The Derwent is a river in Yorkshire in the north of England. It is used for water abstraction, leisure and sporting activities and effluent disposal as well as being of significant importance as the site of several nature reserves. It is the subject of conflicting interests as well as having an interesting ice age past and a long recorded history.
Derwent is also the river that runs through the village Stamford Bridge, famous for the Battle of Stamford Bridge September 25. 1066.
http://en.wikipedia.org/wiki/River_Derwent,_Yorkshire