For slope stability estimations, the soil pore-water conditions need to be accurately specified. The influence of cracks in clay was previously observed significantly to modify soil water response. In this study shrinkage cracks were monitored in a clay embankment where the soil water response to precipitation had been shown to be more rapid than the clay micro-permeability would predict. The cracks were shown to increase the hydraulic conductivity of the clay at all times of the year and to be the cause of the rapid soil water potential responses monitored. X-ray examinations of closed crack sites indicated that fractures at these sites formerly extended to greater depths.