An NPPF (National Planning Policy Framework) compliant Flood Risk Assessment for Holiday Homes in Norfolk
About the project
Ambiental was approached to undertake a National Planning Policy Framework (NPPF) compliant Flood Risk Assessment (FRA) for a change of use development of an old Rugby Club campsite located at Romney Marsh, Norfolk.
An image of the site in 2016, pre-development
A little more about the project
The project was for the proposed demolition of existing structures on site, including former holiday let buildings which were no longer viable. These would then be replaced with 16 permanent holiday lodges, a welcome centre, and associated hardstanding.
The expected lifetime for the new properties was to be 65 years. Ambiental had meetings with the Environment Agency to discuss which flood events and flood levels would be applicable to assess the risk of flooding to the development. With a reduced lifetime as the development was commercial, Ambiental negotiated flood levels appliable to the lifetime of the development.
The site was located on St Mary’s Bay and had previously been part of the old Coastguard Station, which was later turned into the Rugby Club and a permanent camp for youths in deprived areas of London to holiday by the sea (source: https://www.kentonline.co.uk/romney-marsh/news/holiday-park-plans-given-the-125482/), holding up to 100 people at a time. The condition of the site was poor, and redevelopment was required.
Planning permission was granted in 2012 to refurbish the camp, however this work never happened. Instead, the land was sold in 2016 and a new planning application was submitted to create a more general use space, along with a swimming pool and new holiday accommodation.
Flood Map for Planning showing the Flood Zones of the site
The Problem (High Flood Risk)
The site is in very close proximity to the beach, there was concern that the site would be at risk of flooding from the sea. A review of the Environment Agency flood map for planning demonstrated that the site was within Flood Zone 3 (high risk of flooding). Therefore, any new development in this zone would be required in accordance with Chapter 14 of the NPPF to provide a Flood Risk Assessment.
The proposed development of holiday lodges was also considered to be “more vulnerable” under the NPPF guidance. Using our knowledge of the planning policy and review of the flood data our expert flood risk consultants and engineers worked with the client and their architects to design the lodges that met with their aspirations whilst being appropriate for planning approval. We welcome these discussions with our clients and other consultants as we believe in the benefits that collaborative working can provide in delivering successful projects.
The EA provided Ambiental with site specific data, providing multiple modelled depth location nodes from the ‘Romney Marsh Tidal Modelling and Mapping Study’. Ambiental assess the data nodes provided and selected the most appropriate data node representative of the site’s location.
Using the Shepway District Council SFRA (2015), we further reviewed the existing flood defences available in the area in order to more effectively understand the flood risk of the site.
Within the St Mary’s Bay area, we noted that there is a stepped concrete seawall with a current standard of protection of 1:100 years, with a crest level range that was sufficient to protect the site and was considered to be in ‘good’ condition.
We further reviewed the historic flooding for the area. It demonstrated that these defences allowed for some minimal flooding during 1-in-1000 year events and 1-in-200 year wave surges. The risk of inundation needed to be mitigated.
The data collected allowed our Flood Risk Consultant and Drainage Engineer to recommend finished floor levels for sleeping accommodation and also habitable rooms.
Given the site was positioned within an existing developed area which benefits from the presence of defences and sleeping accommodation would be located above the maximum defended depths through a detailed analysis of all data sources (EA/ topographic / architectural (existing and proposed plans) / sea defences / historic records, etc. ). Ambiental further advised on where the lodges should be located across the site to be mitigate the risk of flooding further. Our team worked closely with the end client and the design team (architects/planning consultant and other consultants) to be provide an assessment that led an agreed solution by all.
Our team further supported with the Flood Evacuation Plan / Flood Risk Management Plan and signing up to the EA flood warning system and creating an evacuation plan.
The development went on to gain planning approval.