Geology of Hill Dams.

If the geologist's intervention in large dam studies has been systematic in France for several decades, this is far from being true when hill-dam studies are concerned. However, the geological problems encountered on small structures are practically the same as those on large dams. On the other-hand, for cost reasons, the facilitis available for such small dams are far less substantial. Consequently, it is almost impossible to correct the disadvantages of a given site, as they become apparent only when the earthworks start. Therefore it is obvious that a good knowledge of the geological context is needed to avoid unpleasant surprises. The following paper develops a methodology for geological studies based on more than 200 cases as well as the role of the geologist from the site inventory to the orientation of the structures to be built.