Rain has eased across the state, but flood risks remain in many areas as catchments unload record deluges.
About 1200 people across NSW remain under evacuation orders and another 1500 are being told to prepare to flee.
The body of a 68-year-old man was found in a submerged van in Sydney's southwest on Friday.
It's hoped the pop-up classrooms will be ready for 1200 students and 150 teachers from the start of term two at the end of April.
Education Minister Sarah Mitchell said ongoing wet weather had hampered efforts to set up the temporary structures.
"As soon the ground is sufficiently dry, our Department of Education teams will be getting them in place," she said.
"Having visited the flood-affected schools a few times now, I am in awe of the spirit of generosity and incredible efforts from principals, teachers and school staff to get the best learning and wellbeing supports in place for their students."
The pop-ups cover primary and secondary school students in Blakebrook, Broadwater, Lismore, Condong and Tumbulgum.
19°C