Drought, pollution, floods: Avon in Devon tells story of UK rivers in distress

A journey down the waterway in an area of outstanding natural beauty highlights troubles facing UK rivers

The thick mist hangs low over the high moor where the river rises from a boggy wilderness. It rushes over granite slabs and waterfalls down rocks, pooling alongside small oaks amid the coconut tang of yellow gorse, before picking up pace once more, fed, at last, by a few days of rain.

Twenty-three miles downstream its brackish flow swooshes at pace into a steep-sided estuary where paddleboarders ride the tidal motion and surfers run into the swell of Bigbury Bay.