The most common and most likely answer to this crossword clue is the 10 letter word WATERFRONT
I've seen this crossword clue in The Daily Telegraph
W
A
T
E
R
F
R
O
N
T
More clues leading to the result WATERFRONT
Buddy explains!

The straight part
We know that "harbour area" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case harbour area = waterfront.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 WATERFRONT mean?
WATERFRONT noun- The land alongside a body of water.
- The dockland district of a town.