CHANNEL MORPHOLOGY OF LOWER FISHING CREEK, COLUMBIA COUNTY, PA

Fishing Creek originates on the southern edge of the Appalachian Plateau and flows south through the folded and eroded Paleozoic rocks of the Valley and Ridge, draining a 450 square mile watershed into the North Branch Susquehanna River at Bloomsburg, PA. The bed of Fishing Creek is often covered with cobbles, though exposed bedrock is visible in several locations. The stream flows through a region mantled by glacial outwash and Quaternary alluvium. Within a few miles of Bloomsburg, the stream channel was modified to support grist and paper mills, iron works, and railroads. More recently, dams, weirs, a floodplain quarry, and the town water treatment plant have been added, and the stream has been diverted and straightened to accommodate construction of Interstate 80. More channel modifications are likely. Watershed and river groups advocate dam removal as a way to reduce river hazards and permit unrestricted flow and fish passage upstream. Townsfolk advocate weir removal and dredging of a large gravel bar to reduce perceived flood hazards, and government agencies have suggested bank stabilization measures should be taken in some locations to reduce bank erosion. To help predict the effect proposed modifications could have on the channel, a preliminary assessment of a 7-mile section of lower Fishing Creek--from Kocher Park in Lightstreet, PA to about a mile from the confluence with the Susquehanna River--was completed over 3 half-day float trips. A Trimble Juno SB handheld GPS and digital camera were used to record locations of large woody debris, boulders, bedrock exposure, tributaries, anthropogenic structures, bank erosion, bars, bank stabilization, and bank stratigraphy. These data provide a snapshot of lower Fishing Creek channel morphology in August 2011. They also record a baseline for that reach prior to the flood of record in September 2011. Aerial photos, topographic maps and LiDAR data were used to measure channel migration after removal of a low-head dam, as well as the development and disappearance of the large gravel bar over time. The bar was also surveyed to estimate the volume of floodwater it would displace.