Floods in Lisbon and the importance of good urbanization policies

Since Lisbon has been built over the years on top of rivers, without proper architectural and urban planning, these scenarios like the ones seen last week are inevitable.

Photo: Filipe Amorim/ AFP https://www.acritica.net/editorias/policia/tempestade-provoca-inundacoes-em-portugal-e-lisboa-fica-embaixo-dagua/637505/

Throughout this week, we have once again seen the city of Lisbon almost submerged by the violent rains and floods in every neighborhood. If it is true that the Lisbon City Council has already approved a fundamental work for the correct drainage of water, it is also true that this is an issue that has been debated for over 50 years.

It was in the winter of 1967, when the city of Lisbon was surprised by floods due to precipitation, that the architect Gonçalo Ribeiro Telles raised the issue for the first time, publicly imposing himself against the current urbanization policies.

In the first municipal elections after the Revolution in 1974, Ribeiro Telles ran for Mayor, with several proposals that relate to this issue, such as limiting construction in floodplains and in riverside areas or with water sources, creation of green areas and green corridors, which should exist to take water to the river, without causing damage in case of heavy rain. At that time, he was not elected.

Jumping to the present, the current Mayor of Lisbon, Carlos Moedas, informed that “if the drainage tunnels already existed, the floods would not have happened”. Thus we see the importance of urbanization policies and their impact on people's lives.

Since Lisbon has been built over the years on top of rivers, without proper architectural and urban planning, these scenarios like the ones seen last week are inevitable. Alcântara was a stream, Avenida da Liberdade was a stream, Av. Almirante Reis too. The area of ​​Sete Rios, as the name implies, was where seven small streams converged. Over the years, the city has grown and rare were the times when it was structurally thought how to fetch rainwater and wash it down to the river, without these floods.

But it is already in March 2023 that new drainage works start in Lisbon. The plan foresees the construction of two tunnels starting exactly at the two high points of the city. The first tunnel, with a capacity of 17,000 cubic meters, will serve to transport water from Monsanto to Santa Apolónia. The second, between Chelas and Beato. “The water, when it arrives at Monsanto, normally goes to Alcântara. We are going to get the water to enter this tunnel”, Carlos Moedas told Expresso.

The €250 million plan exists since 2008, but it has only now started to get off the ground. According to the Lisbon City Council, the Lisbon General Drainage Plan “prepares the city for extreme events caused by climate change”, reducing “significantly floods and floods and the consequent social and economic costs”. But it will only be ready in 2025.

We thus see the importance that correct urban and urbanistic planning has in the active life of a city and the people who live it. Thinking about ways of life and how people inhabit a space is not just the architect's job in a single house, but in the overall scenario. Lisbon is a good example of this, of the necessary evolution and the dangers that exist when structural works are postponed.