Section 1. The Watershed Today
BIOLOGICAL
HEALTH OF THE SCHUYLKILL WATERSHED
A five-year study by the Stroud Water Research Center found that water and
aquatic habitat quality varies dramatically in the main streams that supply
the Schuylkill River. The study sampled stream bottom-dwelling macroinvertebrates
(e.g. mayflies and other insects, worms and crayfish) at 19 locations between
1996 and 2000. Overall, the study revealed a degradation of biological conditions
at eight of the 19 study sites.
The 19 sites included most major tributaries within the watershed, enabling the Stroud Center to draw general conclusions about water quality. The stream sites that scored highest for water quality (given “A” water quality grades) were the West Branch of the Perkiomen and the Manatawny, both predominantly forested and rural. Among the lowest scoring (given “D” water quality grades) were the Wissahickon, which runs through Philadelphia and its suburbs, and the Tulpehocken above Reading. Also receiving low scores were sites on the headwaters of the main stem of the Schuylkill, Little Schuylkill, and West Branch of the Schuylkill, which are all near mining areas. Higher and lower scores potentially occur at sites not included in the study.
The study demonstrates that land use does affect water chemistry, which in turn affects the numbers and varieties of macroinvertebrates. However, because each site reflects land and water use over a large area, the precise source(s) of water or habitat degradation cannot be identified. The Stroud Center is continuing this study through 2003 to gain a better understanding of water quality in the watershed.
Site Design: Tevlin & Clarke
