Debenham Flood Management Project

Debenham is in the headwaters of the River Deben and a number of tributaries meet in the village.

In most summers the river dries up completely, but heavy rainfall events can cause the village to flood. The most recent flood was in 1993 when approximately 33 properties were recorded as having been flooded. There have been other floods in 1912, 1927, 1936, 1944, 1947, 1956, 1968, 1994 and 1995. The Environment Agency currently carries out maintenance through the village twice a year to remove vegetation from the watercourse.

River through Debenham during typical summer

 

 

 

 

 

The management of flood risk to Debenham is complex due to the three tributaries of the river meeting in the village and results, from an Environment Agency study, indicated that the costs of many traditional flood management measures are prohibitive. Thus, we are exploring a natural flood management approach, slowing the rate at which flows enter the river network. Working with landowners and the Essex and Suffolk Rivers Trust, we identified a range of measures which could help reduce flooding in Debenham, and provide water quality and habitat benefits. These include features such as small flood storage areas and ponds.

We incorporated the most promising natural flood management features into a hydraulic model to assess their potential benefits and to ensure that they wouldn’t result in additional flooding to other properties. The model showed that together, these features could reduce flood risk in Debenham in smaller more frequent flood events, but that further measures might also be needed. Click here to view the Natural Flood Management Modelling Report.

At present, three features have been constructed at Debenham Hall Farm, Aspall Hall and Hill House Farm. The work was undertaken by the East Suffolk Internal Drainage Board, funded by Suffolk County Council, the Essex and Suffolk Rivers’ Trust and Regional Flood & Coastal Committee levy. Two of the smaller features were installed for under £10,000 in total, with the larger feature at Hill House Farm costing circa £80,000.

Debenham Farm NFM

Small pond feature at Debenham Hall Farm. Whilst it makes a small contribution to flood risk management, the main benefit of this feature is to capture run off from the farmyard thus preventing sediment and pollution entering the river.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Hill House Farm NFM

Design of Natural flood management feature upstream at Hill House Farm. The total area is circa 0.5 Ha with the capacity to store 6700 m3 flood water. The picture below, taken in June 2018, shows the feature which retains some water. Further planting of wild flowers around the edge will maximise its biodiversity value.

 

 

 

 

 

Cherry Tree Brook NFM

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

We are working with other landowners to persuade them to install similar natural flood management features on their land, using those features already in place as exemplars. The more of these slow the flow features we can install, the better the flood protection for the village – and the greater the environmental benefit. We currently have an offer of £50,000 from RFCC levy towards the additional work.

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