Herring Run Trail Emergency Bank and Stream Restoration

In Baltimore City’s Herring Run Park, nearly six miles of winding trails surround Herring Run Stream, providing extensive outdoor recreation opportunities. For decades, fast-moving flow from the stream, triggered by heavy rain and runoff from impervious surfaces, eroded its streambed. In the winter of 2018, accelerated erosion and bank loss left an 18-foot-high vertical bank face in an unstable condition, creating perilous conditions for park visitors. As well, the hazardous conditions threatened to destabilize the adjacent roadbed and disrupt nearby utilities.

Compounding matters, an exposed 84-inch water force main was diverting water toward the compromised embankment, posing a threat to nearby residents. Combined, these conditions necessitated the closure of a 600-foot section of Herring Run Trail. Working closely with regulatory agencies, the City of Baltimore Department of Recreation and Parks (DRP) received approval for fast-track construction as an emergency repair. Design-build delivery paved the way for project completion in less than three months.

To successfully stabilize and repair the damaged embankment, return the stream to its natural channel, and minimize its migration back toward Herring Run Trail, extraordinary steps were taken to relocate 300 linear feet of the stream twice during construction. At the onset, the project team created an open channel diversion to temporarily divert water away from the compromised embankment, allowing critical stabilization work to occur. The team built a temporary bridge, providing the ability to work on both sides of the stream simultaneously.

The installation of approximately 350 linear feet of sheet pile created a floodwall. The application of conventional stream restoration methods, including natural stream channel design and hard armoring, coupled with adaptive management techniques, such as floodplain modifications, bypass channel operation, and in-stream grade control structures, led to the successful stabilization and repair of the trail and returned the stream to its natural channel. The work also increased the useable space in the park by one-quarter acre. Grading for the project called only for natural, on-site materials, including boulders placed in the streambed channel to direct the water and create wildlife habitat.