Duke University obtains all of its potable water from the City of Durham, which receives its raw water supply from the Lake Michie Reservoir and the Little River Reservoir. The Duke University campus lies along the division line between two major river basins: the Neuse River Basin and the Cape Fear River Basin. The majority of the Duke Campus, including Duke Gardens, flows south into the Cape Fear River Basin. The majority of Duke’s East Campus flows north to the Neuse River Basin. The University and the hospital are the largest consumers of water in the City of Durham, using over 400 million gallons of water annually. The largest water users at Duke are the central chilled water plants, the hospital, and the academic buildings.
Since a historic drought in 2007, Duke has worked diligently to reduce dependence on the city water supply and implement sustained conservation measures across the university and health system. Efficiency measures include fixture and toilet upgrades, correcting single pass cooling systems, and modifying sterilizers at all health system facilities. Duke has also worked to increase use of non-potable water through installation of cisterns for irrigation, capturing condensate from campus buildings to use in the chilled water plant cooling towers and the recently completed Reclamation Pond that supplies over 100 million gallons of water annually to the main campus chilled water facility. This year, FMD utility systems reclaimed over 90 million gallons of alternative water for use in campus heating and cooling systems, the single largest contributor to water reduction.
Through these measures and education efforts around conservation, Duke has achieved a 40% reduction in potable water per gross square foot since 2006.
Landscaping at Duke University is designed in a way to create a natural environment that is not dependent on water. Drought-tolerant plants and green roofs on campus with succulents are significant examples of these efforts. Ornamental stones are used to hold water, manage runoff, avoid rutting, and prevent weeds. These projects are self-sufficient once they are established, making them an economically efficient investment in sustainable practices. When irrigation is necessary, Duke Landscaping services is working to implement a centralized, state-of-the-art irrigation control system that utilizes a weather station and soil moisture sensors to prevent any wasted water. Currently only 3% of potable water used at Duke is for irrigation and this will continue to decrease as the systems are upgraded across campus.
Stormwater is one of the five central utilities managed, maintained and operated by the University. In order to comply with Durham’s stormwater regulations, Duke University has a stormwater system consisting of 32 miles of pipelines, numerous streams and open channels, several cisterns and detention devices, and multiple ponds (in the Sarah P. Duke Gardens, near the Washington Duke Inn & Golf Course, and at the Smith Warehouse).
The first phase of the Duke SWAMP Site (Stream and Wetland Assessment Management Park) was implemented in 2004. Today, this 14-acre restored stream-wetland-lake complex helps protect the Triangle’s drinking water supply by controlling stormwater runoff that drains into the Sandy Creek watershed from campus and 1,200 surrounding acres.
This facility also serves as an outdoor classroom and field laboratory for students and researchers interested in testing new wetland restoration technologies and studying biological diversity, hydrology, mosquito control, invasive plant species, and other environmental concerns.