The evolution of the riversides of wadis, Rdat, Zat and Tensift, depends, principally, on the intensity of floods and inundations generated by torrential rains slaughtered at the level of north mountainside of High - Atlas of Marrakech. The climatic conditions makes of the valleys of the wadis studied favorable zones to floods and to the degradation of the soil. From 21 to 23 November 2014, violent torrential storms, attaining 250 mm in few hours, beat down on the very high peaks of High - Atlas of Marrakech. They have resulted in impressive floods of different wadis that originate in high altitudes. Hurtling down the slopes up to the plains of the Haouz, the Muddy Waters, at high load solid, have carted the soils, trees, crops, houses and road infrastructure.The riversides of the wadis have not escaped this destruction. This degradation of soils, orchards and olive groves can be observed and analyzed by the satellite images and the field studies. As well, we proceeded to a treatment of images with the GIS tools using satellite images of Google Earth at high resolution and the Landsat images(missions of October and December 2014) with a resolution of 30m and 15m (panchromatic band). To highlight the vegetative cover of alluvial plains and its evolution in bare soil during the flood, we have represented the bands the ratios 6/7, 6/5 and 4/2 respectively in red, green and blue using the software ENVI. The analysis of the risk linked to the degradation of the banks of wadis in the study area, revealed three main processes of degradation; the erosion due to the current under the effect of the water, the landslide in mass after a quick drop in the water level and the collapse. The results obtained are very interesting and can be very useful for the understanding and the good management of water hazards and more specifically to the phenomenon of soil degradation.