Answer: heavy
Explanation:
Adjective are the words used before other words to make the sentence more interesting. It is generally placed before noun or pronouns. There are different types of Adjectives. There can be multiple adjectives used in a single sentence. In the above sentence unnecessary adjective is used.
Here "heavy" is unnecessary as the word deluge itself means flood and floods are heavy and destructive. Deluge itself means a severe flood. So "heavy" is the unnecessary adjective.
