The D&L Blog

Photo 1 of the construction site showing the progress being made this week, looking south from the bridge at the retaining wall reinforced ramp.

By Trail & Stewardship Manager Lauren Golden

At long last, I am very happy to say that construction of the Lock 1 Retaining Wall and Trail (Phase II of the Mansion House Pedestrian Bridge) is moving along nicely. Initially this project took a long time to get started, and then once it started it flooded. And flooded again. Three and a half weeks of flooding, to be exact. Precast panels with a stone pattern designed to match the adjacent lock and bridge abutment were installed bit by bit, but they are now all up and being prepped for paint. Alterations to some sewer pipes and the construction of a footer went smoothly and the ramped trail subsurface is in.

Photo 2 showing progress made on the retaining wall within the past week looking north from the trail at the retaining wall reinforced ramp and bridge.

So why did this area flood and how will that impact trail use in the future? Good question! This area is literally the river bank that was between the Lehigh Canal and the Lehigh River. When the river water rises, the bank is submerged. Knowing this, the D&L and our engineers built the Mansion House Pedestrian Bridge roughly 17 feet above the average river level so that this new bridge wouldn’t suffer the fate of the previous Mansion House bridge, which was washed away in a flood. A long ramp was then needed to connect the existing towpath (south of the water treatment plant) to the bridge along the river bank. Not only does this ramp connect the two points in the trail, but it also raises the trail up out of the floodway, so that the trail stays dry even when the river level rises.

Photo 3 shows the flooding of the construction site in May 2019.

You can see in Photo 3 from May that the river was so high that the retaining wall panels were submerged. When the water is that high the contractor cannot access the site, let alone work. This is the cause of the delay in the project. Photos 1 and 2 are from this week, and you can see progress. Additional concrete work remains, as well as resurfacing of nearly a mile of trail southward from the bridge, but we are working closely with the borough to keep the project moving as much as mother nature will allow.

We are grateful to everyone for your patience, but also your excitement. Please continue to respect the contractor by staying out of the project limits, marked by Trail Closed signs. Enthusiastic supporters like you are what have made this project a reality!