Water Resources Program  |  Church Road Constructed Wetlands

The Church Road Stormwater retrofit project consisted of a retrofit of a regional dry detention basin into a constructed wetland facility on Albemarle County MS4-regulated land. The drainage area of the facility is 68.4-ac, with 57% imperviousness. The detention basin was initially created as an indirect consequence of the construction of Incarnation Drive, which dammed an existing intermittent stream. Stormflows in the original basin were originally conveyed under Incarnation Drive with a 24” pipe. In 2001, a riser structure and check dam were installed in the detention basin to provide improved flow attenuation and some water quality benefits. Prior to the construction of the wetlands facility, the detention basin had filled with silt and developed a small permanent pool in the vicinity of the riser. A stormwater retrofit was conducted to provide much-needed maintenance to the existing stormwater facility and to improve its water quality benefits. This constructed wetlands retrofit project was substantially completed in April of 2015.

The basin was converted to a constructed wetlands facility using Stormwater Local Assistance Funding (SLAF) from the Virginia Department of Environmental Quality. The constructed wetlands facility was designed to maximize the area and storage volume of constructed wetlands in the floor of the existing detention basin. A diversion weir installed where the majority of drainage enters the facility directs storm flows into three distinct wetland cells, and an armored drainage swale directs the remainder of offsite drainage into another wetland cell. To maximize biodiversity, stormwater detention, and ecological benefits, each wetland cell includes a deep pool, a high marsh, and riparian upland. Both the wetlands and riparian areas were planted with native vegetation.

The project resulted in a significant reduction of Phosphorus, Nitrogen, and Sediment from stormwater.  These pollutant reductions help Albemarle County address Total Maximum Daily Loads for the Chesapeake Bay and the Rivanna River. The total cost for designing and constructing the Church Road Constructed Wetlands Facility was $411,701.