Hydrology: Checking Channel Cross Sections

[brianchapman]

I need to check my cross sections produced by HEC-RAS.
What formulas needed to decide the water surface in
a cross section based on a steady state analysis, typical
manning's n for banks and bottom, etc.

What my real goal is...to manualy plot the cross sections
in autocad so I determine where my flood limits along
a flow line. If anyone can help please do...yah, I do have the national engineering handbook, urban hydrology, hec-ras, hec-hms, manuals....I just want some help without digging into a whole lot of detail.

Thanks.

 

[dicksewerrat]

What type of channel are you talking about? Concrete, grass, wooded, riprap?

 

[brianchapman]

Yes this is the one that posted the thread...I can't figure out how to append to it, so I am replying.

Its a natural channel, (yah, I know, a steady state is not
very logical, but that's what I want)...I is typical brush,
earth, rocks, etc.

 

[lsp01]

There is a shareware program called "Hydrocalc" by Dodson & Associates you can try it for free (just can't print). It will give to normal water level, critical depth, rating curves, and surface profiles for all kinds of channel/ditch flow. Very handy and quick. Also follows FHWA methods for culvert design.