As I outlined in the first post, in February this year the Queensland Floods Commission of Inquiry reconvened as a result of reporting in The Australian by Hedley Thomas which suggested there had been a major breach of the flood manual for the operation of the Wivenhoe and Somerset Dams (7th revision) and that there had been a cover-up to disguise the fact.
We saw in the subsequent post that the non-compliance found by the Commission was not particularly consequential, so the question remains as to what upset the Commission so much that they referred flood engineers, Robert Ayre, Terry Malone and John Tibaldi to the Crime and Misconduct Commission to see whether offences had been committed against the Criminal Code and the Crime and Misconduct Act, 2001.
When Tibaldi, the author of the Flood Event Report (download from the bottom of the screen) took the stand it was a brutal attack with a senior barrister lunging for the jugular and in the screaming headline “WE”VE BEEN DUPED” in the Courier Mail.
In my opinion, being attacked in that manner by an organ of the state is as bad or worse than being taken out the back and beaten up. Justice Holmes should not have allowed it and people suffering such attacks should be able to sue for damages. Inquisitorial questioning of that kind is not designed to discover the truth. Rather it’s purpose is to bully and trick the presumed guilty into incriminating themselves. That methodology actually downgrades the quality of some of the evidence assembled in the Final Report, having been extorted under duress.
Moreover, the Commission showed little appreciation of what working long hours under extreme stress does to cognitive ability and memory. Nor did they seem to understand that memory is imperfect and suggestible even without stress. They had no concept of days merging into each other under stress.
After that spray, I have to say that I agree with some but not all of the Commission’s conclusions, for example, the need for an improved review process. And there was indeed a legitimate issue about how the engineers represented their decision-making processes in the Report. But the Commission, I think, overestimated the seriousness of what happened and completely misinterpreted the issue of motive.
How the engineers operated
A large part of the problem was that the engineers did not make overt decisions about which of the “W” strategies they were in, or so they said quite consistently in evidence this February. The engineers thought and acted in relation to the information they got from rain gauges, stream flows, dam input and output flows, dam levels and conditions outside the catchment areas, modelled to forecast a stream flow at Moggill 16 hours after dam releases.
What they were meant to do was to pause after gathering the data, check which “W” strategy they were in, and then make decisions. What they did was to go directly to making decisions on the appropriate release levels in relation to the main goals or markers contained in the “W” strategies. They were operating at the next level of detail. The “W” strategies were filled in later as part of the reporting. That’s the way it had always been done, from back in the 1990s. This was confirmed by Mr Peter Allen, the Director of Dam safety in DERM who had in fact worked with some of the engineers on floods in the 1990s.
That being said, there is little doubt they knew when W1 had been left behind and the main concern became flooding in Brisbane. They also knew when it was time to concentrate on saving the wall.
How the engineers reported about how they operated
Unfortunately in the inter-agency communication (eg between the flood operations centre, Seqwater, the Water Grid Manager, DERM and the Minister) during and soon after the event, there was comprehensive confusion about what strategy operated when, and when the switches were made. One donkey (not one of the flood engineers) even said W1 when he should have said W3 and said W3 when he should have said W4. But there was an assumption by all, it seems, that W2 was in the mix because it was thought of as a transition strategy from W1 to W3.
W1 is clear. The dam level is over the full storage level (FSL) of 67m and not yet 68.5m. When the level hits 68.5 or the Mt Crosby Weir Bridge goes under, which it does at 1,900 cumecs (it’s just above where the Bremer joins) you must exit W1.
W3 is clear. Dam levels are between 68.5 and 74m. The main priority is to prevent “urban inundation” in Brisbane. In the manual the marker for this is 4,000 cumecs at Moggill, which is where the suburbs started when the dam was built and just below where the Bremer joins.
W4 is clear. The dam is approaching or over 74m and the prime concern is to protect the dam wall.
W2 is not clear. It is an optional strategy and can be bypassed. A limiter of 3,500 cumecs at Lowood is introduced as well as 4,000 at Moggill. This is a bit curious because Lowood is below the Lockyer Creek junction but probably a good 40km above Moggill which is below the Bremer. When you have 3,500 at Lowood, 4,000 at Mogill would not be far away. If Lowood (population about 1,000) is important, why not mention it in W3? Even more curious is the requirement that releases from Wivenhoe must be below the natural flow at Lowood, excluding water from the Wivenhoe. There is a similar clause relating to Moggill. (The statement in the manual is actually ambiguous, but the alternative meaning is nonsensical.)
I’m convinced in rereading the chapter that the whole pack of them, Tibaldi especially, clean forgot about that relative stream flow clause in W2. Tibaldi on Saturday 15 January at short notice wrote a report in two hours for the Minister. In it he had them in W1 until late Sunday. He later said he had gotten it wrong. He hadn’t slept for a very long time and was so tired he had no memory at all of the day he wrote the report. The Commission said, no, a competent engineer would remember, no matter how stressed and fatigued he was (p494). The report was evidence that his true perception back on Jan 8 and 9 was that the dam was being operated in W1. That was the “only reasonable conclusion”.
Two weeks later, when Tibaldi was preparing the Flood Event Report he noticed from the records that at 8am on Saturday the calculated natural flow at Lockyer was 500 cumecs when the Wivenhoe release was over 900 cumecs. Too much water was being released to fit with W2.
Then he did something really dumb. In the report in Chapter 10 of the Flood Event report he set out a spreadsheet which identified times, then in a column on the left the “W” strategies chosen, followed by a column with the explanations of what they did, and then a column with ‘manual requirements’ on the right.
Unfortunately in the column where he wrote the explanations of what they did he had them operating exactly as they didn’t, making conscious choices about “W” strategies at the appropriate times. Then he invented a W2 bypass choice which never happened and wrote that up. Pure fiction, I’m afraid.
I think the engineers operated according to the main game as laid out in W1, W3 and W4 at the next level of detail. The “W” thing as such really wasn’t important so he didn’t see it as a big lie. It was essentially a communication issue, which wasn’t picked up by the others who checked the text, or by the four formal reviewers.
Then he compounded the dumbness. Tibaldi in giving evidence to the Commission last April waxed eloquent to the Commission as to how they operated in a way that he later had to admit they didn’t. Ayre, when they checked what he said against what he said last year was found to have invented a story. There were suspicions of collusion. I suspect his memory was vague, but under pressure came up with an explanation that he convinced himself was the way he remembered it. Malone was also implicated, but Ruffini got off.
Why? Ruffini got off because it seems the Commission gave up on him, describing his evidence as rambling and discursive and unable to grasp the question he was asked. Ruffini was very upset at the time because someone told him he couldn’t look at a particular spreadsheet before he gave evidence. His stressed state of mind perhaps saved him.
Judicial commissions are understandably upset under circumstances like this. But they can lack perspective at this point. I think it may have led them to a bias against the engineers when examining the issue of substantive manual compliance. A stern rebuke was certainly warranted, but delivered with respect, and a recommendation that someone with editing skills work on the report before it is released. It would have been simple to reorganise the columns so that what the engineers did and why took prominence, then a match with manual compliance indicated in a column on the right.
In any event their treatment of the miscreants in the witness box was a form of punishment in itself, if not revenge.
Substantive compliance with the manual
In the second post from the third paragraph on I gave an account of how Ruffini at 4.50am on the Saturday authorised a change of the gate settings to meet the forecast situation when the dam would cross the threshold of 68.5m thus requiring a strategy above W1, which it did at 8am. The Commission had decided that conscious choice of strategy was required by the manual which led them to obsess about what was in the minds of the engineers. They continued to obsess about what the engineers had in their minds about the “W” strategies when the engineers consistently said they didn’t think that way.
Tibaldi would have done better to nominate the transition to W3 as at 4.50am rather than 8am but the distinction is trivial. The fact that Ayre at 8am didn’t make a decision which had already been made somehow became significant for the Commission. Ayre did nothing, they said, to demonstrate the move from W!. Actually, the option of changing nothing is open under W3.
Also during the following 36 hours the Commission observed that there were several references to W2 and none to W3. The Commission did understand that the dam releases were compatible with with both W1 and W3 and that there was a legitimate concern for the two higher level bridges. The Commission didn’t seem to recognise that 4,000 cumecs at Moggill, the marker for urban inundation downstream, simply wasn’t in play, whereas the higher level bridges, a mandated concern under both W2 and W3, were. Moreover, in five of the six situation reports during the time in question impacts on Brisbane are mentioned, in three cases in millimetres at the Port Office. The exception was Sunday morning which reported the dam level falling.
In the end, after a 50 page tortuous tour of the engineers’ minds by a Commission clearly unqualified in psychology, the conclusion that the dam was operated in breach of the manual comes as a jolt on p504. It seemed to turn on a lack of clear evidence of a choice to leave W1. I think there was such a choice. It happened at 4.50am on the Saturday, but without bells, whistles and bright lights.
The Commission used the balance of probabilities as the standard of proof, along with the notion that no other reasonable explanation was available. I think their finding that the engineers were in breach of the manual is at the very least unsafe.
The engineers ability as engineers was not seriously in doubt. Their actions were found by Babister to be ‘very close’ to the maximum achievable within the constraints of the manual. The Flood Event Report stands as a technical document. So what exactly is the problem here? The issue is about communication, not engineering.
W2 and the manual
The Commission obsessed about what was really in the engineers minds with respect to “W” strategies, whereas in the February hearings they were quite consistent in saying that they didn’t think much about that at all. But the Commission had made a key decision 50 pages earlier (section 16.3) that an engineer would make better decisions if they made a conscious choice of “W” strategy, so the possibility existed for the decisions they made to have been better than good.
I think the engineers were always aware of which of the three main ball parks they were in. The problem is that W2 does confuse the issue.
Take a look at how the manual treats the issue of relative stream flow. It’s on page 27, that’s at 32 on the pdf counter, but for your convenience I’ve done a screen shot of the relevant part:
Consider this sequence:
the combined peak river flows should not exceed, at Lowood, the lesser of the natural peak flow excluding Wivenhow Dam releases, and 3,500 cumecs.
It’s nonsense, but most seem to take it to mean that the releases from Wivenhoe should be less than the natural flow calculated at Lowood excluding water from the Wivenhoe. W2 was variously called “confusing”, “ambiguous” and “somewhat redundant” in evidence. Here’s why W2 may be considered redundant.
By definition if you are exiting W1 you are dealing with a flood in the Wivenhoe. The time you would consider keeping Wivehoe releases below what was coming down Lockyer Creek would be if the rain had eased off in the Wivenhoe catchment but was flooding down Lockyer. In that case you’d hold water in the Wivenhoe to let it pass. But if that happened you’d do it any way under W3.
If you had the option of bypassing W2, why wouldn’t you? To me the evidence is that they routinely ignored that little clause and eventually forgot it was there. Tibaldi as a Seqwater engineer (they own the dam) had put a flow chart into the manual, which simply elides that little conundrum and produces a path which would nevertheless mostly land you in W2 rather than W3. Here’s the flow chart, which is on p28 by the pdf counter of the manual:
If Tibaldi had been aware of what W2 actually said he would never have inserted that flow chart. In any case it is simply wrong. And it certainly would be a distraction to be thinking about this conundrum in W2 when you are dealing with a flood.
I suspect W2 was inserted as a concession to Lowood lobbying generated either by the psychology of townspeople finding themselves downstream from a massive dam with an 80 metre wall or by local farmers who saw their paddocks being flooded by the whims of engineers concerned with the convenience of urban dwellers downstream. To me it has the look of an awkward compromise and should be reviewed..
It needed a review and it got one. It’s a beauty, as you’ll find in the Ninth Revision of the manual released last November. W2 is still there (see p28). The conditions are the same as for W3, but the intent is different. Try this for size:
The intent of Strategy W2 is to limit the flow in the Brisbane river to less than the predicted flows at Lowood and Moggill excluding Wivenhoe Dam releases. This means that releases of water from Wivenhoe Dam should, in most circumstances, be managed to limit the flow in the Brisbane River at Moggill to less than the predicted flows at Lowood and Moggill excluding Wivenhoe Dam releases, while not allowing the radial gates to be overtopped.
It did my head in! By releasing nothing from the dam you still couldn’t get the flow in the Brisbane River down to below where it would be if you where releasing nothing.
In the conditions, they’ve introduced the notion of a forecast level as well as an actual. I think if the dam is actually between 68.5m and 69.5m and also forecast to be between 68.5 and 69.5m, you have no strategy. That’s exactly where some said there should have been aggressive releases.
So I went over to page 29 to look at the pretty flow chart. That did my head in even more. No mention of Lowood. No mention of a maximum release of 3,500 cumecs. But if you answer “no” to four questions in a row you get to stay in W2 whether you answer “yes” or “no” to the fifth. And here’s a new level – 3m predicted above FSL (full storage level), not 2.5 as on page 28.
Also you get to choose which strategy you go into according to what release rate you deem necessary. I thought it was supposed to be the other way around.
If “disruption and damage to urban areas below Moggill” start at 2,000 cumecs, I thought it would be worth a major trigger point, rather than just a comment.
On the W2 flow chart if the predicted peak flow at Moggill is less than 2,000 cumecs or more than 4,000, excluding water from Wivenhoe, you go to W3. So W2 must be for when the flows at Moggil, excluding Wivenhoe water, are between 2,000 and 4,000 cumecs. This isn’t clear on page 28, where they give the maximum release available as 3,500 cumecs under W2.
From the W1 flow chart, W2 is no longer optional.
I’m not an engineer and thankful for that. It’s quite possible I’m missing something but I’d never want to operate under such a manual. I’d prefer broad scenarios with identified parameters and flexibility within. Revision 7 would have given us that if you took out W2 and tidied it up a bit. I’m genuinely interested in what engineers make of Revision 9.