The technical solutions chosen for the project are as follows: to create a general waste collection unit fed by a series of secondary captors situated along the twelve rivers which drain the region.

The general captor is almost 25 km long and has a diameter increasing from 1.5 to 2.5 metres. It disgorges into the water purification station at Guia in the commune of Cascais. This station retains solid waste and treats liquid waste before releasing it into the sea, where it is diluted. The point of release is three kilometres out to sea and 41 to 45 metres below the surface.

Until quite recently, the coast between Lisbon and Cascais was a popular recreation spot for people living in the capital. The beaches were renowned for their beauty and had the advantage of being very close to Lisbon. Affluent families built splendid weekend or holiday homes in the towns of Cascais, Estoril and Oerias.

The grand houses are still there but some of the surrounding beaches are now better known for their contamination. The growth in the population and the economic development of the region have made the rivers which feed into the sea or into the Tagus between Lisbon and Cascais little better than sewers.

Today, the various infrastructure co-funded by the ERDF is up and running. This has now helped some of the beaches in the area win the coveted blue flag for cleanliness. The entire project was completed in 1998. This will give the authorities in Lisbon enough time to comply with the EU directive on the treatment of waste water.

But above all, it will give them the opportunity to cope with the new constraints imposed by local demographical developments. In 1990, the water treatment project covered some 545 000 inhabitants. By 2010, this will have risen to 830 000 and by 2025, the population covered will have reached an estimated 1 500 000.

Instituto de Agua
Phone: +351 21 849 47 87

//

case

Urban Policy > Urban environment > Urban renewal

Waterside development