Lisbon Drainage Tunnels

The design of both tunnels provides for the draining away of once in a century rainfall with a downstream release that minimises the risks of flooding in critical areas of the city.

The main works included in the project were as follows:

- Monsanto-Santa Apolónia (TMSA) Tunnel:

A 4.4 km tunnel with a working diameter of 5.5 m that was completed with a tunnelling machine that was set to work in Campolide and was decommissioned opposite S. Apolónia.

- Chelas-Beato (TCB) Tunnel:

A 1.1kmtunnel to be bored using the tunnelling machine.

- Works associated with the tunnels:

Initial works and diversion of TM1 and TC1 tunnels, 3 drains for incorporation of rainwaters (TM2, TM3, TM4) and works for discharge of water into the Tagus River (TM5 and TC2).

- Regeneration of the external areas of Santa Apolónia:

Installation of “Land Art” works; Largo dos Caminhos de Ferro/Av. Infante Dom Henrique; surroundings of the Ermida do Senhor Jesus da Boa Nova.