As a Site of Special Scientific Interest (SSSI) and Special Area of Conservation (SAC), the River Wensum in Norfolk, which winds its way through both urban and rural landscapes, needs protecting. The Environment Agency is implementing a restoration strategy to prevent the deterioration of the area.
We helped confirm the measures proposed in the river restoration would not increase flood risk. To do this, we commissioned a new channel survey and constructed a hydraulic model of a reach of the River Wensum and Internal Drainage Board drains (IDB). The river restoration features were represented in the hydraulic model, including a series of woody debris, tree enclosures and fry bay, to provide additional support for the flora and fauna of the chalk stream.
Through the hydraulic modelling exercise, we confirmed there was no increase in flood risk to property or communities along the river. In addition, we confirmed the river restoration features should not impact the ability of the IDB watercourses to drain into the River Wensum. The outcomes of this project facilitated the Environment Agency’s discussions with local landowners and the IDB.