Dry, requiring feed of river? Digger produced (6)
I believe the answer is:
trowel
'dry' is the definition.
Although both the answer and definition are singular nouns, I don't see how one could define the other.
I don't understand how the remainder of the clue works.
Can you help me to learn more?
(Other definitions for trowel that I've seen before include "Small garden tool for handling plants" , "Small tool for scooping or spreading" , "Small garden hand-tool" , "Bricklayer's tool" , "Platsterer's tool" .)