Busselton and Wonnerup identified in coastal erosion hot sport report

The report was commissioned to gain a better understanding of where coastal erosion is expected to have a significant impact on public and private property or infrastructure over the next 25 years.

It identified 55 locations across WA which included Locke Estate, Wonnerup, Abbey, Craig and King Streets in Busselton.

Premier Mark McGowan said valued infrastructure, homes and livelihoods were at risk due to major storm events and the global rise of sea levels.

"This is not a problem exclusive to WA, it's a national problem that needs a national response. I have written to the PM and I will be taking this issue further at COAG this week," he said.

"Managing coastal erosion should not just fall onto the lap of local and state governments, especially given the negative impact climate change is having on our coastlines."

Seashore engineering director Matt Elliott prepared the report Assessment of Coastal Erosion Hotspots in WA for the state government.

Mr Elliott said the report was an attempt to find where there were problems in WA, particularly areas that were not recognised as much as others.

He said they hoped to find solutions to problems before they became problems.

"In terms of technical findings, we generally had three or four types of causes of problems and the state is in a very good position in terms of having a coastal policy established in the 1970's," he said.

"We have had 40 years where things have worked quite well. The exceptions are those areas which are termed coastal erosion hot spots."

Mr Elliott said they identified characteristics which were common to hot spots, one being they had persistently tried to manage erosion.

He said coastal defensive strategies like groynes or seawalls tended to transfer the problem along onshore.

According to Mr Elliott, Busselton had a different history to the rest of WA when coastal setbacks were established in the 70's.

"Busselton has a much bigger history in intervention than most of the coast, some of which has been more challenging than others," he said.

"There are at least four locations along the coast which have had either greater erosion pressure on the eastern side or there has been a failure of the structures after a while.

"There were a couple of old timber groynes which were put in, in the 60's and 70's which have failed.

"The other one is Wonnerup which has had the fun times of Port Geographe and the challenges which were much greater than were foreseen in regards to sand management.

"When the groyne was removed we expected a degree of erosion and change.

"With the combination of wrack and sand it became a much more challenging and a far more expensive exercise than was anticipated.

"Wonnerup has suffered a bit."

City of Busselton director of engineering and work services Oliver Darby said the region's coast was dynamic and ever-changing.

Mr Darby said sections of the coast could go through periods where they experienced significant erosion and accretion.

"As we have so much development and infrastructure close to the coast, if the coast is not managed, coastal erosion can and sometimes does impact on that development and infrastructure," he said.

"Approximately $750,000 was spent in total on coastal erosion management. The level of spend can, however, vary from year to year dependent on coastal conditions and works priorities."

The report is available at www.transport.wa.gov.au/imarine/coastal-erosion-and-stability.asp.