Types of activities
Control of dredging operations
Harbour Authorities, port and marina operators, dredging companies, developers, the marine aggregate industry and others carry out a variety of dredging operations including:
- removal of accumulated sediments from harbour channels and berths to ensure a safe depth of water for navigational purposes - maintenance dredging
- similar maintenance works to remove sediment to restore an adequate flow of water to mitigate risk of flooding or protect a sensitive habitat - maintenance dredging (sometimes referred to as environmental dredging)
- excavation of material to deepen or create navigational channels and berths to provide additional harbour infrastructure or provide access for deeper draught vessels - capital dredging
- capital or construction dredging also applies to removal of areas of the seabed during construction works at sea associated with the placement of other materials such as foundations, laying of pipelines, outfalls
- preparation of the seabed to level and remove obstructions preparatory to laying of pipelines and cables - 'pre-sweep dredging'
- extraction of supplies of sands and gravels (marine aggregates) to provide commercial supplies of material for construction works and for 'soft engineered' sea defences and beach replenishment
The statutory control of dredging operations is complex, being the responsibility of a number of regulatory authorities. Many port and harbour authorities operate under local Acts which empower them to undertake dredging works within the limits of their jurisdiction. Such powers often require the endorsement / approval of the Secretary of State for Environment, Food & Rural Affairs.
However in most, if not all, cases a licence is also required under the Food and Environment Protection Act 1985 (FEPA) to dispose - or indeed to place for a beneficial purpose - dredged material in the sea or other tidal waters anywhere below the Mean High water Spring Tide mark (MHWS).
Other authorities, developers and others will normally need to secure a consent under the Coast Protection Act 1949 (CPA) to dredge and/or place any arisings. In addition, a FEPA licence will also be necessary, unless the dredged material is to be taken out of the sea for disposal or use on land above MHWS.
Any proposal to dredge within a harbour area, either under local powers or the CPA, shall be subject to the provisions of the Harbour Works (Assessment of Environmental Effects) Regulations 1999. Proposals to dredge and/or to dispose or use dredged materials within or adjacent to a European conservation site will usually require the consenting authorities to undertake an 'Appropriate Assessment' under the Conservation (Natural Habitats &c) Regualtions 1994.
The MFA , the Cabinet Office and the ports and leisure industries have agreed a draft 'Conservation Assessment Protocol' which is intended to offer a streamlined method for robust but proportionate consideration of the implications of on-going maintenance dredging operations.
Those engaged in working up proposals that will involve dredging / excavation of the seabed are advised to consult at an early stage with the MFA about the availibility of disposal sites in the vicinity of the works since a new site is liable to take time to identify, normally at a cost to the prospective user.