The state of UK rivers

The river Lee near Hackney Marsh in east London. The report, by the official pollution watchdog, the Environment Agency, shows that 117 English and Welsh rivers are ranked on a par with the dirtiest rivers in eastern Europe Photograph: Dan Kitwood/Getty Images

The Lee. The 116 rivers in the worst condition mostly pass through urban and industrial areas and suffer from sewage run-off, increased flooding and greater demand for drinking water Photograph: Scott Barbour/Getty Images

Included in the 'bad' list are stretches of many of Britain's best-known rivers including the Thames (pictured), the Medway and the Lee Photograph: Andy Drysdale/Rex Features

The river Medway - in bad condition. The chemical and biological state of UK rivers, wetlands, lakes, estuaries and coastal waters has improved considerably in the last decade, but the results are highly embarrassing because the government is legally required by Europe to ensure that 95% of all British rivers are in "good" ecological condition by 2015 Photograph: Robert Judges /Rex Features

Thousands of fish died in the river Trent earlier this year due to polluted run-off which had travelled downstream. Rivers like the Severn, the Trent, the Tyne, the Dee in Wales and the Stour estuary have improved in the last decade following investments - mainly by water companies - but remain a long way short of being in good ecological health Photograph: Angling Trust

An aerial view of the QEII bridge, Grays and Tilbury, on the river Thames. It is estimated that it could cost £9bn to get 95% of UK rivers to 'good' status by 2015 Photograph: Ben Cawthra/Rex Features

The Coquet river in Northumberland. North-eastern Northumberland emerged as England's top county for river quality. Four of the 'high status' rivers cascade off the Cheviot hills, running to the rivers Coquet and Tweed. The Ridlees burn, the Barrow burn, the river Till and the Linhope burn are all young, fast flowing and relatively small, full of waterfalls, pools and rippling shallows loved by salmon and sea trout. All are prone to pollution from cattle, but are far from large populations or heavy industry Photograph: Michael Busselle/Corbis

Betws-y-coed, Gwynedd, Wales. The fifth pristine river, the Caletwr in north Wales, is lined with ancient oak woods and tumbles into the river Conwy Photograph: Gallo/Getty Images

A gorge on the river Conwy, north Wales. Otters, water voles, kingfishers and more than 30 species of fish all rely on rivers Photograph: Richard Klune/Corbis