Scour Monitoring

Mapping Rivers and Lakes for Highways: 4 Uses for Hydrography in Transportation

  • Petra DeWall (MNDOT)


A river’s contours are a mystery until they’re mapped. Even then, the river moves and changes with high flows and debris. Lakes, though less changeable, are unknowable without depth mapping. This presentation will provide an overview of river and lake hydrography projects done by the Minnesota Department of Transportation Bridge Hydraulics-Waterways group.

Hydrographic mapping is essential in transportation to (1) measure and repair bridge scour and track it over time, (2) create 2D flow models for bridge design, (3) monitor bridges during and after floods, (4) determine state boundaries at river borders, (5) define lake and river bottom elevations for bridge or road foundations.

MnDOT’s Bridge Hydraulics/Waterways group has mapped rivers and lakes for 16 years with survey-grade depth-sounders and an Acoustic Doppler Current Profiler (ADCP). Depths, flow rate, velocity and direction are measured, mapped in ArcGIS and CADD and applied to project requirements. Challenged by floods and low water alike, our equipment has been adapted to a wide variety of waterways, and we’ll share that experience.

How to Cite:

DeWall, P., (2014) “Mapping Rivers and Lakes for Highways: 4 Uses for Hydrography in Transportation”, National Hydraulic Engineering Conference 2014 1(2014).

Rights: Copyright © 2014, Petra DeWall

Publisher Notes

  • Panel moderated by Laura Girard, FHWA.
  • About the Presenters: Ms. DeWall has worked for the Minnesota Dept. of Transportation for 22 years, primarily in the Hydraulics Unit. She currently heads up the Bridge Waterway Unit whose primary function is to analyze bridges and bridge culverts for size and scour potential.



Published on
21 Aug 2014
Peer Reviewed