The most common and most likely answer to this crossword clue is the 6 letter word URINAL
I've seen this crossword clue in The Guardian
U
R
I
N
A
L
More clues leading to the result URINAL
- Where men go home through river
- For some, it’s de rigueur in a 26
- Where water’s passed in river banks
- Where men go to ruin pants with a lager top?
- River surrounds fashionable place to go
- One of four in a lavatory?
- Behaviour in Aldi somewhat lacking — the ladies won’t have it
- Where to go for a little detour in a limo
- Place of relief, having home swamped by Russian river
- Chauffeur in a limousine’s shown place to go
Buddy explains!

The straight part
We know that "Where water’s passed" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case where water’s passed = urinal.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 URINAL mean?
URINAL noun- A device or fixture used for urination, particularly:
- Any oblong glass vessel shaped like the old alchemist's urinal.
- A room or structure used for urination: a latrine; an outhouse; a lavatory.