Mersea Harbour is sheltered by low islands and headlands exposed to erosion from waves and changing sea levels. Mersea Harbour Protection Trust was formed in 2014 to organise a large-scale reinforcement project using suitable sand and gravel dredged from the approaches to Harwich.
The recharge project
After environmental assessment and licensing, work began in November 2021 and was completed on 16 January 2022, when the final load was placed at Old Hall Point. Material was deposited at Cobmarsh Island, Packing Marsh, Old Hall Point and Shinglehead Point at Tollesbury Wick.
The dredgers Sospan Dau and Scald made 95 trips, delivering approximately 98,900 cubic metres of material (about 158,310 tonnes). Brushwood fencing was installed at selected locations to reduce the movement of material in storm conditions.
Funding and local work
Harwich Haven Authority provided more than £1.2 million towards construction; the Environment Agency contributed nearly £300,000 to recharge costs and supported monitoring. The Trust had also raised money locally to obtain the necessary consents and studies.
Why the sheltered islands matter
The islands help shield the moorings, oyster grounds, creeks and waterfront from waves. They also provide habitat for birds and other wildlife. Strengthening them was intended to slow erosion, not to stop natural coastal change altogether.
Monitoring after construction
Marine licensing required five annual monitoring reports to assess the scheme and look for unwanted effects. The Trust’s published Year One report, released in 2023, recorded that the work had proceeded as planned at that early stage. It should not be treated as a final assessment of the project’s long-term performance.
The Trust’s construction updates and monitoring material provide the available project record.