247,000 coastal homes in Australia are in the firing line if sea level rises reach 1.1metres

ABC News, 22 July 2019:

The latest figures from the Department of Environment  warn a sea level rise of 1.1 metres, considered a high-end scenario, would cost $226 billion nationally by the end of the century.

If that eventuates, it would put up to 68,000 homes at risk in Queensland and the same number in New South Wales.

In Victoria and South Australia, it would be up to 48,000 homes, up to 30,000 in Western Australia and up to 15,000 in Tasmania.

Every coastal community in Australia is doing its own mapping, but Noosa may take it a step further.

The Noosa Shire is now considering how best to warn owners, both current and future, about the risk.

Councillors say the estimated 2,232 Noosa properties likely to be affected by storm flooding in 80 years' time could be told directly via rates notices.

Possible buyers may also be alerted through routine property or rates searches.

Noosa Mayor Tony Wellington said it was "a problem that every coastal council is facing around the world now — and it's an issue of defend or retreat obviously".

"What we have to look at is whether it is feasible and possible to defend property, in a worst-case scenario, or whether it is not possible, and what the cost implications are," he said.

"And then you have to ask whether all residents should be funding for protection of a few properties.

"It's a very complicated issue."

The Mayor also said it was a matter of "buyer beware" and those in low-lying areas ought to know the risks.

In 2015, a report to Byron Bay Council warned that certain homes may become "voluntary house purchases" where the council buys homes at risk of flooding "to reduce risk to life and limb"…..

The Insurance Council of Australia said climate declarations and long-term fears of flooding would not affect premiums, but actual storm or water damage could.

"If you're already at risk and climate change predicts that you will become further exposed, then your premiums over the next 30–80 years will go up to reflect changes in that risk," the council's Campbell Fuller said.

Even the current rate of global sea level rise at 3.4mm each year has the potential to impact on vulnerable coastal towns such as Yamba on the NSW Far North Coast.

Excerpt from Clarence Valley Council Yamba Floodplain Risk Management Plan, February 2009:

Flooding at Yamba can occur as a result of a combination of high flows in the Clarence River, high ocean levels, wind wave action along the foreshore or from intense rain over the local catchment. The risk to life due to river flooding is considered to be low as inundation occurs gradually and with several hours (or days) warning. Similarly, flood hazard resulting from ocean storm surge is also considered low as there is likely to be several hours warning of an event, with the peak of the storm lasting for less than a day. The Floodplain Risk Management Study indicates a storm surge warning time of 6 to 24 hours. It should be noted however that the flood hazard can become high if the low lying community to the west of the town does not respond to flood warnings as the available high ground is only accessible by Yamba Road, which is readily cut by floodwaters. The only road out of Yamba to the Pacific Highway is also inundated in the 10y ARI and greater flood events. [my yellow highlighting]

Ballina is another  coastal town on the Far North Coast. Its CBD is on the banks of the tidal Richmond River where it empties into the sea.

Sea level rise is something Ballina has been discussing for many years because for the Ballina community the evidence is right before residents’ eyes.

This was Tamar Street in the CBD in January 2018 showing saltwater intrusion at high tide.

Photograph supplied by @Captainturtle

Other Far North Coast towns and villages are also under threat of foreshore/beach erosion, wave overtopping and/or innundation, including Wooli, Belongil Beach and Clarkes Beach.