A heavy vehicle attempted to overtake a water tanker and in doing so crossed into the hatched area of the road, at the same time the water tanker attempted to cross the road also entering the hatched area to take an incorrect turn into a fuel station. At this point the heavy vehicle trailer struck the driver side area of the water tanker prime mover. This resulted in damage to the water tanker prime mover and luckily only minor injuries to the water tanker drivers hand.