Notts town acts with river rising (7)
I believe the answer is:
worksop
'notts town' is the definition.
(town in Nottinghamshire)
'acts with river rising' is the wordplay.
'acts' becomes 'works' (work is a kind of act**).
'with' is a charade indicator (letters next to each other).
'river' becomes 'po' (Po is an example).
'rising' is a reversal indicator (going up in a down clue).
'po' in reverse letter order is 'op'.
'works'+'op'='WORKSOP'
(Other definitions for worksop that I've seen before include "Where in England" , "northern town" , "found in Nottinghamshire" , "Town in Nottinghamshire" , "town in Midlands" .)