Abstract: A retaining module for forming a vertical wall for retaining the earth or similar medium from which a pool, pond or stream is to be constructed. The retaining module has a vertical beam and a horizontal beam integrally molded as a single module, or alternatively, separately molded and fastened together. Several such retaining modules are combined with earth retaining blankets and means for anchoring a flexible water tight membrane in the ground to form a substantially permanent and watertight structure to create a pool, pond or stream.