Operations officer Graham Fixter said the unit had done several trips and sent down more than 50 personnel to Waroona.
“We have been fighting fires in Waroona, Lake Clifton, Mount Cooke, Karnup, Canning Vale and Forrestdale,” he said.
“We have been coming across a lot of very stressed-out people who want to get back to their homes.
“Some off the firefighters have been coming off absolutely knackered.”
Mr Fixter said trips to take meals to firefighters had taken hours longer than usual because of all the road closures in the region.
The unit has been sending firefighters from various stations around the southeastern suburbs, including Gosnells, Maddington and Armadale.