The renaissance of Britain's rivers was underlined on Tuesday when waterways once considered polluted to death were revealed as teeming with life.
Among the list of the 10 most improved rivers published by the Environment Agency were the River Wandle, a tributary of the Thames which runs through southwest London.
It was declared a sewer in the 1960s but is now one of the best urban fisheries in the country.
In the northeast, the River Wear in Northumberland and its better-known sibling the Tyne are now the top two rivers in England to catch salmon -- and recent surveys show that more fish are present on the Wear than ever before.
The Environment Agency said the most remarkable turnaround was made by the River Taff in south Wales, which the agency said once ran black with coal dust but is now a leading site for fishing competitions.
The agency attributed the improvement in the rivers' state of health to thousands of habitat improvement projects and tighter regulation of polluting industries.
Ian Barker, Head of Land and Water at the Environment Agency, said: "Work that we have done with farmers, businesses and water companies to reduce the amount of water taken from rivers, minimise pollution and improve water quality is really paying off -- as these rivers show.
"Britain's rivers are the healthiest for over 20 years and otters, salmon and other wildlife are returning for the first time since the industrial revolution."
The recovery of the Thames itself was recognised last year when it was awarded the International Theiss Riverprize which celebrates outstanding achievement in river management and restoration.
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