This architectural drawing is Section through UG water tank in detail AutoCAD drawing, dwg file, CAD file. When planning your subterranean tank, keep these five points in mind. It is crucial to save rainwater and prevent loss. The exterior of the tank should be strong, watertight, opaque, and the interior should be spotless and smooth. Additionally, below-ground tanks must be properly built and plastered in order to avoid collapsing. For more details and information download the drawing file.