The paper presents an analysis of erosive processes resulting from the snowmelt runoff that occurred in the year 2003. The investigation was performed in an agricultural basin in Wielkopole. In the year under study, outflow of water from basin took place four times and amounted to a total of 46435 m3. The runoff water carried away 161.5 Mg of soil suspension and 4.863 Mg of dissolved salts. The total volume of rills amounted to 203 m3, and that of surface-wash to 14.41 m3. The total volume of deposited warps was estimated at 137.4 m3. The damage occurred mainly on fields ploughed for the winter and on fields sown with wheat winter, and also on slopes of ravines and on field access ways. The snowmelt runoff caused the wash-off of a 0.109 mm layer of soil.