7 May, 2021
Climate change pushes council to flood reforms
Central Highlands Regional Council recently endorsed reports into flood mapping the Highlands region.
COUNCIL has endorsed several reports on flood mapping in the Highlands area, including an update of the Emerald and Sapphire models.
The new updated model of Sapphire will extend up to Retreat Creek and does not include Policeman Creek which flooded last month, but they may include it in the future.
The endorsement was the first step in the process of mitigating future flood damage.
In the minutes of the council meeting late last month, it noted an increase in rainfall intensities could rise 20 per cent if the Earth warms by five per cent to the expected 40C by the year 2100.
In 2013, the council adopted the Defined Flood Event (DFE) (a hypothetical future flood event) which considered the adverse effects of climate change on the weather.
Acting Council General Manager (Infrastructure and Utilities) Jason Hoolihan said now was the appropriate time to update mitigation options.
"At the time, when council was doing its flood modelling, we took the best advice that existed,” he said.
Mr Hoolihan said the CSIRO had been talking about a global increase in temperature of somewhere between 2-7C and in Australia we will see an increase in 4C.
The Central Highlands DFE between now and 2100 is at 0.5 per cent (a flooding event occurring every 200 years) which is better than many coastal towns who are now sitting at a flooding event every 80 years.
The one per cent DFE in the council’s reporting is erring on the side of caution.
Moving forward, the council will be more considerate towards new developments concerning their level above the ground.
“It’s more sustainable and sensible development,” he said.
Mr Hoolihan said he was accepting of the council’s “conservative” approach to developing a small DFE.
“Based on the current science, I wouldn’t see any sense in diminishing the DFE even though some individuals may complain that I may cost a little bit more in some parts of town (for development).”
In 2016, the council took into account insurance levies for residents when organising the flood mapping, they seek to do so again with the current round of flood mapping.
“We’d like to take the updated outputs and give them to the Insurance Council of Australia,” he said.
Mayor Kerry Hayse said insurance premiums shot up after the floods, and several customers made the claim the council had not done anything to mitigate flood risk.
“That is completely false, we’ve provided that information for a long period of time” he said.
“Any time we get some evidence of that we should report those people.”