The Aguas Livres Aqueduct ( “Aqueduct of the Free Waters”) is a historic aqueduct in the city of Lisbon, Portugal. It is one of the most remarkable examples of 18th-century Portuguese engineering. The main course of the aqueduct covers 18 km, but the whole network of canals extends through nearly 58 km.
The impressive 18-km (11-mile) Aqueduto das Águas Livres is a national monument with startling baroque stone arches, erected by architects Manuel da Maia and Custodio José Vieira in 1748. Thanks to these, the aqueduct survived the 1755 earthquake, which laid waste to most of the city.
The city of Lisbon has always suffered from the lack of drinking water, and King John V decided to build an aqueduct to bring water from sources in the parish of Caneças, in the modern municipality of Odivelas. The project was paid for by a special sales tax on beef, olive oil, wine, and other products.
Construction started in 1731 under the direction of Italian architect Antonio Canevari, replaced in 1732 by a group of Portuguese architects and engineers, including Manuel da Maia, Azevedo Fortes and José da Silva Pais. Between 1733 and 1736, the project was directed by Manuel da Maia, who in turn was replaced by Custódio Vieira, who would remain at the head of the project until around 1747.
Custódio Vieira conceived the centerpiece of the aqueduct, the arches over the Alcantara valley, completed in 1744. A total of 35 arches cross the valley, covering 941 m. The tallest arches reach a height of 65 m, and many are pointed, reminiscent of arches in Gothic style. It is considered a masterpiece of engineering in the Baroque period.
In 1748, although the project was still unfinished, the aqueduct finally started to bring water to the city of Lisbon, a fact celebrated in a commemorative arch built in the Amoreiras neighbourhood. From this period on, construction was overseen by other architects, including Carlos Mardel of Hungary and others. During the reigns of José I and Maria I, the network of canals and fountains was greatly enlarged.
The Mãe d’Água (Mother of the Water) reservoir of the Amoreiras, the largest of the water reservoirs, was finished in 1834. This reservoir, with a capacity of 5,500 m³ of water, was designed by Carlos Mardel. It is now deactivated and can be visited as part of the Museu da Agua (Water Museum).
Earlier visitors to Portugal considered the Aqueduto das Águas Livres to be the city’s loveliest construction. By this they meant the most impressive section of Lisbon’s water supply system which spans the Alcântara valley to the northwest of the city.
Watter passes above the valley for 941m/3,088ft. The aqueduct is supported by 35 arches (14 pointed arches in the center and 21 rounded arches at the sides), the tallest of which measures 62m/203ft high and 33.7m/111ft wide. Footpaths 1.4m/5ft wide run along both sides of the aqueduct at a height of 65.3m/214ft. The section of the aqueduct spanning the Alcântara valley actually forms only a small part of the 18.6km/11.5mi long pipeline
The full length of the aqueduct, including its tributaries, totals 58km/36mi and 127 arches had to be built. Around Lisbon and within the city itself parts of the Aqueduto das Águas Livres continually appear. In some places the pipeline is supported by pillars, in others, where the water flows underground, only the little ventilation shafts can be seen. The construction of a water pipeline had been under discussion since the time of Manuel I. It was supposed to solve the city’s yearly summer water shortage and the ensuing hygiene problems.
Until 1880 Lisbon’s water demands were mostly met by the aqueduct, but then the increasing needs of the growing city rendered its capacity insufficient and a new main was constructed. Although the whole extent of the Aqueduto das Águas Livres could be used in principle today, it was finally closed down.
The Aqueduto das Águas Livres was open to the public until 1853. It served the inhabitants of the suburbs as a short cut across the Alcántara valley. Attacks by the then famous/infamous robber Diogo Alves, who lay in wait for his victims up on the other side, robbed them and pushed them over the edge into the valley below, together with the increasing number of suicides led to the crossing being closed off. For some years the aqueduct was opened at weekends in the summer for visits and for walking across.
At present it is open only to organized groups by prior arrangement. From the aqueduct an interesting view across the Alcántara valley with its network of roads the Tagus can be enjoyed.
[article source: www.wikipedia.org]