(Galen Hecht | WildEarth Guardians via AP) In this Saturday, April 11, 2020, drone photo provided by WildEarth Guardians, the Rio Grande flows through White Rock Canyon near White Rock, N.M. U.S. forecasters predict spring flows will be less than half of average near the Otowi Bridge gauge and even less downstream, signaling potential trouble for the already stressed waterway.