On the beach in Southern California, it's easy to look at the Pacific Ocean and wonder what would happen if we could drink it. It's already happening in some places, and others from Arizona to the California coast want to expand desalination. If big cities there use more of the ocean and less of the Colorado River, would that leave more water for the southwest? Part 4 of a 10-part series.

For more CPR News coverage of the Colorado River, visited cpr.org/parched.

Host: Michael Elizabeth Sakas