Planning Permission Secured on Appeal in Petersfield
Aegaea delivered a Flood Risk Assessment and drainage strategy for a hotel and cycle centre in the South Downs National Park, securing planning permission on appeal using updated NaFRA2 mapping.
Project challenges
The outline planning application for a hotel and cycle centre development on the edge of Petersfield was initially refused by the South Downs National Park Authority. The refusal cited concerns about the proposed footprint and the placement of a SuDS detention basin within a flood-risk area.
The site's location within the South Downs National Park added additional sensitivity to the planning assessment, and the original flood risk evidence was based on mapping that predated the National Flood Risk Assessment 2 (NaFRA2) update.
How we solved it
Aegaea delivered a comprehensive Flood Risk Assessment and surface water drainage strategy for the outline planning application. Following the initial refusal, the team prepared a rebuttal statement leveraging the updated NaFRA2 mapping released in January 2025.
The revised data demonstrated significantly reduced surface water flood risk across the site compared to the earlier mapping, with negligible risk remaining to the storage basin and no risk to the proposed building locations. This evidence was presented through the appeal process with clear technical justification.
Results delivered
The Planning Inspector's decision acknowledged the updated flood risk evidence. The Inspector concluded that "a suitable surface water drainage scheme could be implemented" and that the site was "suitable for the proposed development," ultimately allowing the appeal.
The outcome illustrates how current flood modelling, technical precision, and expert testimony can overcome planning obstacles related to drainage and flood risk. The use of updated NaFRA2 data was instrumental in reversing the original refusal.
Project Overview
This project involved securing planning permission for a hotel and cycle centre development on the edge of Petersfield, within the South Downs National Park. The scheme was initially refused by the National Park Authority on flood risk and drainage grounds, requiring Aegaea to prepare appeal evidence that addressed the planning inspector’s specific concerns.
The Challenge of Outdated Mapping
The original refusal was based in part on flood risk mapping that did not reflect the latest available data. When the National Flood Risk Assessment 2 (NaFRA2) was published in January 2025, it provided significantly updated surface water flood risk information for the site and surrounding area.
Appeal Strategy
The appeal strategy centred on presenting the updated NaFRA2 evidence alongside Aegaea’s site-specific Flood Risk Assessment and drainage strategy. The rebuttal statement clearly demonstrated the differences between the old and new mapping, showing that surface water flood risk across the site was significantly lower than previously understood.
The technical evidence showed negligible residual risk to the proposed detention basin location and confirmed that the proposed buildings would not be affected by surface water flooding.
Inspector’s Decision
The Planning Inspector accepted the updated evidence and concluded that a suitable drainage scheme could be implemented. Planning permission was granted on appeal, enabling the development to proceed within the National Park.
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