KI Plantation Timbers models coastal currents at Smith Bay

ABALONE FARM: An aerial view of Smith Bay showing the onshore aquaculture facility. The proposed KI Seaport location is about 500 metres to the west (right). Photo supplied KIPT
ABALONE FARM: An aerial view of Smith Bay showing the onshore aquaculture facility. The proposed KI Seaport location is about 500 metres to the west (right). Photo supplied KIPT

Kangaroo Island Plantation Timbers has released initial results of its coastal process modelling at Smith Bay, the site of the proposed KI Seaport.

KIPT says the modelling shows that prevailing westerly currents will protect the nearby onshore aquaculture farm’s water intakes.

But Yumbah Aquaculture, located directly adjacent to the proposed development, says more than 20 years of daily observation of Smith Bay contradicts the claims about tidal currents.

KIPT managing director John Sergeant said the company had been gathering comprehensive data over more than a year.

“The information about water quality and direction, from the monitoring buoys we deployed in the bay, has been used by our marine engineers at Wallbridge Gilbert Aztec to create models which address the effects of the dredging needed to create a berth pocket and to level the seaward approaches for the export facility,” Mr Sergeant  said.

“The results are favourable and show that Smith Bay is subject to natural variation in water quality. Fine materials are periodically deposited from nearby watercourses and then re-suspended and dispersed during periods of wind-driven waves.”

Mr Sergeant said the general area was subject to low-velocity, underlying, longshore currents that were mainly driven by tidal effects in the Gulf St Vincent and Investigator Strait.

“The prevailing direction of these currents at Smith Bay is westwards, so that the net movement of any suspended particles is away from the intakes of the onshore abalone farm located several hundred metres to the east of the site.

“Notwithstanding the general westward current, in certain wind and tide conditions the currents run eastwards. The net effect is that in-water construction work would need to be conducted during periods when there is no likelihood of significant eastwards currents, and with monitoring equipment in place.” 

Yumbah Kangaroo Island general manager David Connell said his company, like other resident and business operators on Kangaroo Island, was curious to see the data supporting KIPT’s assurance to the Australian Securities Exchange that it can prevent adverse effects on Yumbah Aquaculture and the health of Smith Bay and its foreshore.

“Yumbah does not oppose expanded transport and export facilities on Kangaroo Island,” Mr Connell said.

“It remains a mystery that Kangaroo Island Plantation Timbers insists on destroying Smith Bay for its massive KI Seaport woodchip proposal when multiple other sites are more fit-for-purpose.”

KIPT meanwhile says its coastal process modelling had not identified any significant or persistent effects on marine flora and fauna beyond the footprint of the development itself, Mr Sergeant said.

The next phase of modelling would be to address the effect of the in-water structures on coastal processes and  assist in optimising their design, he said. 

“As previously announced, KIPT remains committed to delivering and operating the KI Seaport in a way that minimises negative impacts on water quality. The results show that this is achievable,” Mr Sergeant said.

Full details of this and other studies will be available in the forthcoming Environmental Impact Statement for the project, expected to be released in the next couple of months, he said.