Powderly Creek (also known as Powderly Brook) is a tributary of the Lackawanna River in Lackawanna County, Pennsylvania, in the United States. It is approximately 2.3 miles (3.7 km) long and flows through Carbondale Township and Mayfield. The watershed of the creek has an area of 1.77 square miles (4.6 km2). The creek is an impaired stream. It is impacted by flow loss and is also affected by acid mine drainage. Its waters tend to be acidic. The watershed of the creek is in the Appalachian Mountain Section of the Ridge and Valley physiographic province. The main rock formations in the watershed include interbedded sedimentary rock and sandstone. Culm and silt are deposited in the creek's vicinity and it flows through a large silt basin known as the Bushwick silt basin. A major underground c