Flood Risk Assessments in Sheffield

Flood Zone 3 areas run along the Don, Sheaf, Rivelin and Loxley corridors through the city. The Don Valley, Kelham Island and Neepsend all sit directly in or beside these flood risk areas, some of the most commercially interesting development land in the city. The Upper Don flood protection scheme, valued at approximately 53 million pounds, and the River Sheaf scheme, approximately 40 million pounds, are being developed in phases. But this is important: even where defences exist or are planned, FRAs for development in defended areas must address residual risk and breach failure scenarios. The defences do not remove the FRA requirement. An assessment that relies on the scheme being in place without addressing what happens if it fails is incomplete.

Sheffield’s culverted watercourse network creates a specific and distinctive requirement. Across the urban area, dozens of ordinary watercourses run beneath the city in culverts, some of them dating back to the Victorian and Edwardian industrial period. Sheffield City Council requires specific culvert flood risk assessment for development near these features. This includes assessing culvert blockage scenarios, the consequences of culvert failure, and the flood risk implications of development that may restrict the ability to maintain or access the culvert. This is not covered by national guidance alone.

Surface water flooding from Sheffield’s steep catchment topography is a growing concern. The city’s valley sides generate rapid overland flow during intense rainfall, and Yorkshire Water’s drainage capacity constraints apply across the city. Drainage strategies for Sheffield applications must demonstrate how surface water will be managed on site without increasing runoff rates to the Yorkshire Water sewer network.

• Development in Flood Zone 2 or 3 along the Don, Sheaf, Rivelin or Loxley
• Development near a culverted watercourse requiring specific culvert flood risk assessment
• Regeneration schemes in the Don Valley, Kelham Island, Neepsend or the Wicker in or near defended areas
• Development in defended areas where residual risk and breach failure analysis is required
• Development of 1 hectare or more in Flood Zone 1
• Development requiring a surface water drainage strategy under Yorkshire Water and Sheffield City Council requirements

We understand Sheffield’s specific FRA requirements, culverted watercourse assessment, the Sheffield SFRA 2023 framework, the Upper Don and Sheaf flood protection scheme context, and the residual risk analysis requirements for defended sites in the Don Valley and Kelham Island.

Our FRAs engage with EA Don and Sheaf model data directly and treat the culverted watercourse network as a primary input rather than a secondary check. We know the difference between a Sheffield FRA and a generic river flooding assessment, and we produce the former.

We cover Sheffield City and the wider South Yorkshire area including Rotherham, Barnsley and Doncaster.