In this paper it is analysed if a tax on water may give farmers an incentive to shift to more water efficient irrigation systems and strategies. Two irrigation systems and three strategies for irrigation in potatoes are investigated. It is found that by changing from the present system and strategy it will be possible to save water significantly. With increased taxes on water it may also be possible to give incentives for the farmers to change to new systems and strategies. However the results also indicate that the water taxes should be very high. Therefore a tax on water quantity would not necessarily be a relevant solution from a farm management point of view.