What was found?

The research has given the City of Melbourne a much better understanding of how best to plan for future flooding.

While not definitive, the project has given the council some valuable insights. Among them are:

• Retreat (abandoning the area) is not necessary;
• Even if no protective works were undertaken, it would still be cost effective to continue to occupy the area; and
• Things can be done now to build community resilience to flooding and some "moderate" protection measures across the entire catchment would also be cost-effective.

As an economic study, it considered the costs and benefits only in relation to the 147 hectares in the actual study zone.

Of course, flood waters don't stop at arbitrary lines drawn on maps and both the costs and benefits should be assessed across the entire affected catchment.

And, in the case of Arden Macaulay, the researchers only had data about flooding from Moonee Ponds Creek and could not include more localised flooding from the Arden St Main Drain. Researchers also did not include information about the condition of the Moonee Ponds Creek levees.

It was concluded that more information would be needed if a more highly accurate understanding of the economic benefits of protective works was required.

The process of being involved in the study revealed that suitable governance structures need to evolve to ensure a co-ordinated response to flooding.

Many of the potential "adaptations" examined within the study are actually outside of the control of the City of Melbourne and council has worked well with the responsible authorities.

The City of Melbourne will continue to work in partnership with federal and state agencies to get the best outcomes for its community.

The study found that the cost of flooding in the study area could increase from $220,000 per year (currently) to more than $2.5 million per annum by 2100.

But by 2100, the predicted economic benefits of occupying the case study area far outweigh the potential damages bill ($60.5 million compared with $2.5 million) so there is no suggestion of retreat from the area.

The study did not find that any of the "adaptation pathways" considered for Arden Macaulay were economically viable.

It suggests that actions aimed at making the community more resilient to flooding would give the greatest return on financial investment.

However, the study's authors do point out deficiencies in the available data and suggest that a moderate protection pathway should be pursued.