Possible Clues:

• River has nothing of use
• Great - - , river flowing through Bedford
• Any one of multiple English rivers
• Might one get round to employ this in Yorkshire?
• River at Lewes (Sussex)
• One of several rivers producing slimy mud, say
• Somewhere for a cockney to live in Yorkshire
• River of 1 across
• It's no good having only the bottom of a dwelling in Yorkshire
• River bird without tail