Software Tools for the Changing Environment

HY-8 7.4 and Hydraulic Toolbox 4.2

  • Eric Jones (Aquaveo)


The HY-8 culvert hydraulic analysis program has been used by engineers for decades to design new culvert crossings and analyze existing culvert crossings. HY-8 uses the methods described in FHWA’s HDS-5 manual, last updated in January 2012. HY-8 performs 1-D Hydraulic analysis on culvert crossings with multiple culvert barrels. HY-8 determines if an hydraulic jump occurs and if it does, the location of the jump. HY-8 can analyze broken back culverts as well as horizontal and adversely sloped culverts. It is also used to design energy dissipation structures using methods described in FHWA’s HEC-14 manual.

This presentation will demonstrate the newest feature of HY-8, Culvert Design for Aquatic Organism Passage as described in FHWA’s HEC-26 manual.

HY-8 can be downloaded free of charge from the following FHWA Hydraulic Engineering website:

The Hydraulic Toolbox is an intuitive computer program containing a suite of calculators that perform many of the routine hydrologic and hydraulic computations needed by highway hydraulic engineers and roadway designers. The following calculators are included in the previous version of the Toolbox: roadway hydrology, open channel flow, weir flow, pavement drainage, inlet capture/bypass, ditch inlet capture/bypass, detention basin routing, channel lining design (vegetation, rolled erosion control products, and rock), multiple riprap sizing applications (channel bank revetments; bridge piers, abutments, and guide banks; spur dikes; embankment overtopping; culvert outlets; open-bottom culverts; and wave attack), riprap filter design, gradation analyses via pebble count or digital image, ditch inlet capture/bypass calculator, and culvert assessment tool.

Each of the calculators has the following support functions available:

  • Plotting capabilities with printing and export options
  • A Notes module for documenting information sources and/or input parameter qualifications
  • A Report module for documenting all input and output data for any one or combination of calculators

Hydraulic Toolbox also incorporates a profile system that allows the user to define their own riprap classification system and culvert assessment profiles.

This presentation will demonstrate the utility and function of two of the most recent calculators added to the Toolbox, i.e. the Bridge Scour Calculator and the Horizontal Grade Inlet Analysis. This presentation will also cover the new map or plan view feature, which will allow the user to define a location for their calculators and visually represent their project.

Hydraulic Toolbox v4.1 can be downloaded free from the following FHWA Hydraulics Engineering website:

How to Cite:

Jones, E., (2014) “HY-8 7.4 and Hydraulic Toolbox 4.2”, National Hydraulic Engineering Conference 2014 1(2014).

Rights: Copyright © 2014, Eric Jones

Publisher Notes

  • Panel moderated by Dan Ghere, FHWA.
  • About the Presenters: Eric Jones is the lead developer for the Federal Highway Administration software HY-8, Hydraulic Toolbox, and HY-12 at Aquaveo, LLC. He also works on the development of the Watershed Modeling System (WMS) software at Aquaveo. He has received his B.S. and M.S. from Brigham Young University in Civil and Environmental Engineering. He has received his B.S. and M.S. from Brigham Young University in Civil and Environmental Engineering.

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Published on
22 Aug 2014
Peer Reviewed