This transcript has been edited for length and clarity.
Lake Mead is America’s largest reservoir, supplying water for 25 million people across the southwest. It’s also drying up — a kind of poster child for the ongoing drought in the West. But upstream, a much larger but lesser known source of stored water is also disappearing: mountain snow.
This is how climate change is throwing one of the United States’ most critical sources of water out of whack.
During the winter, storms in the Pacific Ocean carry a lot of moisture to the land. If conditions are cold and wet enough, that precipitation falls as snow in the dozens of mountain ranges throughout the West, and stays frozen until the spring. In a typical winter, snowpack across the U.S. West stores over five full Lake Meads’ worth of water. As the weather gets warmer, that snow starts to melt slowly and steadily, feeding rivers, lakes in reservoirs and even recharging aquifers underground.
This system — one that ends up delivering water when we need it, and stores it when we don’t — is so influential that water managers often look to the mountains to predict h... Read more
