George Washington University
OP-23: Stormwater Management

Three storm water goals from the GWater Plan are as follows: 1) Use GW campuses as test beds for new water reclamation technologies to reduce potable water consumption; 2) Capture rainwater that falls on GW campuses aiming for zero run-off, and 3) 10 percent absolute increase in permeable space over 10 years from FY11 baseline. 4) By 2021 reuse all retained stormwater for greywater systems, cooling towers, and irrigation.

The University's first green roof was installed on the Elliott School building (1957-1959 E St) in October 2008. It is approximately 1,600 square feet (sf) in size. In 2011 GW added 2,685sf of green roof at Ames Hall and 20,900sf at the building complex on Sq 54. The university has added a 1,200sf green roof at GW's Law Learning Center, designed 5,850sf of green roof at the Milken Institute of Public Health in 2014, and 10,150sf of green roof on the future Science and Engineering Hall to open in 2015. There is also a small green roof on the President's house.

Much of the university's property is located in an urban area, with city-owned asphalt streets and impervious concrete sidewalks. The university has been making its own sidewalks more permeable and plans to continue to do so. The GWater Plan calls for a 10 percent absolute increase in permeable space over 10 years from an FY11 baseline. There are also porous pavers in the LEED Sustainable Site on GW's campus (see below for more detail) on Square 80.

The university also has a certified LEED Sustainable Site which was a former parking lot, now a green space, with a rain water collection system and rain barrels to irrigate the grass and plants, and for source water for a fountain. As part of the project planning and management process, the GW Operations Team seized the opportunity to make GW’s urban campus even more environmentally friendly. They embarked on a process to create a plaza in the interior middle of the city block (Square 80) between the surrounding buildings. The vision was to create a space that would be beautiful, enjoyable, and acts as an urban resource that protects the Potomac Watershed. Permeable brick pavers include an under-tray system used to collect rainfall. Three below-ground cisterns totaling 33,000 gallons hold the rainwater. Runnels capture non-permeable hard-scape run-off and direct it into tree pits and planters. Rooftop water is diverted from adjacent buildings into the cistern system. Where parking is required by zoning laws, Grass-Pave™ is installed and planted with Buffalo grass. All plantings are native (70%) and adapted (30%) species, further reducing water demand. The fountain draws from the cistern system, and auto shuts-off when the water supply runs low. Stormwater management devices have been required in Washington, DC for new development projects since the mid-1990s. The university has 13 buildings using a total of 14 stormwater treatment devices. In addition to the treatment system, some of these also include large storage basins similar to storage ponds but located below grade rather than on grade. All of them slow the rate at which stormwater enters the sewer system and they remove solids from the stormwater before discharge. The GW Law Learning Center has two cisterns (8k gallon and 15k gallon) in place. Two new construction sites, The Milken Institute for Public Health and Science and Engineering Hall, GW will be reclaiming stormwater from roof drains for use in flushing toilets and urinals and for cooling tower make-up.