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Hydraulic Engineering

HY-8 Culvert Hydraulic Analysis Program

HY-8 automates culvert hydraulic computations utilizing a number of essential features that make culvert analysis and design easier. An HY-8 User Manual is included with the software installation (access via 'Help' button on top toolbar) to provide important information on the technical features, capabilities, and limitations of the software.

System Compatibility

HY-8 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 HY-8, 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 HY-8.

Download Agreement

By downloading the software, users acknowledge that they have read and agree to the following conditions:

  • The application of this software is the responsibility of the user. It is imperative that the responsible designer 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:

HY-8 Version 7.40 Beta

  • Build Date February 25, 2015. This version contains a calculator to assist with the FHWA's culvert aquatic organism passage (AOP) culvert design procedure, which is described in detail within publication Hydraulic Engineering Circular 26, "Culvert Design for Aquatic Organism Passage, First Edition" (HEC-26).

HY-8 Version 7.3

  • Build Date August 18, 2014. HY-8 7.3 builds on previous versions of the software and incorporates improvements from user feedback. HY-8 7.3 expands the capabilities to analyze special hydraulic situations and culvert shapes and includes an upgrade to the source code to make the program run more smoothly and efficiently.

HY-8 Version 7.2

Reporting Issues

If you believe you have found an issue with any version of HY-8 (including installation errors, calculation errors, interface problems, confusing functions, errors and omissions in the User Manual, and anything else that might impact the functionality and usability of the software), please submit the following information to CommentsOnHY8@dot.gov (please note that in most cases you will not receive a personalized email response from the email administrator):

  • Name
  • Contact info (this won't be used unless there is a question about your HY-8 issue)
  • Computer operating system (Windows 8, Windows Vista, etc.)
  • Complete description of each issue
  • PLEASE attach the HY-8 project file (.hy8) that demonstrates the issue
  • Also consider attaching a screen shot of the HY-8 window if applicable
Updated: 03/03/2015
Federal Highway Administration | 1200 New Jersey Avenue, SE | Washington, DC 20590 | 202-366-4000