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Hydroacoustics and Technological advancements in Streamgaging

In the mid-1990s, a new technology emerged in the field of streamflow monitoring; the Acoustic Doppler Current Profiler (ADCP). It was originally developed for oceanographic work, but was adapted for inland streamflow measurements. This instrument has been transforming the U.S. Geological Survey (USGS) streamgaging program ever since.


Until the 1990s, the U.S. Geological Survey (USGS) had been making streamflow measurements using the same type of equipment for more than 100 years. The Price AA current meter was developed by USGS engineers in 1896. Until recently, the majority of all streamflow measurements made by the USGS were made using this instrument.

Streamflow information is used to predict floods, manage and allocate water resources, design engineering structures, compute water-quality loads, and operate water-control structures. The USGS has progressively improved the streamgaging program by incorporating new technologies and techniques that streamline data collection while increasing the quality of the streamflow data that are collected. The single greatest change in streamflow measurement technology during the last 100 years has been the development and application of high frequency acoustic instruments for measuring streamflow.


Streamflow Measurements

Acoustic Doppler Current Profiler In the Folsom River, New Jersey
Acoustic Doppler Current Profiler tethered to a Cableway across the Folsom River in New Jersey

The first attempt to use an ADCP to measure streamflow was made in 1982 on the Mississippi River by Christensen and Herrick (1982) as part of work conducted for the USGS. In 1985, the USGS purchased an ADCP and developed software for making streamflow measurements, and since then, ADCPs have proven to be useful tools for measuring streamflow throughout the country.

  • For many measurement conditions, the ADCP samples more of the flow (spatially), as compared to traditional mechanical current-meter measurements, resulting in more detailed streamflow information.
  • An ADCP streamflow measurement can be made in 15–20 minutes, increasing efficiency, improved safety conditions, and more detailed streamflow data.