Major civil works proposed for Barron River

A radical flood mitigation strategy to divert the Barron River has been proposed alongside an expected $25m outlay to build a bridge over the newly formed Jasper Creek at Holloways Beach.

A radical flood mitigation strategy to divert the Barron River has been proposed alongside an expected $25m outlay to build a bridge over the newly formed Jasper Creek at Holloways Beach.

During the latest Barron River flood event Thomatis Creek cut a new path to the sea through a section of low-lying mangroves before smashing through a 100m section of Casuarina St and washing the roadway into the ocean.

Cairns Regional Council filled the Casuarina St cut with tonnes of rock and road base was laid on top to allow single lane access to about 50 houses, but this is only temporary solution.

Casuarina Street on the Holloways Beach foreshore on Monday December 18. Picture Emily Barker

At Wednesday’s ordinary council meeting it was revealed construction of a bridge was considered the best way forward, based on hydraulic surveys.

“The initial analysis has indicated a bridge in favour of a land-based causeway will provide improved flood immunity for the adjacent Holloways Beach zone by up to 500mm in a Q100 event,” a briefing from chief executive officer Mica Martin stated.

Road repairs and the construction of the bridge over the creek mouth are expected to cost in the order of $25.5m.

An aerial view of Casuarina Street, Holloways Beach in Queensland, showing damage from Cyclone Jasper. Picture: Cairns Regional Council

Holloways Beach resident and member of the Combined Residents Working Group Paul Aubin said a bridge was the only long term solution to Casuarina St access based on the historical flow of Thomatis Creek.

“Jasper Creek is not new, water flowed out there and in the 1960s it was filled in to build houses on,” he said.

The working group has advanced a push for a new hydrographical survey of the Barron River that considers climate, in a hoped-for update of the 1980 Barron River Delta Investigation.

“(And) storm water needs to be looked at, that needs to be audited and assessed and improved,” he said.

Also on the table is earthworks to remove bending sections of the river to speed up egress of flood water to the sea.

“We have to intervene,” he said.

Holloways Beach resident Paul Aubin sits on the flood lobby group, the Combined Residents Working Group.

“We need to do some major civil works on the Barron River to stop it meandering.

“This is a suggestion and put in some strengthening where the Barron River joins Thomatis Creek.”

Testing of silt deposited in Holloways Beach by flood water has also been requested after reports of E. coli contraction and concerns that contaminated material from the Northern Sands Quarry could have been washed downstream during the floods.

Based on a post-flood site inspection, the Department of Environment, Science, and Innovation in February dismissed speculation that mud sucked out of Trinity Inlet and stockpiled at the quarry escaped the facility.

Other flood works to be priorities by council include repairs at Barron Gorge Rd, reconstruction of the Fisheries Bridge, Savanah St in Palm Cove and numerous culvert and drainage structures across the city.

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Originally published as Major civil works proposed for Barron River