The committee's report stated 18 per cent of the low-lying region was likely to be affected by flooding or "overland flow paths".

About 18,000 properties, valued at almost $2 billion, were "vulnerable" to flooding.

The coastal environment, including Ransar-listed wetlands, were at risk from sea levels and more frequent and severe storm surges, the report stated.

Greg Hunt, executive officer of the South East Councils Climate Change Alliance, had made a submission to the committee painting a similarly dire picture.

The alliance, which includes Casey and Cardinia Shire councils, last year predicted a 0.17-metre sea level rise in Western Port by 2040 and a 0.49-metre rise by 2070.

Mr Hunt said that in the short-term he'd like to see more certainty in state planning laws for those wanting to build waterfront properties, and more security for sea-changers who wanted to move to the region.

"It's not going to be a regular sea level rise. You notice it when the sea gets sloshy, such as with a storm surge.

"At the moment you might see [a flood event] every five years. As we move further into this century, we will see it happen more often."

He said dykes or sea walls were not necessarily a solution. "We need to look at a raft of solutions whether it's to put your house on stilts or retreat or to try to use engineering such as seawalls or drainage to lessen the impact."

Mr Hunt said Casey Council's climate change task force was set to launch forums so the issues could be jointly resolved by the council and community.

Casey Council did not respond to the Journal's enquiries before deadline.

Cardinia Shire Council plans to set up its own climate change taskforce to focus on the greater threats of flooding and fire.