Iowa Code § 102.3: Authority to barricade.

The fire chief or other authorized officer of the fire department in charge of a fire scene may place or erect ropes, guards, barricades, or other obstructions across a street, alley, right-of-way, or private property near the location of the fire or emergency so as to prevent accidents or interference with the fire fighting efforts of the fire department, to control the scene until any required investigation is complete, or to preserve evidence related to the fire or other emergency.