Dredging completed, studies show no damage to seabed

A recent survey carried out to assess the condition of the seabed at Argyle, from which sand was dredged for the construction of the new container port in Kingstown, appears positive.

The dredging phase of the project came to an end on Saturday, June 3, and according to a spokesperson for the port project implementation unit, the final close-out bathymetric survey of the borrow source indicated that there were no incidents, accidents or complaints.

Lenski Douglas, assistant project manager told SEARCHLIGHT on Thursday that the final close-out bathymetric survey was completed on Monday, June 5, and indicates that there was no sighting of marine mammals or turtles; no marine flora or fauna observed in dredged material; and that water quality monitoring results for turbidity and suspended solids, both at the borrow area and reclamation site, fell below the threshold limiting values.

The assistant project manager told SEARCHLIGHT that recovery at the dredge site will be natural. “Natural events can expedite the rate of redeposition of material at the location but a conservative estimate of a minimum of three years is expected.”

He said only 10 per cent of the material at the dredge site within the approved area was removed at an extraction depth not exceeding two metres, leaving behind 90 per cent of the sand.

Last Saturday, June 3, just after midday, the MV Ham 316 made its final journey to Kingstown with a load of sand for the site of the construction of a new container port.

Over the last five and a half weeks, the vessel, a trailing suction hopper dredger, had made the journey almost 300 times in its effort to dredge 1.17 million cubic metres of sand from the seabed off the south east coast of St Vincent to be used to reclaim land in Kingstown Bay to construct the port.

It had been estimated that the dredging would take seven weeks, but working 24 hours a day, seven days a week, contractors were able to complete the job ahead of time. The vessel made six to eight round trips each day.

The next phase of the project, which has been ongoing as of May 27, is the vibro-compaction of the sand to densify the reclamation material and existing seabed within the port footprint.

“This step will be followed by temporary measures to protect the slope of the reclaimed area, followed by the installation of piles around the perimeter,” Douglas said.

He explained that the piling will be done to create a combi-pile quay wall. “This includes alternating circular king piles with sheet piles.”

The piles and equipment should arrive in June, with actual piling scheduled to commence in July on the east wing wall, adjacent to the Kingstown Fish Market.

Douglas said in order to improve navigational safety around the construction site, two lighted navigational buoys were put in place at coordinates 13°09.26’N, 061°13.90’W and 13°09.14’N, 061°13.65’W on June 4 to mark the seaward boundary of the Port Modernisation Project.

These buoys will remain in place until the completion of the project. The appropriate notice to Mariners was also issued to the Maritime Department, Douglas said.

The EC$670 million project is on schedule to be completed by May 2025 and so far, activities concluded under the project include the resettlement of project affected persons from Rose Place beach front in August 2022, and the re-routing and operationalisation of the new sewer line in April 2023.

The contract signed on May 4, 2022, with Aecon Construction Group Inc for the construction of the port is valued at approximately US$170.4 million or EC$460.07 million. Additionally, the contract signed with Sellhorn Engineering, the company tasked with supervising the overall project, is valued at EC$10.7 million.