The invention relates to a method for dredging an underwater bottom in an area (5) using a dredging device. The method comprises the steps, taking place via a digital network (40, 41) under the control of a computer (30), of determining the present positions of the dredging device and of a source of contamination in the area; entering input data (10-12, 20-23) relating to the area (5) into a hydrodynamic model (1) of the area; determining with the hydrodynamic model (1) the degree of contamination at positions in the area (5) resulting from spread of the contamination from the source; comparing the degree of contamination at positions in the area (5) to a threshold value for these positions; and optionally adapting the dredging if the degree of contamination exceeds the threshold value. Underwater bottom can be dredged using the invented method, wherein on the one hand the production is maximized and on the other the consequences for the natural environment are minimized.
