Revival of a Sao Paulo River

ONE OF THE FIRST sights visitors to Sao Paulo, Brazil, encounter is not a pretty one. At initial glance, the stagnant waters of the Tiete River have all the earmarks of an open sewer. What was once a naturally meandering watercourse has today been confined to a channel imprisoned by two of the city's major thoroughfares. The river's banks are virtually devoid of any natural vegetation, and its fetid waters are clogged with human waste; poisoned with runoff from industrial sites; choked with pesticides, sediment, and chemicals; and littered with refuse. According to scientists, the badly degraded river is all but ecologically dead. It is not only an eyesore, but also the source of public-health concerns. Outbreaks of hepatitis have been common among communities that border the waterway.

Since the founding of Sao Paulo in 1554, the Tiete and the city's other river, the Pinheiros, have been the primary source of water for the city's residents. Today, the vast majority of the metropolis's estimated twenty million inhabitants depend on water supplied by these two sources for their daily needs, while water taken from wells that tap the region's shallow aquifers supply the rest. Efforts to provide safe drinking water to the city's residents have become an increasingly daunting task, exacerbated by Sao Paulo's rapid population growth.

Guaru, the city's primary water treatment plant and South America's largest such facility, processes nearly eight thousand gallons of water a second, adding chlorine and fluoride to the over 700 million gallons of water it treats daily. However, a city of Sao Paulo's size should have the capacity to provide almost twice that amount. Wastewater produced by over three-quarters of the city's residents flows directly into the Tiete, adding to pollution woes. At the same time, the region's heavily tapped groundwater resources are being significantly depleted--the water table is sinking over thirteen feet per year.

Serious efforts have been under way since the early 1990s to clean up the Tiete. Today, they are picking up pace. Over $1.1 billion, including loans from the Inter-American Development Bank and locally generated matching funds, has been put into action. Engineering projects to control the introduction of human waste into the river and educational efforts to promote better land-use practices among hundreds of thousands of residents who populate the river's headwaters have been initiated.

One of Latin America's most prestigious groundwater research organizations, the University of Sao Paulo's Institute of Geosciences, is addressing chronic water-quality and quantity issues, while the Companhia de Saneamento Basico do Estado de Sao Paulo is implementing the engineering strategies.

Among the priority projects have been a concerted effort to reduce the amount of untreated sewage from entering the river by connecting an additional 400,000 households to the municipal sewer system and substantially reduce industrial discharges into the river. The construction of a so-called "interceptor" sewer system on both sides of the Tiete and Pinheiros to collect untreated wastewater that would otherwise flow directly into the river systems has also been funded. A companion educational effort is designed to promote better stewardship--encouraging watershed residents not to throw trash into the river and promoting efforts to reduce damaging soil erosion that also contributes to water pollution.

Although the ambitious goals of these projects are far from being achieved, today visitors see increased activity along the Tiete as construction crews tackle a number of engineering projects. Barges with dredging equipment dot the river as it courses through Sao Paulo's urban core, removing tons of refuse. Billboards line its banks, educating residents of basic health concerns. And, proving that even badly polluted water can be cleaned up enough to serve human needs, the local Brahma brewing plant uses treated water to produce some of Brazil's most popular brands of beer.

It's virtually certain that the river will never approach the pristine quality when European settlers first arrived almost five centuries ago. But much can--and is--being done to turn the Tiete from a dead zone into a more functional natural system that will better serve Sao Paulo and its residents.

COPYRIGHT 2003 Organization of American States
COPYRIGHT 2008 Gale, Cengage Learning