If we turned off every tap in every city in the southwest, we still wouldn't solve the Colorado River crisis. That's because 80 percent of the water goes to agriculture — to the lettuce and melons in your produce section, the half-and-half you put in your coffee every morning. Those farmers have some of the preeminent rights to the river. So what if the government paid them to keep their water in the river instead? Part 8 of a 10-part series.