The South Philadelphia Wetlands Park is a testbed for innovative adaptive reuse techniques and technologies that may soon serve as a unique model for urban ecological restoration. As part of the Delaware River Waterfront Corporation’s effort to turn abandoned areas along the Delaware River into a thriving park system, McLaren Engineering Group and the project team are focused on designs for piers 64, 67 and 70 that blend public access with the creation of terrestrial and aquatic habitats that will enhance and revive resiliency and ecological vitality in the area.
Working with the public to develop an ecological, community-centered park, concepts were developed that employ natural processes in riverbank stabilization and innovative wave energy dissipation to ensure a resilient waterfront for years to come.
Comparing designs that consider pier reconstruction, vegetation and habitat, McLaren and the project team reviewed the costs associated with designs with a linear or curvature boardwalk that connect the various piers, and a deep breakwater verse a wave screen and upland habitat. All designs were developed to provide a nature-based public space with an elegant framework, robust ecology and access for all.
McLaren performed underwater inspections to review the existing conditions and investigated whether any part of the failing pier could be salvaged for the waterfront habitat and urban park. The investigation found that most of the structures inspected were in severe or critical condition and due to their current state, current public access wasn’t recommended.
McLaren reviewed high-tide effects of the piers today, in 45 years and in 60 years with sea-level rise to analyze the impact of the various design will have on the city. The piers were also analyzed for a 100-year storm event, a 500-year storm event, as well as the effects on the area of a 100-year storm 60 years from now.
With current public access hindrance, the degrading piers could promote sediment deposition and attenuate wind and wakes from north and south of the piers, thus improving resiliency. So, McLaren suggested leaving the piers to degrade over time, as it could support resiliency and native habitat in the future. Other alternatives like pier in-place maintenance were reviewed and didn’t appear feasible for the expected lifespan of the proposed improvements. Demolition of the existing structures or partial demolition with substructure improvements were suggested as the best path.
McLaren performed a limited coastal study to investigate the wave action within the pier area. Due to the existing shallow depths found, McLaren expects the site to have low to moderate wave heights and negligible current influence closer to shore where wetland habitats are proposed. Wave attenuators can include breakwaters, sill, wooden planks between pilings of boardwalk, mussel reefs or coir logs. A combination of these to protect different areas across the site would be ideal and more fun.
The next phase of this wetlands park is design, engineering and funding of the project.