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Domestic Water Conservation


New Jersey frequently suffers from both surface-water and groundwater drought conditions. Princeton University takes its responsibility to conserve domestic water very seriously at all times, even during non-drought conditions, and whenever possible integrates water conservation efforts with its overall landscape and stormwater management programs

Goal, Strategies & Progress

Goal: Reduce overall campus water usage.

Strategy: Ensure that water-saving measures for building and landscape design are considered for all new construction and renovations. Investigate and monitor new methods for water conservation.


  • Overall campus water usage was approximately 13 percent lower in fiscal year 2011 than in fiscal year 2006.* When compared with 2010, water usage increased by about 21 percent, likely due to an increase at the central plant (cogeneration and chilled water), which uses water in direct proportion to the amount of energy provided for heating and cooling. Both campus heating and cooling demands were significantly greater in fiscal year 2011 than in fiscal year 2010, as a result of severe weather (more cold or hot weather for longer than average periods of time) and new buildings opening (see Figure 11).
Figure 11: Overall Campus Water Usage
Overall water use
Campus water usage decreased by 13 percent between 2006 and 2011.

Reduce water usage in the residence halls by installing efficient fixtures and appliances and transitioning to tray-free dining.  


  • Water usage in all residence halls continued to decline in fiscal year 2011.* Compared to 2010, usage was down by about 5 percent, or nearly 2 million gallons. In the past five years, residence hall water usage has dropped by more than 30 percent, or nearly 18 million gallons, due to the installation of low-flow fixtures and efficient clothes washing machines, among other water-saving measures (see Figure 12).

*NOTE: The baseline year has been updated to fiscal year 2006 from 2001 to better track changes that took place following the adoption of the Sustainability Plan in fiscal year 2007, and to conform with the requirements of the Sustainability Tracking and Rating System, a self-reporting framework for colleges and universities to measure their sustainability performance developed by the Association for the Advancement of Sustainability in Higher Education. Residence hall water data also continues to be refined to reflect more accurate usage, resulting in updated totals from those reported last year. Little Hall water data is not accounted for due to a meter issue.

Figure 12: Residence Hall Water Usage
Residence hall water use
Residence hall water usage has dropped by more than 30 percent over the past five years.
  • In addition to having low-flow fixtures standard in all residence halls on campus, Princeton has continued to install low-flow aerators and low-flow shower heads in off-campus graduate housing units, such as the Lawrence Apartments.
  • High-efficiency washing machines, which use 40 percent less water than standard machines, are now installed in all undergraduate dormitory laundry rooms — a four-year project that was completed in summer 2011. Associated water-savings is anticipated to be greater than 500,000 gallons each month, based on 35,000 washing machine cycles per month.
  • Dining Services has successfully implemented "tray-free" dining in all dining halls. This measure has the potential to reduce water and energy costs by $4,000 per year.

Strategy: Reduce water usage in academic and administrative buildings by installing efficient fixtures and equipment as well as rainwater storage and reuse systems.


  • A microfiber cleaning cloth program that employs reusable cloths that clean more effectively with less water than conventional methods was introduced this past year at the Frick Chemistry Laboratory. A significant reduction in water usage is anticipated.
  • A rainwater and condensate collection system at the Frick Chemistry Laboratory has provided enough water for all toilet flushing needs since the building opened in fall 2010, reducing building water usage.

Strategy: Reduce water usage associated with campus heating and cooling.


  • A new "PowerPure" water treatment system is being piloted at the Baker Rink cooling tower to cool the rink ice. This system uses an electronic process rather than chemicals to remove dissolved solids from evaporated water. The system annually will save more than an estimated 140,000 gallons of water. Because the discharge water is chemical-free, it may be clean enough to release to surface water instead of the sanitary sewer system, further reducing costs.

Strategy: Track and reduce potable water use for irrigation.


  • A pilot test using compost in place of fertilizer is being carried out in the south courtyard at Whitman College in an effort to increase the organic matter and, in turn, improve water retention and reduce the need for additional soil inputs.

What's Next

Short Term

  • Expand the microfiber cleaning cloth program to Butler College, Jadwin Hall and Fine Hall.
  • Implement the PowerPure system at the new High-Performance Computing Research Center.
  • Track water usage reduction resulting from the rainwater collection system at the Frick Chemistry Laboratory.
  • Compile and track installations or low-flow fixtures and aerators.
  • Support behavior-changing water conservation initiatives through student organizations such as the EcoReps and Greening Princeton.
  • Continue to assemble and track data indicating the acreage of areas planted with drought-resistant or native varieties.

Long Term

  • Complete low-flow bathroom fixture replacements in athletic facilities, and academic and administrative buildings.
  • Continue to evaluate drought-tolerant lawn species.
Freedom Fountain

The water level at the Fountain of Freedom on Scudder Plaza was recently lowered by 8 inches, significantly reducing spillover and the need to replenish it with fresh water and salt used for chlorinating it.

Figure 13: Water Collection at Frick Chemistry Laboratory

Rainwater collection

This drawing of the Frick Chemistry Laboratory shows how rainwater is collected on the roof of the building, and condensate is collected from mechanical systems in the "penthouse." The water is stored underground in a 12,000-gallon cistern, and is treated and reused for toilet flushing through high-efficiency, automatic flush valves. Data on stormwater and condensate collection and usage is then analyzed and fed to a video display in the atrium, along with data on photovoltaic panel production and fume hood energy consumption. Click to enlarge.