Assessing the Benefits of Flood
Warning: Phase 2
(March 2007-February 2008)
Background to research
This project has been commissioned by SNIFFER on behalf of the Scottish
Environment Protection Agency (SEPA) and the Environment Agency (EA).
It takes forward the recommendations from the SNIFFER Assessing the
Benefits of Flood Warning: Scoping Study Phase 1 report (UKCC10,
completed by HR Wallingford in September 2006). The Phase 1
report reviewed current practice in the assessment of benefits of flood
warning in the UK and internationally. It gave
recommendations on the components that could be used in future
methodologies and proposed the use of Multicriteria Analysis (MCA) as
the most appropriate assessment method.
Objectives of research
This technical report describes the development of a new Flood Warning
system benefit assessment methodology that takes into account both
tangible and intangible benefits. The assessment method is
presented in the form of a MCA ‘tool’ supported by
Geographical Information System (GIS) procedures.
Key findings and
A new MCA tool has been developed to assess the intangible and tangible
benefits of flood warning. This has been developed and
validated using nine pilot studies in Scotland, England and
Wales. The spreadsheet based tool is supported by GIS
pre-processing and provides a clear audit trail which can support
decision making and sensitivity analysis. The tool is capable
of being used to assess a range of return periods (5 year to 1000
year). As a consequence the tool will be suitable for use by
SEPA and potentially by the EA, with the potential to be transferable
to Northern Ireland in the future.
Keywords: Flood warning, benefit,
tangible, intangible, social, MCA
- Development of national datasets for MCA tool inputs e.g.
- Inclusion of depth and velocity as requirements in Local
Authority bi-annual flood reports, but this would require the
development of a methodology and guidelines in order to ensure national
- Depth and velocity mapping made available as part of
‘hazard’ mapping as a requirement of the EU Floods
- Collection of information on number of people taking
individual flood resistance actions e.g. during SEPA flood awareness
- The MCA score for each study area assessed could be
geo-referenced, and this could be imported into GIS and the MCA results
could be spatially displayed so as to compare graphically results.
- Organise and provide training for EA and SEPA staff.
- Undertake more pilots in England and Wales to allow the
tool normalisation factors to be tailored for England and Wales, with
the use of Flood Warning Areas as the chosen spatial scale.
- Further refine the residential damage category if improved
national datasets become available.
- Consider assessing the scale of disruption for the
infrastructure receptors (e.g. the number of properties served by a
- Potential use of tool to inform the identification and
prioritisation of areas for key investment to bring greatest benefit
e.g. direct focus to public awareness or on flood warning dissemination.
Copies of this report are available from the Foundation, in electronic
format on CDRom at £20.00 + VAT or hard copy at
£25.00, less 20% to FWR members.
The report is available for download from the SNIFFER Website