Only Rain Down the Drain - Dorking

Spotted these popping up all around town, there is even one by the little bridge over Pipp Brook in Station Road, which I don't think qualifies as a drain at all!  Not entirely sure why there is a picture of a fish though, it kind of implies there is resident wildlife we should be looking after -
- (which I suppose isn't entirely out of the question) although the deathly stench after recent flash floods (during summer downpours) when the drains vigorously overflow would seem to indicate otherwise...