Following on from aiding with licensing, Exo were appointed by Brightlingsea Harbour Commissioners Principal Designer and Project Manager of a 4 year dredging and restoration project. This was part of the wider EU Interreg Using Sediment as a Resource (USAR) scheme and  aimed to remove 53,000m3 of accumulated sediment from the harbour and beneficially reuse the majority of the arising material to restore 5ha of local intertidal and saltmarsh habitat.

The dredging and restoration works were carried out over three successive neap tide periods to limit the potential for erosion during high springs. Exo’s role throughout this period was to oversee coordination of works between the harbour, dredging and restoration teams, to liaise with both contractors and members of the public to ensure understanding and encourage support of the project and to confirm all works and mitigation measures put in place were adhered to.

Inevitably, whilst undertaking a complex operation in a logistically challenging and high risk intertidal environment, problems can arise as a result of unforeseen or uncontrollable circumstances. We employ an adaptive management strategy to our dredging and restoration projects, as recommended by the Central Dredging Association (CEDA), to combat and allow the project to remain robust to such uncertainty.

Exo’s site management and expertise allowed any minor issues to be solved efficiently enabling the project to be delivered on time, within budget and with zero harm to people and the environment.

Waterside Marina is situated within a high-end riverside residential complex, within Brightlingsea Harbour on the River Colne Estuary in Essex, UK, and provides moorings and shore side facilities for recreational vessels and boat owners.

In 2015, after a major dredging campaign, Brightlingsea Harbour Commissioners overtook responsibility for the marina. This responsibility included continued maintenance dredging and monitoring of siltation levels; the latter of which Exo Environmental were contracted to survey.

We used a combination of bathymetric and topographic survey techniques to achieve the most comprehensive results possible. This began with an initial bathymetric survey by the Exo Surveyor vessel in all accessible areas, subject to satellite coverage.

Following on from this, we were then able to collect data from inaccessible areas with satellite coverage by using a centimetre accurate GNSS topographic system on a sounding rod, whilst in inaccessible areas without satellite reception, a manual measurement using a graduated rod was taken to ensure 100% coverage of the marina.

Beccles Yacht Station and Boat Dyke has silted up over the years due to run off from the main river and the main town drain. The accumulated silt had to be removed to allow for safe navigation as well improve conveyance of the drainage system.

Exo were appointed to design and manage the desilting works, including site investigations (preliminary ecological survey, bathymetric survey and sediment sampling followed by analysis), licence applications (MMO, EA, BA and NE), facilitate a tender and project manage throughout.

The project was successfully completed in November 2021, and included dredging under D1 licence (EA), Marine licence (MMO) and Broads Works permit with a bank side long reach excavator. The dredged material was dewatered in temporary lagoons before it was transported to a spreading site under a SR2010 No.4 Landspreading licence (EA). The spread and cultivated dredged material will be sown in as a wildflower meadow to improve biodiversity of the grass swards