Rising flood water in the Mary River under the Normanby Bridge in Gympie.
Rising flood water in the Mary River under the Normanby Bridge in Gympie. Renee Pilcher

Fears over quarry flood risk

AN ALLOWANCE of up to 150,000 tonnes of sand and gravel to be extracted beside the Mary River was made despite an extreme flood risk, and the applicant failing to submit a flood study as requested.

Instead Sunshine Coast Regional Council planning committee claims it was presented with “some incorrect” flood levels by the extraction company which were “much lower than what would be expected”.

Despite this lack of accurate data, council planning staff believed the flood risk could be managed by a flood evacuation plan.

Council’s report said: “Flooding is a major issue which has not been assessed by the Department of Environment and Resource Management”.

“The sand extraction site is located on the eastern side of the Mary River between Conondale and Kenilworth.

The grade of the Mary River in these upper reaches is significant which, during flood events, leads to high velocities within the main channel of the river.”

And while the report stated significant scour and migration of the Mary River occurred during flood, it said the extraction area would be “a deep excavation and outside of the main channel and that velocities will not be sufficient to cause scouring to the rehabilitated landform”.

Objectors to the proposed Integra operation believe the staff case for approval was full of inconsistencies and the operation could have a major detrimental impact on the Mary Valley recovery plan.

Opponent Ian McKay was pleased council was looking to toughen up its conditions, such as increasing the recommended 40m buffer zone to the river to 60m, to be maintained at all times as the extraction process shifted on the site.

Save the Mary Co-ordinating Group president Glenda Pickersgill said such an operation on a flood plan could lead to ugly pits, which could change the course of the river and see the road lost.

“There is considerable riparian vegetation damage already occurring downstream of the proposed site following the floods a few months back,” she said.

“It would be unthinkable that Sunshine Coast Regional Council could take the huge risk and approve this controversial sand extraction operation on the eve of a threatened species recovery plan.”

Council received more than 100 objections to application for the 83ha site and two in support.

About 4ha will be used for extraction, the remainder maintained as pastoral and grazing land.