Some stretches of Fishing Creek contain significant amounts of algae because of leaking septic systems in the watershed. The area around the tributary West Creek is the least habitable part of the Fishing Creek area, according to a 2011 study. The water quality of Fishing Creek can vary. Its pH ranges from 4.9 to 8.5, while the concentration of dissolved oxygen ranges from 5 to 17.5 mg per liter. The creek's average discharge is 615 cubic feet per second (17.4 m3/s); its watershed contains gravel, shale and various loams—in particular the Albrights soil series and the Leck Kill soil.