A series of crumbling piers along the waterfront in South Philadelphia will be converted into an ecologically sensitive public park, according to plans developed by the Delaware River Waterfront Corp., a nonprofit organization that seeks to “transform the central Delaware River waterfront into a vibrant destination for recreational, cultural, and commercial activities for the residents and visitors of Philadelphia,” according to its website.
McLaren provided structural evaluations of the existing piers, using underwater inspections, and conducted studies on the effects that sea level rise, high tides, and coastal wave action will have on the piers over the coming decades as well as the potential impacts of major storm events.
Piers 64, 67, and 70 are primarily wooden structures with steel and concrete sections that date to the early 20th century. But as the factories in the region shut down over time, the piers were largely abandoned, notes Todd Manson, P.E., M.ASCE, a senior associate at McLaren and the firm’s lead coastal engineer. Located close to the water surface, the piers are topped by soil and over the years have become heavily vegetated with trees and other plants. In some cases, Miller adds, the tree roots are the only things holding the piers together.
Diving for data
McLaren examined the structures using divers with surface-supplied air and studied the potential of sea level rise, wave action, and other factors by studying historical data from existing gauges in the Delaware River, considering reports and projections on the expected impacts from climate change in the region, says Manson.
The project team studied the effects of high tides on the piers today and over the next 45-60 years. It also considered the effects of a 100-year storm event and a 500-year storm event as well as a 100-year storm event happening 60 years from now. Illustrations created for the public show the relatively modest overtopping of the piers that can occur during high tides today, the more pronounced overtopping that can be expected by 2050, and the near total inundation of piers 67 and 70 that can be expected by 2080.