Major cities at risk of Brisbane-like flooding
Updated
Flood engineers say the huge floods that devastated Brisbane last year could also happen on a similar scale in Melbourne, Perth, Adelaide, the Gold Coast and Newcastle.
They argue that thanks to Australia’s three levels of government, flood planning around the country is patchy at best, allowing for houses to be built where they should not.
On Wednesday, ABC Radio’s PM aired the first of a two-part look at Australia’s flood planning. Now it looks more broadly at how well Australia is prepared for flooding and the battle between development and nature.
Last week Federal Minister for Emergency Services Robert McLelland stood on a levee bank as floods surrounded the southern Queensland town of Charleville. He liked what he saw.
“We’ve literally stood up on the levee bank – dry on one side – looking over the moving water on the other,” Mr McLelland said.
“It unquestionably, unquestionably saved the town and I think from the long-term point of view of resilience, we need to methodically go through these areas that have been effected and look at mitigation steps we can take.”
Talk to any flood engineer and they will tell you that is an admirable proposal, but they want more.
Steve Molino, a consultant who has advised on flood plain planning for 20 years, says places which have not flooded recently also need to be examined.
“You do need to look at the places that have flooded but you also need to look at the places that did not flood,” he said.
“There’s many places in Queensland that got out of the floods this year and got out of the floods last year scot free, but are at just as much risk of flooding as many of the places that flooded last year or this year.
“Those places need to be encompassed in any studies that are done.”
And that is just Queensland.
Mr Molino says the potential flood risk across all of Australia is “huge”.
Hayden Betts, who has a PhD in flood plain management and works for KPR consulting engineers in Brisbane, agrees.
“I’m not sure how many hydrologists and hydro-engineers there are in the country – must be a thousand or two. If they applied their mind to it, I think there’d probably be enough work to keep them going for a decade or three,” he said.
Patchy preparation
But Mr Molino says Australia’s flood preparation is patchy.
“We have places where there are good structural works in place; there are places where structural works are needed,” he said.
“There are places where there is good town planning place; there are many places where better town planning is needed.”
All our major cities have been built for historical reasons around rivers and on flood plains, so there are parts of our cities where we really do need to rethink whether those areas should be vacated and put over to other uses.
Steve Molino
And therein lies the big problem – just who is responsible for planning and dealing with floods in Australia?
“The responsibility falls to local, state and federal government but it varies around the country,” Mr Molino said.
Steve Opper, the director of community safety with the New South Wales State Emergency Service, thinks New South Wales has got the balance about right.
“Our situation I believe is extremely robust,” he said.
“The State Emergency Service in New South Wales is unique nationally in that we control the management of floods in an emergency context all the way from state level to local government level.
“In other jurisdictions, quite often it might be just the local council that’s responsible for planning and they may just not have enough expertise to do that.”
Money is also an issue.
Take the problem of levees – the raised banks which can protect towns from floods.
Often state governments might provide the funds to build levees but then leave it to local government to do the maintenance.
“There are levees that have been built, have settled over decades and are now providing a lower level of protection than they were originally designed to provide,” Mr Molino said.
“And there are many levees that have just been left to their own devices; there’s been no maintenance undertaken on them and therefore there’s cracks appearing in them, there’s trees growing in them.”
Then there is the problem of protecting our big cities.
Mr Molino points to the fact that there have been a number of one-in-a-thousand flood events in Australia in the past five years.
Luckily they have been in sparsely-populated areas, but Mr Molino says the damage would be far worse if a rare flood were to occur in a bigger city.
“If a flood of that frequency were to occur somewhere like the Gold Coast, on the Hawkesbury Nepean river or on the Georges River – they’re major rivers running through Sydney – floods of that type of frequency, and they do occur around the world all the time, were they to occur in one of those areas, we’re talking about tens of thousands of houses under water and many of those homes washed away,” he said.
“And Melbourne is not immune. Melbourne has the Yarra and the Maribyrnong River and other rivers – as Melbourne expands – going into other catchment areas.
“The Torrens through Adelaide hardly ever flows, but it can flood.
“The Swan River in Western Australia.
The balance between how much development we put in an area and the flood risk is a very complex one; between what you can achieve to create housing and places for people to live against the risk that you place when you live almost anywhere.
Steve Opper
“All our major cities have been built for historical reasons around rivers and on flood plains, so there are parts of our cities where we really do need to rethink whether those areas should be vacated and put over to other uses.”
National leadership
For Mr Opper, who has drawn up the plan for evacuating tens of thousands of houses in western Sydney, proper town planning is part of flood preparation.
“The balance between how much development we put in an area and the flood risk is a very complex one; between what you can achieve to create housing and places for people to live against the risk that you place when you live almost anywhere,” he said.
Last year, the state and federal governments signed off on a national strategy for disaster resilience, which deals with floods.
It makes note that all levels of government must share the responsibility.
But some people believe that system does not work.
Dr Anthony Bergin, the director of research at the Australian Strategic Policy Institute, says the Federal Government should be taking the lead.
“Now’s the time for the Commonwealth to take a leadership role in natural disaster planning, particularly flood plain planning,” he said.
“The new Federal Emergency Management Minister Robert McLelland needs to be arguing an economic case for disaster mitigation around micro-economic reform, because a dollar spent in mitigation – flood mitigation – does save somewhere between two and $10 in reduced disaster response and recovery costs.
“And this could be the opportunity for him to leave a legacy of national leadership around disaster management.”
Topics: floods, emergency-planning, federal-government, states-and-territories, local-government, australia, sydney-2000, surfers-paradise-4217, adelaide-5000, melbourne-3000
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