A valve containment assembly for an irrigation system may have a first side wall unit, a grate, a second side wall unit, and a lid. The first side wall unit may be disposed on the floor of a hole. The grate may be positioned in the first side wall unit to support a manifold. The second side wall unit rests on the first side wall unit to cover the manifold and the lid may be disposed on top of the side wall unit. The first side wall unit and the grate elevate the manifold above the floor of the hole to reduce interference of soil and water with the manifold. Additional side wall units may be used to provide additional height. Any of the side wall units may have frangible portions that break away to permit passage of conduits into the valve containment assembly.