SUSTAINABILITY

AROUND THE REGIONS
Dorset
Bovington and Lulworth Ranges
6
Driver training area Bovington © Crown
Bovington
The Bovington Stream drains a
catchment intensively used for tank
training and military exercises which
remove the shallow topsoil, resulting in
mobilisation of exposed sediment
which enters the River Frome (see
Sanctuary No.34, 2005 for details). This
is an ongoing problem which is
currently monitored under contract by
Queen Mary University of London and
the Freshwater Biological Association
at the FBA River Laboratory. Part of the
scheme to control sediment involved
the construction of a small in-line
pond on the Bovington Stream, from
which a diversion channel leads
sediment rich water into a larger pond
during periods of flood. Here most of
the sediment, with the exception of
clay particles, settles out before the
water enters the River Frome. To date,
this has been a successful operation
and the ecological quality of the
Frome below the Bovington Stream
input has remained in the Environment
Agency category ‘very good’ for the
last 10 years. An ancillary effect of the
sediment management regime has
been to create a new stream (the
diversion channel) which despite
experiencing extreme flows has
offered a habitat for 115
macroinvertebrates including 12
mayflies, 14 beetles and 28 caddis flies.
In addition, the sediment control
measures have created the large
settlement pond (Harvards Pond) and
an additional pond at the downstream
end of the Bovington Stream. These
ponds represent new aquatic habitats
and with sympathetic management
will increase biodiversity in the area. In
addition the levels of sediment
entering the River Frome have been
much reduced and photographs taken
on January 21st 2015 compared
sections of the Frome below the
Bovington Stream (no discernible
sediment cloud) with that from a
nearby tributary the River Win.
Patrick Armitage
Bovington and Lulworth Conservation
Group member
Diversion channel in action © Patrick Armitage
78
Sanctuary 44 • 2015