Environmental Engineering Reference
In-Depth Information
Demonstration Project 3: Cowes, Isle of Wight -
contractor Richard Allitt Associates:
This
catchment was again selected for the assess-
ment of the integrated 1D/2D minor/major
UIM modelling techniques, developed at the
University of Exeter. Here it was possible
to make a direct comparison with the outputs
of the 1D/1D modelling exercise, but also
to make a comparison with the outputs
from the 1D/2D water industry proprietary
software Infoworks CS 2D. This latter model
only became commercially available at a time
when the FRMRC research was nearing
completion.
.
to recommend and incorporate any required im-
provements to the research models prior to their
implementation in practice;
.
to apply the newmodelling techniques within a
typical working environment;
.
to test the applicability, benefits and limitations
of the models;
.
to report back to the UK water industry and
model developers.
These aims and objectives were achieved
through a structured programme of three demon-
stration projects. The complexity of themodelling
process was increased on a project-by-project
basis.
Selection of demonstration sites:
data requirements
Demonstration projects 1 and 2: Cowes
and Torbay
Details of the data requirements for consideration
at the time of site selection are detailed in
Table 13.1. The list is not exclusive but serves as
a guide for any future urban flood study.
The overall aim of these studies was for
industry contractors to utilize the research
software and to trial the application of the
1D/1D model. The scope of the projects was set
out in the form of a series of steps related to the
collection of data, model build, model simulation,
model testing and reporting. Specific steps
included:
.
collect and assess all data - produce DEM, ver-
ified sewer model, etc.;
.
review of catchment and incident history;
.
identify discrepancies between DEM and sewer
model;
.
produce 1D surface model;
.
surface pathways with existing modelling of
contributing areas;
.
surface pathways with reallocation of contrib-
uting areas;
.
link surface and subsurface models;
.
field surveys to identify points of connection
and contributions from paved and roof areas
(if necessary);
.
develop a risk matrix and rainfall scenarios for
the study;
.
simulations;
.
benchmark modelling of current system;
.
integrated 1D/1D modelling of new pathways;
.
integrated 1D/1D modelling of new pathways
and reallocated contributing areas;
Catchments used in the study
Two catchments were used in the demonstration
projects:
Demonstration Project 1: Cowes, Isle of Wight -
contractor Richard Allitt Associates:
Applica-
tion of the 1D surface pathways model, devel-
oped by Imperial College, to the catchment at
Cowes on the Isle of Wight: a small town with
known and well-defined surface flooding
problems
Demonstration Project 2: Torquay in Devon -
contractor Torbay City Council:
Torquay had
well-documented large-scale flooding problems
at the centre of a large urban area with some
coastal interaction. The drainage area had been
upgraded in line with the first edition of the
Sewerage Rehabilitation Manual, and was re-
cently used as one of the Making Space for
Water Integrated Urban Drainage pilot studies.
Hence, there was a good understanding of the
system performance against which to test the
new 1D FRMRC software. As with Cowes, the
areas of large-scale flooding were well defined.
