Interesting set of articles on the sewage system of SF. I do like tree-lined streets, especially on the wide streets typical of the US, but I left them out from

Interesting set of articles on the sewage system of SF. I do like tree-lined streets, especially on the wide streets typical of the US, but I left them out from my original list because they can easily live in the strip between the street and sidewalk (or in the sidewalk, if you don't need a strip).