Destroy or raise covering over gully (6)
I believe the answer is:
arroyo
'gully' is the definition.
(arroyo is a kind of gully)
'destroy or raise covering over' is the wordplay.
'covering' indicates a hidden word.
'over' is a reversal indicator.
'oyorra' is hidden within 'destroy or raise'.
'oyorra' back-to-front is 'ARROYO'.
(Other definitions for arroyo that I've seen before include "Dry river gully" , "Dry gully; yo roar (anag.)" , "Rocky ravine" , "Often dry desert ravine" , "Dry watercourse" .)