Man-made lake (9)
I believe the answer is:
reservoir
'man-made lake' is the definition.
(I know that man-made lake can be written as reservoir)
This is the entire clue.
(Other definitions for reservoir that I've seen before include "Lake created to store water" , "Large water store" , "water over a wide area?" , "Man-made lake to store water" , "Lake used to store water for community use" .)