The purpose of this paper is to investigate the potential of artificial wetlands (AW) as pesticide sinks. A microeconomic model is developed and completed by a numerical illustration, based on data from fungicide pollution by wine-growers. It enables us to calculate the value of an AW as a pesticide sink. Furthermore, the author shows that, for a given target mass of pesticides in water, the consideration of AW construction possibility can reduce overall abatement costs and can lower the input charge asked from farmers. This result remains true as long as the cost of constructing a wetland is not too high and it is a function of the target.