Assessment of Bridge Scour Countermeasures at Selected Bridges in the United States, 2014–18

Scientific Investigations Report 2019-5080
Prepared in cooperation with the Federal Highway Administration
By: , and 



Erosion of the streambed, known also as scour, around pier 3 of the New York State Thruway bridge over Schoharie Creek caused the pier to fail, which ultimately resulted in bridge failure during the flooding event of April 5, 1987. The Federal Highway Administration (FHWA) responded to the need for better guidance on the evaluation of bridge scour and the selection and installation of scour countermeasures with the release of several Hydraulic Engineering Circulars. Although this information has been available, used, and updated over the years, an evaluation of the current conditions of scour countermeasures has not been performed. Therefore, the U.S. Geological Survey, in cooperation with the FHWA, began a study in 2013 to assess the current conditions of bridge scour countermeasures at selected sites around the country. The bridge scour countermeasure site assessments included reviewing countermeasure design plans, field inspections, traditional surveys, motion-compensated terrestrial light detection and ranging technology (lidar), high-resolution multi-beam bathymetry scanning, underwater video imaging, and a review of the peak and daily streamflow history for the associated river or stream. A total of 34 bridge scour countermeasure sites were selected in 11 states for this study. The types of countermeasures installed at the bridge scour study sites ranged from riprap, the most common countermeasure in the study, to A-Jacks and cabled-concrete mattresses.

The installed countermeasures were generally exposed to hydraulic forces from floods that equaled or exceeded the 1-percent, and even the 0.2-percent, annual exceedance probability at some of the study sites, but not all. The field inspections and countermeasure evaluations identified areas of shifting, slumping, and some scour holes and damage or washouts to the countermeasures, but generally most remained in place. The high-resolution laser scanner data, photo imaging and traditional survey data, and field notes were provided to the FHWA for expert evaluation of the bridge scour countermeasure performance.

Suggested Citation

Suro, T.P., Huizinga, R.J., Fosness, R.L., and Dudunake, T.J., 2020, Assessment of bridge scour countermeasures at selected bridges in the United States, 2014–18: U.S. Geological Survey Scientific Investigations Report 2019–5080, 29 p.,

ISSN: 2328-0328 (online)

Study Area

Table of Contents

  • Acknowledgments
  • Abstract
  • Introduction
  • General Methods
  • Site Selection
  • Procedures for Survey Data Collection and Site Evaluation
  • Types of Countermeasures Evaluated
  • Procedures for Bathymetric and Topographic Data Collection and Processing
  • Flood History at Study Sites
  • Summary
  • References Cited
Publication type Report
Publication Subtype USGS Numbered Series
Title Assessment of bridge scour countermeasures at selected bridges in the United States, 2014–18
Series title Scientific Investigations Report
Series number 2019-5080
DOI 10.3133/sir20195080
Year Published 2020
Language English
Publisher U.S. Geological Survey
Publisher location Reston, VA
Contributing office(s) Idaho Water Science Center, New Jersey Water Science Center
Description Report: ix, 29 p.; 2 Data Releases
Country United States
State Alabama, Florida, Idaho, Illinois, Indiana, Iowa, Minnesota, Missouri, Montana, New Jersey, New York, Pennsylvania, South Carolina, Tennessee
Online Only (Y/N) Y
Additional Online Files (Y/N) N
Google Analytic Metrics Metrics page
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