Maps pertaining to surface water (historically and currently) in Philadelphia, and the city's water supply and sewerage systems. The site also provides links to many scanned, old atlases, topographical maps, etc. for Philadelphia (including some complete atlas volumes), nearby communities, and counties in southeastern Pennsylvania.
this blog posting "Philadelphia Bicycle News: Schuylkill River Trail Map"
has a link to a good detailed google map of the trail, side trails, train stations etc