Under a Stream Stabilization/Restoration, Environmental, Permitting & Ancillary Services Basic Ordering Agreement, Stantec was awarded a Task Order by the Fairfax County Department of Public Works and Environmental Services (DPWES) to provide Stream Restoration and Stormwater Best Management Practice (BMP) Retrofit Design and Construction Administration services for the Centre Ridge Basin Retrofit project in Fairfax County, Virginia.

This project proposed the retrofit of an existing stormwater management detention basin to improve water quality within a highly urbanized portion of Centreville, Virginia. The retrofit of the basin, nestled within a residential community, consisted of converting the detention basin into a constructed stormwater wetland, removing features such as the concrete pilot channel and introducing forebays, microtopography, and a robust planting palette. Located within an area of substantial bedrock and crossing a sanitary sewer line, the retrofit allowed for flexibility to accommodate key constraints and challenges such as these. As a unique and unexpected benefit from the project, the bedrock harvested from the site was able to be reused on another project under construction at the same time, allowing for a more sustainable solution for both sites. Through proactive collaboration amongst DPWES, Stantec, Fairfax County Park Authority, Environmental Quality Resources, L.L.C. (EQR), the community, and several other stakeholders, aesthetically-pleasing, site-specific solutions were developed and implemented to achieve project goals.

In this presentation, we will discuss the multi-year design process, project challenges and constraints, and flexibility in design and implementation. We will feature the collaborative process throughout the project, including the reuse of harvested materials on other project sites, and summarize takeaways from the project following construction.