Flood risk assessment secures planning permission for a West Yorkshire housing development

Concerns over potential groundwater flooding had been previously raised during the planning process, with previous investigations by different experts reaching conflicting conclusions about the site’s hydrogeological condition. Bellway Homes therefore needed an independent, evidence-based assessment to gain an understanding of the real issues. Without a clear, evidence-based resolution, the submission of a planning application for the scheme risked further delay or refusal on flood risk grounds.

Our team of hydrogeologists undertook a thorough assessment of site-specific baseline conditions, demonstrating the main issue to be related to inadequate surface water drainage rather than groundwater flooding.

Due to the complex interactions between the groundwater and surface water system, we used an integrated modelling approach to assess flood risk, combining 1D/2D surface water modelling with groundwater modelling. We also implemented a 12-month monitoring programme to verify the conceptual model, and prepared a detailed drainage design for the scheme.

Planning consent was successfully obtained for the 130-home development, providing Bellway Homes with the certainty needed to progress the scheme. The evidence-based approach gave the planning authority confidence that the scheme could handle both surface water and groundwater inputs, delivering improved storm attenuation and protection for downstream properties. The drainage strategy also provided a robust basis for managing surface water and groundwater risks as the development progressed.