Come up to stretch between bends (5)
I believe the answer is:
I believe this is a triple definition!
'come up to' is the first definition.
'stretch' is the second definition.
'between bends' is the third definition.
(I've seen this before)
(Other definitions for reach that I've seen before include "Sail with the wind abeam" , "Limits within which something can be effective" , "Put out the hand for a part of the river" , "Arrive at; extend to" , "It's an advantage for a boxer" .)