Townsville Floods

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An article on the SBS News website which claims that the flooding in Townsville is a 1 in 100 year event.

Very strange as the flooding in January 1998 was the greatest in Townsville’s history and was described as a I in 100 year event in the media at that time.

So whilst Townsville was only settled some 155 years ago, there have been two 1 in a 100 year events in the space of just 21 years?

https://www.townsville.qld.gov.au/about-townsville/history-and-heritage/townsville-history/townsville-1901-2003.

Our Townsville store manager called me to advise that the store had been destroyed with the flooding which not only contained mud but also raw sewerage as the manholes had all popped open due to the pressure.

The grubby, bottom feeding insurance company initially tried to weasel out of honouring our claim on the pretext of claiming the flooding was a result of the nearby creek overflowing, an event that they did not cover, unlike Suncorp, whilst most other insurance companies were promptly honouring their customers’ claims.

They insisted on obtaining a hydrologist’s report which confirmed that the flooding was the result of the massive rain deluge which flooded the store prior to the creek overflowing, so they finally honoured our claim.

The total damage from the 1998 floods exceeded $100 million, and this latest event will presumably be a lot more, so hopefully the insurance companies will not try to weasel out on their customers’ claims this time.

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Probably the worst flood in Townsville’s history occurred in the 1940’s, my mother recalls it as being 1948, when the Ross broke it’s banks at one of the higher weirs and followed the old river course through what were then outer suburbs Mundingburra, Rosslea, Rising Sun and around those areas. 1941 was bad and 1927 was also very bad but there were others around those periods. Of course populations and development were nothing compared to now and records are quite scant for those times.

Nowadays we have houses built in areas that “old timers” would shake their heads at in anticipation of the coming disasters.

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The other aspect of the flood flows is the Ross River Dam now concentrates all of the rainfall in the catchment to a single point. Previously the flood flows would have had some room to spread out upstream, possibly flooding a wider area, but to a lesser depth?

From our many years living there the older residents were amazed at the development permitted. Some on what was well known to be a short cut overflow path between the Ross and Bohle Rivers.

It’s possible to find anecdotes about similar approvals for inappropriate development in many locations across the nation. For consumers the individuals responsible never appear to be held to account.

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The meaning of ‘1 in a 100 year’ is best explained by the BOM. It is a statistical chance of an event happening in any single year, it does not mean that event might only happen once per 100 years.

http://www.bom.gov.au/water/designRainfalls/rainfallEvents/why100years.shtml

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Thanks for that.

The other question I have been trying to find the answer for is how does a dam get to 231% capacity?

I can understand a dam being at 110% capacity if the water flowing over the spillway is several metres deep, but at 231% capacity, is the water around twice as high as the dam wall?

image

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Dam’s often have flood storage capacity above the water reserve capacity. The 100% percentage is based on the design water reserve capacity or the nominated capacity which the operator uses to manage its function as a water supply. This 100% is what is maintained after storm events for the long term supply of water. Any water stored above this may be held for a duration after the storm event and then released when it is best to do so.

Think of it as a bath tub where 100% is the normal water level one fills the bath to in order to take a bath. Individuals may have different 100% like each dam having different storage capacities. While the bath is 100% storage capacity for a bath and ready to sit in, it will have additional capacity above this that could be used to hold more water.

During a flood event, dams can significantly exceed the design water reserve capacity. It appears that in the case of the Ross River Dam, the flood inflows to the dam exceed the outflows from the dam gates resulting in the gradual increase in volume of water stored. The dam operator announced on Friday that the dam gates would be fully opened allowing water to rapidly spill from the dam. I suspect that the flood storage in the dam was reaching a critical level where any increase in volume of water stored may have impacted on the integrity of the dam wall.

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Spot on. The Ross River Dam is designed to provide flood control for Townsville. Water supply is a secondary but important benefit. Top up water comes from the Burdekin Dam

It’s Woking capacity is approx 233,000Ml.
It’s maximum holding capacity is more being nearly four times greater at 800,000Ml.

The catchment is approx 750 sq km.
With nearly 1 metre of rain in a week it is just a little too much to fit in the dam at the same time. Given there needs to be some room left for the forecast continuing heavy rain.

The current situation would be worse if the dam had not been upgraded (completed in 2007). The bottom of the spillway is much lower than the top of the dam wall. The gates can fully open or as noted set to control the level to be held back. At 100% working capacity from the top of the wall the dam looks less than half full. :smiley:
Or nearly empty to some! :worried:

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I checked out the photos posted on Google Maps and I now have a much clearer picture of the dam.

Ther was also a great photo of Blue Winged Kookaburras which I have never seen before. We only have the Laughing Kookaburras in our region.

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There are two other aspects to this situation, which are typical and regular events in many other parts of Australia.

One is the personal impact and immediate financial consequence of flooding on a home or business. It always challenges the value and quality of insurances.

The second is the susceptibility of the major road and rail networks in NQ to closure due to flooding. The loss of access makes management of the impact of any flooding more difficult.

The economic loss through business disruption is very substantial.

Consumers in the north of Qld in this instance will bear the brunt of higher costs and economic disruption, much of which would be mitigated or reduced if the main Bruce Highway remained open as well as the Flinders Hwy the west. Despite the extreme levels of rainfall it is the same handful of places that always flood and close the roads.

While we no longer reside in NQ it is amazing to see the extent of Commonwealth and Road funding thrown at less critical needs closer to voter central. Just so people can save a few minutes getting home from work or to school each day.

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An article explaining dam capacities.

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Looks like the ABC are still reading this forum… which is good. It is a bit too coincidental that often an ABC news article appears a day or two after appearing here.

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An article regarding residents helping strangers out during the Townsville flood.

Natural disasters certainly bring out the very best and the very worst aspects of humanity.

On the one hand, there are persons who do all they can to assist others including complete strangers whilst at times placing themselves or their own property at peril.

And on the other hand, there are the low-life scum who see it as an opportunity to steal everything they possibly can by breaking and entering unoccupied premises, as reported in the Townsville floods, the Black Saturday bushfires, and so on.

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Now that the Townsville floodwaters are receding, there is more grief in store for the unfortunate residents.

Firstly, there are the reports of looting by low-life scum-bags with reports that some additional 100 police are being sent to Townsville to attempt to control it.

Two of my wife’s sisters were in Darwin during Cyclone Tracy in 1974 and they were evacuated back to Cairns after it, whilst one sister’s future husband stayed there to assist with the rebuilding works.

He was told that around 70 looters were shot dead after the cyclone. It never appeared in the media, but then again, neither did the true number of causalities of the Japanese bombing of Darwin in 1942.

Secondly, there will be the blow-in, bottom-feeding charlatans arriving to rip-off both the insurance companies and residents alike with grossly inflated and dodgy flood repairs.

The rip-offs that went on after Cyclone Larry flattened the Innisfail region in 2006 were unbelievable, such as these examples.

A farm north of Innisfail lost a pull-start Honda pump and a makeshift housing over it which pumped water from a dam to the house, and a rusted old corrugated iron water tank which was standing on its side near the house.

The insurance company replaced the pump with a remote start, diesel powered water pump housed in a secure enclosure and gave them a massive payout to replace the water tank.

A rural acreage who lost an old shelter for the animals which consisted of some bush-cut poles and an old corrugated iron roof had it replaced with a steel framed shed which the contractor charged the insurance company some $26,000 for.

A former bowls club had obtained a quote to replace their clubhouse roof some months prior to the cyclone for around $18,000, but after they wanted to proceed after the cyclone, the price jumped up to some $45,000.

The brother-in law of a very good mate of mine was living in the area at that time and had his home damaged.
He visited a business in Innisfail that had suddenly sprung up on a vacant commercial allotment, and which was selling salvaged building materials.

He selected a pile of salvaged timber, paid for it, and told the operator he would come back a few days later to collect it when he had a suitable vehicle, but when he returned, the property was cleared and the operator was long gone.

When he visited the Innisfail police station to report it, the officer told him to get in the queue. Apparently, many locals had fallen for the scam of paying for the same pile of salvaged timber.

As I stated in a previous post above, natural disasters most certainly bring out the very best and the very worst aspects of humanity.

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A real shame to see the bad behaviour post-disaster. If anyone hears of any other related stories, please share them here.

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The economic challenges ahead for consumers in Townsville and the surrounding communities are significant and do not need any added pain.

The short term boost of insurance expenditure also requires that locals to spend local. And the local business to not chase opportunistically excessive profits?

A tough time ahead for many.

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My wife sometimes watches the “pretend news” on WIN at 5:00 PM.

Some days ago, WIN managed to excel themselves with their “on the ground” reporter in Townsville during the floods.

Some gems of wisdom included a statement by the reporter stating that locals had never seen anything like it after the flood had already broken all records.

Another was an interview with a man who stated he had been living in Townsville for the past two years and he had never seen anything like it.

What would we do without them?

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I heard the Qld Premier call it a 1 in 500 year flood on the ABC News channel this morning. Go figure! Maybe our governments are finally taking Aboriginal history seriously?

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Sitting patiently in Mackay for the night waiting for the Bruce north to Townsville to open.

It’s no surprise the RACQ road map shows water over the road and road closures in all the usual places. The ones that go under everytime there is a monsoon trough or cyclone or good wet. Sometimes more than twice in the same wet season.

Some might suggest that the main roads see a 1 in 500 year flood every couple of years. With all due respect to the learnings of our earlier Australians. Our politicians appear unable to learn from more recent history?

There seems little respect - period.

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@Astrac. As has already been explained that figure is a statistical fact which means that there is a 1 in 500 chance of a flood this size occurring in any given year. Nothing to do with First Nation history (not that it shouldn’t be taken seriously where applicable).
The Premier’s statement was statistically correct.

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But some would be wrong. There are excellent explanations of the meaning of 1 in 100, 500, whatever in this thread.
And you don’t measure the overall size of a flood by it’s effect on one road, even a main road.