USGS WaterWatch

The U.S. Geological Survey has a fascinating interactive site for real-time information on stream flows, generally updated on an hourly basis. WaterWatch provides maps that show the location of more than 3,000 long-term USGS stream gauges, which show the amount of water flowing in streams and rivers. The maps use colors to represent stream flow conditions compared with historical stream flow; feature point-and-click information; and highlight locations where extreme hydrologic events, such as floods and droughts, are occurring. Visit their website at