The most common and most likely answer to this crossword clue is the 5 letter word AWASH
I've seen this crossword clue in The Times
A
W
A
S
H
More clues leading to the result AWASH
- Crawling out, mostly quiet
- Completely covered in straw, a shed
- Flooded area used to be hot
- Teeming area with wood
- Area close to bungalow remains flooded
- Area used to be hot and seriously flooded
- Flooded a Pacific state — but not in good fashion
- Leader of America and West remains inundated
- Flooded, get wife into a tree
- One bit of wreckage, wood floating helplessly
Buddy explains!

The straight part
We know that "flooded" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case flooded = awash.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does AWASH mean?
AWASH adjective- Washed by the waves or tide (of a rock or strip of shore, or of an anchor, etc., when flush with the surface of the water, so that the waves break over it); covered with water.
- (by extension) Covered, overspread (with or in something).