Sandy Run Watershed and the Holmesburg Water Works
Roberts Mill, Wingohocking Creek, 1871
Drainage area plan, early 19th century
Plans and maps of the Pennypack Creek Watershed in Philadelphia
Wingohocking Sewer across Penn St.
Sewer systems, City of Philadelphia, 1927 and 1929
History of Belfield (1934)
Frankford Creek Watershed: A historical overview of the Philadelphia section
Report on channelization of Frankford Creek for flood control (1947)
Frankford Creek Watershed Historical Timeline