Washington University in St. Louis’ goal is to become a leader in water conservation.


Missouri’s annual average temperature in 2012 was the highest on record and paired with a historic summer drought that compromised agriculture and stressed natural and urban ecosystems throughout the state. These ecological concerns paired with rising water costs over the last 10 years of an average of 10 percent each year has driven the university to create solutions that reduce our potable water consumption and create more resilient campus water systems.

On our campuses, all new construction and major renovations projects are built with low-flow fixtures that reduce water use by at least 30 percent and often over 35 percent relative to code. In addition, landscape projects are designed to reduce irrigation water use by over 50 percent through native and drought tolerant plantings, efficient irrigation systems and rainwater harvesting. We now have four rainwater harvesting cisterns in place with a total capacity of nearly 230,000 gallons of water that replace potable water for irrigation.

We have retrofitted many old domestic water fixtures throughout the university with low-flow fixtures, including shower heads, faucets and dual flush mechanisms. We have upgraded the Danforth Campus irrigation system with more efficient sprinkler heads and deployed a computer-driven system that adjusts irrigation frequency and intensity based on weather data.

Process water used for heating and cooling and in labs is also being conserved through a series of conservation efforts.


Process Water Conservation

water_conservation_giammar_lab_080The highly efficient heat-recovery chillers at both campuses avoid using cooling towers, reduce blow down, and reduce evaporation. Sixteen cold rooms at the School of Medicine now use water from the chilled water system instead of potable water for condensing cooling, saving 7.9 million gallons and over $30,000 per year. Additionally, the School of Medicine’s new 4515 McKinley research building was designed with a process chilled water loop that provides chilled water to hoods and some benches in laboratories rather than sending that water directly into drains.

Water at Tyson

Logo for water usageTyson Research Center significantly reduced on-site potable water use through rain water harvesting and composting toilets. The Living Learning Center (LLC), a Living Building certified project, achieves net-zero water performance through the use of composting toilets as well as a 3,000-gallon cistern and chemical-free water purification system that provides 100 percent of the water needs. In 2014, we added a 20,000-gallon rainwater collection system, that provides irrigation for a 15,000-square-foot ecological research garden.