A system should have been in place to evaluate whether the Flemington Racecourse flood wall actually mitigated flooding, a parliamentary inquiry has been told.
About 600 properties in Melbourne's inner west were inundated when the Maribyrnong River broke its banks on October 14, 2022.
But the Melbourne Cup track remained clear because of a 2.5m wall built in 2007.
Former Federal Court judge Tony Pagone was tasked with investigating the impact of the wall as part of an independent review into the Maribyrnong floods.
His report, released in October, found it was still unclear how the levee contributed to the floods because the modelling was out of date.
Melbourne Water is due to release its updated modelling in April.
But Mr Pagone told a parliamentary inquiry it was odd that there wasn't already a system in place to evaluate how the flood wall was working.
"There was nothing in place within the (Victoria Racing Club) or elsewhere in government to ensure that what was done to mitigate, actually mitigated," he said on Wednesday.
"(That) struck me as a potential deficiency that... legislatures and government ought to look at."
Mr Pagone said questions also remained for the Rivervue Retirement Village, which saw 47 properties inundated and 70 residents displaced because of the floods.
His report recommended Melbourne Water investigate how it was satisfied in the village's 2009 endorsed plans that the flood levels were reduced.
The water body is due to deliver its report by the end of the year but Mr Pagone does not believe it will be made public.
"That's likely to be a trigger for litigation," he told the inquiry.
"Plainly, there was damage. There's a relationship between the flood level and the damage.
"So whatever gave rise to the decision about that is likely to be keenly looked at by somebody affected - it's not rocket science."
