A team of scientists and engineers at NASA and the U.S. Geological Survey (USGS) collaborated to see if a small piloted drone, equipped with a specialized payload, could help create detailed maps of how fast water is flowing. Rivers supply fresh water to our communities and farms, provide homes for a variety of creatures, transport people and goods, and generate electricity. But river flows can also carry pollutants downstream or suddenly surge, posing dangers to people, wildlife, and property. As NASA continues its ongoing commitment to better understand our home planet, researchers are working to answer the question of how do we stay in-the-know about where and how quickly river flows change?