The city of So Paulo approximately possesss 300 streams that present as main function, to carry domestic and industrial sewer. The urban expansion not only in So Paulo, but in practically all Brazil, occurs of intense form, fruit of a disordered population concentration, without planning and no concern with natural environments, thus provoking a reduction in the welfare and the quality of life of the population. The concern with the balanced and sustainable development more had beginning of form accented by return of the decade of 50, however in the diverse attempts of alavancar the growth of Brazil, the ambient questions had been always left for as plain and who more suffered with this, had been our streams and rivers, serving of canal of ousting of leftovers and of that it does not have plus no usefulness. In the past, with a very lesser population of that today we have, the rivers that cut the So Paulo capital, were well cleaner, exactly receiving sewer from the city, still they were rich in fish and with present ciliar bush in good part of its extension. The River Tamanduate, for example, was well different of the River Tamanduate of today, was navigable and for it they passed merchandises that were commercialized in So Paulo. The construction of constructions, the pavement of the streets and other processes of occupation of the city, almost always result in the waterproofing of the ground, causing serious ambient impacts, as the increase of the superficial draining of the water, degradation of freticos sheets, transport of superficial sediments for the gutter of the rivers, increase of the volume of water with consequent damnification of the pavement of the streets, causing social and economic damages to the government and the population in way generality, exactly for who live in distant regions of the great centers, suffer the consequences, therefore the measure that the great rivers lead the sewers, these they are sanded..