Simkins & Bloede Dam Removals – Patapsco River, MD
The removal of the 10-foot-high and 200-foot-wide Simkins Dam and 34-foot-high and 220-foot-wide Bloede Dam in Maryland are part of a larger project to remove all four dams along 175 miles of the Patapsco River and restore habitat to alewife, herring, American shad, stiped bass, and American eel. Inter-Fluve was the prime consultant for design and construction phase services for these projects.
Simkins dam was removed in 2010. Our work included topographic and bathymetric surveying, sediment screening, geomorphic assessment, bank stabilization, and vibration monitoring to prevent damage to a 42-inch sanitary sewer pipe.
The Bloede Dam was what remained of the hydroelectric project constructed in 1906. Power generation was decommissioned in 1920 due to excessive sedimentation issues. The design and permitting of the project was led by Inter-Fluve, which included reconstruction of over 1600LF of 42” PCCP Sanitary trunk line sewer, installation of new dual 12” sanitary siphons under the river, in addition to the dam removal. Total construction cost were $17.9 million. The construction was completed in 2019 and opened over 65 miles of new spawning habitat which supports the local recreational fishery
A critical element to make the Bloede project financially feasible was the passive release of 300,000 cubic yards of impounded sediment. This approach required sediment transport and nutrient analysis studies, a robust adaptive management plan, detailed dam breach planning, and close collaboration with permitting agencies.