A new report has been published by the Environment Agency that examines whether additional dredging in areas of the Lower River Bure would alleviate flooding.

The £13,000 study was commissioned following a public meeting about widespread flooding during the winter of 2023/24. It was funded by a Flood and Coastal Erosion Risk Management Grant in Aid. 

The report used hydraulic computer modelling of different possible scenarios to determine the effect of additional dredging (beyond that undertaken by the Broads Authority for the benefit of navigation) of the area known as the ‘Bure Loop’.  The modelling was based on dredging to depths of 2.5 and 3 metres, almost a metre below the current navigation waterways specification depth. A range of both fluvial and tidal events were explored through the model, as was data collected during Storm Babet.

The modelling report concludes that additional dredging in the Lower Bure does not reduce the risks from flooding in the upper part of the catchment. The most significant impact is an increased risk of tidal flooding at the lower end of the river. 

Conservative estimates put the cost of the dredging for the Lower Bure beyond the current total annual Environment Agency maintenance budget for the whole of the Broads system. Furthermore, regular dredging would be needed to maintain the new depths. 

The additional dredging would also need considerable licensing requirements and environmental considerations such as the disposal of large amounts of sediment that exceed those produced during the current yearly Broads Authority dredging programme for navigation.  

The lack of significant benefits and high costs mean that the work is unlikely to be eligible for central government funding. 

Graham Verrier, Environment Agency, East Anglia (East) Area Director said:

“We are pleased to have been able to deliver this report to explore the possible flood risk benefits of dredging in the Broads and thank our partners in the Broads Authority for their support. Where there is evidence that dredging will reduce flood risk to local properties, without increasing flooding downstream and that meets government criteria and is affordable, we will do it. If dredging isn’t the right solution, or costs more than the flood risk benefit it provides to properties, we will help communities and partners to look at other options to manage the risk of flooding.”

John Packman. Chief Executive, Broads Authority said:

“I would like to thank our partners at the Environment Agency who have swiftly facilitated such a thorough study. Whilst outside the current scope of work of the Broadland Futures Initiative (BFI), the findings will inform the strategic flood risk management approach for the Broads over the next 100 years.”

A copy of the full ‘Bure Loop Dredging Scenario Report’ along with a summary paper can be found here: Broadland Futures Initiative (broads-authority.gov.uk).
Further independent information regarding dredging for flood risk purposes is available from the Chartered Institution of Water and Environmental Management. Floods-and-Dredging-a-reality-check.pdf (ciwem.org)