Abstract: Session A 8:30 am (Back to Session A)
The Bonnie Park Dam Removal and Floodplain Restoration Project
Bradley J. Petru, MS, PWS, ISA-CA,
Hull and Associates
The Bonnie Park Dam located on the Cleveland Metroparks Mill Stream Reservation has been identified by the Ohio EPA as the main contributor to the Non-Attainment status of the East Branch of the Rocky River for Warm Water Habitat aquatic life use. Goals of the project include the removal of the dam and associated legacy sediments and the restoration the of in-stream and floodplain habitats. Maintaining hydrology to the Category 3 floodplain wetland was integral to the project. The Cleveland Metroparks successfully applied for Water Resource Restoration Sponsor Program (WRRSP) grant funding through the Ohio EPA to remove the approximate 10-foot tall concrete, low-head dam, restore in-channel aquatic life use habitat, restore fish passage, improve the connectivity of floodplain hydrology and restore floodplain wetland and riparian habitat. A mixture of LIDAR and field survey of existing conditions were compiled to generate a HEC-RAS 2D model of the floodplain landscape to support modeling of post-dam removal conditions and target restoration measures within the floodplain. The in-stream restoration includes dam removal, constructed riffles, and rebuilding of channel bankfull benches below the dam scour area to restore natural channel dimensions and facilitate sediment transport. Floodplain restoration included the removal of impervious asphalt and concrete pads, grading of new bankfull benches, removal of gabion walls, replacing undersized culverts, neutralizing drainage ditches, wetland restoration and enhancement, and floodplain grading. The construction efforts occurred during summer of 2019 and revegetation efforts will commence in the fall of 2019 into spring of 2020.