DOCUMENTING CHANGES TO AN URBAN RIVER UNDERGOING SEDIMENT REMOVAL: RESTORATION OF THE BUFFALO RIVER, BUFFALO, NY

The Buffalo River is identified as a Great Lakes Areas of Concern (AoC) because of a number of environmental impairments including contaminated sediments. As the river undergoes remediation in order to be delisted as an AoC, a management decision was made to remove the most contaminated sediment in a multi-year environmental dredging project. This project took place between 2011 and 2015. A base map of the Buffalo River was created that included the dredge cells for each year of the dredging project. To determine the volume of sediment removed from each cell, the United States Army Corps of Engineers (USACE) annually conducted high resolution bathymetric surveys. DEMs were made for the period 2010 – 2017 and the stack-profile tool in ArcMap was used to create bank-to-bank profiles. These profiles provide a temporal record that spans the period before, during, and after the environmental dredging project to document how channel geometry changed as a result of sediment removal. Channel cross-sectional profiles illustrate how the river’s width and depth increased, as well as identify locations of possible slumping from bank oversteepening and re-sedimentation associated with dredging and natural processes. To further understand the impact of dredging and its disturbance on the river, annual side scan sonar surveys were conducted between 2011 and 2018. This study offers an opportunity to document how the Buffalo River was affected by the removal of sediment and its subsequent response. The findings also offer insights into other urban rivers where environment restoration includes the removal of contaminate sediments.