Buttressed dams are probably the most technically complex of all dam types. Like gravity dams, they transfer loads to the foundation, but they do so by means of special retaining walls – buttresses. Such construction allows to reduce the required amount of concrete (and therefore the cost) significantly in comparison with conventional gravity dams (by 20-40% and sometimes even by 60%). At the same time, buttressed dams are much more difficult to construct than gravity dams and are more demanding to the quality of the bedrock. By now, more than 500 buttressed dams of different types have been built in the world. Structurally, all buttressed dams are divided into three types: massive buttressed dams, flat slab dams and multi-arched dams.

Massive buttressed dams, the head face of which is formed by the extension of very thick buttresses, are the most common due to their relative ease and technology of construction, earthquake resistance, less demanding bedrock.

Flat slab buttressed dams have a rather thin, significantly sloped head slab, the forces of which are transmitted to the buttresses. While great savings in concrete, dams of this type require large amounts of reinforcement (i.e. they are not concrete but reinforced concrete), so their cost is rather high and they are hardly ever built nowadays.

Multi-arched dams are the most complex but also the most economical of the buttressed. Their discharge front is formed by several arches transferring forces to the buttresses. Both arches and buttresses can be made quite thin, which gives great savings of concrete, especially in wide spans. At the same time, multi-arched dams are technologically complex, demanding in terms of foundation rock quality and temperature regime, difficult to make spillways in them and special measures are required to ensure earthquake resistance.

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