Download ACO Water Management Commonwealth war memorial, Fromelles

ACO Water Management
Commonwealth war memorial, Fromelles, Northern France
ACO StormTank plays key role in integrated surface water management system.
Project:
New Commonwealth war memorial in
Fromelles northern France.
Challenging ground conditions including poor natural drainage and surface water
ponding, inherent at the site of new a Commonwealth war memorial in Fromelles
northern France, have been overcome by a water management system developed
by ACO Water Management. The land around Fromelles typically consists of
heavy clay but by using a network of land drains linked to a high capacity
attenuation cell created using ACO StormTank, the memorial site, together with
its adjacent car park and access road, are kept clear of surface water while the
surrounding areas remain unaffected by any additional run-off from the new
areas of hardstanding.
The new memorial site commemorates the troops
that fell during the battle of Fromelles in July
1916 and is the first such project to be
undertaken by the Commonwealth War Graves
Commission for over 50 years. Whilst few
alternative options were available the location of
the site is ideal from an historical perspective. It
lies at the heart of the village and offers views
over the former front line. “The ground
conditions however presented a number of
technical challenges,” explains Neill RobinsonWelsh – Business Manager at ACO Water
Management. “Although located on an incline
the site has limited natural drainage due to its
heavy clay soil. This combined with a high water
table across the surrounding area, means that the
chosen location is prone to frequent surface
water ponding.”
Problem:
Site has high water table and
challenging ground conditions including
poor natural drainage and surface
water ponding.
Objective:
Kept site and surrounding areas clear of
surface water.
Brief:
1. Provide a fully integrated sustainable drainage system.
2. Control discharge volumes from
the site.
Solution:
60m3 installation of ACO StormTank
attenuation system.
To ensure that the site remains open and
accessible to visitors year round, ACO has
developed a fully integrated sustainable drainage
system that is in balance with the natural surface
water conditions in the area. Run-off from the
site and the surrounding fields is first captured in
a network of land drainage channels. These take
intercepted water to a 60m3 ACO StormTank
attenuation cell that holds and controls the
release of run-off to an adjacent brook.
Critical element of the design
“Hydrological conditions placed tough limiting
values on the depth of attenuation tank we could
use. To achieve the capacity required we needed
to maximise the void volume within the tank to
ensure it could be accommodated within the
available space.” Says Neil Robinson-Welsh.
“An orifice outlet from the tank is sized to control
discharge volumes. It was a critical element of the
design as the delicate surface water environment
in the surrounding area could easily be disturbed
by uncontrolled stormwater surges from land
surrounding the memorial site.”
Installation of ACO StormTank.
ACO StormTank’s innovative design uses high
strength central pillars and side walls to provide
load bearing capacity and structural integrity.
A completed tank only requires side panels at its
perimeter to provide lateral support. The result is
a totally barrier free interior void that can be easily
accessed, inspected and cleaned. The free flow of
storm water entering the tank also avoids having
to use expensive pipe manifolds and additional
pipework to distribute flow evenly.
Watertight, stable installation
The ACO StormTank at Fromelles is configured to
attenuate all the water it receives. To achieve a
watertight, stable installation, the tank is encased
in an impermeable welded geomembrane.
A silt tunnel has also been incorporated within
the tank which directs the ‘first flush’ of any storm
straight through the system to a downstream
manhole where larger debris can be captured
and removed. This alleviates the possibility of
the system becoming blocked by ensuring that
sediment is not allowed to accumulate within
the system over the long term.
Commonwealth war memorial, Fromelles, northern France.
ACO Water Management
A division of ACO Technologies plc
ACO Business Park,
Hitchin Road,
Shefford,
Bedfordshire
SG17 5TE
Tel: 01462 816666
Fax: 01462 815895
e-mail Sales: [email protected]
e-mail Technical: [email protected]
website: www.aco.co.uk