Ratepayers are going to have to cough up $1.5 billion to repair the 84-year-old Story Bridge to meet industry standards.

Lord Mayor Adrian Schrinner told Peter Fegan on 4BC Breakfast, 'before the bridge turned 80, we started towards the 100-year birthday doing that work.'

'But it's just become clear that it's a much bigger job than anticipated and also the other thing that's happened over the last five years is costs of doing anything have increased significantly.

So, what something costs today is much more than it cost five years ago and that's the challenge,' Schrinner said.