ENVIRONMENT AGENCY RESTORES RIVER AFTER CENTURIES OF INTERFENCE

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."