur in the coming years.

In addition to beach fattening, which gained national recognition after works in Balneário Camboriú (SC) in 2021, there is also the construction of groynes, a rigid structure, usually made of stone, perpendicular to the beach to retain sand.

The works aim to mitigate coastal erosion, which affects around 60% of the country, according to the book “Panorama da Erosão Costeira no Brasil”, published in 2018. They also aim to expand leisure areas and tourist development in cities.

“It’s a dangerous race for municipalities. This type of project has to be very well studied and cannot be a panacea. We have to look at the reason for the erosion and take grounded technical procedures, so that what we have already seen happening in many places doesn’t happen: spending a lot of money on fattening and getting nothing done”, says Ana Paula Prates, director of the Department of Ocean and Coastal Management at the Ministry of the Environment.

The use of the beach fattening technique is ancient in the country. The best-known example is Copacabana beach, in Rio, in the 1970s. It gained strength in Santa Catarina at the end of the 1990s. Balneário Piçarras (SC) carried out its first project in 1998. Balneário Camboriú held a plebiscite in 2001 approving the work, carried out 20 years later.

Oceanographer Antônio Klein, from UFSC, sees the growth in the use of the technique as positive. He participated in research in the 1990s to identify sand deposits for projects. “Better to put sand on the beach than rock or concrete.”

Klein refers to riprap works traditionally carried out in emergency cases, such as hangovers. Stone structures spread throughout the country to protect the urban structure of the coasts, but were blamed for worsening coastal erosion in the medium term. They increase the force of the waves’ impact and, consequently, increase the removal of sand from the beach — the so-called “reflective effect”.

“Beach nourishment tries to reproduce the environment and thus create a morphological and biological zonation, rescuing ecological services that no longer existed,” he said.

Professor Paulo Pagliosa, from the UFSC Sea Studies Center, criticizes the fact that beach fattening requires constant maintenance, with new applications of sand over time.

“The idea of ​​widening the beach makes more sense to create more space for tourists to consume and for politicians to benefit. It is an ephemeral project, which requires successive and very expensive maintenance. But there is an increase in the engineering market in this portion. Wow. critical comes from this business and political exploitation of this solution”, he said.

The work in Balneário Camboriú (SC) cost R$66 million, paid for by local businesspeople. Jaboatão dos Guararapes (PE), which expanded the beach in 2013, plans a new intervention at an estimated cost of R$70 million.

Klein states that a monitoring and planning program is needed to replenish the sand. “These monitoring and feedback projects must be included in the budget, as, like all works, they require maintenance. They work for the planned time.”

However, some works of this type that have already been carried out do not even complete their project in its entirety.

Piçarras, for example, fattened with 800,000 m³ of sand in 1999, but did not build the intended groynes to retain the sediments. The waves practically ended the feeding process and new work was carried out in 2012. The stone structures were erected and new fattening was carried out with only half the projected volume.

Something similar happened in Natal (RN) in the Ponta Negra beach expansion project. The state planned to carry out the artificial feeding in 2013, but, before that, it built a riprap to emergency protect the beach promenade. The fattening plant ended up not being placed, and the rigid structure that consumed around R$5 million ended up worsening the erosion.

The two cities are now part of the list of new projects to be executed. Added to those already carried out since 2018, the interventions planned in the country will lead to the installation of, in total, 24.5 million m³ of new sand on the country’s shore — the equivalent of 12 times the volume of the Maracanã stadium. The total cost estimate reaches R$1.8 billion.

Even though there is a boom in these works, Brazil moves a much smaller volume of sediment than the United States, whose coastline is three times the length of Brazil’s. Around 36 million m³ of sand per year, on average, were used there in the 2010s to expand or maintain widenings, according to an article presented at the Association for the Preservation of the American Coast and Beach Conference in 2019.

Oceanographer Ricardo Haponiuk, coordinator of Anama (National Association of Municipal Environmental Bodies), states that the federal government must increase its participation in the creation of projects. For him, it is important to “understand the regional, or even subnational, context to know where that problem is coming from.”

He cites as an example the municipality of Itapoá (SC), where he was Secretary of the Environment. The city began to suffer from beach erosion after the dredging necessary to install a port in the neighboring city, São Francisco do Sul (SC). The city now has the largest fattening project in the country ready, using 12 million m³ of sand taken from the bay at a cost of R$480 million.

“The federal government should take on this role, because many of the problems that were caused in cities are the result of a ministry that, for some reason, promoted or sponsored works”, says Haponiuk.

Dams along rivers also remove sand from beaches. This is one of the reasons given for the destruction of Atafona beach, in São João da Barra (RJ), a classic example of coastal erosion in the country, affected by structures installed on the Paraíba do Sul river.

Another weakness seen is the lack of studies on the impact of interventions along the coastline. Caucaia (CE), for example, attributes the coastal erosion of its coastline to the Fortaleza groynes built in the 1970s. After 30 years of beach destruction, the city neighboring the capital of Ceará has now built its own structures to retain the sand.

“Everyone is running, each in one direction, to try to survive, but there is no organization in this. Everyone is trying to survive on their own. But, in the end, it is a chronic problem that we have in country”, says Haponiuk.

Prates, from MMA, says that coastal erosion should be part of the National Climate Change Plan, currently being updated by the government.

All experts say that the works are not capable of stopping the advance of the sea in the event of a significant rise in the oceans due to global warming.

“In the long term, everything goes down the drain. There’s not much to hold on to. But in the meantime, people are holding on. Protection might provide a guarantee of 30, 40 years. Then, we’ll see how it goes,” said geographer Dieter Muehe, coordinator of the “Panorama of coastal erosion in Brazil”.