The flash floods analysis, representative for Niraj River between 1970-2008. The need to know the characteristics of the flash floods is derived from the number and the intensity of floods occurred in the drainage basin of the Niraj river. Therefore, there were analyzed only the flash floods representatives for the years: 1970, 1995, 1998, 2001, 2008.The classification of the floods was realized according to the genesis and the flash flood hydrograph shape for the period 1970-2008, before and after the completion of the drainage basin planning/management depending on climatic, morphometric and morphological factors.