"Blue Roof" Adds Stormwater Detention Alongside Green Roof in New York

Rooftop design will reduce storm water runoff into the East River and support a new beekeeping business benefiting the formerly incarcerated.

The rooftop design, by Hazen and Sawyer, is being promoted as “blue and green” because a water barrier system joins vegetation on the top of the building. Trays for water detention are expected to reduce runoff from the building’s roof area by 32% during a typical storm, helping to mitigate combined sewer overflow into the East River. Other trays holding soil grow vegetation that provides habitat for bee colonies located on an adjacent roof.

The shallow tray design reduced costs and lessened the system’s weight, making it possible to install on the older commercial building. The project covers 7,200 ft² (668 m²) of the 18,000 ft² (1,672 m²) roof, according to the Wall Street Journal.

The roof shelters the Osborne Association—an organization that offers services to the formerly incarcerated and their families. Osborne plans to use the roof to launch a honey business in 2014, which will supply honey to its current catering business and expand employment opportunities for former prison inmates. Elizabeth Gaynes, executive director of the Osborne Association, stated in a press release that the combined social and environmental benefits of the project “have resulted in a double bottom line.”