I've been meaning to call Thames Water about this for ages, but always on my way to work so keep forgetting. A stream in Forest Hill is quite scenic, but is perhaps not ideally placed on Dartmouth Road. On the back of your post, I've just spoken to TW to find out why they haven't repaired it.

The leak has been reported by several people and the guy on the phone has now increased the repair priority. An inspection will take place tomorrow (Sunday 23rd) and a repair shouldn't be far behind.

As a word of warning, try to avoid passing the pothole as a bus drives over it. Last week, I was spectacularly in the wrong place at the wrong time...