....The question is then, how much communication is there between upper levels of the fire service and the police force so as to enable such evacuations?
I would assume that the AIIMS Planning Officer would complete the forward planning scenarios & thus identify the risk to infrastructure assets. For example, the protection of Renmark township assets by MFS & Helitanker during the Bookmark fires last year.
Within the co-ordinating structure you have liason officers from SAPOL, SES, SAAS, Health, etc at State Emergency Operations Centre, lead combatants State Control Centre and at the incident location AIIMS centre.
So if setup & operating correctly, communication will be at all levels.
But my assumption is that this type of evacuation would be using pre-written & agreed emergency plans. The facilities would have that for incidents at their facility (eg building fire, chemicals, etc).
But think about if you need to move them to another township several kilometers away from a wildfire or flooding risk for a few days