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Giving ' Nature A Nudge'

May 27 2009

Chalk rivers are recognised as being one of the most managed types of river system in the UK, having suffered from excessive dredging and channel re-alignment for land drainage purposes, resulting in watercourses which are too wide and deep for natural river flows. This has destroyed habitats, damaged fish and vegetation communities, silted up gravels and disconnected the river with the flood plain with the resultant loss of wetlands.

In the Wessex area the Hampshire/Wiltshire Avon is a well known classic chalk river, famous for its coarse, trout and salmon fishery as well as its large number of nature conservation designations. It has its source in the Marlborough Downs flowing though Wiltshire, the city of Salisbury and continuing through Hampshire and the towns of Fordingbridge and Ringwood, finally discharging into the sea at Christchurch.

‘STREAM’ (STrategic Restoration And Management) and ‘Living River’ are two collaborative, partnership projects involving Natural England, the Environment Agency, Wessex Water and the Wildlife Trusts and are funded by the European Commission's LIFE-Nature fund and the Heritage Lottery Fund to the tune of £2 million. The STREAM project is focussing on river restoration and aims to restore channels to a more natural size and shape, thereby improving their ability to support the multitude of aquatic habitats. In essence by mending or creating new habitat and giving ‘nature a nudge’ both fisheries and the wider conservation interests can be significantly and sustainably improved.

During the last few years over 7km of river have been restored by introducing new ‘physical features’ into the river channel thereby re-energising the river and creating new habitats. Over-wide river reaches have been narrowed by creating artificial berms improving the velocity of the main river to encourage healthy weed and fish populations, but leaving quiet backwater areas suitable for lamprey and the infamous protected Desmoulins or ‘Newbury by-pass’ snail. Steep banks resulting from historic dredging have been re-profiled to create a gradual slope encouraging colonisation by emergent vegetation much loved as food and cover for ‘ratty’- the endangered water vole. Where dredging has left over deep channels, bereft of features essential for many species, river bed raising has been the answer by introducing many hundreds tons of gravel, now much appreciated by salmon, trout, chub, barbel and even the bullhead, all of which are now using these fast flowing riffles for spawning and nursery areas. The ‘wiggle’ has been put back into straightened channelised sections of river creating the beginnings of a more natural and habitat rich meandering river.

This has been achieved by introducing a series of flow deflectors made of natural woody material in-filled with pre-planted coir or recycled textile mats to encourage the establishment of vegetation. Trout fishermen are finding the end of these structures which bounce the flow from one side of the river to the other particularly good fish lies. Fallen trees were once an incredibly important habitat in rivers but a preoccupation with tidiness has encouraged their removal from the river over past decades. The STREAM project has experimentally re-introduced over 25 full sized trees to the river at a number of sites, securely anchoring them to the bank and allowing nature to take its course, but already they have created fantasic fish refuges for both fry and adults. Management of the floodplain inevitably impacts what happens in the river and STREAM has also looked at ways of managing the plethora of historic channels associated with the old water meadow systems to benefit, where possible, both fish populations and wetland birds. Similarly with over 100 hatch control structures, weirs and sluices on the main river alone, the management of water levels is absolutely critical to the wellbeing of flora and fauna of the river, and therefore hatch operating protocols have been developed to ensure that these interests are not compromised.

The Lottery funded Living River project is closely integrated with, and is running alongside the STREAM project however is more ‘people focussed’. Its aim is to increase awareness of the River Avon and its tributaries involving the people and communities who live and work in the river valley in the conservation of the fantastic natural and cultural heritage of the river and valley. Dozens of river related events have been held throughout the valley from enthusing hundreds of volunteers to remove invasive plants such as Himalayan balsam, training events to engage people in river restoration and learn how to identify and measure the quality of invertebrate life in the Avon. Artistic theatre performances have been produced; ‘The River is Revolting’ is a comic theatre piece for the Salisbury International Arts Festival to highlight issues that the river is facing, and an audio river archive, REverberAVON has also been very popular.

Even sculptures inspired by the river have been constructed; look out for the ‘Dragonfly’ made from a Gazelle helicopter by the apprentice mechanics at QinetiQ as you head south on the A303 at Amesbury. Allan Frake, Project Manager for the Environment Agency commented “I have been particularly impressed how this project has integrated both fisheries and the wider conservation interests, engaging angling interests, conservationists and landowners, but also the lengths to which local communities and the general public have been actively and enthusiastically involved throughout the project…it has been brilliant fun and really made a difference to improving the river and raising awareness to local people” For further information on both projects, visit the websites: