Sandy soils are often water repellent when dry. In sloping areas this may result in surface runoff and erosion. Water repellency in soils can be classified with the solid-liquid contact angle which is difficult to determine. Another method is the water drop penetration time. This method is not only easier to apply but provides a more useful scale for classifying water repellent soils. Moreover, it is directly related to erosion hazard because runoff depends on the time required for the infiltration of rain drops. A close relationship was found between the contact angle and the water drop penetration time in dune soils along the coast of the Netherlands.