Abstract: The paper presents the evolution of drainage within the Motru hydrographic basin over the last 20 years, outlining the influence of the modifications occurred within the forested areas. The different degree of foresting in space (within the three sectors: mountainous, Subcarpathian and piedmont) and time (over the last 20 years) has major consequences over the regime of the water resources. Therefore, the main role comes directly to the azonal factor, which has a regularizing and compensatory role for the water resources, and indirectly to the human factor, more and more obvious, which leads to the withdrawal of forest areas.