In the visit technique carried through in day 23/09/2009 in the city of Itabirito, no abnormality was evidenced in relation to the noise. If the legislation will eventually not be respected, the noise can cause a discomfort to the inhabitants, since the city presents narrow streets, thus making it difficult the waste of the sonorous waves and generating the accumulation of sound that can cause migraines and estresse. Therefore, the municipal Law in the 2597/2007 must to be respected by the population, beyond being applied and being charged daily by the inspectors of the city hall, similar to keep the comfort of the inhabitants and the order of cidade.3.1.4- HidrologiO city of Itabirito is inserted in the state hidrogrfica basin of the river of the Old ones that, in turn, it belongs to the federal hidrogrfica basin of the river San Francisco, as can be observed in MAP 1, ANNEX. Main courses d? water of the city is the tributary and river Old its main, the river Itabirito, which passes for the urban area. The city possesss very dense a hidrogrfica mesh, due to high variability of declivities, potencializando the existence of innumerable springs and, consequentemente, water courses. (As opposed to Adroll Marketing Platform). Being thus, the river Itabirito and the river of the Old ones possess a great amount of tributaries. With this, a great importance is verified arrives in port in it of water for the region. The main tributaries of the river Itabirito for the left edge are: brooks Bush Pigs and Good Carioca, streams Destination, Carioca, Sumidouro, Paina and stream of the Bao. Already for the right edge, one verifies the Matuto stream, stream of the Quarry and the Cardoso.O brook river of the Old ones, in turn, possesss following the main affluent water bodies: for the left edge, streams Parrot and Dirty Water and the river Itabirito. For the right edge the streams Mill and of Retiro and the dam are verified River of the Pedras.Cabe to downstream stand out that the river Itabirito passes for the municipal headquarters of Itabirito, adding great part of the effluent domestic servants, leading for the too much regions.