ENVIRONMENT BULLETIN-BRAZIL: Sao Paulo’s Great Open-Air Sewer

By IPS Correspondents Reprint | | Print |

Adalberto Wodianer Marcondes

SAO PAULO, May 9 1998 (IPS) - Part of the 2,400 kms long Tiete river, that links Sao Paulo with MERCOSUR through the Tiete-Parana system, is in danger of becoming one of the the world’s longest open-air sewers, say environmentalists.

In the past, the river was the main means of communication with the Brazilian interior but in recent years the Tiete has become a canal lined by filthy avenues and a repository for industrial and domestic waste.

Not even an investment of 4 billion dollars, projected as part of a decontamination effort financed by the Inter-American Development Bank (IDB) and the World Bank, can guarantee that the river will regain its life in the section that passes through Sao Paulo, the largest city in South America, experts say.

According to Eduardo Luis Serpa, an engineer at the Technology and Environmental Sanitation Company of Sao Paulo (CETESB), it would take decades for the city to reach equilibrium between the use of the Tiete and improving the quality of its water.

“Although 90 percent of all residual material that goes into the river is treated – a percentage considered ‘excellent’ in Sao Paulo, the 10 percent of raw waste is equivalent to that produced by a city of 1.6 million residents,” said Serpa.

The Tiete has 2,400 kilometers of navigable waters, and more than 6,000 kilometers of river banks. The entire Tiete-Parana system passes through 22 Brazilian cities and has a an area of influence of 800,000 square kilometers, which an average income of 5 ,000 dollars per inhabitant.

In addition, there are 10 hydroelectric plants all along the system which produce 25 million kilowatts, with 10 interlocking systems which will soon allow the direct integration between the four countries that make up MERCOSUR (Brazil, Argentina, Uruguay and Paraguay), and Bolivia, one of the associates.

Despite its geo-economic importance the Tiete, like most rivers in Brazil, has not been helped environmentally by the urban areas buil along its path over the centuries.

Engineer Gaudino Inacio de Souza, also with CETESB, offered a historical explanation: the culture of the Portuguese colonizers mandated that the river pass through the rear of their houses, and serve as a repository for waste. In fact, that was how most

of the rivers in Brazil were treated, and the Tiete in particular. The portion that passes through the city of Sao Paulo was rectified and shortened from 40 to 20 kilometers.

“The flatness of the terrain and the loss of its curves reduced the speed of the river,” explained Serpa. That, according to the engineer, prevented the oxygenation of the waters and facilitated the sedimentation of the riverbed .

The Tiete’s level of contamination is four, the highest on the scale, which means that the river only can be used for navigation and urban use after advanced treatment. It also means the great Tiete-Parana river system soon will have a non-navigable port ion inside the city of Sao Paulo because the quality of the water will not allow it.

Despite their historical neglect of the river, Sao Paulo residents seem to be becoming more conscious about the problem.

A survey conducted by the Social Service of Commerce (SESC), which brings together companies devoted to education and leisure, revealed that 91 percent of adults in Sao Paulo believe that the pollution of the river is a serious problem.