Plumbing Fixture and Cooling Tower Water Use Reductions: Estimated annual savings from plumbing fixture and cooling tower efficiency currently amount to nearly 4.1 billion gallons. We expect savings to skyrocket in the next few years, reaching 46.5 billion gallons of water saved by 2015, and nearly doubling to 86.7 billion gallons by 2020.

Landscaping Water Reductions: To date, more than 5.4 billion gallons of water have been saved through landscaping water reductions alone. We foresee landscaping water savings exceeding 65 billion gallons by 2015, and 118 billion gallons by 2020.

Aggregate Water Savings: Total water savings from combined usage of plumbing, landscaping and cooling towers as of 2008 are 9.5 billion gallons, about 0.3% of annual non-residential water use. By 2015, with LEED floor area approaching 9 billion square feet, this figure is expected to exceed 133 billion gallons annually, or 4.1% of non-residential water, an increase of more than 1,000%. This number will nearly double by 2020, reaching 245 billion gallons of saved water, which represent 7.5% savings of annual non-residential water use.

Wastewater Reductions: Based on the fraction of LEED projects pursuing innovative wastewater treatment, we found that annual reductions of 3.3 billion gallons of wastewater releases have been achieved to date, a 0.1% reduction in annual wastewater generation. This figure is highly conservative, since it does not include the reductions in water use from plumbing and cooling tower savings, nor does it include savings in excess of LEED requirements.

We expect savings of 46.5 billion gallons of wastewater by 2015 and 86.2 billion gallons saved by 2020. These figures represent, respectively, 1.7% and 3.1% reductions in annual wastewater generation.