Alrighty, added a few more 'events' to the timeline up until the SEWS was issued. Notable events include:

1:41pm, Adam Ant's post - Possibility of a wall of water going down Lockyer Creek. -- I call this a heads up
3:23pm, Dave Wx's post - 12.68m reading on Lockyer Creek at Helidon. -- This should have set off warning bells!
3:50pm, AC's post - Hopes there will be a warning issued after both stations recorded peak. -- This definitely should've set off warning bells!!!!
3:56pm, Nellie 1969 post - Youtube footage appearing (after photos have been uploaded in the forums) -- Confirmation of the seriousness of the situation
4:27pm, Dave Wx's post - General flood warning issued for Brisbane River catchment area, moderate to major flooding expected. -- A common warning we'd seen plenty of times already, certainly didn't communicate the seriousness of the situation that HAD occurred
5:04pm, Dave Wx's post - House reported to have been carried away by flood waters in Grantham -- Oh come on Bureau, given the evidence so far, would it be that hard to dig a bit deeper??!?!?!
5:11pm, mickyd's post - SEWS issued by Bureau... -- About freakin time!!! FINALLY!!!

In a nutshell, the bureau issues the emergency warning 3 1/2 hours after eyes on the ground report the seriousness of the situation.

I was erring on the side of giving the BOM the benefit of the doubt, but the evidence collected up until now is telling me a different story. Be it procedural issues or whatever, the information contained in this forum hit the BOM out of the ballpark when it came to delivering useable information in a timely manner, it was just a shame that there was a fair bit of clutter to read through.

What this says to me is that there is no substitute for eyes on the ground at this stage, technology can do so much but it is only as good as the humans that are interpreting it.

Anyway, the timeline the way it stands currently:

Hi guys, I just found this video of the Lockyer creek at Helidon. Please be warned before you view it, it has video of that poor family that got washed away in their 4wd. Two were saved and the father is still missing. The video is taken on the eastern bank of the creek and is looking over the bridge on the warrego highway and helidon park. This is the only video I have seen which really shows the amount of water coming down the Lockyer creek. Dont forget poor old grantham has to deal with this as well as water coming done Sandy creek.

WARNING: THIS FOOTAGE CONTAINS VIDEO WHICH MAY DISTURB SOME PEOPLE

Heres a video of the Lockyer creek at Helidon at 2:30pm before it peaked




For me this video below is amazing. Its taken at the foot of the range on the warrego highway. Its gatton creek which eventually runs into Lockyer creek.

Adam Ant that is absolutely mind blowing. I have never logged onto this thread until this morning and any WZ forum records will show that, I dont have another user name which WZ forum records will prove. It would look like I cheated but I did not. Just people thinking alike.

I had an issue on another thread with someone believing that no one on this site had any idea that this was going to unfold and anybody could be warned. I decided to do a time line and it is almost identical to what you have posted before me.

I had listed the pages a day or so earlier but I did not dissect it until last night. If I had of known I could have just cut and pasted your work.

I am glad that this has been done because it is evidence that we need an over haul of the warning system due to major flaws through out.

They say great minds think alike, yours probably is but I dont think mine is that great

Cheers

Col

I believe Esk might have been the first place to be seriously hit by the cell that went on to Toowoomba - I heard reports on the radio early afternoon about flash flooding in the main street of Esk - and the video linked below is one of several on youtube.

http://www.youtube.com/watch?v=KiXykhtKGnc&NR=1

The clips are not time stamped but it was likely the first real warning that something serious was happening. It would be worth finding out the time they were taken and adding it to the time line.

Is it possible to ask the person who posted the clip what time he filmed it via the Comments section under the video?

Cheers avinet, good idea, in any case I grabbed the flood marker data from the BOM site and have added it in. I'll have to play with the formatting again but all is good

hey andy - i just posted a comment on that video asking him/her what time that was recorded, so we just have to wait for a reply now

One for the archives... (Pretty sure it kept going up after it broke). I have the picture saved on my computer but this image is loading from a photobucket account that I dont know. Everyone make a copy!

Yeah Adam...looking at that video you posted of Lockyer creek (or should we say river) crossing the Warrego at Helidon...how DEEP is it!!! I checked it out on google maps and the bridge looks like a good 20m above the bottom of the creek! (in fact I think I remember you saying something like that in one of the threads the other day)

I definitely remember talking to you about it on Monday arvo Dave. When you told me that height I'm sure I went to gauge it against that bridge in my minds eye and couldn't decide how far over it went. In fact I'm pretty sure I thought the bridge itself would be out of reach but the road near the park/dipping station would have gone under.

Cheers Schummy, hopefully whoever got that video can give us a time estimate.

Hey Dave, any idea on whether the flood data is archived anywhere like the radar data? Or would we need to get that from BOM itself?

No archives that I know of...also of interest is that the Helidon flood gauge has dissappeared from the BoM website, but that isn't really a conspiracy any gauge that doesn't report/fails is removed from the website as I imagine they don't want people to accidentally use the old data on the plot.

That would explain the removal of the gauges just below wivenhoe on Tuesday night.

Incidentally, whilst doing a little background research on pevious flood events I came to the conclusion that the worst case scenario for Brisbane is really still a TC approaching from the North or North East (whilst our dams were still emptying from a lesser early event.)

One of the first TC's I ever chased was Fran back in 1992. It came ashore near Yeppoon (much like another storm did way back in 1893) but then U-turned back to sea near Hervey Bay sparing SE QLD the worst of its rainfall. What is noteworthy about Fran is, whilst passing through Wallis Island in the pacific, Fran dropped 500mm of rain in 12 hours.

So to me our worst case scenario is a TC coming in with a 2-3m storm surge at the same time dropping 500-700mm of rain in less than 24 hours. I doubt theres anything Wivenhoe or Somerset can do on the day this scenario comes to pass.

In the event that this should ever occur, head for the hills!

20m was my guess but it is hard to tell. Heres a photo I took yesterday morning of the bridge which kinda gives you an idea how high it is.

Helidon Bridge

Remember that the water is still running at like 5m when I took the photo. Theres a car driving over the top if that helps out. Looking at the other pictures I have from around that area, I sorta think it would have peaked below 20m

Helidon Park


Helidon Park 2

i meant to say also that i think the first video i posted today with the warning was the peak flow. I dont think it ever went over the helidon bridge. I went over it today and it looked like it went over the edge but not over the main part. Pretty sure i said at one stage that it went 1.5m over the bridge, well that was wrong (like a lot of second hand info). Although it was probably 1.5m over the highway as you can see on the video

Interesting read on pages 44 - 48 (Public Criticism) - could almost be translated directly to this event, only the tragedy is greater and the stakes are higher in terms of cost to human lives. That day, which I spent glued to WZ, remains etched in my mind, as I read with a growing sense of horror, panic and uselessness. This thread is a great idea - hopefully all can learn from it, but especially the bureaucratically top heavy government agencies - lack of eyes on the ground is something implied in the 1974 report; obviously nothing was actioned - perhaps now it will.

On another note, I am surprised at the lack of forewarning too - based on information in the tech thread for this event. I packed up camp and headed home 5 days early based on this information - the signs were all there. Where was the heads up from the BOM from people in danger areas?

Here are some of my observations, concerns and conclusions in regard to the extraordinary and tragic flash flooding event that occurred in Toowoomba 10/01/2011.


Monitoring in the Toowoomba region is insufficient and certainly not of an acceptable standard. Moreso, it can be argued that lives could well have been saved if a more cohesive monitoring network were in place.

The urban area of Toowoomba encompasses over 120,000 people, with an additional 30,000 living within the council district making it the largest inland city in the country behind only Canberra.

Yet despite these figures Toowoomba has only two official rainfall gauges (Toowoomba Aero #041529 and Toowoomba Alert – Mt Kynoch #540162) which are both situated on the urban fringe and just one flood gauge (Gowrie Creek at Cranley #541093) that is useless for urban flood events as it is located downstream from the city.


The storm itself formed just after 11:00am (AEST) as two cells displaying echoes of moderate intensity merged over Esk to form a single system. It then proceeded to move in a general direction towards the southwest, crossing the ranges near Upper Sandy Creek at 12:30pm and passing over the Toowoomba urban area for approximately an hour between 1:00pm and 2:00pm.

Approximate path of the storm is shown below.
(Yellow lines indicate paths of the cells that merged at Esk to form the system; Pink indicates the edges of moderate to heavy rainfall under radar; Red line indicates approximate path of heaviest falls according to radar)





Transect of the path of heaviest falls from radar imaging, displaying the higher elevation of Toowoomba that intensified rainfall outputs.



The steep incline of the Toowoomba Range fired an intense burst of convection, causing very heavy rainfall on the slopes and urban area. For the 24 hour period to 9am 11/01/2011 Toowoomba Alert and Toowoomba Aero reported 117mm and 123mm falls respectively with 60mm falling in one hour as the storm passed at the latter mentioned station.



However many unofficial totals reported much, much higher figures nearby and as has been reported by the media, the BOM have conceded that this would have been the case:

Courier Mail - Jim Davidson

quote: WEATHER Bureau chief Jim Davidson described the downpour that caused the fatal Toowoomba and Lockyer Valley floods as a super storm.
Mr Davidson said reports were received of 80mm of rain falling in just over 30 minutes, but he suspected falls of up to 200mm would have occurred in areas where rain gauges were not set up.

As a further piece of evidence to confirm this, NASA have produced an image of the rainfall totals on that day from satellite analysis, showing 200mm+ falls concentrated in Toowoomba area:



NASA Satellite SEQld Rainfall

This intense rainfall lead to the infamous “instant inland tsunami” in the Toowoomba business district and a wall of water 8 metres high into the Lockyer Valley, both causing loss of property and life on a disastrous scale.


Let’s take a step further into the event and look into other factors involved in why it occurred the way it did and what measures can be learnt to be put in place to prevent future tragedy.

Firstly the storm never appeared unusually intense upon radar imaging, a misleading situation that caused emergency warnings and procedures to be either delayed or held back entirely and no prior notification of what was coming to those who would be potentially caught up in it.

Marburg 128km Radar Archive of Storm

Mt Stapylton 128km Radar Archive of Storm

Toowoomba happens to be located on the edge of an area within SE Qld that the BOM acknowledge is lacking in optimal radar coverage as you can see:



Both the Mt Stapylton and Marburg radars failed to detect the exceptional amount of rain falling in the Toowoomba region in regard to its actual intensity, instead only detecting reflectivities of a moderate status. Marburg (in my opinion) drastically underestimates reflectivities and its resolution (being a WSR74 S Band radar) is poor when evaluating intense, localised rainfall events such as this. Mt Stapylton was able to resolve the shape of the storm complex well but failed to pick up the severe intensity of the rainfall. I believe this occurred due to the fact that Mt Stapylton is located 125km away from Toowoomba and at this distance much of the lower level precipitation would be below the scan of the radar and thus undetected, making it appear that the rainfall in the region is lower than what is actually occurring on the ground.

From this alone it could be argued that an additional radar facility is required west of Marburg to provide coverage of Toowoomba and the Darling Downs (Mt Kynoch potential for a site?). I have no doubt that if such a facility was in place, it would have picked up this event earlier and more completely and people would have more informed about the situation and be able to make decisions about any necessary preparations.


The city of Toowoomba itself is located the top of a range at some 700mASL with no major watercourses flowing through it, hardly the expected place for a major flood event to be expected to occur. But factors combined to cause such an event to take place 10/01/2011.

The urban area occupies the edge of the range and the low ridges behind it. Two valleys run north from the southern boundary, each arising from springs either side of Middle Ridge near Spring Street at an altitude of around 680 m. At the confluence of these waterways, East Creek and West Creek, settlers built the first dwellings where water was most accessible and today this area comprises the business district of the city. North of the CBD the watercourse is called Gowrie Creek and is a tributary of the Condamine River.




Additionally the city is located upon red ferrosols derived from mid to late tertiary age basalts which are famously rich in nutrients and near perfect for cultivation purposes. A characteristic of this soil type is that under normal conditions it is well draining, but under intense rainfall it will hold water and cause the water table to rise, resulting in runoff and inundation.



ANRA - Ferrosols

So under an event whereby 200mm is falling over a short period, these soil types can be expected to result in significant surface runoff – particularly when over the previous 24 hours the area has been exposed to rainfalls in excess of 100mm in some areas as was the case for Toowoomba region that day.



Furthermore Toowoomba had reported no rainfall on just 16 of the last 55 days prior to the event, and water tables would have already been significantly higher than they would be under normal circumstances.

For those interested here is some further reading:
Toowoomba Flood Report - Oct 2009

Considering the CBD is located where the only two watercourses in the city meet, it is surprising and alarming that there are no flood gauges upstream on East and West Creeks.
In fact, there are NO FLOOD GAUGES IN THE URBAN AREA AT ALL! In the event of an inundation, there is currently no way of knowing unless it is an eyewitness report. And so it was for the people of Toowoomba – both East and West creeks burst their low drainage banks and sent torrents of water through the city, converging on the CBD where they became the “inland tsunami” and nobody received any prior notice. It is clearly an unacceptable situation to not have flood gauges in multiple locations on East and West Creeks as currently stands. Imagine if say, Kedron Brook had no gauges and a flood was coming down it – that is the situation in Toowoomba. Lives were lost unnecessarily because of this. Flood gauges don’t cost much and are easy to install – the lack of them in this instance is pure negligence.

The only gauge in the city area is as previously mentioned, well downstream at Cranley so its only use is for alerting Oakey of coming events.



Please disregard the peak on the 12th Jan - it is an error in the data. Also note the gauge was likely affected by debris (which would explain why the reading stayed at 0.30m for several hours, 0.70m below the pre-flood height) and the actual peak height experienced at the station could well have been much higher.


Gauges upstream from the CBD area would provide evidence of an event occurring before it impacts so communications and warnings can be sent out to those in its path. However little time is provided, any warning is better than none. It would not have taken long for people to abandon their cars and evacuate to higher ground had they been aware of what was coming – mere minutes could have sufficed.

The most intense rainfall however occurred to the east of the city upon the slopes:





An extraordinary amount of water accelerated down the steep inclines and combined their mass upon Withcott, Helidon and Murphy’s Creek respectively before the full force of all the flows joined forces to unleash fury upon Grantham in a nightmare outcome that will likely launch a coronial inquest and possible royal commission into how this event was been handled.



At Helidon there was a recorded 8.5m rise in the Lockyer Creek in less than an hour; at Grantham it was likely even higher with the full force of all the flows combining upon the town. Yet once again those living in the area had little knowledge of the wall of water heading their way until it was upon them. (Indeed the SEWS emergency warning from the BOM for the Lockyer Valley was put out just after 5:00pm AEST – TWO HOURS AFTER MAJOR FLOODING WAS FIRST REPORTED IN THE VALLEY. People in their lougerooms were witnessing houses being washed away on tv before the warning was even raised - a simply inexcusable situation regardless of the angle you try to approach it from.

This one instance alone will catalyse reforms in how emergency situations are handled in Queensland. It was appalling at best – the warning became nothing but a cynical move so that authorities can say one went out before they try to pin the blame on each other in the inevitable aftermath. So much for the poor folk who had nowhere to go when 20ft of water hit them, as long as they can say the process was followed then everything is apparently ok.


Once again it must be stated that the number of flood gauges in the area are insufficient. Each creek coming off the range should have at least two gauges prior to Helidon in order to maximise the chances of isolating a flood event in its infancy and get alerts out as soon as possible to those required. Nobody should be in a situation where they look out their kitchen window and see a wall of water higher than the roof coming towards them and have nowhere to go because they were not warned beforehand.


Overall the performance of the BOM on 10/01/2011 was poor.
Their reaction was to wait when urgent action was required and the infrastructure that was needed was simply not in place by means of complacency, ignorance or negligence – none of these are acceptable.

Their poor performance over the course of this event directly affected outcomes for those involved. Lives were no doubt lost as a result of the decisions made not just on that day, but in the months and years leading up to it.