Assessing the Benefits of Flood Warning: A Scoping Study
August 2006

Background to research

Flood warning is the provision of advance warning of conditions that are likely to cause flooding to property and a potential risk to life.  The main purpose of flood warning is to save life by allowing people, support and emergency services time to prepare for flooding. The secondary purpose is to reduce the effects and damage of flooding (Defra, 2004).

The benefits associated with flood forecasting and warning are inextricably linked with the effectiveness of the warning dissemination programmes and the activities of the public and supporting agencies (both voluntary and official) in their response. The total benefits can be defined as ‘the reduction in losses (tangible and intangible) resulting from the provision of a warning when compared to the situation prior to the operation of the warning system’.  

Tangible losses are the cost of the damage arising as a consequence of the physical contact of floodwater with property (direct losses), and the losses which are consequent upon direct flood damage (indirect losses).  Flood warning systems can provide a reduction in direct losses through:
Intangible losses include loss of life and injury, and the damage caused to human health and long-term well-being. Such losses are extremely difficult to quantify in economic terms, but are important considerations when evaluating the benefits of any flood management scheme, particularly flood warning where significant impacts can be made through facilitation of timely evacuation of those at risk.  

Organisations represented by the PSG have recognised that a revised flood warning system benefit assessment methodology is required that takes appropriate account of both tangible and intangible benefits.  This report documents a scoping study undertaken by HR Wallingford, John Chatterton (J Chatterton Associates), and Maureen Fordham (Northumbria University) of the range of approaches adopted to date, and recommends potential components and characteristics that could be used within the development of future methodologies.

Objectives of research

This report delivers Phase 1 of a research project to develop a new method that improves on SEPA’s existing cost benefit assessment technique, considers tangible and intangible benefits, and takes full account of the current legislative framework in Scotland.

This first phase of the research reviewed current practice in the assessment of the benefits of flood warning in the UK and internationally.  The objectives of the review were:
Key findings and recommendations
Key words: flood warning, benefit, economic, tangible, intangible

Copies of this report are available from the Foundation, in electronic format on CDRom at £20.00 + VAT or hard copy at £35.00, less 20% to FWR members

N.B. The report is available for download from the SNIFFER Website