A method has been developed to determine the consequences of changes in the groundwater level underlying agriculturally productive land by means of a GIS. This method is based on the so-called HELP tables, and is applicable only to large areas (50x50 km2). The soil classifications in the HELP tables are grouped into 9 sensitivity classes for agricultural damage due to soilmoisture deficit and 2 sensitivity classes for decrease of agricultural production due to soil water excess. In an example, it is shown how the effects on agriculture can be determined.