A wall for retaining water includes a backing support, formed by vertically arranged sheet piling, a base attached to the sheet piling, and a rock or boulder facade supported on the base. The sheet piling is formed of undulating, interlocking steel sheets. A backing plate is welded to the sheet piling. A high quality plaster is applied between the facade and the backing plate and between the backing plate and the sheet piling. Preferably, the plaster is a pool plaster type, typically used to seal cracks and form an exposed surface in in-ground swimming pools.