Harbours
Our harbours provide safe mooring and launching facilities for small boats and are important refuges along the Dorset coast for any vessels at sea that may be in difficulties.
Harbours can suffer from sediment deposits either from rivers or from the natural action of waves on beaches.
To maintain the safe depths for the navigational channels and water ways this sediment is removed on a regular basis. This process is called dredging.
Dredging was planned for West Bay and Lyme Regis in February and March this year, but the dredging team is returning to West Bay in June / July to complete the removal of excessive sediment remaining in the harbour after the earlier dredging work.
Dredging
This can be done by boat or using earthmoving equipment at low tide. All equipment has biosecurity measures in place to make sure they are free of invasive and non-native species. They also use biodegradable fuels and oils to lessen the release of harmful chemicals into the marine environment.
Every year the accumulated sediment that has deposited over the last twelve months is removed from the navigational channels and used to build up the local beaches.
The area being dredged is a very busy area and doesn’t contain any habitats of note for local marine plants and animals.
We are monitoring nearby reefs as part of the dredging regime to make sure our actions do not damage locally more sensitive habitats.
The beaches
When appropriate, beaches will be fenced off for safety due to the machinery being used.
The colour of the dredged sand is often darker in colour due to the lack of exposure to oxygen on the seabed. Once exposed to the air it returns to the normal colour we are used to. But to make sure the beauty of our beaches isn’t affected we place this dredged sand beneath a layer of the sand that is already there, which we have moved aside for this purpose.
Water quality
Last year extensive testing of the dredging sediment was carried out at Lyme Regis. These tests showed that there was no Escherichia Coli (e-coli) or Intestinal Enterococci released into the water because of the dredging and excavating activity.
At West Bay the dredging is being carried out under an Marine Management Organisation (MMO) licence and in accordance with licencing requirements, the sediment was tested and found to be safe for discharge in the marine environment.
The colour of the sea will change due to the disruption of the seabed with sand particles suspended in the water. Swimming in the discoloured water is discouraged due to the potential for allergic reactions due to these particles.
Dates
The dredging equipment will arrive at West Bay on Tuesday 11 June, and be offloaded into the harbour in preparation for dredging.
The Jurassic Pier and West Beach will be temporarily closed to lay the dredging sediment pipe before the start of dredging the dredging at Bridport Harbour on Thursday 13 and Friday 14 June, and again for the removal of the pipeline at the end of the dredging of Bridport Harbour.