Community & Business
1 October, 2024
Tinaroo Falls Dam flood fears
HIGH water levels at Tinaroo Falls Dam and the approaching wet season have sparked a call from Barron River residents for information on how the dam will be managed, and whether strategic water releases should be implemented.
Mareeba Deputy Mayor Lenore Wyatt told a recent council meeting that she had received many inquiries on whether council had an emergency disaster plan. She said that with the Cyclone Jasper flooding event, there was still “absolutely a lot of anxiety around”.
“The concerns of people living on the Barron River especially ... are that [the dam is] going over. I know we have had communications with Sunwater, but I think it’s something that we really need to be clear about and the community needs to be clear about,” she said.
“What is Sunwater’s disaster management plan, or do they have one when it comes to the fact that we don’t know what sort of wet season we’re about to have?
“If you listen to one person, it’s a drought and if you listen to next person, it’s going to be as bad as the last one.”
Tinaroo Falls Dam recently broke the record for spill days – the number of consecutive days it has been over 100% - at 273. The last continuous spill record was in 1979 at 203 days. The dam was now at at 98.78%.
Council chief executive officer Peter Franks told the meeting Sunwater, which manages the dam, had a very detailed plan registered with council. However, Tinaroo wasn’t a buffer but a water storage dam and “if it’s full, it’s full”.
“They are not going to be releasing water to act as a buffer to mitigate against flooding,” he said.
“If the dam wasn’t even there, that’s what the impacts would be. If you didn’t have a dam and it started to flood, it would flood.”
Katter’s Australian Party candidate for Cook Duane Amos said the council discussion did not “provide any level of comfort” for those living close to tributaries. Feedback on the meeting indicated it was dealt with too briefly”.
“One consistent concern raised is the dam height is at 99.77% capacity currently, and we continue to receive rain and a forecast of more rain to come,” he said.
“Sunwater is quiet on the issue... which also increases the concerns of residents in the lower release areas of the dam.
“Areas in the Barron River at Mareeba, which would normally be dry this time of year, are what is best described by residents whose properties back up to the river as ‘swampy and consistently damp’, so our water table is remaining consistently high allowing flooding and inundation quickly with any heavy rainfall.
“The TC Jasper Disaster Management and subsequent response highlighted the absence of investment in planning for events and how best to operationalise the response necessary to keep our communities safe.”
A statement from Sunwater said dam management was in accordance with standard operating procedures and the dam’s Emergency Action Plan (EAP).
“The EAP outlines dam hazards such as floods, how the hazards or event will be managed during an emergency and dam notifications and warning triggers for downstream communities,” it said.
“Tinaroo Falls Dam is not designed to provide downstream flood mitigation. It is designed to safely pass water once capacity is reached, protecting the structural integrity of the dam.
“In a major weather event, dams do not cause flooding. All rainfall and runoff into rivers, creeks and streams contribute to flooding in a catchment.
“Water flowing over the spillway is simply water passing that would normally flow through the catchment.”
Sunwater explained that Tinaroo was a “fixed crest dam” and did not have the ability to release water in large volumes.
“If water releases were made prior to expected rain events, it would do little to prevent flooding and may impact on urban and irrigation water reliability if the rainfall did not eventuate,” it stated.
