Streamwatch Project
Middle Branch of White Clay Creek: Site 7
Site 7 can be found at North Creek Road downstream from Good Hope Road on the White Clay Creek Preserve, PA. Half of the land in the watershed is in pasture/hay while the other half is predominantly crops and forests. The watershed is not heavily populated and typically of most other sites. Water chemistry variables were also similar to the study wide mean.
Total density and EPT density averaged 8100 individuals/m2 and 1000 individuals/m2, respectively. Typically chironomid midges, a group considered pollution-tolerant, make up 75% of the total numbers. Total Richness (11 taxa/200 individuals) and EPT Richness (5 taxa/200 individuals) were lower than the reference Site 11, but higher than the Site 6 upstream on the Middle Branch and similar to Site 17 upstream on the West Branch. The overall MAIS score ranked this site as Fair (6.7) and long-term trends suggest conditions may be improving at this location. The average MAIS for 1994-1997 was 4.2 (Poor) and for 2003-2005 it was 8.9 (Fair). Upstream sampling locations (see Site 6 and Site 17) suggest the Middle Branch is contributing more to degrading conditions than the West Branch.
| Location | |
|---|---|
| Site number | 7 |
| Description | Downstream from Good Hope Road at North Creek Road |
| Lat Long (hr min sec) | 39°45.699’ N, -75°46.960’ W |
| Land Use | |
| Watershed area above site (km2) | 64 |
| Population density in 2000 (#/km2) | 130 |
| % Population increase from 1990 to 2000 | 33 |
| Percent pasture/hay | 52 |
| Percent cultivated crops | 21 |
| Percent forest | 21 |
| Chemistry* | |
| Nitrate (mg/L) | 3.92 |
| Ammonium (mg/L) | 0.02 |
| Total Dissolved Phosphorus (mg/L) | 0.053 |
| Soluble Reactive Phosphorus (mg/L) | 0.055 |
| Sulfate (mg/L) | 18.83 |
| Alkalinity (as mg/L CaCO3) | 32.22 |
| pH | 7.87 |
| Conductivity (μmhos) | 190 |
| Dissolved organic carbon (mg/L) | 1.77 |
| Macroinvertebrate Data | |
| years sampled | 1994-2000, 2003-2005 |
| MAIS score | 6.7 |
| water quality based on MAIS score | Fair |
 Click on macroinvertebrate name to view a photo | |
| 1st most abundant macroinvertebrate | Chironomidae (midges) |
| 2nd most abundant macroinvertebrate | Hydropsychidae (common netspinner caddisflies) |
| 3rd most abundant macroinvertebrate | Tipulidae (crane flies) |
| 4th most abundant macroinvertebrate | Ephemerellidae (spiny crawler mayflies) |
| 5th most abundant macroinvertebrate | Oligochaeta (aquatic worms) |
*See Methods for number of years each chemistry variable was measured.