Classes were back to normal at Bulli High School on Tuesday after the school was badly damaged by flooding during heavy rain at the end of March.
For the last few weeks of term one, the school operated on a makeshift timetable with classes held in the hall and library while damaged carpets and parquetry were ripped up and replaced.
As well as the waterlogged floors, photocopiers, industrial technology equipment and musical instruments were damaged during the deluge.
Relieving principal Lou Tome said while there were still repairs to be done - including in the industrial arts area, administration block and canteen - good progress had been made during the school holidays, with all classrooms now usable.
"We're in good shape, in so much as we're going back to our original timetable.
"It's all happening, but there's a lot to happen. We won't be short of anything, it will just take time to get everything back in place."
Mr Tome said the students and teachers had been "fantastic" during the disruption.