Water is rare in a desert, especially in a desert that has the fifth-largest city in the U.S.—Phoenix. Recently, newspapers from Arizona and Los Angeles published competing articles about which city's water supply is less sustainable. What's more, the U.S. Bureau of Reclamation says the water seven U.S. states (40 million people) depend on is disappearing.

Many experts say that industrial and agricultural water consumers should turn to reusing. Luckily, Arizona State University is partnering with CH2M HILL and Intel on a program called WaterMatch, designed to make such reuse possible. The university is contributing data on wastewater treatment plants to "match" water reuse consumers with water reuse suppliers.

There are downsides to water reuse, but to focus on solutions, ASU's Global Institute of Sustainability, ASU's Decision Center for a Desert City, CH2M HILL, and Intel will host a gathering of experts to discuss how the Colorado River could be used for water reuse.