"Half of the water flowing through regional river basins starts in so-called ephemeral streams. Last year, the Supreme Court curtailed federal protections for these waterways."
"Last year, the Supreme Court sharply restricted the federal government’s ability to limit pollution in small streams that sit dry for much of the year and fill up only after rainfall or snowmelt.
Now, a new study finds that those bodies, so-called ephemeral streams, are significantly more important to the nation’s waterways than often appreciated.
The research, published Thursday in the journal Science, estimates that 55 percent of the water flowing out of America’s river basins can be traced back to millions of ephemeral streams that flow only periodically. The findings suggest that the Supreme Court ruling, which rolled back protections for those streams, could leave large bodies of water vulnerable to pollution."