Restoration of the Patapsco River Through Dam Removal

The Patapsco River in Maryland was once an important migratory route for alewife, herring and American eel. Since the 1700s, dams have impeded passage and buried fish habitat in large segments of the river. Hurricanes in the mid 1800s and again in 1972 damaged or destroyed many of the Patapsco River dams, but four dams remained in the lower watershed. Expensive fish ladders installed on the lowermost dams did not meet the fish passage expectations of the Maryland DNR, and were difficult to maintain. American Rivers and NOAA, along with their local partners, obtained American Reinvestment and Recovery Act (ARRA) funding to remove three of the four dams. This talk examines the challenges met in designing and implementing the removal of the Simkins and Bloede dams, and discusses the results to date. The Simkins dam was removed in 2010, and the Bloede dam is scheduled for removal in 2013-14. Extensive sediment transport modeling was completed to determine the fate of the 100,000 cubic yards of sand impounded by the Simkins and Bloede dams. Rather than actively remove the impounded sand, passive transport has been adopted as the method for removal of the upstream sediment. This talk will also examine job creation and environmental monitoring made possible by ARRA.