HY8 General Specifications and Limitations

The dialog that controls the primary input for HY8 is shown below and can be used to specify the following culvert hydraulic calculations:

Single culvert analysis - produces an output rating curve for a single culvert that assumes no overtopping.
Minimize culvert width - varies the width of the first culvert and computes headwater for the design discharge until a user-defined headwater is not exceeded or either the maximum or minimum sizes are reached.
Multiple culverts with overtopping - computes the part of flow through each of up to six culverts and over the roadway.

The process of analyzing hydraulics for a culvert using the HY8 program in WMS consists of the following steps:

Enter the minimum, maximum, and design discharges.
Enter the information for the culvert(s) you wish to analyze.
Define the tailwater rating curve.
Define the roadway data.
Save the input file.
Execute HY8 and View Results.

All of these data are accessed/defined from the HY8 Culvert Analysis dialog shown in the figure above. If you wish to run options of HY8 not yet supported by the WMS interface you can open a DOS window, change your default directory the HY8 directory (found where WMS is installed), and type HY8 at the prompt.