on the Linnet Rise site, providing 366m3 and 479m3 of storage
respectively. The tanks were formed using Polystorm cells,
which boast a 95% void fill ratio. This solution maximised the
tanks’ storage volume within the limited space available for an
attenuation system on this compact housing estate. These tanks
will safely store flood water in the event of surface water sewers
reaching capacity following heavy downpours, before releasing
water back into Severn Trent’s watercourse once the downpour
has subsided.
polypipe’s grAvity return design meAns
thAt the two tAnks fill And empty
without using Any pumps or vAlves And
therefore, following instAllAtion, the
system will cost nothing to run And
require minimAl future mAintenAnce
by severn trent wAter.
The two tanks were laid at a 1 in 150 gradient across both length
and width, to facilitate draindown to the primary inlet and outlet
located in the bottom corner of the crates. This will ensure that
any sediment entering the tank from the surface water sewer is
flushed out through the same flow path. Three channels were also
installed in each tank, to promote water flow dispersal throughout
the geocellular crates and provide inspection points along the
length of the tanks, which are accessible via six specialist access
turrets located outside of the site’s car parking bays.
that the system could be installed in a single day, reducing both
contractor costs and disruption for local residents.
Polypipe’s gravity return design means that the two tanks fill
and empty without using any pumps or valves and therefore,
following installation, the system will cost nothing to run and
require minimal future maintenance by Severn Trent Water.
Polypipe’s ability to design and manufacture pipework,
manholes and catch pits off site provided the perfect solution
to the project’s limited working space and the need for quick
installation. The supply of high quality parts, designed to the
project’s exact specification and delivered directly to site, meant
www.polypipe.com
Rosie Cheetham, Marketing Consultant at Polypipe, said,
“This project highlights the capabilities that our SuDS water
management systems can deliver in improving the quality of
life for residents in urbanised areas. Forming a vital part of this
retrofitted alleviation scheme for Linnet Rise, our tailored solution
countered the limitations of the original drainage system to offer
long lasting flood protection. It also ensured that the installation
process caused as little disruption to residents as possible, thanks
to our ability to prefabricate components ready for quick and
easy installation on site. The success of the Linnet Rise project is
an excellent example of how our innovative water management
systems can make retrospective flood protection possible even in
densely populated urbanised areas.”