Streamgages

Most currently available flood maps are used to assist planners in identifying and preparing for flooding scenarios. These maps portray statistics based on long-term historical records to estimate and forecast an approaching weather system. For more...
This seems like a pretty straightforward question, but there are some interesting issues that come up in making a response.First, the words "pure" and "natural" don't really mean the same thing. Pure water is a kind of theoretical concept, it means water...
There are two basic kinds of floods, flash floods and the more widespread river flooding. Flash floods generally cause greater loss of life and river floods generally cause greater loss of property.A flash flood occurs when runoff from excessive rainfall...
The USGS operates and maintains a nationwide streamgaging network of about 7,000 gages. Data from this network are used by a large number of public and private users, including government agencies responsible for water management and emergency response,...
Several kinds of flood maps are available from USGS and other sources.Online USGS map showing real-time flood conditionsUSGS Web site to track flooding in your areaOnline USGS current and past flood mapsNational Oceanic and Atmospheric Administration...
USGS real-time streamflow data typically are recorded at 15- to 60-minute intervals, stored onsite, and then transmitted to USGS offices every 1 to 4 hours, depending on the data relay technique used. Recording and transmission times may be more frequent...
No one knows for sure what would happen if the snow and ice in the polar regions all melted. Sea level would rise, which would flood coastal regions. Climate would be affected worldwide. Isostatic rebound would occur where ice masses were removed from...
Occasionally, a piece of equipment may malfunction or there may be physical problems at a station. USGS tries to correct a station or equipment problem within several days of its first occurrence, and is generally successful in meeting this goal. 
The beginning of a drought is difficult to determine. Several weeks, months, or even years may pass before people know that a drought is occurring. The end of a drought can occur as gradually as it began. Dry periods can last for 10 years or more. During...
Go to the current water resources conditions site at WaterWatch for a map of real-time streamflow in the United States for the day of the year.Learn more: 'From the River to You: USGS Real-Time Streamflow Information.'