wildlife ponds, eventually overflowing
judging by the numbers of Great Crested
demonstrates that the concrete block
into a storm water sewer. Other, level play
Newts seen on the banks during surveys.
permeable paving is a problem-free
areas behind the school are handled in a
These ponds were very good for smooth
technology over the longer term. Care
similar way, with treated, attenuated water
newts too.
of the permeable paving forms a part of
transferred under the building, via flow
control chambers, where it joins the SuDS
management train. Some of these areas
were designed to collect rainwater for
toilet flushing in the main buildings.
Increased Population
Specialist consultants Bernwood ECS have
carried out pre- and post-development
monitoring of the Great Crested Newts on
the whole Hazeley site from 2002 to 2014,
including the two ponds fed from concrete
block permeable paving. The surveys show
an overall increase in the population of
Great Crested Newts and suggest that
‘Favourable Conservation Status’ on site
has been achieved. In fact, it was noted
that they were probably under-counted
due to the ponds’ depth and turbidity,
The project takes a holistic approach
and offers an impressive demonstration
of concrete block permeable paving
providing a controlled flow of clean
water for wildlife habitats. The permeable
paving provides effective water treatment
generally without the need for other
SuDS techniques, such as swales or
filter strips, minimizing land-take. At the
same time, wildlife is protected with
an absence of gulleys and other traps.
It clearly shows that permeable paving
can be applied to sloping ground, with
the general maintenance programme
for the Academy, carried out by a small
non-specialist team using day-to-day
equipment. It is not treated as anything
unusual or apportioned a specific budget.
Correct design and installation is key to
the long-term performance of permeable
paving, including details to prevent silt
runoff from vegetated areas. The concrete
block permeable paving at the school
behaves well in cold weather – far better
than asphalt – and rock salt provides
cheap, simple and effective de-icing.
terraced compartments using flow control
A new case study exploring all these
chambers, and can also accept roof water
aspects in more detail has just been
and runoff from adjacent sealed paving.
Problem-free
published, which can be downloaded via
the Interpave information resource at:
www.paving.org.uk
Experience of the Academy Site Manager
Landscape & Urban Design Issue 16
55