The Colorado River provides water for nearly 40 million people in seven western states, irrigating millions of acres of farmland, and generating thousands of megawatts of electricity. And though an official declaration of water shortage on the Colorado River has never been declared, and that careful planning has ensured Arizona and Colorado are well-supplied with water, residents need to know it’s a precious resource.

That was the message Thursday as the water chieftains of Arizona and Colorado spoke before a crowd of about 100 at the Water/Climate Briefing Annual Keynote Event held by Arizona State University’s Decision Center for a Desert City.