To remedy subsidence in a City parking lot in downtown Lebanon, Ohio, the City needed to address a failing concrete and sheet pile retaining wall constructed in the 1950s along the banks of Turtle Creek adjacent to the historic South Broadway Bridge. The poor condition of the wall was a liability and safety hazard, and needed to be replaced with another stream bank stabilization method. The City also wanted to enhance existing stream bank conditions by clearing invasive species and planting native trees and shrubs.
Working with a design-build partner, B&N completed the design, ecological surveys, and permitting for the stream restoration project. B&N’s scope of work included:
- Environmental investigations and permitting
- Removal of the failing sheet pile wall
- Clearing and grubbing of invasive species
- Excavation/Embankment reconstruction
- Hydraulic modeling
- Re-alignment of the stream channel
- Design/Installation of in-stream riffle structures
- Rock channel bank protection
During the removal of the sheet pile wall and slope excavation, the field team encountered petroleum impacted soils from a former gas station at the site. The field team also discovered a compromised storm sewer that transported stormwater from South Broadway Avenue to Turtle Creek beneath the site. The B&N team quickly defined and remediated the contaminated soils, and designed a new storm sewer and manhole that incorporated channel armoring to minimize future erosion.