Lisbon, March 4, 2026 (Lusa) - The iconic Aguas Livres Aqueduct in the Portuguese capital, Lisbon, will undergo structural consolidation and conservation and restoration work at an estimated cost of €850,000, the water company, EPAL revealed on Wednesday.
"The work is part of the maintenance, conservation and restoration programme for the Águas Livres Aqueduct, a National Monument [since 1910], and includes measures to ensure its stability, material integrity and enhancement of its heritage value, in accordance with best practices for safeguarding built heritage," EPAL said - Empresa Portuguesa das Águas Livres, in response to the Lusa agency.
Regarding the work schedule, EPAL said it is awaiting a favourable preliminary opinion from the Lisbon city council, noting that this is a necessary condition for launching the public tender.
In a private meeting today, the Lisbon city council unanimously decided to issue a favourable, non-binding preliminary opinion on the feasibility of the conservation and restoration work on the historic stone that forms part of the 16 turrets (small dome-shaped ventilation and lighting structures that punctuate the long aqueduct, giving it a baroque aesthetic and technical functionality) to the Águas Livres Aqueduct, in the Alcântara valley section, in the parish of Campolide.
Signed by the Councillor for Urban Planning, Vasco Moreira Rato (independent appointed by the PSD), the proposal states that in August 2025, the public institute Património Cultural issued a "conditional approval opinion", referring to the need to submit the final report on the intervention ‘"after completion of the work and within 30 days".
According to EPAL, after the launch of the public tender for this project, "the tender procedure is expected to take around 180 days and the work is expected to take approximately 800 days to complete", with an estimated investment of €850,000.
Built between 1731 and 1799, the Águas Livres Aqueduct was a vast system for collecting and transporting water by gravity and is considered "a remarkable feat of hydraulic engineering", according to the EPAL website, which also highlights its classification as a National Monument since 1910.
"The system, which withstood the 1755 earthquake, consists of: a main section, 14 kilometres long, starting at Mãe de Água Velha, in Belas (Sintra), and ending at the Mãe de Água das Amoreiras reservoir in Lisbon; several secondary sections designed to transport water from around 60 springs; and five galleries to supply around 30 fountains in the capital," the company said.
According to EPAL, the Alcântara valley arcade, which is 941 metres long, consists of 35 arches, including "the largest stone ogival arch in the world, measuring 65.29 metres high and 28.86 metres wide".
At the end of January this year, the Fórum Cidadania Lx association warned of the state of dirtiness of the section of the Águas Livres Aqueduct next to the Jardim das Amoreiras, where "the arch and the adjoining walls are completely blackened, with plants growing in some places," and noted that this is also the case with the section up to Mãe d'Água, where "the stonework has cracks, there is extensive biological colonisation on the terrace roof, the iron railings are badly rusted and the wooden frames in the openings are in poor condition".
In response to this warning, EPAL said that, through the Water Museum, it "regularly" monitors the state of the Águas Livres Aqueduct system, including Mãe d'Água, through a safeguard, maintenance and conservation plan, "which provides for continuous monitoring and scheduled interventions in accordance with technical criteria of priority and assessment of the state of conservation".
"All cleaning, biological colonisation control and maintenance of metal and wooden parts are types of work that are included in the monument's preventive conservation plan," said the company, reinforcing its commitment to ensuring the preservation, enhancement and proper maintenance of this heritage, guaranteeing its integrity and public enjoyment.
Regarding the application of the Águas Livres Aqueduct to UNESCO World Heritage, which has been part of Portugal's tentative list since 2017, EPAL explained that there was an update in 2024 and it was concluded that this National Monument "remains eligible" to remain on the list, including because it has "exceptional universal value" and preserves "its integrity and authenticity".
In this context, EPAL has developed "a consistent set of preventive maintenance, conservation and restoration interventions" to ensure the preservation of the material and structural integrity of the monument, reinforce its resilience and ensure the transmission of this heritage to future generations, in addition to measures to "minimise and mitigate potential threats to its outstanding universal value, namely urban pressures and the impacts associated with climate change".
At the same time, "in-depth technical and scientific research" has been promoted to provide a better historical, territorial and functional framework for the Águas Livres Aqueduct system, EPAL reported, adding that this constitutes "an essential basis" for supporting the rationale for its outstanding universal value and strengthening the application dossier for UNESCO World Heritage status.
SSM/AYLS // AYLS
Lusa
