Contract for Water Injection Dredging – Swansea Marina

Tender description

Dredging by Water Injection Dredging (WID) methods is required up stream of the River Tawe Barrage, in the vicinity of the Swansea Yacht & Sub-Aqua Club (SYSAC) Marina, to restore the navigable depth in the vicinity of the marina and approaches to the Tawe Lock.The dredging works are to be carried out by WID methods as this is the only method that has been licensed in previous years. A new license application will be made to Natural Resources Wales (NRW) for WID operation in 2024 and 2034.This contract is for the provision of two dredge campaigns, the first in winter of 2024/25 and the second two years later in the winter of 2026/27. The dredging contract will remain in force until completion of the second dredge campaign.Following the construction of the Tawe Barrage in 1994 there was a considerable impounded water depth upstream of the barrage, which provided a perfect location for the establishment of a marina facility. However, sedimentation has progressively reduced this capacity and eventually started to impact on the vessels moored on the floating pontoon structures. This was recognised to be a problem some time before the first maintenance dredging activity was carried out in 2008.Maintenance dredging has been required within the area occupied by the SYSAC marina periodically since 2008. The dredging site is located between the River Tawe Barrage and the Sail Bridge walkway on the impounded river. Typically dredging has been carried out every 2 years, during the winter period between January to March. The timing of the dredging has been based on license conditions, .to minimise the potential environmental impact, and also have the least impact on the marina and lock usersa) WID dredging in the SYSAC Marinab) Fisherman’s Pontoons (optional)c) Swansea Marina Lock Barrel (optional)