17.1 C
Byron Shire
May 19, 2024

Why are we building on floodplains?

Latest News

Brunswick 30 has been delivered to Brunswick Heads Boat Harbour

Following successful sea trials at Yamba the Brunswick 30 was delivered to Brunswick Heads Boat Harbour on Wednesday, May 15. 

Other News

Waiting for Assange

A major turning point in his son’s freedom campaign only twelve days away, John Shipton exuded calm and at times, joy, during an intimate forum in Mullumbimby last week.

Domestic violence

It has occurred to me that as many women who experience domestic violence are forced to flee their homes,...

Foodie fest on the table

Food and culture takes centre stage this week, as Caper Byron Bay Food & Culture Festival returns May 17 to 26.

Local housing prices down over 20 per cent

The region has seen falling house prices, new data from CoreLogic suggests.

Big tech, porn, violence and young blokes

I know it’s time we talked. The trouble is, I don’t know exactly what to say. But let’s try this...

Free all the people

By any account, the current ongoing humanitarian tragedy in Gaza today needs thorough analysis, to objectively understand the causes...

Should we live on floodplains and just expect regular flooding? Photo: David Lowe

Brought to you by Cosmos Magazine and The Echo

And who’s responsible for the building?

Parts of New South Wales are being inundated for the third time in four months as yet more record-breaking rain causes flooding to Sydney and beyond. Add to this the March 2021 floods and it’s the fourth time in two years that some people have watched parts of their homes go under water.

Flood risk has been known to Sydney for nearly as long as Sydney as a European settlement has existed. In 1817, for instance, governor Lachlan Macquarie sent numerous letters warning colonists against building on floodplains. First Nations people have had tens of thousands more years to manage and avoid floods.

Climate change will only exacerbate this. So: why are we still building in the path of floods – and what would it take to stop doing it?

“People built on them in the past because there was quite a high degree of ignorance,” says Professor Jennifer McKay, a researcher in environmental management and business law at the University of South Australia.

This is no longer a good excuse, according to McKay. “No ignorance is possible of the scientific evidence about floodplains. Where there’s a floodplain, there will be a flood,” she says.

Now, the incentives for developers and local councils outweigh the perceived flood risk. Knowledge hasn’t stopped massive developments and influxes of people in flood-prone parts of Western Sydney, which now faces an overflowing Warragamba Dam and a subsequent rising Hawkesbury River.

“Prior to 2021 the previous big flood was 1990 – and this, to me, is the problem,” points out Dr Ian Wright, a senior lecturer in Western Sydney University’s School of Science.

“We’ve had 31 years relatively flood free – my criteria is there’s been no major floods, exceeding 12.2m at Windsor, which is the threshold for what is considered a major flood in the Hawkesbury.”

The three-decade gap, and the growth of Sydney’s population, means there’s little community memory of flood risk.

“Perhaps the height of bridges, or escape routes, hasn’t been top of mind of the community, industry or the elected leaders. It certainly is on top of mind now,” says Wright.

“Warragamba, in a day, has spilled pretty much what Sydney drinks in a year over this last weekend.”

So what should happen?

“The statutes in every state that enable development approval very rarely include the need for the potential area to be assessed for hazards, either fire or flood, and that’s what needs to change,” says McKay.

Development approvals are managed by the states, but McKay thinks there’s a role for the federal government to play too.

“The Commonwealth could step in here and create a law because they’ve got plenty of power. But obviously, it’s politically not expedient to do so,” says McKay.

Wright agrees, suggesting there’s space for such a law under the Environmental Protection and Biodiversity Conservation Act.

“I think a floodplain – and particularly the Hawkesbury-Nepean, which is also the water supply for five million people – that’s a matter of national environmental significance, so it slots neatly into legislation,” says Wright.

More on floods: Rebuilding for flood resilience

McKay adds: “We need to have a decent royal commission on this.

“We need to look at all the state laws, point out what’s wrong with them and get the federal government involved in getting the states to make sure that this issue is considered.”

The housing and rental market being what it is, a house built on a floodplain will still be lived in by someone – but they’re likely to be more economically vulnerable than people who can afford to live in less risky areas.

“Government should be looking at the longer-term, broader perspective, particularly for people who are deprived economically,” says McKay.

“Just letting the market send them to the cheapest places is going to create many more costs in the long run.”

This article was originally published on Cosmos Magazine and was written by Ellen Phiddian. Ellen Phiddian is a science journalist at Cosmos. She has a BSc (Honours) in chemistry and science communication, and an MSc in science communication, both from the Australian National University.

Published by The Echo in conjunction with Cosmos Magazine.

Support The Echo

Keeping the community together and the community voice loud and clear is what The Echo is about. More than ever we need your help to keep this voice alive and thriving in the community.

Like all businesses we are struggling to keep food on the table of all our local and hard working journalists, artists, sales, delivery and drudges who keep the news coming out to you both in the newspaper and online. If you can spare a few dollars a week – or maybe more – we would appreciate all the support you are able to give to keep the voice of independent, local journalism alive.


  1. The problem is that developers are allowed not-to-care about what might happen in the future AFTER they have sold their blocks.
    State governments and Councils need to be able to exercise PROPER planning, without fear of been taken to court, without taking bribes, without being accused of not providing sufficient land for construction.
    The entire system is corrupt and (mostly) the not-so-rich pay the price. This is today’s ‘Fair Go”!

  2. The longer-term is obvious… still ‘making a dollar’ wins every time.
    Laws are needed to stop the skimping. Simple, really.

  3. We are building on flood planes because of mass immigration in a relatively short time frame..
    The population has to go somewhere, and the cheapest land is the flood plane. Unfortunately we are now in the early stages of a Climate Catastrophe and flood planes are flooding more often and more severely.
    The sheer numbers of people needing housing overwhelms the planning system, corners are cut and proper assessment goes out the window.
    Next global heating will throw ocean level rises at us. Millions of existing properties will be threatened with inundation.
    Business as usual is not an option.
    We need housing that will protect us from flooding, severe heatwaves, super cyclones, and wild fires
    Building on and into the sides of hills ,hobbit fashion, would protect us from all the climate threats provided the hills are stable.

  4. Flood planes have ‘the last say’ & we’d best believe it. As for Land Swap realize
    assistance is needed – forget putting-it-on-hold because that is foolish as well.
    The way of the world’s incompetence is due to ‘the ways of mankind’ brought
    to slackness & the love of an easy buck. The sell-out is here to stay. Playing the
    game of numbers no longer works. This avoiding the obvious has got to stop.
    Think on it.

  5. Cosmos got it a bit wrong re flood and fire assessments .. Re floods, there is flood inundation mapping on the NSW coast and i would think state wide for decades which controls development approvals. Before that — we have a problem re existing settlement. Today the problem is councils, engineers and developers try to find ways to mitigate / engineer a solution. Obviously it doesn’t always work and big areas get flooded with an oh well, we tried — don’t sue us.! And with climate change here and predicted to be more extreme by scientists who have now studied the scenario for 50 years – there is a huge problem turning the Titanic around. The insurance industry is the first group manning the lifeboats, others will follow – – but there is not enough lifeboats for the people getting flooded — only a life vest in freezing water.

  6. In the end the solutions are always political — the system of dividing up power and resources. The general public has to take more interest in their lives and where the Titanic is taking them if they really want to survive the trip ! . .


Please enter your comment!
Please enter your name here

Editorial – Just another unjust moment in history

Justice has been served and it’s a shit sandwich: whistleblower David McBride is now the first person to be sentenced to jail in Australia for reporting war crimes.

What do young people want and what do they think needs to change?

The ‘Your Voice, Our Future’ survey has been launched and is asking young people to put forward their views on what is important to them. 

Conciliation meeting over Broadwater floodplain development terminated

Richmond Valley Council refused a development application for a 60-lot residential development on flood-prone land on Rileys Hill Road, Broadwater, close to the Richmond River in October 2023. 

Pickleball takes Alstonville by storm as new courts open

Alstonville now boasts tournament-standard pickleball courts that opened to an enthusiastic crowd and players last Saturday despite the rain.