Flood Warning and Evacuation Plans
Evacuating a Site during a Severe flood
A Flood Warning and Evacuation Plan sets out how a development could be safely evacuated in the event of a severe flood and can be a requirement of the planning permission for a development site.
It should be appreciated that a good knowledge of the flooding regime at a site needs to be gained prior to the preparation of a Flood Warning and Evacuation Plan. Ideally a plan should be completed immediately following the preparation of a detailed Flood Risk Assessment.
The production of a satisfactory Flood Warning and Evacuation Plan will not be possible at all sites.
National Planning Policy Framework
The National Planning Policy Framework (NPPF), applicable in England, aims to direct new development away from areas prone to flooding (ie flood zones 2 and 3). For development to be permitted in these areas it has to pass two tests known as the Sequential and Exceptions Tests.
The second part of the Exception Test requires that a developer demonstrate that a proposed new development would be safe for the whole of its expected lifetime. A Flood Warning and Evacuation Plan may be able to help to do that.
Planning Practice Guidance
The Ministry of Housing, Communities & Local Government's Planning Practice Guidance web site provides assistance on the preparation of a Flood Warning and Evacuation Plan. In particular it emphasises that the plan should cover the whole life of the development and so should address the likely effects of climate change. These effects would include rising sea levels and increased flood water depths in rivers due to more intense rainfall. These increased flood levels can be extremely challenging when considering the safe evacuation of people from a development.
TAN15 (Technical Advice Note 15)
TAN15, applicable in Wales, has similar aims to the NPPF and also applies similar tests.
At the planning stage a Flood Warning and Evacuation Plan, given the right circumstances, can be used to show how a proposed development in a high flood risk area could be safely evacuated in the event of a severe flood. Once the development is complete the plan would then provide a guide as to how the development should be evacuated in practice.
The preparation of a Flood Warning and Evacuation Plan is site specific so please contact us for further information including a free no obligation quotation.
Photograph: Flooding of the River Avon at Fleet Lane near Bredon, Worcestershire.