By ALEX NELSON
It is not just eastern Australia that is at risk of severe – and sometimes repetitive – flooding.
The record shows that Central Australia has also been seriously impacted by these periods, and we are likely to be facing one now.
Yet there is still no decisive action of flood protection for the town.
The authorities are likely to be reacting to events rather than preparing for them, which has always been the case in the past.
The Bureau of Meteorology recognises three triple La Niña periods on record since 1900: These were 1954-57, 1973-76, and 1998-2001.
The damage and disruption caused by widespread flooding on these occasions have left long-lasting legacies, especially for transport infrastructure:
• The isolation of the new Eastside suburb from the main part of Alice Springs in the mid 1950s, including rescues and fatalities of people crossing the Todd River in flood, prompted the construction of the footbridge next to the Wills Terrace Causeway, completed in 1957. The footbridge was intended to be a temporary structure eventually to be replaced by a main road bridge.
• The persistent flooding of the Todd River in the mid 1970s finally did prompt the construction of the Stott Terrace Bridge, completed in 1978.
• There were extensive repairs and reconstruction of low level bridges crossing the Hugh, Finke and Palmer rivers on the south Stuart Highway.
• The frequent long-lasting washouts of the original Central Australian Railway also prompted the construction of the Tarcoola to Alice Springs standard gauge railway, completed in 1980.
It’s worth noting that these major flood events are of limited duration but tend to have significant long-lasting consequences. They especially have serious economic impacts.
PHOTOS of 1988 flood by Hans Boessem, in the CBD and The Gap.
Alice will be flooded again and we’ll be told it’s unprecedented and nobody could have foreseen it — after all memories are very short term these days.
There will be the usual blame game, promises to fix and nothing much will be done.
Yeah, I’m old and cynical!
Just think about it. If nature didn’t do its work, nothing would get done. When will a dam get built? We all know the answer to that one!
NTG’s PAWA completed significant civil engineering / hydrology review and design work decades ago on infrastructure to mitigate the impact of the occasional but serious flooding of Alice Springs.
There are two requirements – dam the Todd upstream, and build levee banks within the city limits along the river’s path.
The key word being “mitigate”. We cannot prevent heavy, exceptional rainfall but we can lessen its destructive impact.
Editor: Noting your declared intention to focus on longer, in-depth reporting; perhaps you could follow up on the previous work by the NT Government. Focus on the 1980s/1990s.)
{ED – Alex Nelson has been working on a flood protection story and expects to complete it in the next few days.]
Ah, a bit of rain and we feel a dam coming on!
One of the many problems with dams is the competing interests and functions.
The original dam proposal was billed as a recreation lake.
Who could forget Harvey Millard’s election posters with little sailboats on the “lake” in the background?
Someone in the then CLP Government realised that funding for a lake was unlikely, so it was rebadged as a flood mitigation dam.
Whoops, problem. You want it full for recreation, and empty for flood mitigation.
Then Mark 2. A flood mitigation structure, essentially a wall with a slot in it that would hold back a major flow, and let it drain at a rate that would not flood the town.
The Aboriginal Traditional Owners sought a guarantee from the the Chief Minister (Perron?)
that they wouldn’t close the slot and turn it into a lake, which would have inundated some important sacred sites.
He declined to do so, and that was the end of that.
Of course it would still have had to get Federal funding, and the chances of that were pretty slim, when places like Lismore had much more urgent and compelling needs.
The flood plain management review of the late ’80s concluded that some lesser works like strategic levees, and changing the building codes, along with town-wide insurance from TIO was the most cost effective course.
But then Adam Giles sold TIO, and that was that. And still is.