This website displays maps, graphs, and tables describing real-time, recent, and past streamflow conditions for the United States. The real-time information generally is updated on an hourly basis. WaterWatch provides stream gage-based maps that:

• Show the location of more than 3,000 long-term (30 years or more) U.S. Geological Survey stream gages,
• Use colors to represent streamflow conditions compared to historical streamflow,
• Feature a point-and-click interface allowing users to retrieve graphs of stream stage (water elevation) and flow, and
• Highlight locations where extreme hydrologic events, such as floods and droughts, are occurring.

The stream gage-based maps show streamflow conditions for real-time, average daily, and seven-day average streamflow. The real-time streamflow maps highlight flood and high flow conditions. The seven-day average streamflow maps highlight below-normal and drought conditions.

WaterWatch also provides hydrologic unit code (HUC) maps. HUC-based maps are derived from the stream gage-based maps and illustrate streamflow conditions in hydrologic regions. These maps:

• Show average streamflow conditions for 1-, 7-, 14-, and 28-day periods, and for monthly average streamflow,
• Highlight regions of low flow or hydrologic drought, and
• Provide historical runoff and streamflow conditions beginning in 1901.

WaterWatch summarizes streamflow conditions in a region (state or hydrologic unit) in terms of the long-term typical condition at stream gages in the region. Summary tables are provided, along with time-series plots that depict variations through time. The tool also includes tables of current streamflow information and locations of flooding.