Despite advances, PSDB leaves a legacy of pollution in Tietê that reflects lack of sanitation

Milk cartons, plastic bottles, styrofoam packaging. It doesn’t take more than two minutes by the riverside to see several different forms of garbage being dumped into the Tietê by the Tiquatira stream, in the east zone of São Paulo.

This is the situation even three decades after the beginning of the Tietê Project — in which, since 1992, US$ 3.4 billion (about R$ 18 billion, at current prices) have already been invested, according to Sabesp. The program is in its fourth phase.

Although it started under the baton of Governor Fleury Filho (MDB), most of the project was developed over the 28 years of toucan governments in São Paulo. In 1994, for example, one of the closing events of Mario Covas’ victorious campaign (1930-2001) was a boat trip along the Tietê river, committing himself to cleaning it up if he were elected.

Similar promises were repeated by those who came later: Geraldo Alckmin said he would deliver the river without smell; José Serra, who would significantly expand the treatment of sewage discharged into Tietê; and João Doria stated that the main tributary of the river, the Pinheiros, would be clean and with its banks recovered by 2022.

There have been advances since then. The Tietê pollution patch in the state has decreased considerably, going from more than 500 km in length, in the 1990s, to the current 122 km. Despite this, in the last year it grew 43%, and the stretches where the water quality is considered good have decreased. Monitoring is carried out by Fundação SOS Mata Atlântica.

The river is far from being considered clean — or even looking like a river. The deafening sound of traffic, the cement banks and the strong smell in no way resemble the Atlantic forest that once covered the region. The landscape is so distorted that, instead of fishing, there are those who make a living from there by collecting recyclables that float in the water.

Stretching 1,100 km, the Tietê crosses the state of São Paulo — it starts in Salesópolis and, running in the opposite direction of Serra do Mar, goes to Itapura, where it empties into the Paraná River. Along the way, it encounters other contaminants, such as pesticides and fertilizers. But it is in the Greater São Paulo region that pollution is most critical.

Gustavo Veronesi, coordinator of the Observando os Rios program, from SOS Mata Atlântica, explains that the biggest challenge is not the physical characteristics of Tietê and Pinheiros, but the place where they are located: the largest metropolis in the country.

“There are 20 million inhabitants in the Alto Tietê basin, which is basically the metropolitan region of São Paulo. Almost 10% of the Brazilian population lives in a place that is 0.1% of the national territory. There are a lot of people living, a lot of economic activity, in a reduced space”, he says.

Today, the main source of pollution for the two rivers is domestic sewage —which is directly linked to the lack of basic sanitation and housing deficiencies.

“We create urban voids in the center and push the poorest populations further away, not providing this population with services”, he points out. “The river only tells us what happens in a certain basin. If we have this difficulty in cleaning up the river, it’s because things aren’t working.”

According to Sabesp, three decades ago, at the beginning of the Tietê Project, the sewage collection rate in Greater São Paulo was 70% and, of this total, only 24% were treated. Today 90% of sewage is collected and 73% of this total is treated.

The Pinheiros River itself ended up becoming an example that investment in sanitation results in a proportional improvement in water quality. Currently, the strong smell of sewage no longer appears in several parts of the river, such as the Cidade Universitária bridge. The report also found tilapia and some water birds at the outlet of the Corujas stream.

With the campaign promise to transform the banks into a “Puerto Madero Paulistana”, in reference to the revitalized port region of Buenos Aires, Doria concentrated her efforts on cleaning up Pinheiros, which is 25 km long and passes right in the middle of the financial heart from the capital of São Paulo.

According to Sabesp, since 2019, 650,000 properties have been integrated into the sewage treatment system in the region and 86,600 tons of garbage have been removed from the river.

“The Pinheiros River is clean. It is not suitable for swimming. No one promised to go swimming [no rio]”, says Benedito Braga, CEO of Sabesp. “Today the river can be used for leisure and tourism, like urban rivers all over the world, like the Seine, in Paris, or the Thames, in London”.

Braga says that now the water has oxygen and, therefore, can shelter fish.

However, for Veronesi, although it is possible to recognize the advances, to say that Pinheiros is clean is “an exaggeration”.

The National Water Agency classifies the quality of water bodies into five levels, ranging from special (mandatory in conservation areas) to class 4 (low water quality, used only for navigation and landscape harmony). He points out that only now did Pinheiros reach class 4.

“A clean river would be from class 3, with good oxygenation, and could be used for several uses”, points out the researcher. “The new governor needs to be committed to continuing this work because if he thinks it’s resolved and stops, we’re definitely going to have regression.”

Fernando Chucre, state secretary for Infrastructure and Environment, believes that the legacy of the so-called “new Pinheiros River” can also be used for other measures in Tietê.

“The Pinheiros River becomes the new reference from a technical point of view, of efficiency, of what can and what should be done in Tietê to reduce pollution, so that, soon, Tietê will arrive in a situation very close to that of Pinheiros is today.”

It is worth remembering that Pinheiros was also the target of the “flotation” technique, adopted by Alckmin in 2001. The method consisted of agglomerating dirt into flakes on the surface to be removed afterwards. The idea was abandoned after ten years of public investment.

José Carlos Mierzwa, professor of hydraulic and environmental engineering at the USP Polytechnic School, considers that one of the difficulties in cleaning up rivers is the lack of integration between state and municipalities. “I’m talking about something that doesn’t just concern the governor’s will,” he points out.

“There is a broader problem which is the participation of city halls in the process of improving sanitation conditions”, he says, adding that it is their right and obligation to deal with water supply, rainwater drainage and treatment of sewage and solid waste.

An example of this is Guarulhos. The second largest city in the state, which is bordered by the Tietê River and crossed by several streams, only signed a contract with Sabesp in 2019. According to the company, since then, sewage collection and treatment in the municipality has gone from 12% to 20% —until 2024, the goal is to reach 40%.

For Mierzwa, it is the mismatch between the growth of cities and the provision of these services that culminates in sewage and garbage ending up in the river. The solution would be to find a balance between population growth and infrastructure, maintaining a continuous and integrated work.

Another important point is that it is not enough to focus efforts only on Tietê and Pinheiros. It is through the streams that most of the garbage and sewage falls into the rivers.

“Basically, cleaning up the river means preventing sewage from reaching the river”, sums up Veronesi. “If we want the Tietê to be unpolluted, we need all the little rivers that flow into it, directly or indirectly, to be unpolluted.”

Since 2007, Sabesp and the City of São Paulo have developed a project with this focus, called Córrego Limpo. According to the company, in 15 years, 161 streams in the capital were the target of depollution and maintenance actions — but the level of pollution in each of them varies from time to time, demonstrating the need for continuous actions.

“Pollution is a process and depollution must also be a process”, says the specialist from SOS Mata Atlântica. “The Tietê depollution project will never end, because the city continues to grow.”

In September, the government of São Paulo announced a new investment of US$ 100 million (R$ 500 million, at the current exchange rate), for the recovery and preservation of the Tietê springs. Of these, US$ 80 million should come from financing from the IDB (Inter-American Development Bank). The project is expected to begin implementation in 2023.