 A new study is looking at the nation's most temperamental waterways known as ephemeral streams. These fill with water only after it rains. They're hugely important to the country's water quality. But as NPR's Nathan Roth tells us, those waterways in the U.S. no longer have federal protection. Ephemeral streams lost their federal protections last year after a ruling by the U.S. Supreme Court which also removed protections for more than half of the nation's wetlands.