Visitors and Wanganui residents will be unable to ride the No12 tram until summer because the June flood damaged its motors.
"The tramshed itself wasn't too badly affected," Tramways Trust chairman Kritzo Venter said.
The building's electricals needed to be checked and certified after half a metre of water got into the shed.
"It was up to a level where it just got into the electrical motors of the tram," Mr Venter said. "We need to disassemble and get the motors refurbished."
They would then need to recommission the tram and hoped to have that done by summer. It meant the new track for a second tram would have to be postponed.