The Resource Management Association, comprising CEMEX UK Marine, Heidelberg Materials Marine (formerly Hanson Aggregates) and Tarmac Marine Dredging Ltd, was seeking approval from the Marine Management Organisation (MMO) to remove the existing licence condition in Area 472 (situated adjacent to Culver Sand in the Inner Bristol Channel), which limited extraction to a volume equivalent to a uniform 1 m deepening across the licence area.

Specifically the licence holders wished to dredge from Area 472 a volume equating to a maximum 2.5 m lowering of the bed. In order to achieve consent for the proposed dredging, an impact assessment was required of the dredging carried out to date and the proposed future dredging.

We reviewed bathymetric and geophysical survey monitoring data collected during the previous 5 years to determine the effects of dredging on the local seabed morphology, especially to the form and function of the sandbank. We also undertook a sediment transport and coastal impact study to determine whether dredging to a depth of 2.5 m would be acceptable.