Land At Hillside, Woolley Bridge, Glossop,
The Brief
RIDA Reports was appointed to undertake a detailed flood risk assessment for Land At Hillside in Woolley Bridge, Glossop. The proposed project involves the demolition and removal of a single existing dwelling to accommodate a new residential development comprising seven new dwellings.
Why the Client Chose RIDA
The client required specialist consultancy to navigate the complexities of replacing a single dwelling with a multi-unit “More vulnerable” residential development. RIDA was selected to ensure the proposed scheme met the stringent criteria of the National Planning Policy Framework (NPPF) and to provide the robust technical evidence necessary to support their planning application.
The Challenge
A primary constraint was the site’s proximity to the River Etherow, which is located just 18 metres away. Although initially mapped within Flood Zone 3, detailed Environment Agency level data placed the workable development area within Flood Zone 1. Despite this, the site faces a high risk of groundwater flooding and a low risk of surface water flooding, culminating in a significant overall design flood water depth calculated at 1.73m. Furthermore, local soils are classified as having “impeded drainage”, and the project was required to formally pass both the Sequential and Exception Tests.
The RIDA Difference
RIDA conducted a detailed flood risk assessment to evaluate all local hydrology and flooding mechanisms. To address the specific 1.73m design water depth, our team specified a robust ‘water exclusion strategy’ utilising highly flood-resilient and resistant construction materials. We also recommended designing specific flow paths to safely direct any potential groundwater emergence away from the new buildings.
To overcome the impeded drainage conditions, we outlined a tailored Sustainable Drainage Systems (SuDS) approach to ensure there would be no increase in surface water discharge rates. Crucially, the report laid out a clear argument demonstrating that the development passes the Exception Test by providing wider sustainability benefits, including the integration of multifunctional SuDS with green infrastructure.
The Outcome
The comprehensive assessment successfully provided the robust evidence necessary to support the planning application. It demonstrated full compliance with the NPPF and the Environment Agency’s requirements, confirming that the seven new dwellings will be safe for their 50 to 100-year design life without increasing flood risk elsewhere.
