Limehouse Basin Dredging Goes With the Flow

The project was carried out on behalf of British Waterways, who have previously used the WID process in the Gloucester and Sharpness Docks.

British Waterways commissioned extensive background research by HR Wallingford to assess possible environmental impact on fish stocks within the basin.

From this research, low production WID was selected as the least environmentally hazardous method of removing accumulated silt from the Limehouse Basin Marina.

Works started late last year and by completion, some 13,000m 3of silt had been removed from the basin. For this operation Ballast Ham Dredging deployed their road transportable WID unit Baldur , assisted by support vessel Roerdomp . The production of the dredger was strictly controlled to minimise the rates of sediment transfer from the basin into the River Thames, all as had been specified within the HR Wallingford research.

Ballast Ham Dredging used the WID process to move silt sediments from the basin to the lock entrance, where British Waterways controlled their release into the Thames through the lock gates. A disposal license is not required for the operation, only the consent of the local conservancy manager. The settled sediments are merely returned to the natural transport system of the river or water body.

The Baldur is well suited to dredging locations such as the Limehouse Basin due to its manoeuvrability and ease of transport. It is equipped with DGPS for accurate positioning of both the vessel and dredging depth control. Similar projects have been successfully completed within marinas at Newhaven and Herne Bay.

For larger scale projects, Ballast Ham Dredging deploys self-propelled water injection vessels such as the ‘Jetsed’, which have been successfully completing WID campaigns within the Thames Estuary for a number of years.

MJ Information No: 18331