Home » General Geology » Stream Gaging Station


What is a Gaging Station?


Stream Discharge Monitoring


Gaging stations are facilities used by hydrologists to automatically monitor streams, wells, lakes, canals, reservoirs, or other water bodies. Instruments at these stations collect information such as water height, discharge, water chemistry, and water temperature.

gaging station
stream gage data transmission

These stations collect information about the stream and transmit it to the USGS via a satellite communication system. The data is then processed and delivered to the public via the internet. Image by USGS.

gaging station map

The US Geological Survey has gaging stations at thousands of locations across the United States. Each dot on the map represents one USGS stream gaging station in their real-time stream flow data system. Image by USGS. Enlarge map.

stream discharge hydrograph

Measurements from these stations are useful for a wide variety of flood prediction, water management, recreation, and navigation purposes. USGS realizes the public demand for this information and allows anyone to use it. Check on a stream Gaging Station near your home. Image by USGS. Enlarge graph.

ADVERTISEMENT


There are many different types of stream gages. The photos below will give you some idea of their variety, expense, size, and technical basis. All of these gages measure the stage of the stream (height of the water above a datum). Stage values can be converted into discharge values if a rating curve has been established for the stream at that location.

staff gage - river
Staff gage in a river.

ADVERTISEMENT


Staff Gage

The simplest stream gage. A "giant ruler" mounted on a pier, bridge support, post or column. Stage height is read manually.

staff gage - stream
Staff gage in a stream.

wire weight gage
Wire weight gage.

Wire Weight Gage

Permanently mounted on the side of a bridge, a wire weight gage has a weight, a reel of wire, and a manual crank. The weight is lowered until it touches the water. A calibrated spool accurately determines how much wire was required for the weight to reach the water. This number is used to calculate the stage of the stream.

vertical pipe gage
vertical pipe gage on bridge
Vertical pipe gages.

Vertical Pipe Gage

This type of gage is mounted above a pipe that penetrates the bottom of the stream or sediments along the stream's bank. Water flows into the pipe through perforations or through the sediment and fills it to the same level as the water in the stream. Pressure sensors or a float/wire system is used to determine the height of the water. Some of these gages record the height of the water in a memory - which is then downloaded to a laptop during occasional visits by the hydrologist.

Gage House

A permanent house that holds stream gaging equipment - typically a gage of some type, a computer, and a satellite uplink. Frequently a stilling well or a vertical pipe is beneath the gage house.

Images on this page are from USGS and NOAA.

gage house
Photo of a gage house.

gage house
Diagram of a gage house.

More General Geology
  Fossils
  Igneous and Volcanic Features
  Geology Dictionary
  Diamonds
  Minerals
  Divisions of Geologic Time
  Land Below Sea Level
  Gifts That Rock

geology store

Find Other Topics on Geology.com:


Rocks
Rocks: Galleries of igneous, sedimentary and metamorphic rock photos with descriptions.
Minerals
Minerals: Information about ore minerals, gem materials and rock-forming minerals.
Volcanoes
Volcanoes: Articles about volcanoes, volcanic hazards and eruptions past and present.
Gemstones
Gemstones: Colorful images and articles about diamonds and colored stones.
General Geology
General Geology: Articles about geysers, maars, deltas, rifts, salt domes, water, and much more!
Geology Store
Geology Store: Hammers, field bags, hand lenses, maps, books, hardness picks, gold pans.
Earth Science Records
Earth Science Records: Highest mountain, deepest lake, biggest tsunami and more.
Diamond
Diamonds: Learn about the properties of diamond, its many uses, and diamond discoveries.