A person may not erect or permit to grow an airport hazard on land adjacent to the end of a runway of a public airport without a permit issued by the department. The area upon which these hazards are prohibited is the width of the runway, and extends from the airport boundary at the end of the runway, away from the runway in a direction parallel to its centerline for a distance equal to the length of the runway. An obstruction situated in an area not previously designated as an airport hazard area by the department is not a hazard if its height does not exceed five feet for each 200 feet distance from the boundary of the airport. The vertical measurement of the structure starts on the same plane as the surface of the runway.