Navigation and archaeology in the Haven

22 September 2021

Commercial and recreational navigation

Given that the approach channel provides access to Felixstowe, Harwich International Port, ABP Ipswich and Mistley (amongst others), there is a high level of commercial vessel traffic within the approach channel, as well as commercial fishing and recreational vessels. HHA is responsible for the navigational safety and traffic regulation of all vessels and operates management schemes such as the Vessel Traffic Service (VTS) and ongoing maintenance dredging. There is also a traffic separation scheme in close proximity to the disposal site.

Provided that standard mitigation measures are followed, any impacts during the deepening works and subsequent management of the channel to navigation are predicted to be of negligible to minor significance. Such measures would include complying with international regulations on preventing collisions, establishing safety zones around active dredging works, publishing Notice to Mariners and using the VTS to inform mariners of activity.

Marine archaeology

A Marine Archaeological Assessment has been undertaken to gain an understanding of the marine historic environment in and around the approach channel, which has helped to identify heritage assets and archaeological features that may be affected by the deepening. There are wrecks and other maritime artefacts present, and the Archaeological Assessment indicates there is the potential for other submerged and intertidal archaeological material to be present.

Potential direct impacts through damage to known and unknown heritage assets and submerged prehistoric archaeology within the approach channel have been assessed to be of minor to moderate significance. To minimise such impacts, a pre-dredge survey will be undertaken to determine the nature and archaeological potential of features within the dredge footprint, and a reporting protocol will be implemented to capture and record any material brought up during the dredging. With mitigation in place, the impacts are predicted to be of negligible to minor significance.

Indirect impacts may occur to heritage assets in the intertidal zone and marine environment as a result of dredging and changes to coastal processes. However, the small level of sediment accumulation that is predicted to occur on the seabed during or following the deepening works (a maximum of 10mm outside the immediate dredge area) may be beneficial to exposed marine heritage assets by protecting such assets.