Editorial: Wivenhoe Dam operators made right call

Whether they just got lucky or their reliance on the manual paid off, our dam operators appear to have made all the right calls, writes the editor.

The Wivenhoe Dam gates ahead of Cyclone Alfred. Picture: Peter Wallis

Whether they just got lucky or their reliance on the manual paid off, our dam operators appear to have made all the right calls as Cyclone Alfred loomed over the southeast.

Regardless, it was a good thing they did not listen to armchair experts such as former Queensland premier Campbell Newman, who – in the seemingly endless days before the cyclone finally crossed the coast – took to social media to urge Seqwater’s engineers to release water from Brisbane’s Wivenhoe Dam before the heavy rains arrived.

He argued: “Getting a head start on this can make the difference between some properties being flooded or not.” And he expressed disbelief that the government authority wanted “to wait until the rain falls before dam releases start”.

Seqwater instead played it by the book, literally – the dam’s flood mitigation manual, which dictates that decisions about when to release water should be based on rain that has actually fallen rather than making calls based on forecasts.

As a result, Seqwater began releasing water from Wivenhoe only on Tuesday evening, after the rains had stopped and the dam level was approaching 90 per cent of the normal water supply level – well below the dam’s extra flood mitigation capacity.

And so the system worked. The decisions made by dam engineers were based on pre-calculated technical assessments and the best judgment of trained experts.

We understand Mr Newman’s deep interest in protecting Brisbane from flooding – he was, after all, lord mayor of the city during the 2011 floods (which prompted a full rewrite of the manual, after a commission of inquiry probed the dam release strategies in that disaster).

Mr Newman is also a trained civil engineer with the army, which presumably gives him a level of technical understanding most other armchair experts do not have.

He has also long championed the idea of pre-emptive releases of Wivenhoe water to prepare for bad weather, and as premier in rain-soaked January 2013 he ordered Seqwater to open the dam gates to make room for possible flooding rain, before it might have otherwise done if it had stuck to the manual.

Current Premier David Crisafulli was at pains this time to leave it to Seqwater to make those decisions, but many residents downstream of the dam would no doubt agree with Mr Newman – what’s the harm in letting out some water before predicted bad weather arrives?

But predicting the weather is always challenging. So too is managing a dam such as Wivenhoe, which serves the dual purpose of providing a reliable water supply and flood mitigation for what is now a substantial capital city. Water is valuable, but at what point do you literally let it run down the gurgler to prepare for flooding rains that may or may not arrive?

The whole point of Wivenhoe’s 155-page flood manual is to provide detailed guidance for the dam’s decision-makers rather than being captive to the whim of politicians.

The manual must also be one of the most analysed documents in Queensland, pored over by the horde of lawyers involved in that multimillion-dollar commission of inquiry into the 2011 floods.

The commission found that the then version of the manual was ambiguous, unclear and difficult to use and was not based on the best most current research and information. It is now updated to address the commission’s concerns.

Managing unpredictable nature will always be an imperfect science – just think of the almost-drunken stumbles of Cyclone Alfred as it dawdled to the Queensland coast.

Imagine being an engineer trying to make hugely consequential decisions about whether to release water from Brisbane’s biggest dam.

We suspect you’d rather have a detailed manual to help you, so you can tune out all the passionate pleadings of armchair experts.

PARKS ARE FOR ALL OF US

Brisbane Lord Mayor Adrian Schrinner should be congratulated for his decision to shut down the homeless tent cities that have sprung up in recent years in two inner-city locations – Musgrave Park and Kurilpa Point.

He is right to act because this is not about evicting people with nowhere else to go, as was the case at the height of our rental housing crisis two years ago.

Since then, services have caught up with the demand and those who had been forced into homelessness have long-term accommodation.

No, these are people refusing to leave the parks they are illegally squatting in, and Cyclone Alfred proved this as every rough sleeper in Brisbane was offered alternative accommodation in the days ahead of it making landfall. These people refused that help – and so it is time for them to go.

The encampments are an eyesore, and there is evidence of drug-taking and public drinking – not to mention the rubbish, and even human waste, that is visible.

The impact the tent cities have had not only on the parks but on our lifestyle is huge. Residents no longer feel safe walking through them, particularly at night.

And so enough is enough. Our city’s parks are for everyone. And after today, they will be again.

Responsibility for election comment is taken by Chris Jones, corner of Mayne Rd & Campbell St, Bowen Hills, Qld 4006. Printed and published by NEWSQUEENSLAND (ACN 009 661 778). Contact details here