CPD Specifier May 2015 issue January 2015 | Page 11
Civils & External Works
STANTON BONNA ELLIPTICAL
PIPES MINIMISE
FLOOD RISK FROM
GREENFIELD SITE
PROJECT
Barratt Homes ‘Greenacres’ housing development, Pontefract
BRIEF
Efficient attenuation system needed to restrict
stormwater peak flows to ensure minimal impact
on environment of housing development.
PRODUCTS SUPPLIED
Elliptical Pipes and Circular Pipes
KEY BENEFITS
High strength at low depth; Efficient hydraulic flow;
Watertight; Cost effective system; Sustainable solution
Stanton Bonna Elliptical Pipes provide
a sustainable solution to help manage
stormwater peak flow at a new housing
development.
The demand for new housing in Pontefract led
to an £8m investment by Barratt Homes which
included 48 properties on a 3.2acre site just off
Pontefract Road.
They then selected Stanton Bonna’s elliptical
pipes since they offer the following benefits:
l perfect profile for low cover levels
l in situ secondary inverting is not required for
dry weather flows
l no extra jointing materials required due to
integrated watertight elastomeric gasket
l Stanton Bonna elliptical pipes were cost
effective due to their low cost and quick
installation
With the area being a greenfield site, the
developers, Barratt Homes had to ensure that
the local environment
was not impacted. The
brief was to ensure
stormwater peak flows
off site ‘mimicked’ the
existing situation.
Luke Martin continued, “The use of elliptical pipes
was a lower cost option than box culverts when
restricted to
keeping the
attenuation
within the
adoptable
carriageway”.
The site had its
challenges with the
landscape being quite
steep, limited depth was
available for the installation and the attenuation
tank would need to accommodate vehicle loading
to Highways Agency standards.
The Stanton
Bonna technical
team worked
closely with
the design consultants on the side entry manhole
fittings, a bespoke spigot fitting and end walls to
complete the design and layout.
Luke Martin, Engineer for Barratt Homes,
explained “...circular storage pipes would not have
a large enough cross sectional area to keep the
attenuation in the lower part of the site. We would
have needed very deep drainage with extensive
costs associated.”
A total of 31 x 2.4m lengths of elliptical pipe (DN
2650 x 1500) were supplied, including fittings
with end walls, a 600mm diameter spigot and
18 degree bend. A further 22 x DN 1600 circular
precast concrete pipes were supplied on request
in replacement of originally specified plastic pipes.
The project was originally specified with 2400
x 1500mm box culverts with dry weather flow
channels installed at the invert in three runs.
Stanton Bonna’s Site Support Technician, Chris
Taylor, assisted the contractors, PJ Towey
Construction Ltd, with on site training and support
before the products were delivered, as this was
the first time they had fitted this type of system.
“We were really happy with the
products, service and
ease of installation..”
Mar ѥ