At least 37,000 houses across Melbourne could be flooded above floor level in a repeat of freak storms that swept across the city in late 2003 and early 2004, according to an Auditor-General’s report tabled in the Victorian Parliament last week.

The report found the suburban cities of Bayside, Boroondara, Darebin and Glen Eira “did not have a clear appreciation of the flooding risks” in their catchment areas and recommended that Melbourne Water step up its program to protect vulnerable properties.

The Melbourne Water Corporation estimates that 82,000 properties and their surrounds would be vulnerable to flooding from overland flows if a 100-year storm event passed over its local drainage catchment.

The report says 37,000 properties are vulnerable to stormwater penetrating interior living spaces from a 100-year storm event.

Insurance Council of Australia spokesman Rod Frail says the report underlines the concern that the insurance industry has had for some time.

“Governments at all levels have not spent enough on infrastructure to reduce the impact of drainage overflow and mainstream flooding from watercourses,” he said.

The report said flood exposure reduction will require a range of responses from improving community education, upgrading drainage systems, introducing better planning controls and addressing legislative gaps.

“The Department of Sustainability, Melbourne Water and local government need to work collaboratively to raise stormwater flood protection levels for metropolitan Melbourne,” the report said.