Erosion & Siltation

Although water quality in the upper Bushkill Creek watershed is generally quite good, the same cannot be said for the lower watershed downstream of Stockertown. Two tributaries are formally listed as Clean Water Act Impaired Streams (303d list) due to wastewater and quarry discharges, and our monitoring efforts have periodically documented high nitrates, sediments, and conductivity, and poor macroinvertebrate diversity near Easton. Bushkill Creek has the dubious distinction of having the worst water quality at its mouth of all lower Delaware tributaries surveyed by Delaware River Basin Commission in its report Lower Delaware Monitoring Program: 2000-2003 Results and Water Quality Management Recommendations. Clearly there is much work to be done. 

A serious challenge to the stream is the rapid pace of development. The recent connection of Rt-33 and I-78 has further increased development pressure in the upper watershed. Development increases storm runoff to the stream and may reduce recharge to groundwater. It also increases siltation problems due to poor erosion control and damage to stream buffers. However, development can occur without these effects, and the Bushkill Stream Conservancy is supportive of growth that is compatible with maintaining watershed quality.

Inadequate erosion control leads to sediment problems in the Bushkill; Silt fences and erosion along Bushkill Creek


Industrial land uses also pose a challenge to water quality. These include a large regional landfill, abandoned slate quarries, operating cement quarries, and a variety of industrial sites along the stream in Easton. Quarry discharges containing fine sediment and sinkhole activity between Stockertown and Tatamy are major problems in our watershed.

Over the past 20 years, sinkholes have been developing along the Stockertown section of the Bushkill Creek. These sinkholes have led to decreased water levels in the stream. Several fish kills have been reported at times of extremely low flow. Multiple hydrogeologic studies and extensive reporting have been completed, but a long term plan for management of the sinkholes has not been developed and the sinkholes continue to significantly impact the health of the stream.

A sinkhole near the Bushkill Creek.

For more information about the Stockertown sinkholes, additional resources are available at Lehigh University’s Lehigh Environmental Initiative website.

The Final Report for the Geotechnical Investigation of the Bushkill Creek Site is available here.