A concrete or masonry dam which is curved in plan so to transmit the major part of the water load to the abutements.
Curved masonry or concrete dam, convex in shape upstream, that depends on arch action for its stability; the load or water pressure is transferred by the arch to the Abutments.
An arch dam is a thin, curved concrete or masonry dam structure which is curved upstream in plan so that the force of the water against it squeezes the arch, compressing and strengthening the structure and pushing it into the ground. An arch dam is most likely used in a narrow site in a mountainous area with steep walls of sound rock.