Townsville’s 2019 floods

The Townsville flood of January-February 2019 was, like cyclones Althea and Yasi, one of the extreme weather events which define people’s lives in the city. Two months later, “How did you go in the floods?” is still the first question we ask friends we haven’t seen for a while. There’s a lot for Green Path to say about it but whatever we publish now will be incomplete so we will update and extend it as appropriate, in separate posts if justified by the amount of extra material.

Let’s begin with an overview of the weather event and its immediate consequences.

The weather event

A low in the monsoon trough over the Gulf became a rain depression and drifted South and East until it settled over Townsville, where it stayed much longer than “normal” (we will have to return to that concept later) and dumped an inordinate amount of rain on us over about ten days – say 29-30 Jan to 7-8 Feb. 

Variations on this pattern bring our heaviest rainfall episodes – even more rain than cyclones, contrary to most residents’ expectations. One of them, for instance, brought  nearly half of last year’s rain.

Comparable floods

Long-term residents naturally compared the 2019 event with other big floods as far back as World War 2, that being roughly the limit of “living memory” now. The four mentioned most often were:

  • The Night of Noah, Jan 1998: whether the flooding this time was worse than that event depended a lot on where you were, but the events were broadly comparable.
  • Cyclone Althea, 1971: similar levels of flooding but (importantly) before Ross Dam was built. That suggests that both 1998 and 2019 would have been far worse than Althea.
  • Before that, 1946 and 1953 are mentioned; but in those days, Townsville was less than a fifth of its present size.

If we wanted to compare weather events as such (rather than their effect on such different built environments), rainfall figures would be a more realistic and objective measure. The BoM’s Special Climate Statement 69 (http://www.bom.gov.au/climate/current/statements/scs69.pdf) makes those comparisons, and its Executive Summary is worth quoting in full:

• An active monsoon trough and a slow-moving low pressure system over the northern tropics produced extremely heavy rainfall in tropical Queensland from late January 2019 into early February.

• In and around Townsville, the accumulated totals from consecutive days of heavy rainfall set many new records. The highest weekly accumulations were comparable in terms of geographic spread, duration, and intensity of rainfall to those of January 1998 and January 1953.

• In the seven days to 4 February 2019, the Bureau’s site at Townsville Aero recorded 1052.8 mm, and 1259.8 mm in the ten days to 8 February. Prior to this event, the Townsville record for a 7-day period was 886.2 mm (January 1998) and for a 10-day period was 925.5 mm (January 1953).

• There were several sites in elevated areas including Paluma, Woolshed, and Upper Bluewater that reported 12-day accumulations of more than 2000 mm.

• In the Gulf Country and North West Queensland, record-breaking rainfall also occurred in previously drought affected regions, including at Julia Creek and Richmond.

If you want more information but the statement’s thirty pages of data seems too much, ABC News reported on the climate statement here.

The Climate Change connection

Climate Change, aka Global Warming, is a proven theory about long-term changes in our weather patterns. We have the data to show that, for instance, Townsville’s average annual rainfall has been falling for decades. Quite frankly, we need the data for this job, since our rainfall varies so much from one year to the next that picking out long-term patterns is almost impossible without it.

But climate change does not just alter long-term averages: it also supercharges short-term events.

Saying that a particular event is “due to” or “caused by” climate change is rarely justified, but saying that it “was made more likely” by climate change may be valid. In fact, there’s a whole subsection of climate science, attribution theory, which studies the subject; this US site introduces its key concepts.

The BoM’s Special Climate Statement 69 is cautious about attributing our recent flood to climate change: a two-word summary of its one-paragraph conclusion could be “quite possibly.”

Seriously nutty weather

NOAA satellite image
An enormous streamer of dust from NSW into western Queensland, while the Flinders River floods cover much of the Gulf country on 14 Feb.

Ten days after the peak of the rain, Western Qld still featured a river 200 km wide, Townsville people were still dealing with the mould – and worse – but there was so much haze in the air at midday on Feb 14th that Mount Stuart was barely visible from Mundingburra, a distance of four or five kilometres. Why? Dust was blowing up from the south-west, from inland NSW and southern Queensland.

And six weeks later, around March 22, we had two cyclones at once in the Top End. Trevor approached from the East, crossed Cape York Peninsula, re-formed in the Gulf and crossed the Southern coast of the Gulf on March 23 as a Category 4 storm to dwindle into a rain depression as it drifted SE. At the same time, Veronica was approaching the Pilbara from the Indian Ocean as a Category 3 system.

Consequences

How many of us were “affected by the floods”

Published numbers vary but, really, 100% is the correct answer. Many people lost a lot of their worldly possessions – cars and bikes, couches and fridges, carpets, teddy bears and computers, if not their whole house. And those not directly affected either at home or at work helped out flooded friends and family, or had to cover for flood-affected co-workers, or struggled to find child care because nearly all schools were closed, or couldn’t buy groceries because shops were shut and roads cut.

Some of these consequences are described in a separate post, Townsville’s 2019 floods – consequences in daily life.

Insurance

Household cover sometimes includes floods from rivers and/or rainwater run-off, sometimes covers lost rent, extra living expenses up to and including temporary accommodation. It never covers the time spent by owners or tenants in cleaning up the mess – usually many hours – although it may cover cost of materials (e.g. paint).

I saw some evidence of tradespeople quoting for work which wasn’t strictly necessary, and of course the delays caused by the huge volumes of claims and repair work added a hidden cost for many of us.

Natural justice was nevertheless sometimes achieved. For instance, the new-for-old cover on some very old house contents could go some way to compensating us for our hours of cleaning and repairs. However, I’m sure we’re going to see the insurance payout reflected in increased premiums in the near future.

Government assistance and “a boost to the local economy”

Getting the $1000 disaster relief payment was not difficult and the money was certainly welcome. Most of us us will spend it immediately on replacing goods lost in the floods, so it will be a big boost to the local economy – around 50,000 people by $1000 each is a $50 million cash injection in a city which has been in the economic doldrums for some time. One can almost see Townsville Enterprise and the City Council celebrating the news. But are we, the people, actually any better off? No. The $1000 vanishes into replacing stuff (and usually won’t replace all we’ve lost) and we’re really back where we would have been without the flood – but tireder, because we’ve all spent so many hours cleaning up the mess.

Property losses: rain events, population growth and planning failures

In the nearly-thirty years I’ve lived in Townsville the city has grown from roughly 150 000 to 220 000. Much of the new housing has been built on land previously considered unsuitable because everyone knew it was flood-prone. “Wouldn’t build there!” the locals would say … except for the Council officers who saw the $$ signs and let the developers go ahead. “Wouldn’t buy there!” the locals would say – but people new to town (or too young to heed the stories of earlier floods) would go ahead anyway.

Idalia is the stand-out example. It always was a flood plain and, sadly, became one again. There is a lot of anger in the community about the fact that development was ever approved there, and some disquieting rumours about the approval process.

Fairfield in 2019 floods
Aerial view from near the intersection of Bruce Hwy and Abbott St, Fairfield on Feb 4

This aerial photo (from facebook, so I can’t credit the photographer – sorry) looks West along University Road over Fairfield Central shopping centre. Ross River, near Fairfield Waters shops, is in the centre-distance and Idalia is on the right of the picture.

Hermit Park was badly flooded, too, but it’s a much older suburb and most of the houses there were built for the conditions, unlike the generic-modern low block houses in Idalia. Possessions were lost but far fewer houses will need to be demolished than in Idalia.

All of the newer suburbs contributed to the severity of the flooding for another reason, too: big houses on small blocks mean that there is little open ground to absorb the rainfall, so it all has to run off into the stormwater drains, the streets and, eventually, the rivers.

Apart from making extreme weather more likely, Climate Change messes up our calculations of of flood probabilities, as the BoM says:

This Special Climate Statement provides estimates of annual exceedance probabilities based on historically recorded rainfall for the region. However, these historical estimates may not be an accurate guide to the actual probability of the recent heavy rainfall event, and are likely to underestimate the probability of such rainfall in the future. This is because the climate system is changing, and global warming increases the likelihood of heavy rainfall events in most locations.

The Disaster Management Centre set up by Townsville City Council issued a media release as early as Feb 7 which said that, “the flood levels in the Ross River were greater than a 1 in 500 year event,” and, “There were rainfall totals over parts of the Ross River Dam catchment during the past week that were in excess of 1 in 2000 year rainfall events,” but both claims are dubious in the light of climate change.

Management and mitigation

Very briefly –

    • There have been suggestions that management of the Ross Dam contributed to the flood damage because of delays in opening the dam gates, i.e., the gates should have been opened earlier. Many were reminded of the handling of Wivenhoe in the 2011 floods.
    • There have also been suggestions that the weirs, (Black, Gleeson’s and Aplin’s, should have been removed years ago so that any flood water released from the dam could get away immediately, and indeed that there was a 2010 flood mitigation strategy report to that effect. It seems reasonable, especially to someone like myself who saw the floodwaters backed up behind Aplin’s Weir spreading into Aitkenvale via Thompson St.
    • Wally’s Weather’s retrospective has a few recommendations for better flood management.
    • Brian Gunter makes rainfall comparisons here  and discusses the consequences of different dam water release options.
    • Townsville floods show cities that don’t adapt to risks face disaster on The ConversationThe Conversation has a series on Australia’s weather hazards, indexed here. This one is about medium-term weather patterns which change the flood risk in SEQ; it doesn’t talk about the tropics but the possibility that similar patterns are yet to be discovered here is intriguing.
    • This brief article on Wikipedia has some useful links.
    • A photo album collected at the height of the emergency.

Western Queensland

A flood so vast it can be seen from space –

The tropical low on the monsoon trough continues to move east over the Coral Sea, taking much of the heavy rainfall which caused widespread flooding in Queensland with it. While sunny conditions have returned for much of the state, satellite images reveal the extent of the flooding on the Flinders River where tragically, widespread agricultural impacts and stock losses have been reported. Flooding in the Flinders, the longest river in Queensland which feeds into the Gulf, is the most significant we have seen in more than 50 years, with flooding likely to continue well into next week.

That is from a BoM press release.

Major Flood Warning for the lower Flinders River and Moderate Flood Warning for the Norman River
Issued at 8:54 am EST on Sunday 17 February 2019
Flood Warning Number: 40
Floodwaters across the lower Flinders River have continued to very slowly ease, based on satellite imagery. Major flooding will continue along parts of the lower reaches of the Flinders River during Sunday and into next week.
The Flinders River has experienced its most significant flood in at least the last 50 years. Record floodwaters in places has also broken out into adjacent catchments.
It is recommended to look at satellite imagery (http://satview.bom.gov.au) to appreciate the full extent of the flooding in and around the Flinders River area, particularly the lower reaches of the Flinders River which extend into the neighbouring catchment area of the Norman River.

The satellite images associated with the press release and warning seem to have been taken down but I saved one, virtually a close-up of the NOAA image above.

Flinders River floodwaters
Flinders River flooding into the Gulf on 12 February (BoM image) Scale: approx 1000 km from one edge of the map to the other.

21 thoughts on “Townsville’s 2019 floods”

  1. Climate change could slash $571b from property values, study warns

    A Climate Council study warns the value of Australian real estate could plunge over the next decade unless future governments have the political will to deal with climate change. The research estimates residential property value losses of $571 billion by 2030 related to increased extreme weather events, inundation of some low-lying coastal properties and higher insurance premiums.
    That would wipe approximately 9 per cent of the nation’s total residential property value — about as much as has been lost so far in the current property downturn, which is on track to be the worst in Australia’s recent history. However, these losses would not be evenly spread, as an estimated 5-6 per cent of property owners bear the brunt of climate change risks. …
    The report estimates $4 trillion could be wiped off economic growth over the next 80 years if carbon emissions do not fall.

    Read more on ABC News, https://www.abc.net.au/news/2019-05-09/climate-change-could-wipe-571b-off-property-values/11096768

  2. The Magpie has a few pointed comments about the flood report at http://www.townsvillemagpie.com.au/that-flood-report-the-townsville-bulletin-says-it-asks-the-tough-questions-we-want-answers-to-well-the-magpie-has-a-few-for-you/ but you will have to scroll past a few other matters to find, e.g., “The devil in this detailed report is in the original scope as developed by QG. It solely looks at the operation of the dam and specifically excludes all the questions people (such as above) legitimately want answered:
    – what happened to the promised flood maps which were released late and in an unreadable format
    – why did the much touted “point of truth” dashboard fail at about midday on Sunday and not provide any up to date information to residents
    – why were a string of confusing, contradictory and simply wrong texts and voicemails sent out, by whom and why,” and “… control of the dam was handed back from SunWater to council 48 hours before the full release because the engineers couldn’t agree on when things should happen. The council has no expertise in dam management. SunWater recommended opening the flood gates 2 hours after the actual time to work with the tide on the night. This would have resulted in a 200ml lowering of the flood level. It would have saved $millions. Of course, people in the know were not consulted for the report. It’s a serious whitewash of events.”

  3. An important article on two kinds of “attribution science” – attribution of emissions to fossil fuel producers, and attribution of extreme weather events to global warming.

    WHILE THE CLIMATE science community was initially cautious about attribution science, lawyers were immediately intrigued.
    “I think they recognized that it was a bit of a game-changer,” said Cullen, the climate scientist.
    The two scientific breakthroughs – the ability to link global warming to the intensity of storms, rising sea levels and worsening heatwaves combined with the ability to trace historical emissions to individual companies dating back to the Industrial Revolution — have laid the legal groundwork for a string of lawsuits getting underway in coming months.
    “We can actually close this causal chain now,” said the Environmental Change Institute’s Otto . “If the first judge has the guts to actually accept such a claim and give a verdict against a big polluter, then that will force these companies to change their business models.”

    Read the whole article at https://www.politico.com/agenda/story/2019/10/22/attribution-science-fossil-fuels-climate-change-001290

  4. MSN news reported on 29.11.19 that:

    A Supreme Court judge has ruled in favour of thousands of [southern] Queenslanders who lost their homes and businesses in the 2011 floods.
    The massive class-action lawsuit from Maurice Blackburn Lawyers took on SEQWater, Sunwater and the Queensland Government over the management of Wivenhoe Dam.
    The plaintiffs argued that if the dam gates were opened earlier, the flood that inundated much of Brisbane would have been lessened.
    Justice Robert Beech-Jones ruled that a “reasonably competent” engineer would have taken more action to mitigate the flood damage from earlier dam releases. …
    Seven thousand victims of the floods had signed on to the lawsuit, making it one of the biggest in Australian history.
    More than 22,000 homes were flooded in and around Brisbane, and thousands of businesses were also inundated in the 2011 disaster.

    This ruling certainly increases the likelihood of a similar class action in regard to the Townsville floods, as Peter Newey of the TRRA said recently on the WFTAG facebook page.

  5. An overview of difficulties, for both insurers and homeowners, with insurance against weather events in the era of climate change.

    “The whole basis of insurance is that it is underpinned by that element of uncertainty. It’s a little bit like gambling, you might win, and you might lose and that’s how insurers make their money and remain solvent companies,” she says. “But if you’re looking at properties that are definitely going to be inundated by sea level rise, that’s at odds with the entire concept of property insurance. It’s more akin to something like life insurance — you know that you’re going to die, you just don’t know when it’s going to happen.” And that kind of change, she says, will likely result in a steep rise in premiums.

    https://www.abc.net.au/news/2020-05-14/home-insurance-as-climate-change-and-disasters-affect-industry/12227466 is longish and a bit complicated but worth the time.

  6. Charleston, the largest city in the U.S. state of South Carolina, is discovering it has a very similar climate-driven flooding problem. Here’s the beginning of a big research series in their local paper. https://www.postandcourier.com/rising-waters/forget-about-climate-change-the-real-story-is-climate-speed/article_b0785be0-8e2f-11ea-bc3f-3bd7afe8bdf2.html

    A two-hour cloudburst drenched Charleston on Wednesday, turning downtown streets into swirling rivers. Nearly 5 inches fell over the city’s hospitals, turning the medical district into an island. Five inches fell on Johns Island, turning parking lots into lakes. It was a mess. And it’s not normal.
    Set aside the notion of climate change. The climate has always changed. The real story is about speed. The pace of change. From rain bombs to higher sea levels, the impacts are coming faster. This is as real as Wednesday’s storm. And the one four weeks ago. And so many others in the past five years.
    In the coming months, The Post and Courier will explore these accelerating forces and their many ripple effects. We’ll explore the underlying science and responses by our elected leaders. We’ll look at the winners and losers. We’ll examine potential course corrections.
    And we’ll do this in real time, as the king tides rise, the hurricanes gain strength, amid the thunder and lightning. Why? Because a breaking news story only skims the surface of what’s really happening. Deeper currents can remain hidden amid the immediate need to stay dry or move your belongings to higher ground.

  7. It’s Sydney’s turn now: https://www.abc.net.au/news/2021-03-22/nsw-flooding-forces-evacuations-and-school-closures/13266072
    We do sympathise but can’t let the event pass without commenting.
    The ABC is usually very good but it managed to write about the causes of the flooding without mentioning climate change, extreme weather, or the effect of covering the land with roads and buildings. To extend the author’s own bathtub analogy, we’ve glazed a porous tub and started filling it with a fire hose: https://www.abc.net.au/…/nsw-floods-explained…/100019728
    And they have similar issues about planning approvals for building on a flood plain, and similar debates about operating (and raising) their dam: https://www.abc.net.au/news/2021-03-23/plan-for-warragamba-dam-after-sydney-flooding-explained/100021180

    1. The BoM has compiled a special report on the 2021 NSW floods, as it did on our 2019 floods. The ABC report on it here – https://www.abc.net.au/news/2021-04-20/nsw-floods-break-120-year-old-rain-records/100079400 – is headlined “NSW floods break 120-year-old rain records during March rain event, BOM says” and says that while individual local records fell, the real news is that the rain was so widespread and prolonged. A blocked weather system was responsible, as it was for us. The full BoM report is at http://www.bom.gov.au/climate/current/statements/scs74.pdf

  8. Another extreme rain event caused, in part, by a blocked weather pattern. This one spread from Gympie and Maryborough through Brisbane and down into the Lismore area. Here are some pictures and a few figures. https://www.abc.net.au/news/2022-03-01/brisbane-queensland-nsw-flood-weather-as-it-happened-pictures/100871726

    A few key stats from it:

    Last Wednesday more than 400mm fell in less than 24 hours near Gympie, and parts of the Sunshine Coast received 140mm in just one hour. …
    In just two to three days, Brisbane received about 80 per cent of the rainfall it would normally get over the whole year … More than 30 suburbs across the south-east received more than a metre of rain. Then during high tide on Monday morning, the Brisbane level peaked at 3.85m — its highest level since the 2011 floods. On Monday more than 18,000 homes across south-east Queensland are thought to have been flooded, and almost 60,000 homes across the region were without power.

  9. July 2022, and flooding rains in (particularly) NSW and SE Qld have already made it the wettest year on record in many locations, and there’s more to come. Why? La Nina on top of La Nina, but also

    …while Australia has always had floods and other extreme weather, climate change is making them longer, more intense and more destructive. According to the weather bureau, Australia’s climate has warmed by around 1.47 degrees since 1910. The bureau says we’re also seeing more rain come from intense, short, rainfall events than we have before. “We know that air can hold 7 per cent more water for every degree that it warms,” Dr Ridder says. So for every degree of warming, we have 7 per cent more water that can fall as rain.”

    https://www.abc.net.au/news/2022-07-16/nsw-queensland-sydney-weather-rain-flood-records/101238094

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