Barrage (5)
'barrage' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for salvo that I've seen before include "Discharge of weapons in unison" , "Artillery salute" , "Burst of rapid fire" , "Barrage" , "Sudden round of applause" .)
(Other definitions for flood that I've seen before include "Overwhelming amount" , "Deluge" , "lot of water" , "Light" , "Inundate" .)