Dredging to maintain navigational channels in West Bay and Lyme Regis harbours will get underway today (Tuesday).

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. 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. Dorset Council is monitoring nearby reefs as part of the dredging regime to make sure these actions do not damage locally more sensitive habitats.

During the work, areas of the beach 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 its normal colour.

To ensure the beauty of our beaches isn't affected, Dorset Council says the dredged sand is placed beneath a layer of the sand that is already there, which has been moved aside for this purpose.

Last year, dredging happened later in the year when the Environment Agency were carrying out their routine sea water quality tests (between May and October). These tests showed that there was no Escherichia Coli (e-coli) or Intestinal Enterococci in the water because of the dredging and excavating activity.

Dorset Council says that any change in the colour of the sea is due to the disruption of the seabed with sand particles suspended in the water, but swimming is discouraged due to the potential for allergic reactions due to these particles.

The dredging equipment will arrive at West Bay today (Tuesday), offloaded and then towed to Lyme Regis where dredging will start a few days later to coincide with a spring tide.

Dredging at Lyme Regis will be completed by March 24. They will then move back to West Bay where dredging will re-start and be completed by April 21. Timing is weather dependent and may change.

Find out more about dredging