Minebank Run Stream Restoration

The restoration of an urban stream ensures long-term channel stability while providing a wide diversity of native aquatic habitats.

Like many urban streams, Minebank Run had been degraded by years of stormwater runoff from upstream development. In the 1960s, authorities attempted to stabilize the stream using concrete flumes and in-stream weirs. These structures ultimately failed and accelerated erosion. Recognizing the need for stream restoration, Baltimore County turned to Biohabitats to craft a long-term solution.

In 1998, using geomorphic principles and best available data, Biohabitats developed a natural channel design to restore Minebank Run. In the 20+ years since that design was constructed, the practice of stream restoration evolved significantly, and advances in modeling have allowed Biohabitats to better understand this highly urbanized system and how its ecological function within the watershed could be further enhanced. In 2019, the County again turned to Biohabitats to adapt and repair the original design to be more resilient to contemporary and future flow conditions.

Biohabitats incorporated recent stream flow data and updated rainfall projections into the hydrologic modeling to determine design flows. These flows were evaluated in a 2D hydraulic model of existing conditions to delineate areas of excessive velocity and shear. Data was correlated with field observations to define areas in need of repair. Of primary concern were blocky rock weir and step-pool structures used in the original design, which had caused plunging flows and associated scour. These were retrofitted into riffle and cascade structures that transition high energy flows across a longer structure to reduce erosion and bed scour. Biohabitats also corrected meander geometry, increased the channel flow capacity, protected sewer infrastructure, and repaired outfall channels.

Biohabitats collaborated with the County’s on-call contactor, Meadville Land Service, on the constructability and adaptive reuse of materials during design and implementation. Biohabitats will provide post-construction monitoring through 2028.

TAGS

• Assessment+Monitoring
• Design
• Ecological Restoration