The summer arrived in Brazil before it was expected. During the last weeks, Sao Paulo City, per example, had storms and rains bigger than normal happen during rainy summers. Some projects have been made (cleaning the big river's affluents and making urbanization on the suburbs near the lakes) but it's not enough. The dredging on Tietê's river is late and the big pools for rains were not built like was on the projects. Because of that, many neighborhood are flooded during weeks.

How can these things happen nowadays in the richest city of South America? These are just basic problems surpassed per many cities around the world, that Sao Paulo didn't do yet because of a sequence of problems and mistakes.
- First was the rivers crossing the city, Pinheiros and Tietê. They were channeling more than one century ago in a bad way, losing their lowland areas to build roads and residential zone. It was a natural huge pool that could take an important part of the rain, redistributing the water in the time-line;
- Second big problem was all the governments passed that were not caring of the suburbs and low social areas. Because of these, many residential areas have problems without sewer and with the little canals (Pinheiros and Tietê affluents) polluted. It makes the flood even worse;
- The third problem is soil sealing around the city. The big population density with the pavement basically asphalt, decreased a lot the infiltration potential of the city's ground;
- Other relevant problem is the pollution of the rivers. The Billings reservoir was projected to receive the water from Pinheiros river and send down the mountains to Santos, generating energy. With the pollution it is not possible anymore;
- In the end is important the governments create a better plan of drainage, urbanism and cleaning river, more integrated and available.
The public administration is making thing to try to fix this problem, but anyway the big pools for rain must be made, the dredging shouldn't stop never leaving always the projected ground level and the governments should have more social projects, different that is happening in the last three decades.
Another hope comes from the Hydraulics Laboratory of the University of Sao Paulo. A research led by José Rodolfo is trying to create a different kind of asphalt, more porous. This new material, was supposed to drain the water like the sand. If this study conclude happily, it will give an important help to solve this problems happened in the city.
Let's wait now all the projects to be made seriously for the governments, and with the population helping, we manage to see in a soon future a city with better conditions for everybody, like it need to be done.
(L. Alves)