Embankment dams comprising broadly graded materials of glacial origin have, in the past, been identified as being more prone to developing sinkholes than dams composed of materials of other origins. Sinkholes on the crest of a dam are, in many cases, an indication of internal erosion. Internal erosion can initiate and continue to develop for many reasons, but are mainly due to root causes coming from core/filter properties and interaction, possibly affected by the dam design and/or from construction-related reasons. In this paper a review is made on moraine core dams in the literature in relation to performance history of internal erosion. Dam data comprising ninety existing moraine core embankment dams has been compiled and assessed, with the objective of investigating the occurrence of indicative properties of dams that have developed internal erosion. The data set of dams consists predominately of Swedish dams, but also includes moraine core dams located in the rest of Scandinavia, North America, Russia and Australia. The investigation shows that a coarsely graded filter, grading instability of the core and filter, and high susceptibility for filter segregation, are properties that are over-represented and possibly indicative for moraine (till) core dams with a performance history of internal erosion.
