Walking around Lapa you may not realise that the structure of old colonial arches was designed and functioned as an aqueduct. It was responsible for supplying the city with water from the Carioca River and was a work of great importance for urban development. Prior to the construction of the aqueduct, enslaved people used to walk long distances to the mouth of the Carioca River to fetch water.
The water distribution works began in 1719 with the channelling of the Carioca River springs. The project was completed in 1723, but in 1744, Governor Gomes Freire ordered a rebuild. The decision was made because the initial structure, built with iron pipes, had not withstood the effects of time and weather conditions. The new project employed the technique of mixing stone and lime with whale oil, forming a concrete composition that was extremely resistant.
The Carioca Aqueduct was built by enslaved African and indigenous labourers. It was completed in 1750, the arches being the most evident part of the whole structure. The entire water supply system was about 8 km long and transported water from the slopes of the Corcovado mountain to the Carioca Fountain, at the foot of the Convent of Santo Antônio.
The Carioca Aqueduct has been depicted by national and foreign artists as a symbol of modernity, utility and beauty. In the mid-19th century it became obsolete as a way of supplying water to the city, due to urban expansion, the channelling of other rivers and the emergence of new methods. However, the structure did not lose its significance and in 1896, the arches began to be used as a viaduct for the new Companhia de Carris Urbanos trams, that were the main way of going from the centre of town up to the Santa Teresa neighbourhood. The trams were the most modern form of urban transportation at the time.
From aqueduct to viaduct, the Arches have become one of the city’s most famous landmarks. When IPHAN (National Institute of Historic and Artistic Heritage) was set up in 1938, the structure was listed as one of the country´s cultural, historical, and natural heritage sites.