Dredging

Dredging is one of our key tasks, both to maintain adequate water depth for boaters and as part of our work to improve water quality.

DredgingOver the years sediment has increased as a result of environmental changes, specifically more algae in the lakes and more soil erosion. We hope improvements in water quality, measures to reduce bank erosion, improve bank protection and manage flood risk will lessen the need for dredging.

To protect navigation channels and this internationally important wetland we aim to:

  • Identify how much sediment is coming into the Broads
  • Work with other organisations to reduce the amount coming in
  • Define desired channel dimensions in order to plan what future dredging will be needed
  • Reuse dredged sediment wherever possible

The two dredging methods routinely used are grab (or excavator) and suction. Suction dredging uses a floating platform with an engine that powers a pump. The sediment is passed along tubes to an adjacent disposal site, often a field of low ecological quality. 

Award-winning projects

We have won awards for our innovative dredging techniques which were developed and carried out under the Promoting Integrated Sediment Management (PRISMA) project.

PRISMA is a European Regional Development Fund project under which we were given £800,000 which we have match-funded for implementing dredging solutions in the Broads. It involves working and sharing expertise with Dutch, Belgian and French partners allowing us to:

  • Work out and implement better ways of reusing dredged sediment
  • Improve areas which haven't been dredged in recent years
  • Deliver already planned projects under the Sediment Management Strategy.

One of the three key projects in the Broads was rebuilding a bank and reed bed at Salhouse Broad, which was awarded the UK's first Working with Nature Certificate of Recognition, one of only three to be awarded in Europe. It was also commended in the 2013 Water Renaissance Awards.PRISMA project at Salhouse Broads  

The other PRISMA projects were the creation of a spit of land in Duck Broad using gabion baskets filled with dredged sediment and the commission of a new mud wherry. You can read more about all of these schemes on our Projects page.

Useful links

PRISMA project page

PRISMA website