There may be several items that you may gift to your father. For example, a professional quality laptop or (if he does not have one), civil engineering practice related books on construction, structural design, geotech, water resources etc. (whatever he likes), handbooks, design codes (ACI, AISC, ASCE,...) etc, etc. it will however be better to select the item depending upon specific interests and requirements of your father as a civil engineer. It will also depends upon the amount you plan to spend for this purpose.
