A dam structure for retaining water in a reservoir includes precast concrete panel assembly forming the face or upstream side. A bonded impervious liner means is provided on the downstream face of the precast concrete panels assembly. The liner means includes individual membranes bonded to adjacent panels, and heat welded impervious strips are provided along the joints between the panels. A poured concrete curtain wall is provided adjacent the liner means of the precast concrete panel assembly. Roller compacted concrete (RCC) is then provided in layers on the downstream side of the poured concrete curtain wall. The broadest aspect of the method of constructing a dam according to the invention includes the steps of erecting a tier of concrete panels to form a dam face; pouring a layer of concrete adjacent and downstream of the concrete panels to form a curtain wall; spreading a layer of roller compacted concrete adjacent and downstream of the curtain wall; and repeating each of these steps until a dam of the desired height is completed. |