Was in charge, we hear, so naturally dropped water supply (6)
I believe the answer is:
rained
'dropped water supply' is the definition.
Although both the answer and definition are past participle verbs, I can't see how one could define the other.
'was in charge we hear so naturally' is the wordplay.
I cannot quite see how this works, but
'in' is found in the answer.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for rained that I've seen before include "Poured" , "showered" , "Precipitated moisture from sky" .)