Britain's lost 'red river' resurrected, 100 years on
17 October 2013 Last updated at 09:47 BST
More than 9,000 miles of rivers were diverted underground or re-routed as Britain's cities expanded during the Victorian era.
Now the Environment Agency is set to uncover so-called "lost rivers", and return them to the nation.
Ben Moore visits Manchester's Medlock, known for running red, white and blue in the 1800s, but lost for a century.