THE River Thames is now cleaner and healthier than at any time within living memory thanks to improvements in sewage treatment.

The past ten years have seen widespread improvements in river quality in the Thames region according to a recent survey by the Environment Agency.

However the agency is not resting on its laurels. It warns there is still much work to be done if standards are to be maintained.

Dr John Haines, water quality planner for the agency, said: "A mixture of careful regulation by the agency and extensive works by Thames Water has brought about an impressive restoration of some of our rivers across the region."

In 1990, when the current round of surveys began, only some 80 per cent of rivers in the region could be described as good or fair. This proportion is now 94 per cent.

Despite the good news there are still problems that need to be tackled. The levels of plant nutrient in the region's rivers remain high.

Dr Haines added: "These nutrients are essential to life in our rivers but high concentrations can be a problem."

The 2000 survey also measured things like colour, odour and litter with 72 per cent of the regions survey sites scoring good or fair.

Dr Haines said: "There is still room for improvement. Efforts by the public to avoid flushing disposable products, such as cotton buds, down the toilet and to reduce litter and fly-tipping in our rivers can all make a big contribution."