An attempt by a Condamine River Crossings protestor to draw comparisons between a culvert at a river crossing in the Junabee district and the as-yet-unstarted bed-level crossing projects at Condamine River Road has met with a firm rebuttal by the Southern Downs Regional Council.
Killarney woman Barbara George has criticised the council’s work at Braithwaites Crossing Road which she described as ‘wrecked in just five months’.
“The crossing, which was completed only at the end of last year, is a box culvert crossing which means it is not constantly under water, unlike the bed-level crossings planned for Cambanoora which will be permanently submerged and exposed to much faster river flows, being higher up in the catchment,” she said.
“With only very light traffic going over it and only one minor flood, the Braithwaites Crossing is already in very bad shape. It has been severely eroded.
“Compare that to the hundreds of 4WDs and the severe floods experienced in the Cambanoora Gorge and you have to ask, is the $2.2 million the council is spending on the gorge crossings going to literally be ratepayers’ money down the drain?
“We are calling on the council to explain why Braithwaites Crossing has deteriorated so badly and so quickly, and to explain to ratepayers how this will be prevented at the gorge crossings.
“The Braithwaites Crossing has bitumen going up to the cement, similar to what is proposed for the gorge and it has taken just five months for the bitumen to be badly washed out.
“Apart from the cost of ongoing repairs, bitumen washed into the river during flooding events will pollute the sensitive environment, habitat to multiple threatened aquatic species.”
She sent photographs and a letter explaining the fears of the Cambanoora Gorge protest group to the council.
The council has replied to address ‘perceived comparisons between upgrades to Braithwaites Crossing and upcoming works to our crossings on the Condamine River.’
Director of Infrastructure Services Gary Murphy said there were significant differences in the engineering designs of the two projects based on habitat, the impacts of flood events, government requirements and environmental advice.
“The upgrades to the Braithwaites Crossing were designed to meet the minimum requirements of the Department of Agriculture and Fisheries (DAF) at the time of construction,” he said.
Mr Murphy said the low-level box culvert structure, situated at the junction of the Condamine River and Swan Creek, was subject to high velocity flow over the width of the crossing when the culvert was flooded, but the crossing was not concreted (at either end) as it was a low priority road with minimal traffic and no additional funding had been available.
“The crossing has been flooded several times since construction, with the largest flooding of approximately 2m over the culvert occurring on 31 January. There have since been several smaller floods over the culvert. As the crossing does not have concrete across the full width of the bed, minor damage was caused to the approaches following these weather events,” he said.
Repairs were subject to Queensland Reconstruction Authority funding and approvals, with no significant improvement provided to the other elements of the structure. Bitumen was added to the approaches due the constant flooding that prevented the approaches from consolidating after construction. The bitumen had also assisted in preventing scouring of the crossings during subsequent flooding, he said.
Mr Murphy said the Braithwaites Crossing design was very different to the proposed designs for the Condamine River Road and a better comparison would be Watsons Crossing which had been in place for many years on the Condamine River Road and was a full width concrete causeway that had sustained no damage from flood events.
“The new crossings proposed for the Condamine River Road are concrete bed-level crossings, concreted to the entire width of the river, with cut-off walls down to bedrock and having additional concrete wings/approach slabs extending between 5m and 10m up the approaches on either side,” he said.
“This is the area of high velocity flow during flood events.
“Bitumen will be laid above the concrete extremities to aid vehicle traction and stabilise the remainder of the crossing approaches from scouring. The bitumen will be elevated away from higher velocity flows and above the bed level.”
He said Long Crossing, Blackfellow Crossing, Mill Crossing and then Second Crossing would all be upgraded with permanent floodway structures that allowed for the normal flow of water through the river system, including facilitating the movement of fish and wildlife on their natural migratory paths through the Condamine River ecosystem.
“The installation of permanent floodway structures at these four crossings, together with depth gauges and electronic signage, will significantly improve safe access on the road for both residents and tourists,” Mr Murphy said.
The crossings had been designed to be resilient and comply with barrier works and legislative requirements through the Department of Agriculture and Fisheries, he said.
