The Romans enjoyed them, Constable painted them, Thomas Hardy and Isaac Walton wrote about them, and today Prince Charles fishes in them. But now the chalk rivers of England, a valuable and irreplaceable part of our national heritage including the Test, the Itchen and the Avon are under significant threat. On Thursday 29 July, the UK Biodiversity Action Plan Steering Group, led by the Environment Agency with support from English Nature called for urgent action to protect this fragile ecosystem, with the publication of The State of England’s Chalk Rivers, the first ever report of its kind.
Chalk rivers support a diverse range of rare and endangered species and provide water for drinking, industry, and agriculture. Many rivers are world-famous for their fly fishing and offer popular walking routes, forming an integral part of our cultural heritage.
The pressures on chalk rivers are many and varied. Urban development and intensive agriculture have both played key roles in the deterioration of chalk river habitats. Whilst half of the sites surveyed, including much of the Hampshire Avon, Frome, and Mimram, are of high or very quality, nearly one-third are poor or very poor, including many reaches on the Tarrant, Bourne and Lark*.
Chalk rivers are reliant on autumn and winter rainfall to recharge underground water stores and maintain flows throughout the year. When flows are reduced by abstraction, habitats for fish and other wildlife are lost. Pollutants are less diluted and algae frequently choke the channel in summer as a result of increased nutrient levels.
Most chalk rivers are located in the densely populated south east of England, where rainfall is relatively low. In some river catchments, there are no other sources of water for abstraction. Around 40 chalk river stretches are already under investigation for low flow problems, but climate change and increases in development and population are likely to intensify the pressure on chalk rivers and water supplies.
In a 2000 water quality survey**, only 37% of chalk rivers were very good quality in both biological and chemical terms. The main threats to water quality are from sewage works and farmland. Also a cause for concern are toxic pollutants from industrial effluent, sewage and urban runoff, and pesticides from agriculture and watercress farms. Without careful management, these activities threaten the chalk river resources on which people and wildlife depend.
The report sets out an Agenda for Action to protect and enhance our chalk rivers which aims to:
- Maintain and enhance the characteristic plants and animals of chalk rivers
- Restore water quality, flows and habitat diversity
- Identify cost-effective means of restoring damaged river reaches
The Agenda calls for involvement from Government, industry, local authorities, interest groups, landowners, and the public as a whole, as well as setting out a considerable role for the Environment Agency, in maintaining and improving this precious resource.
Sir John Harman, Chairman of the Environment Agency, said, ‘Our chalk rivers are a valuable part of the English landscape, but they are currently under huge pressures. Whilst much work is being undertaken to protect some chalk rivers, there is still much more that needs to be done.
‘We need policy-makers, environmental regulators, businesses and local communities to take up the challenge of restoring this fragile ecosystem. Let us work together to ensure that generations to come are able to enjoy the unique heritage that chalk rivers represent.’
Water companies also have a large part to play in protecting our chalk rivers. The environment programme, as set out in the water company business plans currently under review by Ofwat, contains actions to protect chalk rivers.
“We expect to see this work funded under the water price review. Water companies must make sure that their activities do not cause further damage to these important habitats,” continued Sir John Harman.
Chris Mainstone, English Nature’s Senior Freshwater Ecologist, highlighted the part local communities can play. He said: “Whilst the major problems faced by chalk rivers need to be resolved by Government, statutory agencies and industry, the UK Biodiversity Action Plan emphasises the role of local people in improving conditions for wildlife. Local action groups are critical in pushing for improvements to water quality, river flows and the physically damaged river sections and in controlling non-native invasive plant species such as Himalayan balsam and Japanese knotweed.”
Chalk river wildlife
Ten chalk rivers are designated as river Sites of Special Scientific Interest (SSSIs) for their wildlife. The Rivers Lambourn, Itchen, Wensum and Hampshire Avon are of European importance and are candidate Special Areas of Conservation (cSACs) under the Habitats Directive.
While water-crowfoot communities and otters are recovering from past declines in chalk rivers, stocks of salmon remain seriously low and decreasing fly life has been reported. Species under threat include the water vole and white clawed crayfish.
The spread of invasive species, such as mink, signal crayfish and exotic plants, notably Himalayan balsam and Japanese knotweed, have had major impacts, respectively, on water voles and native crayfish and plant communities. Whilst water voles are mounting a recovery in some areas following the co-ordinated trapping of mink by river keepers, their situation is still serious.
Much of today’s fly fishing on chalk rivers is dependent on stocked trout. It is likely that their natural reproduction is being impaired in the same way as salmon, by silty spawning gravels. There are concerns that overstocking of trout may impact upon wild populations of trout and salmon.
The prospects for chalk river wildlife depend largely on progress with actions to tackle problems of river flow, water quality and habitats. Whilst the problems are complex, improvement schemes show that much can be done to improve local conditions, and wildlife populations often recover rapidly.
* National network of River Habitat Survey sites
** GQA survey
The Environment Agency
The Environment Agency for England and Wales is a Non-Departmental Public Body (NDPB), set up under the Environment Act 1995, to take an integrated approach to environmental protection and enhancement in England and Wales. The Agency has major responsibilities for controlling industrial pollution and wastes management, regulation of the water environment, and for protection against flooding from rivers and the sea. The Environment Agency’s primary aim is to protect and improve the environment and make a contribution towards the delivery of sustainable development through the integrated management of air, land and water.
