Scour Monitoring

Underwater Acoustic Imaging for Scour Monitoring

  • Greg Heringhaus (Collins Engineers)
  • Roy Forsyth (Collins Engineers)
  • Mike Todsen (IOWADOT)


Underwater acoustic imaging has emerged as a tremendous tool for hydraulic engineers and inspectors performing scour monitoring. This paper will discuss innovative methods for documenting scour and stream stability with “photographic quality” imaging below water. Underwater acoustic imaging can provide 2-D and 3-D visual images of channel bottom contours, waterway embankment slopes, undermined bridge foundations, and culverts potentially clogged with timber debris during flood events.

Of the approximately 603,000 bridges in the National Bridge Inventory (NBI), approximately 502,000, or 83%, are built over waterways. Additionally, there are literally millions of culverts that exist across the nation to maintain proper drainage under our vast highway system. When the scour potential is the greatest during a flood event, underwater acoustic imaging can provide underwater vision of existing submerged conditions. The light-weight reliable equipment can easily be used at a site via a boat or waterway crossing structure such as a bridge deck.

IowaDOT is one of many state highway agencies that has utilized this technology during flood events to obtain timely hydraulic information. Every asset owner has the responsibility to monitor their assets to ensure the safety of the public during a flood. Since technology now allows visual documentation to be easily collected for inspection, design, and construction practices, owners can utilize underwater imaging to provide a greater level of reliability and safety. The new technology also provides more accurate measurements thereby reducing public inconvenience due to overly conservative bridge closures, reducing repair contractor risk of a previously unseen submerged site, and reducing project monitoring / repair costs for scour.

This presentation will discuss how underwater imaging provides asset owners with new reliable method for collecting channel bottom data next to structures during floods, as well as how hydraulic engineers can benefit from the high definition images to monitor waterways and hydraulic control structures. Case studies will be discussed regarding the successful use of underwater acoustic imaging on waterways in the State of Iowa including Iowa STH 175 over the Missouri River (see attached images) and Interstate I-29 over Horse Creek in Fremont County, Iowa.

How to Cite:

Heringhaus, G. & Forsyth, R. & Todsen, M., (2014) “Underwater Acoustic Imaging for Scour Monitoring”, National Hydraulic Engineering Conference 2014 1(2014).

Rights: Copyright © 2014, Greg Heringhaus, Roy Forsyth, and Mike Todsen

Publisher Notes

  • Panel moderated by Laura Girard, FHWA.
  • About the Presenters: Mr. Heringhaus has over 19 years of experience in the field of marketing and communications. His background includes experience in sales, advertising, event and marketing management, project management, and marketing communications. While at Collins, Mr. Heringhaus has played a key role in the development of the firm’s underwater imaging division and is certified by Teledyne BlueView on the 2D and 3D imaging formats.

Download HTML



Published on
21 Aug 2014
Peer Reviewed