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The UDC Bertie Backus Campus Green Infrastructure Treatment Train Project is located at 5171 South Dakota Avenue, NE, Washington, DC 20017, within a few short blocks of the Fort Totten Metro Station in a rapidly transforming neighborhood.
The Project Site has a total area of 17,775 square feet, of which the parking lot has a contributing drainage area of 15,245 square feet, and an adjacent small yard space adds an additional 2,530 square feet. The parking lot (0.34 acres) generates 1,505 gallons of runoff by the 1.7-inch storm.
The primary BMP is a 494 square foot triangular shaped bioretention tucked into the western-most corner of the parking lot, capturing runoff draining from east to west. The bioretention is configured between, and constrained by, the existing storm sewer and a gas line. Additionally, a ‘diverter bump’ was utilized to encourage as much runoff as possible into the bioretention. This approach was selected over a traditional trench drain in-order to transverse the existing storm sewer, minimize excavation and materials costs and simplify surface maintenance.
Due to these site constraints, the bioretention is restricted in size, and able to capture 6,022 gallons, or a 0.68” storm event. One way the design team brainstormed to finesse some additional performance out of the site was to connect a new rainwater harvesting system to the bioretention. Two 1,700-gallon underground cisterns were daisy-chained to the underdrain pipe to capture all the flow-through during larger rain events. Additionally, the bioretention media serves as the pre-treatment filter for non-potable water reuse. With the assistance of electric pumps, the water collected from the cisterns is pushed back up into a drip irrigation system that is threaded across the 2,530 sq. ft. conservation landscape.
To transform this space into a conservation landscape, the soil was first amended with 15 yards of DC Water biosolids, Bloom, and tilled in with skid-steer-mounted trencher prior to planting. The planting plan calls for water-loving bald cypress in the bioretention, as well as under the drip irrigation in the adjacent conservation landscape.
All of these innovative approaches resulted in the UDC Bertie Backus Campus Green Infrastructure Treatment Train Project being selected as a finalist in the Best Ultra Urban BMP category for the 2023 Best Urban BMP in the Bay Award contest! (by the Chesapeake Stormwater Network).
Project Status: This project is now complete.
For questions or more information, please contact:
James Woodworth: [email protected] | 202-535-2244