BWB Consulting - Integrated Engineering and Environmental Consultants

Services:

• River Modelling
• Flood Risk Assessment

Sectors:

• Coastal and River Engineering
• Planning Support and Appeals
• Residential

BWB were appointed by Morris Homes to provide flood risk assessment and engineering design for a proposed residential development alongside the River Soar in Anstey, Leicestershire.

Although the Environment Agency (EA) had previously modelled this reach of the River Soar, they had only done so to a strategic level and the model did not contain sufficient detail to assess the true effects of two bridges in close proximity to the site.

BWB obtained aerial survey data from the EA and supplemented this with a detailed survey of the bridge structures. We then prepared a detailed hydraulic model of a 3 km length of the river, its associated floodplain and bridges to identify the source and nature of flood risk to the site. The model identified that flood risks to the proposed development were significant and required mitigation.

Several options were tested to mitigate the flood risk including defence realignment, off-site floodplain compensation and flood routing and on-site floodplain compensation and flood routing. The option promoted was that which enabled all works to be undertaken on site, on land within the developer's control.

Floodplain compensation and flood routing was achieved along the access road through the site, with floor levels and gardens of properties set above the area of flood risk. Careful topographical design ensured that a dry pedestrian access was available during a flood to most plots and that the predicted depth and velocity of floodwater through the site was acceptably low.

BWB helped secure planning permission by giving a presentation to Councillors in the Planning Committee on flood risk mitigation proposals. We were subsequently appointed to undertake the detailed engineering design for the project.