I find things get attended to more quickly if you report them via the Lovelewisham website (http://www.lovelewisham.org). Once you've done that, you can track the progress and see who is responsible - as long as the manhole is Lewisham's responsibility. It may be the responsibility of one of the utilities.

In general, though, the Lovelewisham website is the way to go. The two potholes I have reported that way this month (using the iphone app) have been patched within a few days.