The present work is reserved for a presentation of the impact of climatic factors on the floods which, among the more serious, known to the region are the floods of October 2008 caused by intense precipitation with a height of 108, 40 mm. In addition, we are interested in the physical parameters such as the sections and the slope of the valley Bécharwhich is at the origin of the disaster. The profile along the valley shows a slope steeper, which produces an acceleration of flows, the calculation of the sections of the valley's various points also reveals the variations at the level of the slope, which sub-tends to the bad behavior of the water flow at the level of the section reduced. Though it is as well, these investigations have guided and alerted us once more on the need for a development integrated space taking account of regional specificities.