The Port Royal Gully Stabilization Project began construction in March 2026 after more than two years of planning, design and regulatory review. The center will mark its completion with a tree-planting event Saturday.

During heavy rain, water ran down Port Royal Avenue and collected at a low point with no drainage. It then rushed downhill through the woods, carving three gullies and carrying soil and debris toward the pond. About one acre of land was affected. The erosion also exposed tree roots and threatened habitat used by fish and waterfowl.

The new system includes a rock-lined channel that guides runoff down the steep site in a series of steps, slowing the water and reducing its force. Drainage at the roadway’s low point is also intended to ease flooding on Port Royal Avenue.

Stephen Goin, who has worked at the center for 12 years, said he saw a tree’s roots become increasingly exposed before it was eventually washed downhill. He described the runoff as powerful enough to move boulders and logs.

The project team considered a culvert but chose an approach designed to blend into the landscape. The work uses natural stone, biodegradable materials, existing soil and native vegetation. The design was developed with Terracon, the Philadelphia Water Department, Flyway Excavating and the Hinge Collective.

The center also planted 800 trees and shrubs to restore habitat and help guard against future erosion. Goin said visitors who come to bird-watch, spend time by the pond or hike will benefit from the improvements.