Sediment Management
Dredging
The Broads Authority, as navigation authority, has adopted a river catchment approach to sediment management. Our aim is to provide a means of ensuring the sustainable long-term management of sediment within the Broads. The location, volume and movement of sediment, from its sources to where it is deposited, is key information required for successful management. This type of approach is needed within the Broads to protect both the inland navigation and the internationally important wetland.
Our objectives for managing sediment are to:
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Identify the volume of sediment entering the Broads
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Reduce sediment coming into to the waterways through working closely with other organisations
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Clearly define the desired channel dimensions within the waterways, which will inform the future dredging requirement
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Maximise beneficial reuse of dredged sediment
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Maintaining adequate water depths for navigation is an important river management task for the Broads Authority. There are two main dredging methods routinely used: grab (or excavator) and suction. Suction dredging works by having a floating platform with an engine that powers a suction pump. The bottom sediment, with a high water content, is passed along tubes to an adjacent disposal site, often a field of low ecological quality.
Over the last 60 years, rates of sedimentation have accelerated as a consequence of the environmental changes in the Broads, particularly from greater numbers of algae in the lakes and increased soil erosion. We hope that improvements in water quality, preventative measures taken to reduce the causes of bank erosion and improved methods of bank protection will ultimately lessen the need for dredging.
To find out more see our Sediment Management Strategy and Sediment Management Strategy Action Plan
European funding for dredging
This year the Broads Authority has been awarded around £800,000 from the European Regional Development Fund to develop innovative dredging solutions for the management of the waterways.
The project, which is called PRISMA (Promoting Integrated Sediment Management) will enable the Authority to develop disposal opportunities across the Broads and benefit areas which haven’t been dredged in recent years as well as delivering planned projects highlighted in the Sediment Management Strategy.
The project involves working with Dutch, Belgian and French partners, comparing dredging techniques and learning how we can better reduce sediment coming into our waterways and sustainably remove it.
Three of the key projects in the Broads are the extension of the island creation scheme in Duck Broad, rebuilding a bank at Salhouse Broad and building a new mud wherry.
