Heigham Sound Broads Dredging Plans on Hold

The Broads Authority has been forced to delay plans to dredge Heigham Sound on the Upper Thurne after permission to dispose of the sediment on land next to Candle Dyke was withdrawn by the landowner. It had been planned to remove 12,000m3 of mud in Heigham Sound and restore the disposal site over the summer. However, those plans are now on hold until a new disposal site can be found. Heigham Sound urgently requires dredging to improve the water depth within the navigation channel. It has silted up to a depth of 90cms in places causing some sailing boats to go aground. Rob Rogers, the Broads Authority’s Head of Construction & Maintenance, said “We are disappointed that the landowner has changed his mind but we remain committed to maintaining the navigation channel and we are pursuing a number of different options to progress the dredging of this important area.” Maintenance work on the markers which define the channel will still go ahead as well as a small amount of dredging to ‘top-up’ the trial island created at Duck Broad last year. Officers will also continue progressing the consents and permissions required to extend the island with the aim of carrying out the work over the winter.

The island was created as an innovative method of dredging disposal. Its perimeter is formed from gabion baskets and the central void has been filled with sediment. Reed is already growing and it is hoped that, once established, it will start to replace reed marsh lost through erosion and provide shelter for overwintering wildfowl. The larger island which is planned would measure approximately one hectare and provide a significant site for sediment disposal. Despite fears that dredging in the area could cause an outbreak of Prymnesium parva algae, which can prove toxic to fish, the water quality has remained unaffected. Daily monitoring during the island’s construction phase revealed counts well below the trigger levels for any remedial action but regular assessment will continue. Carrying out future works over the winter will also help to reduce the risk.