A system and method to create or elevate a berm of a liquid retention facility by placement of lightweight liquid impervious. The system and method can also be used to elevate the liquid retention height of the berm in combination with impervious liner retention material. By constructing the berm system on an existing levee, the effective height of the levee can be increased. The lightweight fill material provides the shape of the berm or levee extension. The liquid impervious liner material provides a watertight surface, the media for joining of the lightweight fill material, and the anchoring of the lightweight fill material to the existing berm or levee structure. The system may use solid wall hollow body structures to elevate the berm. The system may also use lightweight frames to support the vertical elevation of a liner above the berm.