No, Kirpich is not currently in HydroCAD. This is the first request. I'll add it to the wish-list for further consideration.

Peter Smart
HydroCAD Software
www.hydrocad.net

It's the method that shows up in nomograph form in all the drainage manuals down here, and it's a much simpler one than some of the others. I like to at least run it as a check against the SCS methodology, which as you know is highly spurious due to being heavily weighted towards sheet flow properties that aren't necessarily characteristic of the regional watershed.

Hydrology, Drainage Analysis, Flood Studies, and Complex Stormwater Litigation for Atlanta and the South East - http://www.campbellcivil.com

Peter, TxDOT is using Kerby-Kirpich method for overland-channel flow TOC estimate (TxDOT 2014 manual: http://onlinemanuals.txdot.gov/txdotmanuals/hyd/hy...)
Also, to account for flat topographic slope areas, TxDOT proposed a modified Kerby-Kirpich method based on a 2012 Paper by Cleveland et al. (http://www.depts.ttu.edu/techmrtweb/Reports/Produc...).

I would like to see HydroCAD have the full TxDOT method implemented so that the users have the options to do the following different calcs at their choices:

1. Kerby method only;
2. Kirpich method only;
3. Kerby and Kirpich
4. Modified methods to #1,2, and 3 to account for flat slopes.

Thanks for the details.

Peter Smart
HydroCAD Software
www.hydrocad.net