Designing for surface water runoff control : end-user requirements in Ireland

Since 1975, flood estimation in Ireland has generally
followed methods as outlined in the Flood Studies Report
(Natural Environment Research Council, 1975). An update
of this for conditions in the Republic of Ireland commenced
in 2005 and included research in Urban Catchment
Flood Analysis. To inform this work, a scoping study of issues
relating to flooding caused by urban runoff was undertaken
by a team from the Centre for Water Resources Research
at University College Dublin and some of the findings
are described in this paper. It focussed on quantitative and
qualitative research methods (self-completion questionnaires
and Focus Groups) to review the methods of flood estimation
for urbanised catchments currently in use in Ireland. It assessed
the nature of deficiencies associated with urban-runoff
control and identified achievable and realistic objectives for
further research. A questionnaire was developed around a
number of key themes pertaining to flooding caused by urban
runoff and circulated to 291 stakeholders in target sectors
that ranged from Engineering Consultancies to Academic Institutions.
A total of 100 questionnaires were returned giving
a 34% response rate. The study found; (i) a proliferation of
methods are used in practice resulting in significant differences
between the estimates; (ii) some methods are sometimes
being used for inappropriate spatial scales; (iii) there
is a lack of clear guidance on the use of the methods and/or
associated software packages; (iv) there is little appreciation
of the uncertainties associated with the methods and (v) there
are significant deficiencies in some of the basic information
available.
A list of recommendations was produced, to guide the
commissioning of future research to improve the methods
available to designers.