By ERWIN CHLANDA
“It would have been a flood high enough to have covered all of Alice Springs except for the crest of Billy-goat Hill and other similar high points on the edge of town.”
This occurred in about 1830 concludes historian Dick Kimber in his report Cultural values associated with Alice Springs water, drawing on historical records and oral sources.
“Later scientists in town, Geoff Pickup (an expert on slack-water deposits, formed during periods of high floods) and American Mary Bourke, a geomorphologist who was doing her PhD on floods in deserts, found evidence hundreds of years old and, in some cases, tens of thousands of years old, that indicated that there had been rare floods of much greater size.
“Remnant evidence from these super-floods of ancient times, ranging from about 400 years ago to tens of thousands of years ago in the Pleistocene period, was normally viewed as part of the natural form of the country by the Arrernte.”
Today, with Cyclone Ellie uncomfortably close and La Niña dumping big rains on Alice Springs, the town has cause to ask: What’s the government doing about flood mitigation?
The answer is not much, judging by what a local committee recommended and what of that has actually been carried out.
The Alice Springs Flood Mitigation Advisory Committee, chaired by then Mayor Damien Ryan, was convened on March 1, 2016. That is six years ago.
It recommended to “test structural mitigation options and their associated cost benefits with a new digital flood model [and] measures include detention basins in the upper catchments … strategically located detention basins … behind an embankment”.
If you think the committee (see photo) is tippy toeing around something you’d be right.
Serious flood protection work, with bulldozers already in place, ceased on May 17, 1992: Federal Aboriginal Affairs Minister Robert Tickner stopped the NT Government from building a dam in the Todd, upstream from the Telegraph Station, described by a report at the time as the only effective solution for saving the town.
Mr Tickner acted on requests from traditional owners seeking to protect sacred sites.
Junction Waterhole, site of the Todd dam proposed 30 years ago.
These “structural mitigation options” are clearly a dam but like the war in Basil Fawlty’s hotel, this is a word not to be mentioned.
Mr Tickner imposed a 20 year moratorium, which expired 10 years ago. Using it as an excuse for doing nothing has long since ceased to be credible.
People dying when the river rages notwithstanding, the governments – plural – keep sitting on their hands.
What would the dam recommendation from the committee cost? $500,000 for initial modelling / testing and a capital works budget of $30m over a five to 10 year timeframe.
Is that measured from the convening of the committee? From the release of the undated report? Has it started?
Making the digital flood model may have, but bulldozers are nowhere in sight.
The committee report estimates at $25m “to construct preferred technical option as per the Mount Johns Flood Immunity Project … supported by a flood study which demonstrates that any new infrastructure proposed does not negatively impact the existing flood profile of Alice Springs.”
This has apparently been started but it is not clear what stage it has reached. That is one issue included in the questions the News has put to the government.
The next one is the doozy of all the committee’s recommendations.
It’s worth $100m: “That an engineering investigation is undertaken to gain the necessary data to determine the technical feasibility and the flow on effects of widening the river bed as it passes through Heavitree Gap.”
What will they do with the road?
Elsewhere the government has contemplated elevating it on stilts as it goes through the town’s most magnificent landmark and linked to dreaming tracks spanning The Centre.
Another oddity in the report is this drawing (at right) in the report suggesting the railway line should run trough a tunnel at the base of the ranges, at the western side of The Gap.
This has been suggested by the News, was described by the nation’s most experienced tunnel builder as eminently feasible, and would be used to channel flood water when necessary, following an example already in operation in Malaysia.
The idea was apparently raised in the town council but went nowhere.
We will report government replies if and when we receive them.
COMMITTEE, pictured above, from left – front: Russell Lynch and Mayor Damien Ryan. Rear – Ken Lechleitner, Rod Cramer, Jimmy Cocking and Michael Sitzler.
UPDATE January 14:
The Department of the Chief Minister and Cabinet provided information, replying to the Alice Springs News, about emergency activities in the event of local rivers flooding.
How many measuring points are there?
The primary surface water monitoring sites used as part of the flood alerting system for the Alice Springs township can be found on the Bureau of Meteorology website: Todd River at Wigley Gorge, Charles River at the Big Dipper and again in the Todd River at Anzac Oval and at Heavitree Gap.
These are part of a larger network of monitoring sites the Department of Parks, Environment and Water Security (DEPWS) operates and maintains, including monitoring rainfall, which is used to predict flood events.
What is the maintenance routine for flood warning devices:
Monitoring sites are continuously monitored via telemetry to ensure they are in working condition with alerts sent to officers when errors are detected. Key monitoring sites are inspected by officers on a regular basis however, additional inspections are undertaken before and after significant flow events to ensure equipment remains in working order. Officers are also on a 24 hour duty roster to respond to issues as they arise.
What is the process of alerting the public of flood danger?
The Bureau of Meteorology is Australia’s national weather, climate and water agency. Its expertise and services assist Australians in dealing with the harsh realities of their natural environment, including drought, floods, fires, storms, tsunami and tropical cyclones.
Through regular forecasts, warnings, monitoring and advice spanning the Australian region and Antarctic territory, the Bureau provides one of the most fundamental and widely used services of government.
For riverine flooding where there are gauging stations, flood advice and warnings are issued to the public by the Bureau and shared by SecureNT and PFES platforms (websites and social media).
Please refer to Local Emergency Plans for advice dependent on the locality. Updated LEPs for 22/23 are due to be published soon.
What are the measures the Government undertakes to help the public in the event of floods (the Todd breaching its banks)?
NTES is responsible for facilitating emergency management planning, raising public awareness of potential disasters and providing a response capability for emergency events through dedicated volunteers.
To prepare the communities of the NT for the impact of storm, flood, cyclone, earthquake and tsunami, the NTES Community Engagement Unit offers free education and awareness programs to the public, as well as creating public safety displays at public events and publications.
NTES Community Engagement Officers deliver public Flood Briefings throughout the NT, in culturally and audience sensitive contexts for all ages groups, including for businesses, schools, and aboriginal communities.
The hierarchy of NT Emergency Plans provide a list of functional groups from across NT Government outlining the designated roles and responsibilities during the response and recovery phases of an emergency event. General advice on floods is available here.