How about landfilling the Lagoon?
Recently launched by Cidade Viva publishers, the book Lagoa Rodrigo de Freitas – Uma discussão cententária (Rodrigo de Freitas Lagoon – A hundred-year old discussion) brings together already-proposed gaudy solutions to the problem of one of Rio’s main postcards. Among them, the project to completely landfill the lagoon due to the risk represented by the space to public health, and the idea of building wind mills to pump sea water into the geographic accident.
The Lagoon is one of the prettiest places in Rio. However, its environment originally hostile to occupation inspired extravagant ideas over time – including of completely landfilling the area. This is what is revealed in the book which was launched last month. In the book, engineer and ex-president of the State Foundation of Enviromental Engineering Victor Coelho tackles the characteristics, history and studies involving the area in the Zona Sul.
The proposal to end the Lagoon is from 1905. Its author is doctor Saturnino Nicolau Cardoso. For him, the measure was justified due to the location representing a large risk to public health, due to the immense consentration of mosquitos – among other reasons. “Landfilling is easier and more economic than treating the problem, but it is definitively not a solution”, comments Victor. Another unusual project forsaw the construction of 40 wind mills with the aim of pumping sea water into the Lagoon. Suggested by Baron of Tefé in 1880, the initiative also didn’t leave the planning stage. “There was a great bother with the so-called miasmas, which are gases eminating from the Lagoon”, said Victor.
Behind the ideas that cause a strange feeling today, is the challenge represented by the natural dynamic of the Lagoon. To exist, the body of water depends on constant exchanges with the sea. They guarantee the oxygenation and other factors that interfere in the balance of the ecosystem. Without the salty water, the number of algae in the location is growing quickly. The launch of untreated sewage stimulates even more growth, which has negative consequences. The algae consume oxygen to decompose and end up creating a dead layer at the bottom of the Lagoon. When a strong wind or another phenomenon moves the water, the level of oxygen also falls on the surface, killing fish and generating the so-called fish kill. That’s why it’s important to maintain the Lagoon in contact with the ocean.
From rowing to stand up paddle
With close to 2 km squared, the Lagoon is relatively shallow. It’s deepest points only go down 4 meters. “One of them is around the Calombo curve”, reveals Victor. However, the location brings together close to 6 million cubic meters of water. Today, a population of 160,000 people live around the geographic accident. Inhabited by capybaras, egrets and monkeys, the region is one of the cariocas most preferred areas to practice sports. They go from rowing, which starts at 5:30AM, to stand up paddling. Different from beaches, the Lagoon isn’t (and never was) a place to take baths. “This happens because, when it rains, it receives water contaminated by animal feces and other remains”, explains Victor.
- In the image from Fon-fon magazine in 1922, construction near the Lagoon
As one may know, the Lagoon was not landfilled. But other less drastic works were done with the aim of facilitating the occupation of its surroundings. The biggest of them dates from the start of the 1920s. Taken up by the firm Lafayette, Siqueira & C, the intervention starting in April 1921 used close to 300,000 cubic meters of stone and more than 2 million cubic meters of landfill to give life to avenue Epitácio Pessoa and a system created to guarantee the circulation of salty water in the Lagoon. Through the project of engineer Saturnino de Brito, the sea currents would enter the body of water by means of a channel on avenue Delfim Moreira, from where they would follow a path that crosses the streets General Garzon and Visconde de Albuquerque. “The idea was that the flux re-encounters the ocean in Leblon, around where Vidigal is. But it didn’t work because the system entrance is constantly clogged by sand”, says Victor.
The channel on avenue Delfim Moreira is already done. It’s all made of reinforced concrete, with powerful steel locks. Vidigal beach is also in full construction, and the respective works are well advanced (…) Thanks to these artificial communications, which man is opening up, the unhealthiness of the Rodrigo de Freitas Lagoon disappears completely, whose waters, no longer being a permanent foci of diseases, will always be renewed by the ocean (Gazeta de Notícias, 07/03/1923)
Research shows that the first indigenous groupings in the Lagoa region arose in the 6th century. However, the beginning of the colonization of the area only happened in 1575, with the creation of the D’El Rei Mill in place of the current Botanical Garden. The name Rodrigo de Freitas is a tribute to the husband of Petronilha Fagundes, who married the heir of the lands in 1702. Among the illustrious visitors that the Lagoon has received, is the English scientist Charles Darwin. On June 25, 1832, he described in his diary the charm with the “waters stained purple by the last rays of the twilight.” Some decades later, in 1889, the Wool and Corcovado Fabrics Company factory settled in the surroundings of the body of water, beginning its industrialization. “The Lagoon has already concentrated a large number of laboratories, industries and favelas on its banks,” recalls Victor.
Aerial view of the Lagoon from Leblon beach
The current configuration of space begins to emerge in the 1950s, with the closure of factories that existed in the region. In the late 1960s, Praia do Pinto, Ilha das Dragas and other favelas were removed, anticipating the boom in the next decade. In the book, Victor reveals that the construction of the buildings that exist today at the edge of the Lagoon often involved the landfill of sites without the authorization of the city hall. The result was the loss of almost half of the original area of the body of water. “In recent years, pumps and tunnels have been built that have improved water quality,” he says. In addition, the engineer highlights the creation of a control center by Cedae and the daily monitoring of temperature and other indicators by the city as positive measures.
Since the problem of the internal balance of the Lagoon has not yet been resolved, new proposals continue to emerge. One of them foresees the extension of the Garden of Alá canal to the sea, with the deepening of its outline. Another is the installation of four pipes of more than 3 meters in diameter in the same region. The two projects have an objective in common: to inject salt water into the body of water. “Today, investments in this are stagnant. We have to wait for better times for new experiences,” says Victor. Without doing away with the Lagoon, any solution is valid so that Rio has an even more beautiful postcard in the future. – Source (PT)
(One year ago, I was researching the entire past of the Lagoon for a longform article I hoped to have published in a big newspaper, but I only ended up with lots of research and several paragraphs before something more pressing took priority. I look forward to reading this book.)