Gerwig Lane Spillway

The Gerwig Lane embankment dam located in Howard County, Maryland was the first high hazard dam approved by Maryland Dam Safety utilizing HydroTurf®.

The Gerwig Lane Pond is a SWM pond in the Patuxent River Watershed. The Gerwig Lane embankment dam is classified as a High Hazard dam due to its risk of flooding roadways. Breach of the dam would impact four roadway crossings which would impact roads, structures and people. The existing dam was failing due to several deficiencies which would be addressed in the proposed repairs. 

As the probable maximum flood (PMF) storm event will cause overtopping, HydroTurf® provides protection for this high hazard dam by providing stable conveyance of the PMF storm through a controlled section of the embankment. The extensive research and testing proving Hydroturf’s ability to handle flow velocities up to 40 ft/sec with no failure provided project stakeholders with a cost-effective, engineered solution to rehabilitate the earthen embankment.

Throughout the installation process, the engineer, Greg Adolph with McCormick Taylor said that “everyone on the Watershed Geo team was very responsive,” making it easy to address issues as they came up. One of the reasons that the product was chosen was due to the quick responsiveness from Watershed Geo.

In addition to effectiveness, HydroTurf provides many ongoing benefits. The advanced revetment system is also very lightweight, which does not burden the existing embankment which could lead to unnecessary settlement. The revetment system can be laid over an existing structure, creating an aesthetically pleasing solution for uniquely shaped geometry challenges. The engineered turf significantly lowers long-term maintenance cost and efforts as it does not need any type of vegetation maintenance.