27 Apr, 2019

RammSanderson Ecology Ltd was commissioned by the IDP Group on behalf of the Arden Estate Partnership to provide advice and guidance with regards to the potential risk of flooding associated with proposals to provide supported housing for residents with mental health, physical disabilities and learning disabilities at four locations across Warwickshire.

An initial site check report provided by the client and completed during the initial feasibility study detailed risks associated with flooding from fluvial and pluvial sources, ground water and sewer flooding and breach of nearby flood defences. Consequently further investigation of the associated flood risks was required to support the planning applications for the proposed developments.

The preliminary site check reports showed all sites to lie within Flood Zone 1 (land assessed as having greater than a 1 in 1000 year annual probability of flooding) but within close proximity to the designated ‘main rivers’ and areas more susceptible to flooding. The Environment Agency were consulted to confirm the sites proximity to the floodplain, to request historical records of flood events and to discuss any nearby flood defences. This was then supported by a review of the local Strategic Flood Risk Assessment (SFRA) confirming information provided and considering the locations of sequential preferable sites.

In terms of Flood Risk Vulnerability Classification given in Table 2 of the Technical Guidance to the National Planning Policy Framework (NPPF), the proposed use at each site (supported housing for residents with mental health, physical disabilities and learning disabilities) could be categorised as a “Residential Care Home”, implying a vulnerability classification of “more vulnerable”.

A review of the above concluded that the risk of flooding from fluvial sources was minimal. A simplified breach analysis following the DEFRA report FD2320/TR2 Methodology was completed for one of the sites, concluding that there was a minor residual risk to human life in the event river bank defences were breached. Due to the proposed use at the site the occupants were considered to be at slightly greater risk, it was therefore recommended that this risk was managed through the implementation of a flood warning service and evacuation procedure.

Consideration of the existing site layout, topography, development proposals, aerial imagery and a site visit were all completed to appropriately inform recommendations.