Because of this , sometimes they put the two together , making a `` district '' ( e.g. Rotorua ) . Or sometimes they changed the name to `` district '' ( e.g. Waimairi ) or `` city '' ( e.g. Manukau ) . The result was often a merger of the two into a `` district '' ( e.g. Rotorua ) or a change of name to `` district ' ( e.g. Waimairi ) or `` city '' ( e.g. Manukau City ) .