The Selwyn Aquatic Centre was damaged in a storm on Wednesday.
The centre has been repaired after it was battered by hail and lightning on Wednesday afternoon.
"We may have some lanes closed from time to time in the main pool area throughout the day to take care of some final small fixes, but we will aim to complete these during quiet times," said a centre spokesperson.
"Thanks to the help of our fantastic contractors, Armitage Williams, we are in a position to open to the public as normal (Friday) from 6am."
She said the storm caused a power surge, which shut down the centre's heating and air handling systems.
When the systems restarted it caused a vibration through the air ducting, which resulted in some of the supporting bolts being pulled from the ceiling in the main pool area.
