Overview
Located in Ilford, the Capital Gate site presented a nuanced planning challenge. While the site technically sits within Flood Zone 1, (low risk from rivers and sea), it was identified as being within a Critical Drainage Area with significant susceptibility to surface water (pluvial) flooding.
Recent changes to the National Planning Policy Framework (NPPF) and Planning Practice Guidance (PPG) have tightened the requirements for the Sequential Test. Local Planning Authorities (LPAs) are now explicitly guided to apply the Sequential Test to all sources of flooding – not just fluvial or tidal. This meant the surface water risk on-site could potentially trigger a borough-wide search for “safer” alternative sites, a process that is time-consuming, costly, and often a major hurdle for approval.
The challenge for Medina Capital and Aegaea was to demonstrate that this site was suitable for residential development despite these surface water constraints, without becoming subject to a more complex Sequential Test assessment beyond the site boundary.
Aegaea’s Approach
Aegaea’s Flood Risk team, led by Daniel Cook and Jack Allen, adopted a strategic, design-led approach. Rather than simply accepting the need for a standard Sequential Test, the team leveraged a deep understanding of the specific guidance provided to local authorities.
Aegaea identified and applied the critical provision which states:
‘You may not need a sequential test if development can be laid out so that only elements such as public open space, biodiversity and amenity areas are located in areas at risk of any source of current or future flooding.’
Key Strategies Implemented:
- Sequential Approach to Layout: The site layout was meticulously optimised to ensure that the most vulnerable elements (residential dwellings) were located in the areas of lowest risk. This was supported by Aegaea being able to produce a bespoke surface water flood model (hydraulic model) to show the baseline and post development impacts and managing the water on site in accordance with the guidance.
- Strategic Water Management: The design directed potential surface water flooding (specifically the 1% and 0.1% annual probability events) away from homes and into designated public open space, biodiversity zones, and amenity areas.
- Robust Evidence Base: The Flood Risk Assessment demonstrated that by utilising these “wet” zones for compatible uses like biodiversity enhancement, the development remained safe for its lifetime without increasing flood risk elsewhere.
- SuDS Integration: A Sustainable Drainage System (SuDS) strategy was developed to manage runoff, ensuring the site not only mitigated its own risk but contributed positively to the local Critical Drainage Area.This SuDS strategy complied fully with National Local policies, including the SuDS hierarchy and ensured that the development itself did not result in any increased flooding downstream to wider areas
The Outcome
By applying the Sequential Approach within the site boundary effectively, Aegaea successfully negated the need for a site Sequential Test. The proposal demonstrated full compliance with the updated NPPF and London Plan policies, proving that the site could be developed safely and sustainably.
This approach turned a potential planning constraint into a design feature, utilising flood-prone areas for biodiversity and amenity value, a win-win for the developer and the future community.
Why Aegaea?
This project perfectly highlights Aegaea’s ability to navigate the shifting landscape of planning policy. By recognising the subtle but powerful changes in the Sequential Test guidance, we saved our client significant time and resources.
- Policy Expertise: We don’t just read the rules; we interpret the guidance to find the most effective path for your specific site.
- Design-Led Solutions: We work with your masterplan to integrate flood resilience, rather than treating it as an afterthought.
Commercial Awareness: We understand that avoiding unnecessary regulatory hurdles is key to project viability.
