In the AutoCAD Civil 3D pipe style, the Hydraulic Gradient Line and Energy Gradient Line are turned off (Display set to Off) by default. To display these properties, create a new pipe style with these options turned on and save the pipe style for future use. Also, if you want to display the HGL/EGL information in labels (in addition to the profile view), create a new pipe label and/or structure label that contains this information.