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In 2020, with La Nina confirmed in the Pacific pointing to months of well-above-average rainfall, Launceston's flood levee system could face an even larger challenge than that posed during the 2016 floods.And since then, a 700-metre levee has been added at Newstead. But what level of flooding could cause inundation of low-lying areas such as Invermay? And with climate change predicted to increase the frequency and intensity of flooding in Northern Tasmania, how prepared is the city?
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The floods of June, 2016, were caused by rainfall often exceeding the one-in-100 year levels, but Launceston's new flood levees prevented widespread damage. However, it needs to be said, only just prevented a a very unwelcomed flood event .
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Mayor Albert van Zetten said that even with the improved protection afforded by the levees, it was impossible to defend against all flood events. It made preparation all the more important.
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"It is important for Launceston residents to be aware that the levees are not a guarantee against flood," he said.
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"There will always be a risk of a flood event greater than what the levee system can provide protection for.
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"Given the ground conditions in Invermay, there is also a risk of failure. Although the council and the Launceston Flood Authority continually inspect and maintain the levee system, the adequacy of the system can't be guaranteed in every scenario." .... [DrTV...WILL MAYOR VAN ZETTEN BE REPEATING THESE WORDS AND PROVIDING ASSURANCES TO THE COMMUNITY WHEN HE CONSIDERS THE UTAS DEVELOPMENT APPLICATIONS? ON THE EVIDENCE. IT APPEARS THAT THE COUNCILLORS DID NOT]
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MORE ON FLOODING AND CLIMATE IN LAUNCESTON: COUNCIL VIDEO
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Spring, summer flooding possible in Tasmania as La Nina confirmed in Pacific Ocean
Warming climate could worsen South Esk flooding: CSIRO
Mapping tool shows impact of climate variations on Launceston
In 1929, Launceston's now famous flood event, the city was effectively at the mercy of the rushing flood waters as they destroyed 2000 homes and buildings in low-lying areas. The flood level system was started in the 1960s and put to the test in 1969 when, again, the convergence of the North Esk, South Esk and kanamaluka Tamar rose.
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In the 2010s, a further 12 kilometres of earth and concrete levees were built, including about 20 Bauer and sliding flood gates with a network of river height sensors.
In 2017, a Bushfire and Natural Hazards CRC report found the system prevented $216 million in property damage during the 2016 floods. [DrTV...BUT CAN THE LEVEES BE RELIED UPON AS LISMORE RELIED UPON THAT CITY'S PRAGMATIC DECISION RELATIVE TO ITS FLOOD MITIGATION PLANNING ... SEE http://lcc63.blogspot.com/p/the-lismore-flood-history-and-that.html]
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It is said that the 'new system' can protect against a one-in-100 year flood, but authorities also have the latest mapping for worsening future scenarios. [DrTV...BUT THE QUESTION HANGING IS ANYONE LISTENING AT TOWN HALL OR ARE THE COUNCILLORS PROMOTING/ ENDORSING THE IDEA THAT BUILDING IN A FLOOD PRONE ZONE IS A RISK WORTH TAKING? IF SO FOR WHOM?]
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In a one-in-200 year event under current climate conditions, buildings in the area stretching from Newstead College, across Invermay and all the way to Star Theatre could be unsafe for people and vehicles, and vulnerable to structural damage. [DrTV...BUT AGAIN ARE THE COUNCILLORS LISTENING ?]
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In a one-in-500 year event, flooding could extend to Heritage Forest, with all building types in Invermay "vulnerable to failure". [DrTV...YET AGAIN IS ANYONE ACTUALLY LISTENING? IF SO TO WHOM? OR ARE THERE ANY ALARM BELLS RINGING IN A CLIMATE EMERGENCY CONTEXT?]
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Related: Heavy rain and strong winds expected across Northern Tasmania on Thursday
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As climate change scenarios by 2040 are laid across the maps, the picture in Launceston becomes even more dangerous for these areas with waters deepening and the flood footprint extending - in the worst case scenario - across Launceston College, Woolworths and towards Brickfields Reserve. [DrTV... AGAIN, IS ANYONE LISTENING OR DO THE DECISION MAKERS SEE THEMSELVES 'OUT OF THE GAME' WHEN DISASTER HITS AND WELL SAFE FROM BEING HELD ACCOUNTABLE?]
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IN 2O20, Cr van Zetten said current modelling indicated that intense rainfall events would become more common in the North and South Esk catchments throughout the 21st century.
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"This modelling indicates that while Launceston won't necessarily be at risk of more substantial flooding events in the future, rainfall events will happen with increasing frequency due to the impacts of climate change," he said. "Launceston's reconstructed flood levee system has been designed to a high standard and is expected to provide flood protection to low-lying parts of Launceston for many decades.
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Watch: City of Launceston workers test the Charles Street Bauer flood gates in 2018: https://www.examiner.com.au/story/6958799/levees-at-the-ready-but-how-much-flooding-can-launceston-take/?src=rss&utm_email=61a75ef2ad&utm_source=The+Examiner&utm_campaign=72e4778da9-\
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"However, no system is failsafe, and Launceston should not be complacent about flood risk." [DrTV...BUT THIS IS THE LINE, ESSENTIALLY, THAT NSW'S LISMORE COUNCILS RELIED UPON FOR 17 YEARS UNTIL THEIR LEVEE PROVED INADEQUATE WHEN BUSINESS AND RESIDENTS SUFFERED $MILLIONS IN LOSSES]
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In 2020,Jim Collier, a long-term advocate for sediment raking in the Tamar, believed either a dredging or raking program should be carried out in the river's upper reaches, and levees raised further.
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"If a significant major flood event does occur, and it really is not a case of 'if' but 'when', this flooding event will only be exacerbated by the risen river bed as the river's upper reaches have, slowly but surely, filled up with more and more sediment since the last raking/dredging program," he said.
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In response, Cr van Zetten said a review of sediment raking had found it ineffective in flood defence. [DrTV...ABOUT THIS, THE MAYOR IS QUITE CORRECT NONETHELESS HIS APPARENT ACCEPTANCE OF 'THE FLOOD RISK' LACKS CREDIBILITY AND HIS APPARENT PREDISPOSITION EXPOSE THE CITY'S COMMUNITIES TO A LONG LIST OF RISKS IS UNFATHOMABLE]
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"The City of Launceston completed a review into its sediment raking trial in 2019, with the review finding that sediment raking and prop washing did not achieve their primary goal of net loss of sediment from the upper estuary for the purposes of flood defence," he said.
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Cr van Zetten encouraged residents in low-lying areas to have a plan in case of flooding. [DrTV... HOWEVER, WHAT MIGHT HE SAY TO PEOPLE WHO NOW PAY VERY HIGH INSURANCES IN LAUNCESTON'S FLOOD PRONE AREAS, THAT IS THOSE WHO CAN GET, OR EVEN AFFORD, INSURANCE DUE TO VARIOUS COUNCILS OVER TIME TAKING WHAT THEY ASSUMED WERE ACCEPTABLE RISKS?]
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NOTE : IT IS HIGH TIME THAT LAUNCESTON'S COUNCILLORS LOOKED AROUND THEMSELVES AND CEASED TAKING UNACCEPTABLE RISKS WITH PEOPLE'S LIVES, LIVELIHOODS, INVESTMENTS AND LIABILITIES ... Dr T Vale
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