Rice University
OP-26: Water Use

During the 2011-2012 school year Houston was experiencing one of the worst droughts ever recorded. Thus, this was adopted as the baseline year to offer worst-case scenario data.

Condensate harvesting: Air conditioning systems provide a constant source of clean, cold water that is well suited for reuse. In the fall of 2008, Rice began capturing condensate water from the air conditioning systems of the Biosciences Research Collaborative to use as make-up water in the cooling towers of the South Plant. This is a free source of water that Rice would otherwise have to buy from the City of Houston during the summer of 2011, Rice completed a project to capture condensate water from many of the science buildings to bring back to the Central Plant's cooling towers. Combined, these systems are estimated to save at least 12 million gallons of water per year, which is equivalent to about 5 to 6 percent of Rice's annual water consumption in a typical year.

Several Rice buildings are individually metered for building-level water consumption, including (but not limited to) Alice Pratt Brown, Dell Butcher Hall, The Rice Stadium, the Greenbriar building, McNair Hall, the Rice Children’s Campus, the Gibbs Recreation and Wellness Center, the Biosciences Research Collaborative, and the President’s House. Otherwise, many buildings are served from master meters. Irrigation water is typically metered separately.

(1) Dual–flush toilets are located in Duncan College, McMurtry College, the Biosciences Research Collaborative, Brockman Hall, and the Gibbs Recreation Center. There are more than 405 dual-flush toilets on campus. The toilets have two options, full flush and partial flush. Full flushes use 1.6 gallons of water and partial flushes, which vary between buildings due to toilet model, use either .8 or 1.1 gallons of water. It is estimated that 788,715 gallons of water per year will be saved because of the dual-flush toilets. (2) During the spring of 2011, the Rice Housing and Dining department partnered with the student eco-rep for Hanszen College to test a new showerhead that reduces water consumption by 40 percent with an economic payback of just a few months. The student and his roommates reported that the low-flow showerhead provided a better shower than the showerhead it replaced. With student support, during the summer of 2011, both Hanszen and Lovett Colleges were retrofitted with these new showerheads. 3) Generally speaking, most old toilets across campus were replaced in the late 1990s with newer fixtures that meet current federal standards of 1.6 gallons per flush.

The University tries to select plant material that is native or well adapted to the area. Additionally, Rice’s irrigation system has evolved to utilize drip irrigation for the campus’ landscape which is much more water-efficient than conventional watering systems.

Each irrigation controller has a simple rain sensor attached. The sensor delays irrigation until it has dried out.

Baseline enrollment: http://oir.rice.edu/uploadedFiles/Office_of_Institutional_Research/Content/Common_Data_Set/CDS_2011-2012%20Short%20CDS.pdf Baseline year data is from the fall of 2011 Performance year data is from the fall of 2012 Note: We considered the number of beds to be a proxy for the number of on-campus students. While the number of students living on-campus changes constantly during the year, the number of beds is stable each semester.