OpenStreetMap
I went to slippy map today to see the results of mapping from last week. I was amazed to see that I had succeeded in flooding a large portion of Birsfelden (outside Basel). I guess tagging a stream with layer=-1 is not only lazy, but also dangerous when the stream conjoins a major river at layer=0.
Discussion
Comment from robx on 9 July 2008 at 14:41
That really shouldn't cause flooding. As far as I know, only natural=water causes areas to be filled. Either there was a way with natural=water when the Mapnik-tiles were last generated, or it's a bug in that renderer, I'd think. You could try filing a bug report.
By the way, it's impressive how Basel has improved in the past few months.
Cheers
Robert