Springs are all sources of water, surface or underground, that can be used for public supply. This includes, for example, rivers, lakes, dams and groundwater. To fulfill its function, a spring needs special care, guaranteed in the so-called state laws for the protection of springs. In these rules, the main point is to avoid water pollution, something very difficult to achieve in a country like Brazil. Around here, the expansion of the big cities happened in a super messy way, compromising the water sources close to the metropolises. The best known – and sad – example is the Tietê River, which cuts through the capital of São Paulo and much of the interior. In theory, the most famous São Paulo river could be a source of water for millions of inhabitants, but almost 100 years of pollution ended up transforming the river into a huge open sewer. To make things worse for the people of São Paulo, other important water reserves are being compromised. From the 1970s, the city began to expand towards the Guarapiranga dam, with thousands of clandestine occupations that dump sewage into the spring without any treatment. “Today, it is not feasible to remove people from there. The best way out is to collect sewage and treat it to reduce pollution,” says sociologist Ricardo Araújo, from the Basic Sanitation Company of the State of São Paulo (Sabesp). Unfortunately, São Paulo is not the only place in Brazil where springs are in danger. In the box on the side, we tell a little more about the drama of the Guarapiranga dam and four other cases of disrespect for water sources in other metropolises.
Reservoirs at risk Uncontrolled growth threatens water quality in the country’s largest urban areas
GUARAPIRANGA DAM (São Paulo, SP)
Polluted by sewage from irregular subdivisions and slums, the Guarapiranga dam suffered from the demographic explosion: according to Sabesp, the population in the region jumped from 330,000 inhabitants in the 1980s to 750,000 in the year 2000. As a result, treatment costs of water have increased tenfold in the last 15 years. As removing all these people is not feasible, the state government promises to invest in the urbanization of slums and increase the sewage network around the main reservoir of the city
RIO DAS VELHAS and VARGEM DAS FLORES dam (Belo Horizonte, MG)
The capital of Minas Gerais is supplied by these two springs with pollution problems. The Vargem das Flores dam receives sewage from surrounding houses, while the Velhas River ended up being contaminated by heavy metals dumped by the steel mills built along its banks. The good news is that the das Velhas river is already showing signs of improvement after a revitalization process started in the 90s
PIRACICABA RIVER BASIN (Interior of São Paulo)
The water of this river and its main tributaries becomes polluted after passing through large cities such as Campinas and Limeira. But, before all this mess, the capital of São Paulo “steals” about 50% of its supply capacity from this system. Worse for the populous cities in the interior: with dirty rivers and little potable water, rationing and water rotations are already starting to become common in the region
GROUNDWATER (Recife, PE)
As the capital of Pernambuco does not have permanent rivers capable of supplying water to its 1.5 million inhabitants, the way is to draw water from groundwater. The problem is that most of these reserves are compromised. First, the large amount of uncollected sewage seeps into the ground and pollutes the groundwater. Second, overexploitation lowered the level of the reservoirs, leaving the water with a lot of salt and jeopardizing consumption.
GUANDU RIVER (Rio de Janeiro, RJ)
Defiled by sewage, one of the main springs in the capital of Rio de Janeiro needs the help of the Paraíba do Sul river to reduce its pollution. Today, the Paraíba do Sul swells the volume of the Guandu six times compared to the original flow. But the dirt was not diluted enough to supply the city of Rio directly and Paraíba do Sul was left with less water to supply the cities in the south of the state.