Duke University
OP-26: Water Use

In October of 2007, The North Carolina Drought Management Advisory Council (NCDMAC) listed Durham County, along with 54 other counties, in the highest category of D4- Exceptional Drought. As a result of the extremely dry conditions experienced by the entire state, Duke University convened Water Conservation Steering & Working Groups, which analyzed all potable water use on campus. In order, to measure progress since this point, Duke adopted fiscal year 2005-2006 as our baseline for this utility.

A new reclamation pond will collect rainwater and runoff from 22 percent of the main campus area for use in a nearby chilled water plant, which pumps water across campus to cool buildings. The pond is expected to save about 100 million gallons of potable water a year. Condensation in University, Medical Center and Health System cooling systems is reclaimed for use in Duke's Chilled Water Plant's cooling towers. Cooling tower blowdown water is sent through an RO system and reused in cooling towers. Water from the Asiatic Arboretum pond in Sarah P. Duke Gardens is used to water seasonal plants in the terrace beds of the Gardens. Additionally, in the Charlotte Brody Discovery Garden at Duke Gardens, rainwater is collected to water the surrounding landscape. Duke Gardens staff have also hosted workshops focused on rainwater harvesting at home. The Fitzpatrick Center for Interdisciplinary Engineering, Medicine and Applied Sciences (FCIEMAS), which opened in 2004, has a 70,000-gallon cistern underground to collect rainwater that is used to irrigate the nearly two-acre complex. Duke has multiple cisterns installed across campus that collectively hold approximately 260,000 gallons of stormwater. Water from cisterns is used primarily for irrigation. All irrigation water used on Duke's golf course is non-potable stormwater, which is collected from ponds on site.

Water meters currently track the water consumption from ~ 90% of campus.

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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. In the Duke Gardens, water conservation is a high priority and xeriscaping plays a large role in plant decisions. Plants are preferred that require little irrigation once established, and plants that need more water are sited appropriately for efficient water use. Proper mulching is also a standard procedure for all planting areas.

Rain sensors are an ordinance in the city of Durham. After a quarter inch of rain, programmed irrigation systems at Duke University shut down. The Duke Gardens and the new Duke Comprehensive Cancer Center site have Smart Controllers for their irrigation systems. The irrigation system for the Doris Duke Center is currently controlled by a ‘smart’ control valve. This system has sensors that respond to recent rainfall and adjusts the duration of irrigation accordingly based on soil moisture. Where feasible, Duke University Grounds and Sarah P. Duke Gardens use drip irrigation to further conserve water used for landscape irrigation.

Recent Initiatives Conservation measures identified by a water audit of 6 buildings in 2012 are expected to produce an 8 million gallon reduction in water consumption each year at Duke. A new reclamation pond will collect rainwater and runoff from 22 percent of the main campus area for use in a nearby chilled water plant, which pumps water across campus to cool buildings. The pond is expected to save about 100 million gallons of potable water a year. Duke is also helping to improve the watershed it relies on through a stream restoration project on campus. Sustained Conservation Through dedicated efforts on campus, Duke reduced its water use by 50 percent month over month from the previous year during the drought. In the years following the drought, there has been an estimated sustained reduction in water consumption of 35 percent. While many of the measures below were first initiated during the drought, they continue to contribute to sustained water conservation on campus. Conservation Measures – Buildings - Installed over 3,000 low-flow aerators on lavatories - Installed over 3,000 low-flow flush valves on urinals and toilets - Installed over 500 low-flow shower heads - Corrected single pass cooling on lab equipment - Installed hand sanitizers in residential hall bathrooms, kitchens, laundry room and common areas - Installed 200 new high efficiency front load washing machines - Modified sterilizers at all Duke University Medical Center facilities - Performed a water audit on campus buildings - LEED green building commitment Conservation Measures – Central Plants - Piped the reclaimed reverse osmosis water (RO) and air handler unit (AHU) condensate from campus buildings to use for make-up water in the Chilled Water Plant cooling towers - Installed a RO system on the cooling tower blowdown to clean this water and reuse in the cooling towers - Drilled two wells to provide tower make up water - Pumping water out of the creek for cooling tower make up - Installed a condensate transfer system to move condensate between East and West Steam Plants - Alternate sources of water accounted for over 40 million gallons of water (33%) in FY10 at Chilled Water Plant 2 Reclaimed Water Conservation Measures – Irrigation - Installed drought-tolerant landscaping on campus - Designed temporary system to irrigate essential athletic fields that involves the use of reclaimed water. Tanks installed under the bleachers at Soccer/Lacrosse Stadium - Installed cisterns to collect water for watering of Williams Field - Increased the size of irrigation ponds on golf course to allow for more natural water storage Conservation Measures – Educational and Community - Supplied the University and Medical Center staff, employees and students with 10,000 free low flow shower heads for their homes (total savings of ~73 million gallons of water) - Raise water conservation awareness by strategically placing signs at decision-making points like faucets, showers, water fountains and toilets - Several of the monthly Green Devil Challenges have focused on water conservation

GSF #'s exclude parking decks that do not have water infrastructure