People in seven western states and Mexico rely on the Colorado River for water. As the climate warms, the mighty river's flows are expected to shrink—straining its ability to meet demands of cities and farms. As water managers brace themselves for potential shortages, they're keeping a watchful eye on Colorado's snowpack, where much of the water originates. More snow means more runoff—and for that reason many are participating in a little-known tactic to "fire up" more snowflakes from winter storms. H2O Radio reports.