Washington Park Stream Restoration and Bioretention

Hazen provided site evaluation, design, and construction phase services for bioretention cell construction and stream restoration within Washington Park, located in Winston-Salem, NC. The project included improvements on both sides of Salem Creek, an urban stream identified as an impaired water by the North Carolina Department of Environmental Quality

Stream Restoration Along Unnamed Tributary to Salem Creek 1.5-Years Post-Construction - Hazen provided site evaluation, design, and construction phase services for stream restoration within Washington Park, located in Winston-Salem, NC. The Washington Park project included improvements on both sides of Salem Creek, an urban stream identified as an impaired water by the North Carolina Department of Environmental Quality.

Hazen designed 640 feet of priority I/II natural channel design along the eroded tributary to Salem Creek establishing stability with riffle grade controls, rock sills, floodplain reconnection and bank protection. Channel cross-section dimensions were sized and sloped for stability; floodprone areas were graded to accommodate frequent, flashy urban storm flows.

The upper section was horizontally constrained due to an adjacent property, tight topography, and close proximity to an existing sanitary sewer line. Lateral stability was secured at this location through stone toe treatment on the outside bends of pools. Two stormwater wetland cells were excavated out of the largest floodprone area to provide flood storage, water quality treatment, and habitat diversification. The existing undersized CMP culvert was replaced with a triple box culvert. The new culvert accommodates flooding and provides continuity of the newly created bankfull benches from the upstream portion of the restoration to Salem Creek. The final section of stream below the box culverts includes an ‘at grade’ concrete cap encasement to protect a 36-inch waterline crossing. A newly reconstructed 8-inch DIP sanitary aerial crossing significantly improves vertical clearance; a stone cascade at this location serves as a stable tie-in to Salem Creek.

Tim Schueler specializes in the restoration of heavily degraded urban streams with limited site area access.

Project Outcomes and Benefits

A bioretention cell was installed to treat stormwater drainage from dog park area through physical, chemical, and biological processes.
640 linear feet of stream was restored including stabilizing a stormwater outfall.
Active scour and erosion were arrested by re-establishing floodplain access, installing grade controls, shaping stable channel geometry, and re-establishing vegetation with native seed mixes and plantings.
Stormwater wetland cells were installed in the adjacent channel floodplain for flood alleviation, water quality treatment and diverse wetland habitat creation.
Sanitary sewer assets and a water supply line were protected through natural channel stream design.
A failing culvert was replaced with a triple box culvert to accommodate flooding and provide secure utility maintenance and safe public use of a popular greenway.