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Hydraulics Engineering


FHWA Hydraulic Toolbox, Version 4.10


There are a number of improvements to the existing version of the software as well as several new calculators. One of the more significant bug fixes repairs a problem that some users experienced when trying to print reports. There are now calculators that can be used for estimating bridge scour that uses many of the procedures presented in Hydraulic Engineering Circular 18 (HEC 18), Evaluating Scour at Bridges, Fifth Edition, 2012. A calculator for evaluating inlets on horizontal grades has also been added.

This version also contains new tools for culvert assessment and for making decisions on repair and/or replacement. The assessment decision making criteria can be based on a predefined profile or a user defined profile that would more specifically meets a user's criteria. A tool to develop a Rock-Sediment Gradation Analysis Calculator that will compute gradation information from pebbles counts conducted in the field (in accordance with the Wolman Count procedure) or from high resolution digital images of any surface composed of discrete particles is also included. The tool will compare those field gradations to control gradations by viewing them together on standard, semi-log gradation plots. The calculator is primarily intended to produce gradation plots for riprap and stream bed sediments. The digital imaging tool is quick and can be very accurate. However, because of the potential impacts of shadows and color variations, the resulting gradations should be considered approximate. Therefore, this technology should not be used to reject manufactured rock. If gradation results are questionable, a manual pebble count (e.g. Wolman procedure) is recommended for final rock acceptance testing.

A FHWA Hydraulic Toolbox Desktop Reference Guide is included with the software installation to provide guidance on the technical features included in the software.

Download Agreement

The Hydraulic Toolbox (Toolbox) is a 32-bit program, but it is fully compatible with 32 and 64-bit Windows-based operating systems (XP, Vista, and Windows 7) and runs in 32-bit mode on these operating systems. When installing the Toolbox, make sure you have permissions on your computer to install programs (usually this requires administrator permissions or a username and password for an administrator account). If you do not have administrator permissions on your account, you need to right-click on the installation program and select the "Run as Administrator" option if running Windows Vista or Windows 7. Windows XP users should login to an account that allows you to install software before installing the Toolbox.

As stated in the FHWA Hydraulics website, by downloading the software, the user is agreeing that they accept responsibility for understanding the following conditions and limitations, and agrees to them:

  • FHWA does not provide user assistance or support for this software.
  • The application of this software is the responsibility of the user. It is imperative that the responsible engineer understands the potential accuracy limitations of the program results, independently cross checks those results with other methods, and examines the reasonableness of the results with engineering knowledge and experience.
  • There are no expressed or implied warranties.

I agree to these conditions, download the software (.zip, 11 mb)

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Dave Henderson
Office of Bridges and Structures

Updated: 07/03/2013

United States Department of Transportation - Federal Highway Administration