Snowmibiles needed to get to Blackrock Creek streamgage
Why might USGS streamflow data be revised?
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
Data are reviewed periodically to ensure accuracy. Each station record is considered PROVISIONAL until the data are published. The data are usually published within 6 months of the end of the water year.
Data users are cautioned to consider the provisional nature of the information before using it for decisions that concern personal or public safety or for business that involves substantial monetary or operational consequences.
Learn More: Streamgaging Basics
Related Content
Is there a way to get alerts about streamflow conditions?
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.
How can I obtain river forecasts (flood forecasts)?
River forecasts (flood forecasts) are made by the National Weather Service River Forecast Centers and released through local Weather Service Offices. This NOAA website has a map showing the location of the forecast centers, their areas of responsibility, and by clicking into a region the location of the gages they use. The also provide a section for long-range river flood risk . The vast majority...
Why are there sometimes differences between USGS and National Weather Service river stages?
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...
What does the term "stream stage" mean?
Stream stage 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, sometimes very...
Does "stage" tell you how much water is flowing in a stream?
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...
How is a rating curve used to convert gage height into streamflow?
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...
Sometimes the USGS real-time stage data seems too high (or too low). Are the USGS data inaccurate?
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...
Where can I get real-time and historical streamflow information?
The best starting point for USGS streamflow data is the interactive National Water Information System (NWIS): Mapper website. Zoom in to your area of interest or use the search options in the left navigation window. The map displays active surface-water sites by default, but you can change the type of water site (surface-water, groundwater, springs, atmospheric) and select to show inactive sites...
Why do some real-time streamgaging stations stop transmitting data for extended periods of time?
The USGS usually corrects any equipment or station problems at our streamgages within a few days of their occurrence. Occasionally, replacement parts or equipment might not be readily available, or a station might be inaccessible due to weather conditions. Most USGS streamgaging stations are operated in cooperation with other agencies. At some stations, the stage transmitting equipment is owned...
How often are real-time streamflow data updated?
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...
Snowmibiles needed to get to Blackrock Creek streamgage
Snowmibiles needed to get to Blackrock Creek streamgage
Servicing a Streamgage at Barker Reservoir Following Hurricane Harvey
USGS scientist Tom Pistillo wades through the waters of Barker Reservoir to ensure accurate reservoir water-level data are being measured, which are critical for helping the U.S. Army Corps of Engineers and Harris County Flood Control District make informed reservoir operation decisions.
USGS scientist Tom Pistillo wades through the waters of Barker Reservoir to ensure accurate reservoir water-level data are being measured, which are critical for helping the U.S. Army Corps of Engineers and Harris County Flood Control District make informed reservoir operation decisions.
Ice jam at Ponca Creek at Verdel, NE, February 15, 2017
USGS Nebraska Water Science Center hydrologic technician, Nathan Shultz, collecting depth and velocity data at the USGS streamgaging station 06453600 Ponca Creek at Verdel, Nebraska during an ice jam on February 15, 2017.
USGS Nebraska Water Science Center hydrologic technician, Nathan Shultz, collecting depth and velocity data at the USGS streamgaging station 06453600 Ponca Creek at Verdel, Nebraska during an ice jam on February 15, 2017.
Ice Jam Remnants
On April 29, hydrologic technicians Anthony Underwood and Jeremiah Pomerleau visited the USGS gaging station on the St. John River at Ninemile Bridge and found a sea of broken up, dirty ice left behind by a recent ice jam.
According to Anthony, photos don't do the size and scale of the ice chunks any justice.
On April 29, hydrologic technicians Anthony Underwood and Jeremiah Pomerleau visited the USGS gaging station on the St. John River at Ninemile Bridge and found a sea of broken up, dirty ice left behind by a recent ice jam.
According to Anthony, photos don't do the size and scale of the ice chunks any justice.
Streamflow Gaging Station and Measurement on San Pedro River, AZ
USGS employee, Hanna Coy, talks about stream gauging.
USGS employee, Hanna Coy, talks about stream gauging.
Streamgages: The Silent Superhero
Whether you drink water from your tap, use electricity or canoe down your local river, chances are you benefit from USGS streamgage information. So what is a streamgage and what does it do for you? This CoreCast episode gives you the inside scoop on your silent superhero.
Transcript and captions available soon.
Whether you drink water from your tap, use electricity or canoe down your local river, chances are you benefit from USGS streamgage information. So what is a streamgage and what does it do for you? This CoreCast episode gives you the inside scoop on your silent superhero.
Transcript and captions available soon.
Related Content
- FAQ
Is there a way to get alerts about streamflow conditions?
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.
How can I obtain river forecasts (flood forecasts)?
River forecasts (flood forecasts) are made by the National Weather Service River Forecast Centers and released through local Weather Service Offices. This NOAA website has a map showing the location of the forecast centers, their areas of responsibility, and by clicking into a region the location of the gages they use. The also provide a section for long-range river flood risk . The vast majority...
Why are there sometimes differences between USGS and National Weather Service river stages?
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...
What does the term "stream stage" mean?
Stream stage 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, sometimes very...
Does "stage" tell you how much water is flowing in a stream?
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...
How is a rating curve used to convert gage height into streamflow?
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...
Sometimes the USGS real-time stage data seems too high (or too low). Are the USGS data inaccurate?
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...
Where can I get real-time and historical streamflow information?
The best starting point for USGS streamflow data is the interactive National Water Information System (NWIS): Mapper website. Zoom in to your area of interest or use the search options in the left navigation window. The map displays active surface-water sites by default, but you can change the type of water site (surface-water, groundwater, springs, atmospheric) and select to show inactive sites...
Why do some real-time streamgaging stations stop transmitting data for extended periods of time?
The USGS usually corrects any equipment or station problems at our streamgages within a few days of their occurrence. Occasionally, replacement parts or equipment might not be readily available, or a station might be inaccessible due to weather conditions. Most USGS streamgaging stations are operated in cooperation with other agencies. At some stations, the stage transmitting equipment is owned...
How often are real-time streamflow data updated?
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...
- Multimedia
Snowmibiles needed to get to Blackrock Creek streamgage
Snowmibiles needed to get to Blackrock Creek streamgage
Snowmibiles needed to get to Blackrock Creek streamgage
Servicing a Streamgage at Barker Reservoir Following Hurricane HarveyUSGS scientist Tom Pistillo wades through the waters of Barker Reservoir to ensure accurate reservoir water-level data are being measured, which are critical for helping the U.S. Army Corps of Engineers and Harris County Flood Control District make informed reservoir operation decisions.
USGS scientist Tom Pistillo wades through the waters of Barker Reservoir to ensure accurate reservoir water-level data are being measured, which are critical for helping the U.S. Army Corps of Engineers and Harris County Flood Control District make informed reservoir operation decisions.
Ice jam at Ponca Creek at Verdel, NE, February 15, 2017USGS Nebraska Water Science Center hydrologic technician, Nathan Shultz, collecting depth and velocity data at the USGS streamgaging station 06453600 Ponca Creek at Verdel, Nebraska during an ice jam on February 15, 2017.
USGS Nebraska Water Science Center hydrologic technician, Nathan Shultz, collecting depth and velocity data at the USGS streamgaging station 06453600 Ponca Creek at Verdel, Nebraska during an ice jam on February 15, 2017.
Ice Jam RemnantsOn April 29, hydrologic technicians Anthony Underwood and Jeremiah Pomerleau visited the USGS gaging station on the St. John River at Ninemile Bridge and found a sea of broken up, dirty ice left behind by a recent ice jam.
According to Anthony, photos don't do the size and scale of the ice chunks any justice.
On April 29, hydrologic technicians Anthony Underwood and Jeremiah Pomerleau visited the USGS gaging station on the St. John River at Ninemile Bridge and found a sea of broken up, dirty ice left behind by a recent ice jam.
According to Anthony, photos don't do the size and scale of the ice chunks any justice.
Streamflow Gaging Station and Measurement on San Pedro River, AZUSGS employee, Hanna Coy, talks about stream gauging.
USGS employee, Hanna Coy, talks about stream gauging.
Streamgages: The Silent SuperheroWhether you drink water from your tap, use electricity or canoe down your local river, chances are you benefit from USGS streamgage information. So what is a streamgage and what does it do for you? This CoreCast episode gives you the inside scoop on your silent superhero.
Transcript and captions available soon.
Whether you drink water from your tap, use electricity or canoe down your local river, chances are you benefit from USGS streamgage information. So what is a streamgage and what does it do for you? This CoreCast episode gives you the inside scoop on your silent superhero.
Transcript and captions available soon.
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