Water

Yes! The U.S. Geological Survey WaterAlert service provides notifications to your email or phone for changes in water conditions based on thresholds you choose.

River forecasts (flood forecasts) are made by the National Weather Service - National Water Prediction Service. The overall map on the website uses color designations to give a quick overview of current conditions. A legend and other information can be selected in the right column. From the main map, click on a station to bring up a box which includes a graph showing current information and a...

The spelling of “gage” is part of our very rich USGS history. We have used that spelling for over a hundred years. In 1888, USGS Director John Wesley Powell met a very forward-thinking graduate student named Frederick Haynes Newell. Powell was so impressed that he made Newell the first full-time appointee to the new Irrigation Survey, which was created to investigate the potential for dams and...

Not directly. You cannot say that because a stream rises (doubles) from a 10-foot stage to a 20-foot stage that the amount of flowing water also doubles. Think of a cereal bowl with a rounded bottom. Pour one inch of milk in it. It doesn't take much milk to make it up to the one inch level because the bowl is at its narrowest near the bottom. Now, pour in milk until it is two inches deep -- it...

“Reach” can have slightly different meanings, depending on how it is used. A reach is a section of a stream or river along which similar hydrologic conditions exist, such as discharge, depth, area, and slope. It can also be the length of a stream or river (with varying conditions) between two streamgages, or a length of river for which the characteristics are well described by readings at a single...

Stream stage (aka gage height) is an important concept when analyzing how much water is moving in a stream at any given moment. "Stage" is the water level above some arbitrary point in the river and is commonly measured in feet. For example, on a normal day when no rain has fallen for a while, a river might have a stage of 2 feet. If a big storm hits, the river stage could rise to 15 or 20 feet...

At some USGS streamgage installations, NOAA’s National Weather Service (NWS) maintains a separate stage sensor that is serviced by NWS technicians. Calibration of any sensing device can occasionally drift from a "true" value, so there might be differences between USGS and NWS data reports. USGS personnel visit installations on an interval of 6 weeks or less to maintain equipment and make required...

In order to convert gage height (or "stage", usually expressed as feet) into streamflow (or "discharge", usually expressed as cubic feet per second), USGS hydrographers must establish a relationship between them. This stage-discharge relationship is called a rating curve. It’s developed by making frequent manual discrete discharge measurements at stream gaging stations. The rating curve depends on...

Real-time USGS streamflow data are PROVISIONAL, meaning that the data have not been reviewed or edited. These data might be subject to significant change and are not official until reviewed and approved by the USGS. Real-time streamflow data can be affected by: backwater from ice or debris such as log jams algae and aquatic growth in the stream sediment movement malfunction of recording equipment...

There can be occasional equipment or database problems where erroneous data are reported for short periods of time until corrections can be made. This is why it is important to look at a record of streamflow (like the 7-day hydrograph plots) rather than a single point in time. However, most of the time the USGS has a high level of confidence in its real-time stage data. During low streamflow...

USGS real-time streamflow data are typically recorded at 15-minute intervals, stored onsite, and then transmitted to USGS offices once every hour, depending on the data relay technique used. Recording and transmission times might be more frequent during critical events (floods, for example). Data from current sites are relayed to USGS offices via satellite, telephone, and/or radio telemetry and...

Water Data for the Nation (WDFN) is the home for USGS streamflow, groundwater, and water quality data. Through WDFN you can find different tools to look at historic and real-time streamflow data, find sites of interest, and access using USGS water data application programming interfaces (APIs). State pages (e.g., California) allow you to discover real-time data in your state, or you can create a...