Baltimore County Department of Environmental Protection and Sustainability retained Kleinfelder to provide assessment, design, permitting, and construction oversight services for approximately 3,991 linear feet of stream restoration and floodplain reconnection along Bens Run in Randallstown, Maryland. The project aimed to restore stream stability, improve water quality, and enhance ecological function.

Complex Urban Environment

The stream system exhibited channel instability, erosion, sediment transport, and nutrient loading that contributed to watershed degradation. Baltimore County required a resilient restoration approach that would reduce pollutant loads, reconnect floodplains, and improve aquatic and riparian habitat while accommodating existing infrastructure. The project corridor included heavily urbanized stream reaches that limited opportunities for traditional floodplain restoration. Numerous utility crossings, exposed sewer infrastructure, and existing stormwater outfalls needed to be integrated into the design without compromising restoration objectives. In addition, permitting requirements, wetland resources, and long-term hydraulic performance needed to be addressed while maintaining public access and protecting adjacent infrastructure.

Comprehensive Assessments and Design

Kleinfelder completed comprehensive geomorphic, hydraulic, and ecological assessments to characterize existing stream conditions and inform restoration design. The team developed a natural stream-wetland valley restoration for the adjacent unnamed tributary and a nested floodplain corridor for Bens Run that balanced ecological goals with site constraints. Detailed hydrologic and hydraulic modeling using TR-20 and HEC-RAS supported channel sizing, floodplain reconnection, and stability through the 100-year storm event. Restoration features included stream-wetland complexes, boulder stabilization structures, sewer protection measures, native riparian plantings, upgraded drainage outfalls, and a new pedestrian footbridge to enhance site access.

Project Results

The completed restoration improved stream stability, enhanced aquatic and riparian habitat, and reduced nutrient and sediment transport throughout the watershed. The project generated credit for 205 acres of impervious area treatment and achieved annual reductions of 2,222 pounds of total nitrogen, 719 pounds of total phosphorus, and 684 tons of total suspended solids.

Project Details

Location:
Randallstown, MD
Owner:
Baltimore County Department of Environmental Protection and Sustainability, Watershed Restoration