An arsenal of new technology is being put to the test fighting floods this year as rivers inundate towns and farm fields across the central United States.
Drones, supercomputers and sonar that scans deep under water are helping to maintain flood control projects, and predicting just where rivers will roar out of their banks.
U.S. scientists said in their spring weather outlook that 13 million people are at risk of major inundation from flooding, with another 41 million people are at risk of moderate flooding.
Forecasters with the National Oceanic and Atmospheric Administration are now able to monitor a vastly larger part of the nation's river system with a new computer model.
Emergency officials also can simulate various scenarios, predicting what could happen if flooding washes away a levee or crashes through a dam.