. . . but the water vole is still declining

But the agency admits there is still a serious problem and says farming practices will have to change if Britain is to comply with the new legislation.

WWF blames "a legacy of habitat destruction and pollution" for the problems it has identified.

Rivers it has singled out as needing remedial work include the Severn and the Trent in England, the Dee in Wales, and in Northern Ireland the Foyle, the Lagan and particularly the Bann.

All are listed on WWF's Water and Wetland Index, a listing being compiled over a two-year period which began in April 2000.

It is assessing the water quality and ecological state of freshwater habitats according to indicators such as the state of threatened species, threats from non-native invasive species, and pressures from agricultural, domestic and industrial water use.

Constant threat

The index covers freshwater systems in the UK and 15 other European countries. It is assessing their ability to meet the requirements of the EU's Water Framework Directive.

WWF says it found that France, Spain, Greece, Bulgaria and Turkey also have inadequate monitoring systems and lack the basic information they need to make improvements.

It says the index shows "UK rivers as a whole to be in relatively good health, and well monitored".

But other wetlands, it says, are a different story, "under constant threat from development, pollution or water abstraction".

WWF's freshwater campaigner, Dr David Tickner, said: "The wetlands of the UK are like sponges in the landscape, soaking up water during heavy rains and helping to prevent floods.

Parts of the Lake District are damaged

"Wetlands also act as the kidneys of the environment, filtering pollution and reducing the costs of water purification."

On rivers, Dr Tickner said: "Despite some excellent work to improve water quality and to ensure the majority of the UK's rivers rate with the best in Europe, pollution is still a major problem for many rivers.

"The Severn, for example, falls below the standards of comparable rivers in Hungary or Estonia.

"The challenge now is to bring all our rivers, large and small, up to scratch.

"Fresh water needs to be an integral part of the great debate on sustainable rural development in the aftermath of foot-and-mouth."

But the National Farmers Union's environment policy advisor, Jacob Tompkins, said the union was already working with the water companies to try to reduce pesticide pollution.

"Farmers are not intentional polluters," he told the BBC Radio 4's Today programme. "Pesticides and fertilisers cost farmers money - the last thing they want to see is them being lost from their land."

Mr Tompkins added: "The way forward is education - working together with environmental groups and with government to look at the way we can educate farmers."

Money needed

Alien species found by WWF in UK rivers include mink, the North American signal crayfish, and a water weed called the Himalayan balsam.

Another problem identified is artificial modifications such as the concreting of river banks.

WWF says the relevant government agencies do not have the money to monitor fresh water properly, and are often powerless to act even when they find problems.

David Cowdrey of WWF told BBC News Online: "It'll take at least 10 years to get these rivers up to standard, and without more money that just won't happen."

Problems identified by WWF include:

• sewage pollution in the Severn and the Cumbrian Derwent
• loss of habitats and wildlife along the Trent, and highly variable river quality
• excessive algal growth and pressures from recreation in several parts of the Lake District
• drainage, urban development and peat cutting on the Somerset Levels
• the threat of drought in the Fens, and loss of birdlife on the Pevensey Levels in East Sussex.

Otter and vole photos courtesy of WWF