On Mar 11, 11:40*am, wrote:
I was always fascinated by thie at GPS. About 8 years back, they had
copper troughs underneath drippy platform areas which fed into pipes
where the water drained to.

I guess it's just a feature of the station

Hatton Cross underground has a veritable stream running out of the
westbound platform wall into the gutter below the tracks.

There is a spring at Tooting Broadway, probably part of that mind-
boggling River Wandle complex. It is far below ground. A copper pipe
has been connected to the wall to direct the flow into a gutter. I do
not know where the gutter goes. The water is clear and looks
drinkable, but the pipe is so near the floor that it is hard to get
any reasonable amount of the water into a cup. I would estimate that a
pint comes out every 15-20 seconds.