19/09/2005 - Work to restore
a river ecologically scarred by centuries
of dredging started on 5 September as the
Environment Agency aims to re-create a thriving
natural habitat in the River Evenlode once
more.
The River Evenlode at Blenheim Park, part
of the Duke of Marlborough's estate, has been
modified by man for centuries. Straightening,
widening and deepening of the channel has
increased the volume of water it can carry,
draining the surrounding land allowing it
to be farmed.
But increased crop yields came at an environmental
cost, with few places left for wildlife to
shelter from fast-flowing water during the
winter months, greatly reducing the diversity
of wildlife.
The Environment Agency's aim is to reintroduce
some of the lost natural features of the river,
and help recreate a rich and dynamic ecosystem
once more.
Parts of the river at Blenheim will be narrowed
by placing locally-sourced limestone and creating
gravel beds in the river on alternate sides,
in order to create small meanders. This will
also vary flow speeds allowing wildlife, including
juvenile fish, to seek refuge in the slower
moving sections during high winter flows.
The scheme will also create two backwater
bays to act tranquil areas for fish during
times of high flows.
The gravel beds will also create the necessary
breeding habitat for fish, such as barbel,
chub and dace, and as other aquatic wildlife,
such as plants and invertebrates, spread along
these beds, the once fast flowing stretch
of river will be thriving with wildlife once
again.
The Environment Agency's project manager,
Simon Whitton, explained: "This is a
very important environmental project and we
are grateful that Blenheim Palace has allowed
us to carry it out.
"There are many stretches of river around
this area which have been dredged, deepened
and even straightened to ease drainage. As
we've seen with the Evenlode, this has reduced
the number of breeding areas for fish and
generally reduced the varied habitats that
we should have, with wildlife struggling to
survive the fast winter flows."
The work will also allow some of the higher
flows to spill out back into its natural floodplain
at Blenheim, where it will be contained until
the flows reduce and the flood waters gradually
flow back into the river.
Simon Whitton added: "We want to see
these areas restored back to their natural
state as it not only improves the environment,
but if more rivers are allowed to over spill
into their natural rural floodplain, this
could help reduce flood risk for towns and
villages further downstream.
