From the powerful torrents of Scotland to the flatlands of East Anglia, Griff barges, canoes, swims, walks and sails his way along this often hidden network which has been the life-blood of the country.

In London Griff explores the relationship between cities and rivers and discovers the vital balance between water coming in - and waste going out. Heading north, he travels from Liverpool to the Humber across Britain's working rivers. In Scotland Griff travels east upstream from Kinlochleven into one of the most remote areas of the country and follows the fast and furious course of water downstream to Perth. In the West Country he follows the mighty Severn from its source in the Welsh hills to the estuary 200 miles away. And in East Anglia he sees the extraordinary contrast between the man-made ditches of the Fens, the Swallows and Amazons country of the Broads and the picturesque windy river Stour which finally leads him home.